Des' projects or "Musings from the Shed"

Still alive - some news

2011-11-14T20:09:00.000-08:00

Well it's been a while since I posted - lots happening.
Long story short, I'm in the middle of moving house due to a change in my employment conditions. This means for the past 4 weeks I've been working shifts, and had the house in boxes... and those boxes won't open for another few weeks, and I'll continue on shift even after that.

Longer term this means a shift in my projects whilst I shake down the house, and get the shed/s up. For quite some time, the projects will be limited to small things done in the field desk, and a lot of home renovation/ repair work.
Whilst I'm in the shift situation, I will be flying a lot, and getting very little done except on my off swing - then it's flat out getting work done at home.
I don't want to be doing FIFO (Fly In, Fly Out) and shift long term, this was a decision accepted based on the conditions under which I currently work, my scope for promotion, and other factors. I am applying for other work within the company since it is a great company to work for, and I don't really want to leave it if at all possible.

Current challenges:
trying to keep losing weight whilst surrounded by "camp food"
trying to remain busy developing my skills in Control Systems, Electrical Engineering, and Managemnt (Personelle and Project)
trying to keep busy with my hobbies and interests
trying to not let the distance and seperation from my family cause issues or concerns

Next challenges:
Overcome whatever obstacles prevent me from obtaining my next job - the one which allows me to spend time with my family, and still meet my financial commitments.
Underfloor ventilation in a building built in the 1950's (or was it 1850's?)
adjustments to various sewerage/septic systems
repairs alterations to fencing - boundary and pool
repairs and alterations to existing "shed"
minor extensions and modifications to house
construction of shed/studio on site to suit my needs - now and future
construction of granny flat (ancillary accomodation) on site

That's it for now - Once everything is unpacked, and settled down, I'll update this with some archived projects, and some of the "home owner" projects as they arise. Hopefully I'll be in a position to accept a new role, and spend more time with my family, and less time away from them.

Construction Photos for Serial Cable kit - Mk3/4

2011-09-17T06:52:00.000-07:00

The serial cable kit was formally released at work last week - the usage instruction manual was completed, and the construction manual as well. Confirmed cost came in at $48.87 per kit if 20 were made, $97 to make a single using company approved vendors and their MOQs for certain parts - If Ebay was used, the price per single kit still sits around $40. Either way you look at it, it is a dramatic reduction in price compared to the Mk2 kits I made back in 2008 - they came in at $400 per kit for the same functionality as the Mk3/4 Kits.

In the meanwhile here are a few photos taken during construction, and a couple of snapshots of the finished kit, and construction manual.

Photo 1 - breadboard cut to form baseboard

The baseboard is a small segment of breadboard anchored to a baseboard which incorporates the breadboard, the serial cable terminations, cable anchors, and module "ejection mechanism"

Photo 2 - Baseboard and anchor plates - under construction

Everything in this kit was designed to minimise costs, and as such salvaged materials were used wherever possible - including salvaged screen-door extrusion for the anchor plates -the construction manual has drawings of all parts to be constructed, and alternate dimensions/ drawings if the extrusion was substituted with pieces made from simple sheet metal.

The "modules" are simply modified IC sockets, which are later labelled and "potted" for protection and resilience.

Photo 3 - "Modules" under construction

The serial cable is modified to suit the cable kits requirements. All construction for the prototype kits was made using tooling and equipment in my field desk - including the third-hand, modified pliers, solder pens, etc

Photo 4 - Serial cables being modified to suit kit

Compact/ resilient storage of the kit and components was one of the deliverables I placed in the kit design. I accomplished this by modifying a commercially available storage box, and then constructing stack-able compartments which slid inside the outer case.

Photo 5 - Completed modules in stacked storage compartment

The user manual was deliberately formatted so when printed it could be trimmed to fit in a designated space in the the container - the finished manual measures 245 x 185mm (9 5/8 x 7 1/4") and is around 25 pages thick (printed in duplex, but with 6 pages of blank paper for notepaper)

I will have to "de-crest" the manual/s if they were published here since they reference work, and the department I work in - since they were the target audience of the design.

I've blanked out the company/ section details, and my address information on the thumb-drive label - hence the white blotches

Photo 6 - Completed kit with instruction manual in lid

The construction manual contains a number of progress photos, drawings, tips and alternate materials discussions. I wrote the manual with second year electrical apprentices in mind - some familiarity with basic hand-skills, interpretation of drawings, and the sense to know what holes get changed if you change a countersunk screw from 3/16"-24 to 4mm. The manual printed out to 29 pages of duplex A4.

Photo 7 - Sample page from construction manual

As mentioned, I'll have to de-crest the manuals before publishing them here - not a huge amount of work, but still anything which adds to my "TTD (Things to Do) list" is not overly welcome right now. If I get some time spare, I'll do it in the next week or so, and add them here: (links will reference google docs)
User Manual
Construction Manual

I'll post again when something is completed, progressing, or worth discussing.

solder pens, electronic tooling, and catch up

2011-09-03T08:31:00.000-07:00

I was at a course the other day and one of the whiteboard markers ("dry-erase" markers according to Dilbert) ran out - I intercepted it before it got tossed out to make another "solder pen" No-one at the course had heard of them, so here is a quick explanation and construction article.

When I first started in electronics I simply used solder held in my hands - quite mindful of the warnings regarding lead poisoning, and always washed my hands after working. I don't remember where or when, but somewhere I saw someone use an old de-soldering wick packet to hold small coil of solder (see picture) - this became my preferred soldering method for the next 10-15 years.

When I built the field desk, I set about duplicating my old faithful toolkit, and found I didn't have any spare de-soldering wick packets...hence I turned to the soldering pen idea. I can't claim credit for it's invention, it's been around for years in various guises from clear containers with the solder poking out, to references on aus.electronics to people filling chemy pen (permanent markers) cases with solder.

Photo 1 - Original "solder - holder" and de-soldering wick

So how to make a solder pen - select an old marker which has run out of ink, and remove the nib (pliers simply pull it out) and then get the cap at the end out. Sometimes it's necessary to trim away about 10mm (3/8") of the outer case at the end to allow the end-cap to be removed.

Photo 2 - dismantled marker pen

Then measure the internal length of the casing, and select a screwdriver or other thin smooth rod as a mandrel.
Wind the solder around the mandrel to match the length of the length of the case internals leaving around 50mm (2") of solder free at the start - this starting piece will end up being the first of the solder to be used. once one layer has been wound to the correct length, carefully wind back over for a second layer, stopping about 2-3 turns shy of the beginning of the first layer. Keep winding back and forth adding layers neatly until the wound solder is a loose fit in the case.

Photo 3 - screwdrivers being tested for length

Cut or break the solder at that point, and gently remove the screwdriver (I found gently rotating it made extraction easier). The bundle of solder will be quite flexible so care must be taken to not stretch or kink it.

Photo 4 - solder bundle completed

Straighten the starting piece of solder, and centre it along the axis of the bundle, then feed it into the marker case so the starting piece protrudes where the nib used to be... this means the coils of solder will feed from the inside of the bundle, hopefully preventing tangles.
Replace the end cap, and you can fold the protruding solder over the nib holder and replace the original cap.

photo 5 - Solder test inserted into marker body

In use, simply remove the cap, tug an inch or so of solder out, and apply solder as required by holding the marker body. As the protruding solder is consumed, simply tug more out of the marker body as required.

I measured the weights of all my solder pens, and found they averaged 50gm (about 2 Oz) of solder in each one.

Photo 6 - solder pens completed with other tools

A bonus tip...
When I was at uni, I got on to a bulk purchase of quality electronics tools - cost us $120 to get excellent tooling - a fortune back then. When I duplicated my kit into the field desk, I wanted similar shape and quality tools, but did not want to spend too much money.
I purchased cheap pliers from the local KMart, and then using grinders, and files, reshaped them to suit my needs. In photo 6 you can see 2 pairs of pliers I've reshaped - the yellow handled pliers are just as good to use as the expensive ones in my old kit. The red ones are too small for use, but are handy for periodic use with the yellow pair for straightening or bending wire.

What else to talk about....
I finished the serial cable kits - Mk3 and Mk4 in total. Mounting boards, storage containers, etc. I've practically finished the user manual, and have only 2 sections left in the construction manual to finish... Mostly final edits in the sections, then renumbering the photos and illustrations. Still deciding if the documents should be published here or not, but I'll most likely add some of the construction photos at the minimum..

Various things happening at work... not much to talk about yet, but I daresay I'll have something to talk about soon.

Serial Cable Kits - Mk1 to Mk4 - the answer for versatile industrial connection

2011-07-31T00:58:00.000-07:00

Now for something a little different

In my day job, connecting a PC (laptop) to various industrial devices is fairly common. As is typical of these types of devices (VVVFs, Sensors, CPUs, etc) each manufacturer will require a different cable pin-out for their devices, (and some like Siemens require different cables for different models)

When I first started in my role, the "cable kit" comprised of a couple of cardboard boxes full of cables - each cable was around 1800mm (6') long, and sometimes labelled to say what it was used for.
I consider that the "Mark 1 cable kit" - large clumsy, difficult to use, and quite heavy.

I made up the "Serial Cable Kit" - this comprised a single full length DB9 straight through cable, and a number of "dongles" which were fitted to the end to change the internal wiring configuration. Each dongle was labelled, and an instruction book allowed the user to look up the device they intended connecting to, and the manual would tell them what cable and dongle combination to use - eg Siemens Masterdrive would require cable "C1" and Dongle "D2".

Photo 1 - Mk 2 Serial Cable kit in case

This system worked for a few years - it was well received by all who used it - a number of the kits were stolen, and other parts were added as new devices were added to the plant equipment.
Since I made this kit from home, I tried to keep the costs as low as possible (using double ended connectors proved cheaper than using 2 DB9 head shells with a short intermediate cable), the carry case was one from the local K-Mart (Think Wallmart) and modified.
The new kit was a considerable improvement over the original system, but after some time, and sick of fixing/ replacing missing parts, I decided a newer iteration was in order...

Figure 2 - Mk 2 Cable kit concept drawing

If the box of cables was "Mk 1", then the original "Serial Cable kit" would have to be "Mk 2"... Mark 3 would need to be smaller again, cheaper, lighter, and more versatile...

Photo 3 - Mk2 cable and dongle on relevant instruction page

The "Mk 2" dongles were 2 DB connectors separated by a distance of around 40mm (1 3/4") with the cores between being short lengths of flexible cable.. I could accomplish the same effect using a piece of bread board (electronic prototyping board) and a number of pre-terminated jumper wires. That would significantly reduce the weight, cost, and increase the versatility infinitely. I bought some cheap breadboards off the internet and got one of my spare straight through DB9-DB9 cables. I cut the cable at the PC end, at around 400mm. In use the breadboard area would need to be close to the laptop so it was supported, not hanging off the front of a panel in a substation.

Photo 4 - Mk 2 Dongle with dongle schematic

I belled out the pins and soldered the cores to a short length of header strip in order - pin 1 at the top, pin 9 at the bottom. This was repeated for the second length of the cable (around 1500mm (5') long.
The two header strips were inserted into the breadboard with pin 1 in row 1, and the same on the other side of the center strip. - This gives each pin of the serial cable 4 holes to connect cables into - the same for each pin on the outbound cable.
Using the diagrams in the Mk 2 instructions, I know I can rearrange the jumpers to make any combination of cable schematic, and I also know 4 holes per core is enough since the most any current dongle uses is 3 cores to one pin.

Photo 5 - Mk 3 prototype configured as if Dongle 2 in place

The shields from the two parts of the split cable are joined to the backing of the breadboard underneath - Once it passes all tests, the breadboard will be enclosed in a small metal tin to complete the shielding.

The Mark 3 version sounds great doesn't it?... meets all requirements, how could it be made any better? - it can be.

Mark 4 (or Mk IV if you prefer)

Photo 6 - Mk 4 "dongle" in place for Master drive communications

Currently the Mk 2 kit has 12 dongles in it - these are used to access over 20 different devices on site. Imagine the scenario where you are working on a fault - you need to talk to a VVVF drive, then talk to an ultrasonic sensor, then back to the drive, then to the PLC CPU... with the Mk 2 kit, you simply changed dongles as you moved from device to device... With the mark 3 you would be constantly changing the jumpers... if you're tired, distracted, you could too easily make a mistake - you could damage equipment, or at least waste time complicating your own fault-finding strategy. I needed a way to make the Mk 3 system as easy to use as the Mk 2...
The step to Mk4 was easy - simply use the existing breadboard to hold a "dongle" which had the jumper configuration in it. Make it removable, and make it "labelled". Immediately the concept of using a DIP IC socket sprang to mind. If I used a 18 pin DIP socket, that would give me 9 pins up one side, 9 up the other, and a small space in the middle to solder in the jumper configuration. The DIP socket has a notch for Pin 1 which can be used to ensure the correct orientation when inserting it, and I could pot in the jumpers to provide a space for a label.
NB: I chose machine pin DIP socket since the pins are stronger and round - making them better for the breadboard when compared to typical cheap DIP IC sockets.

I ordered a fistful of machine pin DIP 18 pin IC sockets from Futurelec (along with some other goodies) and started planning the next design. Once the sockets arrived, the first dongles were being made.

Since I don't have a Siemens VVVF at home, I cannot show photos of the system in use, but if possible I will get one from work.

In use the new kit will comprise of the Mk3 and Mk4 parts. The Mk3 cable and base forms the base kit, and 12 jumpers will be included for new or experimental equipment. The current manual will be re-written for the Mk4 "dongles" which will need to be renamed, and stored. This new kit has more versatility than the current kit, and is significantly cheaper to make up. Each "dongle" in the Mk 2 kit costs over $7 AUD, whereas each "dongle" in the Mk 4 kit costs $0.40 AUD. The new kit is much smaller, lighter to carry, and should be cheap enough to make as a "personal issue" tool - that last bit is handy to reduce theft and loss of parts.

I keep talking about "versatility" - it's the ability of the kit to handle making a new configuration out in the field - The Mk 1 kit had none, the cables were made "as -is", the Mk 2 kit had one spare unassembled dongle of each configuration (M-M, M-F, F-F) in the kit to permit making a new dongle, whereas the Mk3 (and Mk4)have the breadboard space and jumpers to create new configuration cables on the fly.

Photo 7 - Showing size comparison for Mk 2 dongle and Mk 4 dongle

So the Mk 3 and Mk 4 work on the same principle of changing pin assignments, the difference between the Mk 3/4 and the Mk 2 is that it's done "inside" the cable, and reduces the amount of needed hardware.

Figure 8 - Mk3 and Mk4 concept schematics

There was one dongle which needed a special case... D12
All other dongles in the Mk 2 kit terminate with either a male or female DB9 connector - the Mk3 and Mk4 kit has a female connector at the end of the cable, and a miniature gender bender included for when a male connection is required... but dongle "d12" however terminates with a RJ11 connection - this is used for the HMI AnyBus equipment.
I had 2 options... option 1 was to reuse the existing "d12" dongle and simply have a "straight through" dongle for the breadboard... Option 2 is to have the 4 core cable for the RJ11 come off the "dongle" and leave the remaining 1500mm length of 9 core cable unterminated. I've made both, but look forward to testing option #2 since it makes for a more consistent approach.

Photo 9 - Mk 4 version of Dongle "d12" for 4 core RJ11

Some statistics (estimated where shown *) - excludes Siemens Simocode Pro cable and USB-RS232 Adapter from all comparisons - based on cables/ configurations to perform tasks of Mk 2 kit.

Mk 1 kit - weighed 4000g*, volume 400x400x400mm* = 64L, cost ~$400-800 - No labels, no instructions, no versatility

Mk 2 Kit - weighed 1800g, volume 360x290x70mm = 7.3L, cost ~$250 - Labelled, instructions, limited versatility

Mk 3 Kit - Weighed 300g, volume 250x200x50 = 2.5L, cost ~$45 - No Labels, instructions, versatile

Mk 4 Kit - Weighed 350g, volume 250x200x50 = 2.5L, cost ~$50 - Labels, instructions, versatile

Labour? - all costs do NOT include assembly labour - I made the Mk 2 kits myself over the period of 2 weeks working 4 hours each night (7 kits) - I've made my own Mk 3 kit, and will complete the Mk 4 kit over the next week or so... what takes the longest is writing the instructions, and hand construction of the dongles. - you should allow between 15 and 30 mins per dongle based on intermediate hand skills.
What's not shown in any of the photos is the base plate for the Mk 3/ 4 set - I'm still trying to design and construct a "flipper" to permit easy extraction of the IC sockets - I was using an IC extractor in testing, but would prefer something "captive" so it can't be lost. In the meanwhile testing continues with another piece of breadboard for the noise immunity of the Mk3 and Mk 4 designs.

If you think this is a good idea and want to manufacture them - go for it - please give credit where due though... I do when I write the manuals.

Field desk - Part 7 - Carry strap

2011-06-25T03:36:00.000-07:00

I finished the field desk and took it for a walk up and down the driveway a few dozen times and decided that if I had to carry the field desk any significant distance, the handle would become uncomfortable quite quickly. I determined I'd need to fit a strap of some description...

I designed a few options based around a quick dis-connectable strap which would have been based on an inset plate, with a "key-hole" shaped hole which would have allowed a strap to be connected without load, and lock in place under load. I planned on making this from the brass strip I have, and make a mushroom post to enable this function. Easily within the scope of my skills and materials, but the more I looked at the idea, something just felt wrong about it - still haven't figured out what.

Figure 1 - Front view of desk with carry strap as if carried

Under further consideration, I figured it might be easier to make a strap which would fully support the desk from the bottom, and also the sides - the previously mentioned solution would have used the top edges of the sides to carry the weight. I designed a strap which essentially followed a path under the base, up each side, and up over my shoulder. A "waist" strap would go around the desk in the horizontal plane, and have a clasp to permit it to open on the door side.
A few lengths of salvaged seatbelt material, a clasp from an old salvaged life-jacket and about one hour on the sewing machine and this is the result...

Figure 2 - Side view of desk in carry strap as if carried

Since none of the lengths of seatbelt material were long enough, I made the bottom strap as one piece, and added a brass "adjuster" at each end to permit attachment and adjustment of the shoulder strap. These adjusters were made from (50x75x3mm) 2" x3" x 1/8" brass strip. A sliding dog was made from offcuts of the same strip brass.

Figure 3 - Front view, close up of clasp

A piece of scrap denim was sewed in behind the clasp to reduce it rubbing into the paintwork of the desk, and all sewing was done with over-sewn double runs, and polyester thread.
The strap can be left in place and the door easily lowered, or just as easily totally removed, and reinstalled when it's time to move the desk.

Figure 4 - Front view of desk with strap unloaded on top

When I collected the seatbelt material from the training cars (what was left of them) I found one car had those detachable seatbelt pads - Given the final weight of the filled and complete desk, I elected to place those seatbelt pads on the shoulder strap to even the load and reduce any chance of bruising from carrying the desk for a long time.

Figure 5 - Front view with clasp undone to permit door opening

A lesson learnt on this construction - when sewing seatbelt material, the upper thread tension on the sewing machine needs to be increased - otherwise the lower side threads all bunch up - my guess is the thickness and weave of the belting makes it harder for the thread to pull up enough under normal thread tension.

Figure 6 - Door open with DPScope on desk surface

The last photo is of the DPscope I purchased with some recognition money I recieved (a program they do at work to recognise efforts put in by staff) - The DPscope is a DSO scope which connectes to a PC via USB and has 2 channel capability. Since it only arrived yesterday, I haven't had time to play with it yet, but will do so over the next week - hopefully.

That is it for the strap - hopefully I won't need to carry it far that often, but now I can. I don't know what the next article sets will be - I've heaps of books to review, many projects in the WIP box (WIP = Work In Progress), and a lot on my plate outside the shed. This past week has been a series of quite long days, and in the next 2-3 weeks I hope it will bear fruit in many forms - the least of which will be my Cert 2 in Emergency Response... the rest - that's my secret for now.

Field desk -Part 6 - contents

2011-06-17T03:52:00.000-07:00

The contents of the field desk reflect it's intended purpose.. a portable electronics experimental/prototyping workstation.

Figure 1 - Desk opened

The bottom shelf (LHS) contains 2 deep containers - the bottom containing tools (pliers, strippers, third-hand, soldering tools, etc) whilst the top container houses the current project, some breadboard, veroboards, etc - This container should be fairly empty since I won't want my project being damaged.

Figure 2 - bottom containers out - light in place and IEC cord inserted

The middle shelf (LHS) contains 4 shallow containers - each of the type which has movable dividers. One container is filled with Resistors, another with capacitors and some mixed semis (BC (NPN and PNP), diodes, MOSFETs, 555/556, opamps,regulators, etc) The next unit has mix of parts including variable resistors, LEDs, header strips, sockets, buttons, switches... a bit of a grab bag of useful stuff. The last container contains the PICAXE chips (08M, 18M2, 28X1) plus other minor bits and pieces.
I am going to have to modify at least one of these containers so the keypad, and LCD screens can fit in there - currently they're in the "Projects" container.

Figure 3 - component trays out on display

The top shelf/drawer (LHS) is for documentation and software. It will also contain the USB/Serial adapter, connection cable, and a USB thumb drive for software. I plan on being able to use my work laptop when I'm in accomodation, or my shed PC when I'm at home.

Figure 4 - Top drawer

Figure 5 - light stowage area, and soldering station in box

The RHS compartment (under the power box) houses the 58W soldering station I bought on Ebay. Above that is a old lunch container filled with various colours and grades of hookup cable. Some of the cable is Cat5 solid cable - useful for breadboarding and veroboard work, some is stranded cable salvaged from various sources, stripped and coiled in... there are a couple of sizes of cables so I can build for signal, and power requirements.

Figure 6 - Cable container, and spare trays on open door/desk

Stats for the finished project..
Size - 600mm W x 450mm H x 300mm D (24" x 18" x 12")
Weight (loaded) = 15Kg (~33 lb)
DC supplies - -12, -5, 3.3, 5, 12 volts with total power output of up to 450W - input is 240VAC at 0.8A normal, but up to 10A for GPO loads.
Build time = Cabinet and sheet-metal construction - 4 days, painting (not including drying time) and trimming = 2 days.

The objective of the desk is to be able to work on projects, learning or simple construction, in a self contained environment. When I leave my roster, I simply stow the desk in a secure location, and take with me a thumbdrive, and "lunch box" containing the finished project to take home. The thumbdrive will contain the copies of source code, etc, and a shopping list of parts to collect and bring back with me on my next roster. The notebook, and code copies in my laptop will remind me where I'm up to upon my return.

Next postings.... hard to say - I've a few work and community commitments which will prevent me taking on any new projects. I have already started cleaning up the shed (while the varnish and paint was drying) and packing away some gear in preparation for these commitments. Over the next couple of months I hope to get these upcoming changes and commitments settled in, and then get back into the swing of designing, and completing these projects... believe me, the "to do list" is not getting any shorter.

Field desk - part 5 - Painting and trim

2011-06-17T03:05:00.000-07:00

The painting and trimming of the field desk.
Painting was straightforward...
Undercoat,
filling,
masking and
top coats of "Bender grey" (the darker grey used to paint Bender's arms and legs)

In keeping with the Futurama theme, and tying in the fact that this desk is designed and made for use in electronics and microprocessor experimentation, I decided to theme the trim on the concept of the desk being a "Momcorp" product, a prototyping/ repair kit for Momcorp products using microprocessors.
From that concept, it wasn't too hard to look at this as an "Experimental Brain Surgery Kit" (Always wanted a tool box with that written on it!!!) for robots and robotic devices.

Figure 1 - Momcorp logo pages drying after clear-coating and spraypainting

I created a version of the Momcorp logo (The nicer one, not the authoritarian vertical MOM one) and decoupaged it to the front and back of the desk. I printed the logo I made on the thinnest paper I could find, then spray painted the back white to increase the opacity - I clear coated the front to stop the ink running.

Figure 2 - Decoupaged logo on door of field desk

I then got to thinking... if I was in the year 3xxx and a technician, I wouldn't leave my travelling toolbox looking so bland. It would have stickers on it ....

from places I'd been authorised into (HAL institute for criminally insane robots),
stickers from products (Mom's old fashioned robot oil, bachelor chow, slurm),
stickers which reflected the world around me (political, social fads, social commentary, humourous),
and at least somewhere I'd have my name.

Based on that, I started cruising the internet finding images from the show, and editing them into a sticker style format. I found a few in that "cafepress" site which were already done, and used their look as my template. I downloaded a few fonts, and made a few (how I made the Momcorp logo) and then printed them in my inkjet printer.

Figure 3 - several pages of "stickers" drying after painting

All of the "stickers" where clear coated over (to stop the inkjet ink running when varnished), and most were spray-painted white from the back to improve the contrast and opacity - but not all. A few of the images were deliberately scuffed and aged just to add a "worn look" to them. - given the less than perfect cabinetry, a few bumps and scratches here and there will be well and truly "in character: A couple of the stickers were not painted white from the back so they'd appear to be made from newsprint paper... just for variety.

Figure 4 - Back of Field desk with stickers applied

Stickers include: The vitruvian robot drawing, robo-fresh, the feminista bumper sticker, WWZJD.....

Figure 5 - Door of Field desk (Outer side)

several Slurm stickers, Mars University, Scary Door, a binary expression....

Figure 6 - LHS of Field Desk

Nixon's reelection campaign poster, robot oil sticker, "I love Snu-Snu" bumper sticker (who doesn't?)....

Figure 7 - RHS of Field desk

A hypno-toad sticker, a trekkie bumper sticker, robot oil ad, more slurm.....

Figure 8 - Top of Field desk, including "protest sticker"

more Slurm (it really is addictive!!!), the Earthican flag, a "Morbo" bumper sticker, HAL institute sticker, a NNY sticker, and a "protest sticker".
The protest sticker was written up in the Futurama "alien" font - it's the font used throughout the show. I won't give out the meaning, but it's a very well known sentiment amongst those whom nanny-states will try and govern.

That's it for the trim - I did have a bachelor chow sticker, but it got damaged during painting (Wind got it while it was wet) - I was going to put a DOOP sticker on as well, but it was starting to look cluttered... we'll see.

All that's left now it to show the unit with the contents in it. That article is as much for the PICAXE forum as any other groups since they helped me with the shopping list of things going in there.

Field desk - part 4 - Tray and lighting (additional information)

2011-06-16T06:02:00.000-07:00

A little more information on the lighting, and a quick article concerning the tray for the top shelf.

About 5 minutes after finishing part 3 of this series, I was filing the folder for that article when I found the additional photos I took as part of the lighting design...

Figure 1 - Lamps tested for use in the desk - LED lamp on left, incandescent on right

Photos of the two lights I trialed, including the LED lamp I used in this project, and a photo of the desk with a piece of DIN rail used to measure length and placement of the lamp.

Figure 2 - Trial of lamp placement using DIN rail

Paper Tray - Top Drawer
The other photos in this article cover the construction of a "paper tray" which is designed to fill the top shelf of the field desk. I plan on keeping an A4 notebook, CDR (with manuals), a couple of pens, etc in that shelf. The easiest way to achieve this is to have a drawer.

Figure 3 - Sheet metal cut out, prior to folding

The paper tray is simply folded up from sheet metal (more of my salvaged colourbond "signwhite") to make a simple tray, with a folded top edge on three sides, and one extended edge on the front. This extended edge forms a handle which allows the drawer to be pulled out from the shelf.

Figure 4 - Drawer in place on shelf

Since I haven't had the time to build a finger brake yet (still on the ever growing "things to do" list), I did all folds using the clamp over bar, wood and hammer method. One thing I found during that exercise was that you shouldn't hammer anything whilst you have a cold - all it does is screw up your inner ear whilst your sinuses are stuffed - Not a nice sensation.

Figure 5 - drawer painted

Once folded up, a couple of pop rivets to hold it all together and then it's painted up in "Bender Grey". In fact the entire exterior of the desk will be painted "Bender Grey" and will carry a suitable theme in the trimmings.

Figure 6 - Finished drawer showing folded handle on LHS

The painting and trim of the field desk itself will be the next article, then all that's left is a brief discussion about contents and that project is complete.

Field desk - part 3 - Electrical System and lighting

2011-06-16T05:16:00.000-07:00

Electrical services into, and within, the field desk.

Electrically speaking, the field desk will have one power lead into the desk, with a double switched GPO, and a variety of DC power sources available. A task light will also feature in the design.

Electrical enclosure

The electrical enclosure was designed to contain all components, and attach in the top of the RHS bay. The front panel will contain all interfaces - plugs, switches, etc. The original design was to use an old PSU from a 1900 series switch, but upon checking the PSU, it was found to have some of it's pins non-commissioned (-12V and - 5V) - thank fully the size of the enclosure was dictated by the GPO, and banana sockets, this meant I had room to look at alternate options.

Figure 1 - Basic Enclosure unpainted

The front panel holds all connections, and has the receptacle for the light in the top RHS. - The receptacle is simply a short piece of DIN rail, and the lamp holder sits inside the rail.
The front panel of the power box is made of 3-4mm thick plexiglass, drilled, cut filed to hold the GPO, IEC socket, and banana posts. To prevent scratches showing on this panel, I marked the terminal values on from the back, and then spray painted over them from the back - this means the paint cannot be scratched from outside the case. Interesting note was when the paint dried, I could suddenly see this invisible cracks around the banana posts - it looks almost surreal to see "reversed cracks" filled with paint.
The enclosure is designed to sit in the top of the field desk, therefore all ventilation is through the floor (or the front) - I simply replaced the floor with some punched mesh, and then used sheet metal shields to redirect any airflows from the back, through the PSU fan, through the PSU, and then into the front section, through the enclosure floor. Each "side" of the PSU has around 12 sq inches of floor vent available to induct, or expel air.
The enclosure (power box) is held in the top of the desk by means of some brackets, and a folded lip at the back. None of the retaining hardware obscures the ventilation grid, and removal of the power box is accomplished with the removal of one screw, since the forward brackets tilt to permit removal.

Figure 2 - Close up of front panel, with first sheet metal divider removed

The only parts of the enclosure which are painted are those parts visible in normal use - ie the front panel/s, and the bottom. The sides were deliberately not painted since the paint would simply rub off on the walls of the cabinet during insertion, or removal.

Figure 3 - Mesh base to enclosure used for ventilation of PSU

Lighting
A 12V LED lamp was purchased from the local variety store (KMart) - I had looked at an incandescent lamp, but compared to the LED lamp, it was pale and yellow. I considered one of the halogen lamps I use when I sew, but they do throw some heat, and I considered that would not be wise in the planned location - not to mention wasted energy as heat.
The lamp was gently disassembled (no warranty voiding yet) and tested for it's ability to "hold up" from a horizontal plane - it was discovered that if held at a 45 degree angle, the lamp's "flexible arm" would support the lamp to the maximum reach. Based on that, a bracket was made (from plexiglass) to hold the base at 45 degrees. The bracket slides into a short length of DIN rail which is used as a track. This track is part of the enclosure and is accessible from the front panel.

Figure 4 - Power box in place in field desk with lamp inserted

The lamp will be removed to close the door, so the plug which supplies power to the lamp was cut through the opened switch, and additional wiring soldered on. The wiring is then terminated to the connections for 12VDC (and COMmon) so the lamp will run whenever the PSU is on. This should have worked but during final testing it was found that the light actually needed more than 12 VDC - the "wall-wart" power pack put out 14VDC unloaded - typical for a 12VDC cheap supply, so I connected it to 12VDC - the light was so dim, you'd have thought it was off. I moved the negative cable from the COM to the -5VDC (giving 17VDC) and she lit up beautifully. - Now the cables are between the -12VDC and the 3.3VDC connectors giving 15.3VDC for the light.

PSU
Since the planned 1900 PSU was abandoned, the next most affordable option was to use a surplus ATX PSU. There are a number of articles on the web which discuss the conversion - most centre on forcing, or redirecting the softpower "On/Off" wire, and providing a load to stabilise the regulation circuitry. I started going through my collection of surplus ATX PSUs looking for a reasonably low powered unit which worked, and could be used in this project. I tested some of my surplus ATX PSUs and found a 450W which worked OK. I originally planned on using a "wiring harness" to connect everything up, but the space was too tight for that option.

Figure 5 - Wiring harness (Mk 1) which was too big for use

What I ended up doing was opening the PSU case, removing the IEC socket (and other mains supply switch and components) and soldering in a hardwired cable. At the same time I cut the ATX plug off, and trimmed all HDD/FDD cables at the first Molex connector. This gave me a bundle of wires about 350mm (14") long. I tied the green wire (PSU_ON) and one black wire (COM) to a toggle switch, and then grouped all other wires together based on their colours and connections within the PSU. Purple (Standby 5V) and the Grey (PSU_OK) cables were tied off inside the PSU since I didn't need them.

Figure 6 - Internals of ATX PSU being modified for use.

The rest were soldered to brass tabs made to suit the backs of the banana sockets (with 2 sets each for COM (Black) and 5V (Red)) The blue and white wires (-12V and -5V) looked so lonely on their tabs when all other tabs had 5 or more cables soldered in. A 7W wirewound 10 ohm resistor was added across the 5VDC rail for a regulating load (although most supplies theses days don't seem to need that - I'll remove the resistor for now and see if the PSU behaves)

Figure 7 - Modified PSU in enclosure with earthed divider panel.

As mentioned previously, the enclosure needed some way to direct air through the PSU fan, and back out of the enclosure. I accomplished this by bending up sheet metal dividers - the one closest to the front also being Earthed, and the one at the back being used to restrain the PSU, and block the holes in the casing where the IEC sockets were removed.

Figure 8 - Completed power box with second divider in place for ventilation redirection.

All Done!!! (although I haven't put in the 2 self tappers in the top corners yet!!)

Figure 9 - Completed power box ready for use.

As can be seen in the background of some photos, the desk cabinet is already being painted. The next article will cover the painting and trimming of the desk.

Field desk - part 2 - Hardware

2011-06-04T06:35:00.000-07:00

Hardware fabrication

Hinges
Using the design I created, I needed to be able to remove the door to use as a work surface. I built two hinges from brass - 1/8"T x 2"W brass strip, and some brass rod salvaged from the spindle of an old household tap.

Figure 1 - Hinge materials

The hinges were patterned on a half barrel hinge style similar to those used on trailers for the tail gate - I choose that design so the door could be removed in a similar fashion.

Figure 2 - Hinges under construction - engaged

The spindle was cut and then turned in the lathe (Taig) to make the parts. Once made, the strip brass was cut and filed to suit the parts, and then all pieces soldered together.

Figure 3 - Hinges under construction - released

Once the hinges were finished, I inlaid them into the floor and door of the desk, and rebated in the backing plates on the reverse side of these surfaces. The screws securing the hardware are all 3/16" UNC (10-24 for our US cousins) into a nut plate on the reverse side.

Figure 4 - Hinges fitted - engaged

A notch has been cut in the RH side panel to permit the door to be removed similar to a trailer tailgate.

Figure 5 - hinges fitted - door released

Locks
Next thing to make was the locks. The requirements on the locks was that the door had to be perfectly flat on both sides - the outside so it would lay on a table top and not scratch the table, the inner surface needs to be flat so it can form the working surface when I'm using the desk.
I planned on making disc-locks, but after reviewing my stock of materials, came to the conclusion that cam locks would be the design. I did not have much in the way of 1/2" diameter brass rod, so I decided to use a cartridge case (.243 Win) to form the shaft. (I have a stash of around 20 of these cartridge cases which were given to me for scrap brass). The cam plate was roughly made up, and then soldered to the cartridge case at the appropriate height to permit the base of the cartridge to be used as actuating surface outside the door.

Figure 6 - Cam lock under construction

The front and back plates were made up, and the lock assembled. Only once assembled was the cam shaped to its final length, with some easing to improve its alignment when turned. The base of the cartridge was spot-drilled to match the "keys" I made - basically a small pin-wrench.

Figure 7 - Pin-wrench "key" under construction

The pin wrench started life as one of those promotional key-chain bottle openers, but after cutting and drilling a pair of nails were driven in and cut and filed to make the pin-wrenches. I made 2 of the keys so I have a spare.

Figure 8 - Finished lock - in locked position

Once the front and back plates were completed, a top plate was made and soldered to the front plate. Clearance slots for the cam operation was made, and suitably relieved for easy use. The holes in the lock were drilled to indicate the lock status - vertical holes indicate the lock is "locked", horizontal holes indicate unlocked - there is only 90 degrees of movement in the lock mechanism.

Figure 9 - Finished lock in unlocked position

Door opening mechanism - The Pusher
Since the door has to be perfectly flat on both sides, there is no handle. I considered a flip out handle, I considered simply drilling a hole to poke my finger through - both ideas had aspects which did not appeal to my sense of this project... What I really needed was something inside the desk to push the door out once the locks were released... What I came up with was "the pusher".
The pusher is nothing more than a simple spring loaded detent plunger - but instead of pressing into a detent hole, it simply pushes the door away from the locked position by about 1/2" - more than enough to get my finger on to lower the door to the table top. The pusher uses another .243" cartridge casing for the spring holder, and the plunger is made from more tap spindle stock. Who knows where the spring came from, I've boxes of salvaged "useful junk" which gets pawed through when I do jobs like this.

Figure 10 - Pusher components

The spring casing is rebated into the riser, and the cover plate relieved into the edge so there is no protrusion other than the plunger.

Figure 11 - Pusher spring casing installed

This piece of hardware is the only one secured with normal wood screws into wood - all others use the nut-plate method described in the hinges. The screws into timber should be able to hold the minor force of the spring at the end of its travel.

Figure 12 - Pusher installation nearly complete

Once the locks are unlocked, the pusher moves the door about 3/4" if the LHS doesn't grab (that bowed panel as mentioned when I built the carcass), 1/2" if it does rub... either way I can still open the door easily.

Figure 13 - Result of pusher on unlocked door

Handle
The other piece of hardware to build was the handle. Most of my toolboxes have handles which protrude on the lid - making it nearly impossible to stack things on top. Given the intended use of this desk is in a "accommodation camp" where I may need to stack a laptop, or books on top, I was insistent that the handle design had to leave the top surface perfectly flat. The ideal scenario would have been to use the folding handle from the top of a 7.62 x 51mm ammo can - but I couldn't find any. I did not trust my skills to make one, so I looked at every box and case I owned looking for a low profile handle - I stole this idea off an industrial first-aid cabinet.

Figure 14 - Handle components

The basic strap (handle) is made from 2 layers of pallet strapping - the 3/4" wide blue/black metal banding you find on pallets of bricks and other heavy things. I drilled and slotted it, then shrunk two layers of heat-shrink tuning over it to make the handle comfortable. I then made a pair of brass "sockets" which hold the handle, and allow it to slide in it slot for extending under weight, or retracting when not in use. I made the top plates for the sockets larger than required and drilled 2 large holes in each for attaching labels (addressing, or shipping labels).

Figure 15 - Assembled handle

Since I'd already glued the carcass together (my enthusiasm bit me hard there) I had to make my own "T-Nuts" to engage from the underside. Basically cylindrical spigots soldered to shim brass which were then friction fitted into holes in the timber. I wasn't feeling overly confident in the solder joints, so I backed the nuts up with some Loctite CA glue. If the nuts pull through, I'll have to look at redesigning the handle nuts, but so far OK.

Figure 16 - Completed field desk with all hardware

Since nothing was rebated in, and the finished handle is proud by 1/4", I still had protrusion to deal with, so the only quick answer was to cut an overlay board of 1/4" plywood and screw it on top to raise the surface of the top around the handle. - Not ideal, but I'd rather do that with 1/4" ply than the 1/2" ply I'd have needed for the commercial handle the local hardware store had. (trying to keep the weight down)
The additional sheet can be seen in Figures 16 and 17. It comprises some 1/4" (6mm) plywood, and an interposing sheet of cardboard (edges covered with masking tape) - this effectively recesses the handle, with minimal weight gains.

Figure 17 - Demonstrating use of tag holes in handle

All screws for the hardware had to be cut down in length so there was no protrusion to scratch the tabletop. A dab of thread-locker will be applied during final assembly just to ensure they don't come loose during travelling.

Still to come:
Electrical section
Trays and containers
finishing

- apologies for the number of photos - next time I'll do this as two articles.

Field desk - part 1 - cabinet

2011-05-30T06:23:00.000-07:00

Construction of the field desk

I have need for an electronics tool and experimentation kit which is self contained. I looked around on the internet for some ideas, but failed to find anything which suited my needs, or seemed practical for my planned budget.
The military used to use field desks (you occasionally see one in the old episodes of M*A*S*H if you want to see an example of a real one) and I thought that would make a good starting point for a design.

I googled (is that a real word yet?) "field desk plans" and found some dimensions from early American history re-enactors and museums. Most centered on dimensions of 24"W x 18"H x 10"D (nominally 600mmW x 450mmH x 250mmD) and that seemed like a reasonable size for my intended purposes.
Whilst planning the cutting for the timber I had, I decided to use an external depth of 12" (nominally 300mm) instead of the original 10" mentioned previously due to the depth of the plastic containers I am planning to use.
My timber was the remains of a UPS packing crate which I salvaged from a job about 2-3 years ago. The timber from the sides of the crate was 6mm (1/4") plywood, and the side which doubled as a ramp was 10mm (3/8") plywood. I drew up some plans and cutting lists using the 10mm ply for the top, bottom, riser, back and sides. I planned on using 6mm ply for the shelves, and some 12mm (1/2") plywood for the front. Due to a cutting error I ended up having to use some of the 12mm ply for the sides as well.

Figure 1 - Raw plywood material


Figure 2 - Cut into basic panels

After marking the timber to the largest finished dimension for each panel, I cut the panels out using a circular saw.
The rough panels were then marked up with the slots, dovetails, etc which were cut in using a jigsaw, hacksaw, and portable drill (the drill was used to start the slots for the finger joints. All external joints were made as dovetail joints to help the box stay together, whilst the internal joints (supporting the shelves) were made as finger joints (tab and slot).

Figure 3 - partially assembled carcass

During the construction I would clip the unit together to mark up the next panel - for some reason I got confuzzled at the end of the first day and assembled the desk with one piece reversed. This then meant the finished carcass went together upside down, and mirrored. Thankfully the photos I'd taken earlier in the day were able to be used to show me the correct orientation of the pieces, and allowed me to assemble it correctly the following day. Being right-handed, I really wanted the section for power to be on the RHS.

Figure 4 - Carcass assembled, but with pieces mirrored by accident - rear view

The back was marked up for dovetails and slots, then cut and fitted.

Figure 5 - Back panel marked up and cut for dovetails and finger joints.

Once happy with the finished carcass, I dismantled it and sanded all panels before assembling with construction adhesive (aka "Liquid nails") and PVA glue.

Figure 6 - Back panel in place on carcass of field desk, shelves not in place.

The front door was then cut and tested for fit. I found a slight bow in the LHS side panel - I'm still trying to determine if I can remove it,or if I will need to alter the door slightly to compensate. UPDATE - I modified the door slightly by allowing a slight amount of slack in the hinges, and put a heavy chamfer on the inner edges of the door, this allows the door to close and adjust it's centre based on the 1-2mm bow in the LHS panel.

Figure 7 - Field desk with shelves filled with sample material

Whilst the glue dried, I commenced work on building the hardware... hinges, catches, etc.

Next articles will include:
Hardware - hinges, catches, etc
Electrical - Lighting, PSU, etc
Finishing - Painting, trim, etc

Since I didn't get much done last week on the desk, I'm hoping to complete it over the next two weeks or so.

Dividing Head for Taig (and others) - Part 4 - sector arms, plunger, etc

2011-05-14T05:34:00.000-07:00

Last article for the Dividing head.... What's left to discuss?
Sector arms
Plunger arm
Retaining Knob and spacers

Sector arms
The sector arms are patterned on the arm design from Tony Jeffree's website. The arms were first patterned out in cardboard, then cut out using a hacksaw, files, and drills.

Figure 1 - Sector arms with locking screw

The lower arm is then soft-soldered to a brass boss which protrudes to form a spigot for the upper arm. A screw has been drilled and threaded so it fully engages in the boss, but it's head overlaps the moving arm. A small brass cylinder was made to concentrate/ exaggerate the clamping force from the screw head.
In normal operation the screw is loosened by about 1 turn, and the upper arm can rotate freely on the spigot of the lower arm, once set at the appropriate arc angle (hole spacing), the screw is simply re-tightened to lock the arms in positions relative to each other. Both arms are still able to rotate as an assembly on the spigot of the plate carrier.

Figure 2 - Sector arms on plate retainer

A cover, which is actually a spacer, sits over the arm assembly in use, but serves no functional purpose other than to increase the distance between the arm, and the surface of the division plate.
Not long after starting to use this dividing head, I found the tips of the arms were difficult to operate if they crossed each other - kinda like trying to open scissors by using the tips... To alleviate that issue I turned the tip of the upper arm upwards to form a handle. I could have added a nice little knob, but I was worried about the extra weight on the slender arm.

Figure 3 - Spacer cover on sector arms

Plunger arm
The plunger arm - the arm which actually rotates the worm, is made of 1/4" thick brass strip. A slot (1/4" wide) was made through the middle by the use of chain drilling, and filing. This slot engages the flats filed on the worm shaft. A brass plunger mechanism was fabricated and the body soft-soldered to the arm.
The slot was made so the division plates could have multiple rows of holes, although typically I use only 3 rows of holes per plate at most.

Figure 4 - Plunger arm fitted to worm shaft

One problem I have with this plunger is that the threaded portion which holds the shaft and handle together will sometimes spin undone whilst using the knob for rotating the worm. I'll remember to dab a drop of superglue in there one day, but until then I remember to tighten the threaded joint before use.

Figure 5 - plunger arm secured by retaining knob

Retaining Knob and spacers
The retaining knob is simply a brass turned object, and my first attempt at knurling. The picture makes it look better than it actually is... the knob won't roll of the table because there is a flat spot on the bottom where the knurling "crunched up" - I can't explain why it happened, and I've since tried to rebuild the scissor knurler, but I keep having issues there.

Figure 6 - Retaining knob in profile

As mentioned with the sector arms, there is a cover which acts to space up the plunger arm. There is another spacer which sits above the arm to space the retaining knob. With both spacers in their correct locations, the arm is essentially clamped to the worm shaft not only by the slot, but also by the clamping of the spacers. It basically removes any clamping effects from the knob on the sector arms, since if I place the upper spacer in the wrong position (under the plunger arm) it will attempt to turn the sector arms when I operate the worm.

Figure 7 - Spacer ring above sector arm

Most of the brass was from the scrap merchant I mentioned in my previous articles, but the brass sheet for the sector arms was bought as scrap from the local radiator place (along with a clapped out 8" bench grinder which only needed $12 worth of bearings), and the brass for the plunger arm was purchased from the scrap bin of a local fabrication mob (NOT cheap)

As previously mentioned, the spigot at the rear of the dividing head body permits the plate/worm assembly to rotated through about 180 degrees allowing the dividing head to be used vertically, or horizontally and still have the sector arms, division plate, plunger arm facing the operator.

Figure 8 - Plate assembly rotated 45 degrees to illustrate movement

That's about it for the Dividing head.. it's been used on and off over the years for a few jobs and will continue to be used for many more. The most recent job was making up a wrench called a "Torx-plus" so we could access the internals of a harddrive enclosure. The Torx-plus is a 5 lobed version of the more common 6 lobed "torx" bit. I made the bit by drilling holes in the end of a piece of steel shaft to create 5 holes on the appropriate PCD, and then turned the holes away to only leave half the hole. The metal between each hole was used left in place to form the 5 lobes needed to turn the screws out of the enclosure.

I'll have to sit down one day and see if I can improve the design around the sector arms and plunger - it works, now, but it does need some improvement so the spacers aren't necessary - they are a pain if the top one gets put in out of sequence (below the plunger arm).

The field desk is progressing along, and will be the next article series at this stage. I've designed the locks and latch, and have commenced designing the hinges, support arms, lighting and handle. Somewhere in all that I'll need to decide what colour to paint it. This week I have jury duty, so it's possible I may get an hour each arfternoon/evening to work on the hardware.. here's hoping.

Dividing Head for Taig (and others) - Part3 - division plate generation

2011-05-12T04:29:00.000-07:00

The division plates used on this dividing head are made from old Hard Disk platters - the part of the harddrive which actually stores your data.
Each 3.5" hard disk will contain one or more of these disks which is 5.25" in diameter, with a 1" hole in the middle. The nominal thickness of the disks is around 1mm (less than 1/16") - I say nominal because I've found the more modern disks typically are thinner (less rotational inertia), whereas the older drives are thicker (up to 1/16")
The only thing you can rely on is that all disks in the same platter (collection of disks) will be the same thickness.

Figure 1 - Collection of platters destined to become division plates

I've been collecting hard disks for salvage for quite a while. The magnets are useful (see shed tip #1 ), and I also salvage bearings from them. The disks get shuffled into the pile for making division plates, and the casings go into the scrap aluminium bin (for foundry supplies) - only the boards, screws and little plastic doo-hickies get tossed. I learn a fair bit about mechanical design from looking inside the harddrive as well - there's some really clever braking mechanisms used to return the head, lock it, and so forth simply driven by ground effects from the spinning disk platter.

To make up a division plate:
I insert this mandrel into the back of the spindle of the dividing head. (see figure 2)

Figure 2 - Direct indexing mandrel

The mandrel is made to expand and grip the inside of the spindle once the 1/4" nut is tightened up. A gear is placed between the 2 large washers which is an exact match (or multiple of) the desired index count. When I generated the 40 hole plate, I used a 40 tooth gear, but I could have used a 80 tooth gear if I had one.

Figure 3 - Mandrel in place

The mandrel is sized to match the collection of C218 changewheels I purchased a few years ago. Those changewheels are the basis for the leadscrew of the Taig lathe and are the same metric mod 1, 20 degree PA changewheels used in the myriad of 7x12 lathes available in the US and other locations.

I place a chuck on the dividing head, and use a holder to grip the blank division plate in the chuck.
A centre drill is gripped in the lathe chuck using an arbor supporting a normal drill chuck.

Figure 4 - Dividing head spindle nose

A detent plunger mechanism is attached to the dividing head body which engages the gap between the teeth of the gear wheel. Turning and locking the spindle turns the blank plate, and all I need to do is feed the head into the drill to make the holes in the plate. The bracket supporting the detent plunger system is made from an offcut of an aluminium angle extrusion. The bracket is bolted to the body with two socket-head screws, and has holes to pass over the heads of the body bolts. Figure 5 (below) illustrates how it is fitted, with one securing bolt removed for demonstration purposes.

Figure 5 - Detent plunger system fitted

The detent plunger has a wedge shape when viewed from the side, but an inverted V shape when viewed from the front - this is to allow the indexing of the tooth tip instead of the gap between the teeth. This means I can index in the gaps of a 20 tooth gear, then rotate the plunger 90 degrees, and then index off the tooth tip and obtain another 20 positions - allowing me to generate a 40 hole plate from a 20 tooth gear.
The mount block for the detent plunger is bolted to the vertical arm of the bracket in one of 3 positions, allowing for a wide range of gear diameters. The large hole drilled through the body (from it's previous scrap origin) is used to secure the plunger with an elastic band if the internal spring is needing a little help.
The last article will cover (albeit briefly) the sector arms, plunger arm, and retaining mechanism.

Next project for documentation will be the field desk if I get it completed on schedule.

Dividing Head for Taig (and others) - Part2 - plate carrier and worm

2011-05-10T06:48:00.000-07:00

The plate carrier was made from 1/2" plate. A piece similar to the brake was made and the plate carrier was bolted to it. One bolt holds the piece on, and another engages a curved slot which is used to adjust the amount of backlash in the worm/spur gear engagement.

Figure 1 - plate carrier/ worm assembly

Another piece of metal is made which has a 1" diameter spigot which is about 0.5mm thick. This spigot is made to match the hole in the middle of a hard-disk platter. A piece of 1/4" brass has been drilled in to intersect the edge of the hole and a corresponding notch is cut into the platter to stop it rotating. A cover plate is made with a corresponding hole and screw to lock the plate (Hard-disk platter) in place. Yes that's chatter marks from turning... that work was done on a stub arbor.

Figure 2 - plate carrier with spigot

Figure 3 - Plate mounted on spigot

The plate retainer is basically a brass plate with a hollow spigot on it. The worm shaft passes through the spigot, whereas the sector arms rotate about the spigot.

Figure 4 - plate retainer holding plate on spigot

The other main feature of the plate carrier is that the part which carries the plate can be rotated through approx 90 degrees. This was cut from a piece of plate, mounted on a stub arbor, and turned to match the curvature of the mating piece. A slot was cut in the side rim whic mates to a threaded hole in the main part. The purpose of this is to allow the plate carrier (and attached plate) to be rotated independently from the worm itself over a 90 degree range. Why? Imagine you mount something requiring 13 divisions in the chuck on the dividing head, and then need to index another section of the same piece with 19 divisions and one section needs to be perfectly in line. I can mount up, cut one set of indexed points, apply the spindle brake, then change the plate, and move the plate to align exactly with one plate hole, then re-commence indexing for 19 positions. Maybe something which will only happen once in a blue moon, but it cost me little but time to add it into the design.

Figure 5 - one extreme of plate carrier adjustment

Figure 6 - another extreme of plate carrier adjustment

The worm itself was cut down from the original shape when removed from the sewing machine. A triangular groove was turned in it which intersects with a pointed socket-head screw used to lock it in longitudinal position, and a pair of flats and 1/4-20 thread was cut into the end. These correspond with the sector arm, and retaining nut respectively.

Figure 7 - worm in carrier showing flats and threaded sections

All bushings in this part of the dividing head are simple yellow brass, not bronze. At the time I built this I could get surplus electrical test probes from the local salvage place for a couple of dollars. Each probe comprised about 12" of 1" diameter nylon with a 1/4" bore, and a corresponding length of 1/4" brass rod in the middle. A few other bits made up the probe, so I was able to get nylon (for rail buttons) and brass rod quite cheap. The interface disk from the probe was used to make the plate retainer since it was 1 1/2" in diameter, and about 1/4" thick. I miss that shop. Pretty much all the remaining brass I have is from various scrap merchants, or salvaged from all sorts of junk.

I'll cover generating plates and direct indexing next.

Dividing Head for Taig (and others) - Part 1 - Body and introduction

2011-05-08T02:03:00.000-07:00

The dividing head was inspired by the work done by Tony Jeffree, and then heavily modified to suit my own circumstances and situation. (Note - Tony has a second design which uses a Taig spindle - see this link)
All photos in this series of articles were taken after construction had concluded since I did not have a camera during the build. This build occurred in Q2-3 of 2005 and was documented on Nick Carter's page back then.

Figure 1 - Dividing head in use on Taig Lathe

You can buy dividing heads - example shown here from Amazon, and there are books which touch on building your own (another example from Amazon) - in short, you need to decide what resources you have,and determine the best course... in my case I did not have a great amount of money, and I did have some time, and a willingness to learn - this meant I made my own. If I had the money... the start of many dreams. I don't have either of these products, but show them as examples of alternatives to scrap metal, wrecked sewing machines, etc.

Building the dividing head body and base.
I started by making up a spindle. Tony's one used a drill chuck, but after reading many text books which talked about not disturbing work in chucks, I decided it would be better to make my dividing head use the lathe chuck if possible. This meant I had to make a spindle with a nose of 3/4"-16 tpi, with a 30 degree included angle for collets, and a through spindle bore of at least 3/8".
I had previously bored the spindle of my Taig lathe to 7/16" not long after purchasing it so I could pass 3/8" stock through the head - I used the same drill size to bore out the spindle of the dividing head.

Using a larger lathe (Thanks Dad!) I turned a 3/4-16 thread on a piece of 3/4 shafting, and drilled/bored the 7/16" through hole. I then made a collar which was shrunk on to form the register face for the lather spindle nose. This register face ensures the alignment of the lathe chuck. Whilst facing the register face, I also bored the tapered seat for the taig collets.
At the same time as all this lathework, I also threaded the other end of the spindle (3/4-16) to use for thrust nuts, and securing worms , etc.

By the time I'd finished the spindle, I was back home, and unable to access Dad's lathe - this meant all subsequent work was done on the Taig Lathe.

The body of the dividing head was made from a short length of 50x50 (2' x 2") aluminium I picked up at the scrap dealers.
The base plate of the dividing head was made from some 1/2" plate which was a reject from some CNC mob (I picked it up at the same scrap dealer as the 2"x2" piece)
I found if I stacked the 2" x2" on the plate, on the carriage, the centreline was in line with the spindle. Perfect for my immediate plans, and in line with my longer term goal.
The theory was I'd build the head on the plate base, and then should I every need to use the head on another lathe, it was simply a case of making a new base plate.. all other parts will transfer across.

The base plate was cut to square the end (The off-cut piece became the handle of my 3/16" allen key) and appropriately drilled and counterbored for the Taig slot pattern.

Figure 2 - original base plate shape - allen key handle made from off-cut.

The square body was then bolted to the plate, and line drilled and line bored on the Taig. Somehwer in all the line boring I used a shaft as an arbor, and turned the square body on the shafting to form a spigot at one end of the body.

The line boring provided a clearance fit for the 3/4" diameter spindle, and a light press fit for the bushes used at each end.

Figure 3 - Body on base plate

A brake was made and fitted to the front of the body which engages the collar shrunk onto the spindle.

Figure 4 - Front of body showing brake on collar

The spigot which was turned on the rear of the body is used to support the plate carrier. I saw somewhere that some dividing heads are used horizontally and vertically, and that some models allow the position of the plate to be changed to make things easier on the user... seemed like a good idea to incorporate into my build.

The worm and gear for my dividing head was salvaged from an old Singer sewing machine I found on the side of the road on curb dump day. It's a 24:1 ratio set which is OK for this design. I bored out the spur gear to suit the spindle, and cross drilled and threaded some grub screws in place. A normal 3/4-16 nut was cut down and faced to become a thrust adjustment nut. The other half of the thinned nut is often spun on to the spindle after the spur gear as a lock-nut. The grub screws on the spur gear engage in filed flats in the spindle thread.

Figure 5 - spigot, thrust-nut and worm on spindle.

The plate carrier will be discussed in another article, but here is a photo of it in it's place on the spigot.

Figure 6 - Plate carrier in place on spigot

The body really isn't much more than support for the spindle, and a means to hold everything else on the dividing head. I tried to design the body to make the head transferable from one machine to another - the base plate is the designed mechanism to permit that.

The plate is designed with holes in a grid to allow the plate to be mounted on Taig T-slots either parallel, or perpendicular to the slots.

Next articles: Plate carrier, plate generation, and sector arms and worm driving.

In the meanwhile I got the carcass of the field desk made yesterday, and hope to have the woodwork completed over the next week or so, then make up the catches, hinges, and handle over the next week, then inletting, finishing and it's complete. Everything takes time since I only have one day per week to do work - I try to keep the Sabbath holy, and work does a good job taking the other 5+ days... My wife is a darling since she encourages me to spend at least half of every Saturday in the shed - for that I'm most grateful.

Third hand - electronics tool

2011-05-01T07:06:00.000-07:00

I have some work on the horizon where I may be away from my shed for periods of time. It's still up in the air, in the hands of Heavenly Father, managers, and others. In the meantime I'm getting things ready...

One of the things which I'm going to need is a portable electronics kit. My current setup is based on an old fishing box full of tools, and several tubs full of parts in various trays, etc. I've decided the best method to deal with the proposed situation will be a "field desk" with the minimum of what I require, and a contained work area.

The desk will be covered in another article series, but this article introduces the first tool made for the field desk... the third hand.

Figure 1 - third-hand in use - salvaged PCB from old fire-panel

For those who aren't familiar with the term, a "third hand" is simply a means of holding something whilst keeping your own two hand free. I used a third hand whilst at uni and found the design quite good and duplicated the essential features here.

There are other designs out there. most work on the principle of a heavy weighted base for stability, and then posable arms terminated with clamps. The one I used at uni (made by the lab techs there) used lightweight materials and a door hinge for the "pos-ability".

The only concession from their design to mine was that mine had to be collapsible so it took up less space in the field desk. The original unit did not come apart, and as such occupied a space of 200 x 125 x 150mm (8"x 5" x 6") - this design occupies the same space in use, but folds down to 180 x 125 x 35mm (7" x 5" x 1 1/2") for storage.

Figure 2 - flipped to other side for soldering work.

Since the unit can flip too far in one direction, a small piece of perspex can be inserted to limit the travel of the hinge as shown in Figure 3.

Figure 3 - inserted piece of perspex limits hinge travel.

I used some of the perspex I salvaged from some shop shelving, and cut it to utilise the existing lip which was on it.
A pair of pieces were cut to match and support the hinge, and this pair were then drilled to sit between the two halves of the base.
Some bolts were modified to make them "tool-less" by soldering their heads into a brass piece which had a square washer affixed - I'd have preferred wing nuts and wing-bolts but didn't have any.

The clamp which supports the PCB is simply one leaf of the hinge, and a piece of aluminium which is made from a drawer divider. The cranked over fold is used to form one part of a toe-clamp, and to provide clearance over the nut which holds the bolt in place.
A stiffening plate is captured under these bolts to provide more gripping surface. Again due to my lack of wingnuts I made up some nuts using brass. The brass used for making the wing nuts (and bolts) is from discarded tap spindles, the sheet from an old door strip.

Figure 4 - cross- view of PCB clamp with perspex gripped for illustrative purposes

Figure 5 - View of base assembled showing component parts.

Figure 6 - dis-assembled third-hand showing all parts

Soldering is simply done with a propane torch, using "Baker's fluid" as the flux, with normal 60/40 soft solder. Only the minimal amount of solder is applied, and excess is trimmed away to prevent absorption through normal use.

Figure 7 - Third-hand collapsed ready to be stowed

The field desk will be built with PICAXE projects in mind. I have a few which I need to get completed, and since all I can have at the camp is books, and minor electronics (no Lathe or other powertools) I figure this will make good use of what spare time I have.
Even if this proposed change falls in a heap, the investment in making this desk, and associated tools will still benefit my electronics hobby.

DTI Mag-Base repairs

2011-05-01T02:42:00.000-07:00

a while ago I discussed a broken mag-base I salvaged from being tossed out. That article discussed the dis-assembly of the mag base.

In an effort to get the "To Do List" a little smaller I finished off the repairs to the indicator base.
I used the spindle from a discarded tap to make up an actuating system for rotating the mag-core. I simply filed the required square shape into the section which used to hold the jump valve.
The threads which actuate the original tap were turned away, and replaced with a parallel section.

Figure 1 - Tap spindle filed to square

A plastic bush was turned to locate the mag-core inside the void in the mag-base, and to provide support to the spindle. The plastic was from a sheet of 25mm (1") thick plastic (nylon I suspect) that I rescued from a bin. A suitable square was cut from one corner, and a 10mm hole drilled through it. A 10mm bolt and nut were inserted, tightened up, and used as an arbor for the turning. Whatever the plastic was, it certainly was "stringy" in the swarf.

Figure 2 - Commencing turning the plastic bushing

A brass indicator/ handle was made from an old brass fitting, and some sheet brass, and soldered together.

Figure 3 - Actuating knob and pointer prior to soldering

The spindle was designed to pass through the front plate which was made from some brass strip. The front plate is shown on the RHS of the exploded view below (Figure 4)

Figure 4 - exploded view of mag-base

In the above exploded view, everything to the right of the magnetic core, and everything above the magnetic base were made from salvaged materials.

The magnetic core was filled back to remove the old damaged paint, and engraving markings. A few minor dings were cleaned up, and then the base was primed with cold-gal paint (Zinc-it) then followed up with a couple of light coats of Silver Hammer finish paint.

Upon assembly it was deemed too difficult to re-drill the existing holes to their proper spots, so new holes were drilled for securing the face plate.

Figure 5 - the magnetic core in the base with the spindle and bushing in place.

Figure 6 - The mag-base assembled

One of the salvaged lengths of steel from a gas strut was used to make the mast on this base - although a brass socket and washer was turned from an old extinguisher part (CO2 nozzle) to stiffen the joint instead of simply using the M8 thread.

Figure 7 - The mast on the mag-base made from gas strut

An offcut of the gas strut remains, being about 125mm (5") long which will most likely be used for making one of the connecting rods.

Figure 8 - The completed mag-base next to the Taig lathe.

I've possibly made the mast too tall, but standing next to the Taig lathe, it has sufficient height to ensure access to anything I put in the lathe, or the vertical slide. I've yet to make the other smaller poles, joiners, and DTI connectors, but that should be fairly easy to do over the next few weeks.

That said, guess who's added more projects to the list... You'd think I'd have learnt by now, or maybe it's my curse (or is it blessing) to always have more jobs than hours to complete them...

I did up a quick explanation of how a mag-base works for someone, and decided to include it here in case anyone else needs to know how they work. I've since cleaned it up and converted it to a JPG.

Figure 9 - Theory of operation - magnetic stand

And now for something completely different - some quilts I made

2011-04-25T06:33:00.000-07:00

Just for something a little different - much different than driving the lathe.

Everyone who knows me knows I have a myriad of interests, and will have a go at just about anything. I started sewing properly back in 1990, and have dabbled ever since. I've no plans to make a career out of it, but I've already saved a lot by doing alterations and repairs. Here is some photos of the two quilts I've made, or helped make.

Gift 2004 - Noah's ark quilt 1330 x 1560mm in size

Central panel hand quilted by my wife - panel is one of the preprinted style available through the fabric stores.
Surrounding panels have a set of themes.
The two side sets (vertical set of 4 panels per side) are the land animals
The top set of panels (5 panels) are the animals of the air (birds and bugs)
The bottom set of panels (5 panels) are water animals.

The borders to the panels sets are made in the colours of the rainbow and orientated to form a circular pattern around the ark.
The corner panels also have a theme which commences in the low RH corner and is read in a clockwise direction.
Low Right Hand Corner - the rains commence and the waters start to rise
LLHC - the rains continue and the waters are significantly higher
ULHC - the dove brings back the olive sprig
URHC - the waters recede from off the face of the earth

All panels with the exception of the large central panel are made from machine based applique methods.
All fabric is poly cotton - pre-shrunk, and sewn with polyester threads.

The rain in the lower corner panels is over-sewn with a silver metallic thread for effect.

A sample of some panels are shown in the photographs

The panels were designed by downloading images from the internet of animals (I found colouring pages to be the best for size and line detail), or I simply drew the images myself. I then made the applique pieces, turned them, and sewed them in place to create the panel. Detail such as leaves, bubbles, etc were then added, and the panel completed.

The dove was particularly painful due to the colours of the rainbow.

I did a dragonfly, and used a chinzy tule to make it's wings so they retained their translucent effect... that was interesting to sew.

The quilt was made as a gift for my wife's best friend, and we both considered the effort we put into it time well spent for the recipient.

A quilt which I made for my beloved wife...
2006 - "Friends put a Bounce in your Heart" Winnie the pooh - 2100 x 2300mm in size

Started with a picture I downloaded from the internet which I blew up by clipping a sheet of builders plastic (orange translucent sheeting) to an overhead projector screen, and then opening the picture in a PC connected to a data projector.
Then it was simply a case of tracing the projected image onto the plastic and using that drawing for my cutting pattern.

Fabric was standard polycotton - preshrunk, sewn with polyester threads.
Style was normal machine applique.
At this stage the tracks of the bees and butterflies form the only quilting in the border panels.
The corner panels are each quilted with one letter of "POOH"

This quilt was made during a holiday where my wife left town to visit family, and I built my furnace - My better half was gone for about 8 days, and I would get up each day and work on the furnace from 7am until 2pm, then clean up and work on the quilt from 2pm until 11 pm. I think I threw in a couple of full days 7am-11pm) as well just to ensure this was done before she returned. It then sat in storage for a few months until it was given to her for a Christmas gift.

There is a panel stitched into the back with the title and dates of the quilt.

Equipment:
I have 2 sewing machines, and one overlocker - All I'm missing now is a table tennis table so I have a large foldup surface for laying out patterns and pinnings. Currently I use old doors on saw horses.
The sewing machines are nothing fancy - an old Elna air electronic I purchased secondhand, and a cheap Toyota which we bought when the Elna was looking like it was struggling repairing heavy fabric clothes (denims) - both machines have functioned flawlessly as long as we look after them.

I don't make quilts often - too much on "the list" as it is, but I'm often sewing at least once every month or two doing clothing repairs, or making some little doo-dad. Two weeks ago I made some ID card holders since the one I use at work fell apart and I blamed it on the poor design... let's see if my new design lasts longer than 3 months, then I can skite about it. My multimeter case worked well and has held up for quite a while now without concern.

This is how the kitchen table looked whilst I was making the panels for the Noah's ark quilt... another reason why I don't make quilts too often.

Many many thanks to those people who have taught me various sewing tricks over the years... Mostly Lyn for first teaching me how to use a sewing machine, then Rosemary for first teaching me how to use an overlocker, and Myjalessa for all the fancy tricks. I know I've missed others, but those three certainly started me off with this.

Taig lathe cabinet -control panel and switches

2011-04-25T04:07:00.000-07:00

To conclude the discussion about the construction of the lathe cabinet, I'll now cover the switches, and finer points of the control panel

In my day job (which seems to cover days, nights, weekends, and other times as well... but that's another story) I am quite familiar with industrial emergency switches - aka E-Stops, or "Lock off stops" (LOS)
Industrial E-stops tend to have replaceable contact blocks which bolt to the back of the switch mechanism, and these contact blocks can be double sided, stack-able, and able to be used in a variety of configurations to suit the control need.
I have one or two of these switches which I've salvaged from discarded equipment, but the contact blocks add at least 40mm (1 1/2") of depth behind the faceplate - unsuitable given the space constraints at the tail stock.

Figure 1 - Two N/C switches with perspex circles glued on

Since I only had 18mm (3/4") behind the switch at the tail-stock, I decided to build my own e-stop switch until a commercial alternative presents itself. I purchased a number of N/C (Normally Closed) momentary push-button switches from one of the e-bay stores (Virtual village from memory) to use as e-stops.
I also purchased some N/O (Normally Open) momentary push-button switches as well... for some reason the N/C switches were only available in Yellow, and the N/C in Red - no matter.

I then cut out some suitable sized circles of perspex (Hole-saw with the pilot drill removed - whole job done by clamping in a drill press) and glued the circles on the button face using a cyano-acrylate based glue (Loctite Prism, or some other form of "super glue" - aka "crazy glue")

Figure 2 - N/O switch with smaller perspex circle glued on, next to bored out PET bottle cap

The two e-stops were then painted red using a sheet of paper glued over the perspex, and paint sprayed onto that. The paper makes the perspex opaque, and helps it take the paint better.

A similar method was used to make the button on the N/O switch slightly larger, and painted green.

The N/O button was to become the "Start" button, and as such I felt should be shrouded to prevent accidental activation. I could have made a nice professional shroud using pipe with an end cap soldered in and bored out, or I could simply grab a lid from a PET soft-drink bottle and bore it out to match the switch body.

Figure 3 - Test fit of "Start" button in shroud - using tail-stock mini-panel for support.

The panel was marked out and drilled for all switches prior to painting, and the back was marked up to make wiring easier.

The PWM circuit (commercial kit from Oatley electronics - Kit K252 ) was grafted on to a surplus Pentium heat-sink, which was then screwed to the top inner surface of the control panel so the fan blew directly on it. The on-board potentiometer was replaced with a wired external unit which is accessible as the speed control knob on the control panel. I had a few hiccups with the kit, but not as a result of any problem of Oatley's... All resolved now, but issues included one terminal block cracking when tightened up, and a dodgy soldering job on one oscillator pin.

Figure 4 - Back of control panel with PWM circuit assembly resting on it

I used some of my salvaged spiral wrap for the cabling - turned out to be a disaster since the wrap was so old the plastic was brittle. I had a chat with Wayne at Rexel and bought some more.. cheap chinese stuff instead of the the Cabac brand we use at work, but certainly much cheaper... and it seems OK for my use.

Figure 5 - Control panel front view prior to painting or labelling.

The cabling of the control panel was covered in my previous post and will not be repeated.
The control panel was simply painted "Bender grey" along with all the panel work and a label was made up.
The label was made from creating the text and dial markings, warnings etc in Paint, and then assembling them on a page and printing it out. I then cut the paper up, and rearranged them to match a tracing already done from the finished panel. Securing screws, holes for breakers, relays, controls etc were marked in and the text placed around them. Once completed, the finished sheet was then placed through a colour photocopier and trimmed for effect. A pass through a laminator and re-trimmed and it was ready to be glued to the control panel. Peter Homman described a similar method for the prototyping of control panels for products, including membrane switches - it's a good idea I was grateful to be able to learn from.

Figure 6 - completed control panel with paint and labelling

A quick few notes:

I won't be adding anything more to this Taig lathe cabinet article series unless someone needs clarification on something... use the "contact page" to send through any questions.

I don't plan on offering any drawings or plans.. I can take a few more photos, but that'll be only if requested.

If you're in Australia... look at Oatley for cheap kits and other interesting bits and pieces. The motor currently fitted to this lathe is one of their 300W scooter motors. Since there isn't a cheap source of treadmill motors in oz (similar to the big surplus stores in USA) this is a good alternative. I've bought from Oatley over the years and found their prices and range reasonably good for a number of products.

Lastly... what would I do differently if I repeated this project?

Use a finger brake for the panel work for a neater finish
Make the swarf gate bigger, and the swarf container smaller (so an industrial E-stop with contact block can fit)
Use more flexible cable for the 20A DC wiring
Add a separate circuit breaker to allow the motor drive (PSU, and PWM, etc) and the fan to be operated separate from the supply to the GPOs

In the words of Porky Pig, "That's all folks"... next post will be back on one of the many other projects I'm trying to get off my "to do list"

Taig lathe cabinet - schematic and cabling

2011-04-19T22:08:00.000-07:00

I started out designing the cabinet by deciding what I wanted (features list).
I wanted:
a) - drawers accessible from the front
b) - shelf above main deck for commonly used things
c) - a deck to support the lathe, with enough room for accessories
d) - the deck needed to be thick enough for drilling and tapping into
e) - the deck needed to be magnetic (for DTI bases)
f) - the deck needed to have a raised edge so things couldn't fall off it
g) - preferably no "traps" for swarf to build up in
h) - a way to easily remove swarf
i) - motor mount which permitted unloading of belt
j) - accessible power points
k) - variable speed motor
l) - reversing motor
m) - task lighting
n) - controls accessible without reaching through rotating parts
o) - cabinet wired as an "appliance"

Points J to O are basically electrical in nature and influenced the electrical design.
The electrical design was done with a sketched up line drawing based on the salvaged parts I had (from some scrapped switching machines)

Figure 1 - Hand drawn schematic of circuit

Whilst building the cabinet, I used a hand drawn schematic, but then once completed, I drew it up properly (Paint then exported to jpg) for the "point to point" testing.

Figure 2 - Schematic done to a more professional standard

The variable speed motor was accomplished with the use of a Pulse Width Modulated (PWM) controller, with a large (6800uF electro) capacitor added for smoothing - subsequent discussion on aus.electronics demonstrated that this smoothing cap should not be added, so it was subsequently removed. I added a 20A DPDT toggle switch for accomplishing the reversing function.
The mains voltage design started with a IEC socket (with line filter) which is switched through a 10A MCB (miniature circuit breaker). The circuit supplies a pair of double GPOs, and a fan which pulls air into the control cabinet. The supply to the PSU is controlled through a 10A DPDT relay which uses latching circuitry on one set of contacts to hold the supply on to the PSU, dropping it when either "E-Stop" button is pressed. The relay pulls in if the start button is pressed, but loss of supply will release it, and restoration of supply will not automatically re-close it without another button press. This supplies the No Volt Release (NVR) functionality I wanted for safety.

Supply from the PSU is fed through a SFKOL (GE motor start over current protection device) and to the PWM speed control. The SFKOL protects the PSU from a short in the motor, cabling, or PWM circuit.

Figure 3 - Wiring commencement

Figure 4 - Wiring continued

All 240VAC wiring was done with 2.5mm2 cabling, and all 24VDC wiring done with 4mm2 cabling. I tried to maintain the wiring code relevant to Oz with respect to colours of cables, and marking of earth, etc.
The majority of cabling is contained within the control cabinet, but there is some cabling which is outside the cabinet. The motor cable, and base "E-stop" circuit are passed through the floor of the control cabinet using cable glands in a non-ferrous gland plate. Both cables have an Earth core, although the motor cable earth is not connected to anything at the motor.

The E-stop cable has a protected connection on the rear of the backboard where connection can be broken for service. The cable to the RHS base E-stop (tail stock E-stop) is routed inside the tube frame for protection, and a 5mm (3/16") thick support rod was welded into the frame to support the cable so it couldn't foul against the drawers, or the swarf gate. The support rod is shown with a light gauge test cable. The heavier (orange sheathed) cable is held in place with the support rod using cable ties (aka zip ties).

Figure 5 - Tailstock cable support rod test

The back of the tail stock E-stop is shielded by a sheet metal cover, which terminates the Earth core. Bonding of this Earth to the base frame is accomplished by the face mounting screws, and another bonded cable.

The entire lathe cabinet is technically an appliance, and as such was tested for Earth Leakage, insulation resistance, etc prior to powering on. All tests passed.

Still to be described - the panel controls and constructing the switches.

Taig lathe cabinet - control panel and top tray

2011-04-12T05:55:00.000-07:00

So far we've designed this cabinet, planned out it's size and requirements, then tweaked it as we went into construction. All that's left now is to build and fit the panels and tray which are mounted on the back board.

The backboard contains two parts - interconnected but with separate purposes.
a - the control panel which contains all the electrical circuitry for controlling the lathe including protection, speed and direction control. The control panel also contains the breaker for the GPOs (General Purpose Outlets - aka "power points")
b - A tray for holding items used often, or needing to be up out of the way.

Figure 1 - Two parts of the top tray

The top tray was designed as a simple tray, with a false bottom which contained some GPOs. The front face of the tray was angled so the GPOs pointed downwards to prevent ingress of swarf, or coolant. I could have mounted them on the bottom face of the tray, but prefer the idea of being able to see the state of the switches at a glance.
The tray was simply folded up out of sign-white sheet metal in two pieces - the tray proper, and the supporting structure.
Holes were cut into the front face for the GPOs, and an access hole was cut in the LHS wall for cable entry.
The two halves were then riveted together, and sealed with silicone sealant to prevent anything from the top tray leaking into the false floor.

Figure 2 - Top tray assembled

Figure 3 - Top tray bolted to backboard - view from RHS.

The control panel section is a simple box. The top, rear and bottom faces are all folded from the same piece of metal forming a "U" shape. Flangles are folded inwards to form faces for the ends and front to be screwed on.
Each end piece is a separate sheet with the LHS containing a cutout to match the cable entry hole in the tray. The RHS sheet has a variety of holes cut in it for ventilation and power entry. Both side sheets have a bent section to form the side flanges for securing the front sheet.
Heavier gauge sheet metal was used for the side and front sheets to provide strength to the structure, and to support the control switches.

Figure 4 - front view of control panel showing internal flanges

I determined the size of the control box by lumping all the planned components into a pile, and then estimating it's volume. A considerable factor for cooling, wiring, and access was then added and the resulting dimensions then used.
Once built, the components were thrown into the box to test the layout and volume.

Figure 5 - Volume test of finished control box

A drawing of the box and it's airflow is shown below. The issue of the heat the 500W PSU generated was a concern, so I tried to design effective airflow into the cabinet. The PSU has a small fan inside it, and it blows hot air out one end... to make this more efficient, I folded up a small shroud to extend the fan end of the PSU to the LHS side wall of the control box, and cut a matching hole in the sidewall. A larger fan (surplus from when I upgraded my welder) was installed in the same sidewall - so cold air is sucked in, circulated through the control box and expelled through the PSU.

Figure 6 - sketch of air-flow and major components in control box

The front panel of the control box has been bolted on for the next photo. The front face is a simple sheet of galvanised sheet-metal.

Figure 7 - Plain front face of control box

Some paint, and then a handmade label, assorted holes, controls and an indicator lamp and this is how the control panel turned out...

Figure 8 - Finished control panel

The label was made using techniques attributed to Peter Homann along with a myriad of minor tricks I picked up over the years. The warning labels cover the real risks of the lathe cabinet, and operating the lathe including: electrical, rotating parts, read instructions, wear PPE (Personal Protective Equipment.. eg safety glasses) and the most important of all... I copied and modified the logo from Hack-a-day with the advice to "not let warnings put you off being creative, or learning" since I believe too many in today's society become too scared of warnings to actually try something new.

What else about the control box? There is an aluminium gland plate in the bottom face of the box for the passage of cabling to the motor and to the E-stop at the tail-stock.

The entire cabinet was painted with "Bender grey" paint - the darker of the two colours used to paint up Bender. The colour is nice, and I have over 5L ( about 6 pints) of paint left from painting Bender so I'll be painting a few things with it over the next few years.

The only topics left to describe with this project is the electrical systems including:
Schematics, wiring, switch construction, and controls. I daresay those topics will be covered in about 2 more articles, and then that will be it for the lathe cabinet unless there are questions.

taig lathe cabinet - drawers, slides and lock

2011-04-11T04:26:00.000-07:00

On a roll here - hopefully the 'phone won't ring...

Drawers for the lathe cabinet.

A few design criteria I specified;
a - accessible from the front of the cabinet - previous stand was from the RHS (under tailstock) - never used because it required too large of a footprint on the workbench
b - no "un -viewable" space - the drawers had to be able to be viewed in their entirety.. to often the tool I need is found hiding in the very back of the drawer
c - drawers needed to be big enough to be useful, but small enough to be hard to overload
d - preferably lockable - more for controlling little fingers rather than theft.

To the "bin of useful junk"... and I returned with 2 pairs of drawer slides I had previously salvaged from some BIG photocopiers. These slides were used to house internal mechanisms (or was it 2000 sheet paper feeders.. I can't remember) so they're made tough, and best of all they extend out to 2.5 times their length.

Figure 1 - Salvaged drawer slides

When I built the base frame, I included some flat rails for bolting drawer slides in place. I had pre-drilled them to match the slides and simply welded them inside the frame. The centre rail was effectively double-sided since it was designed to hold a rail on each side, plus I made it longer to provide a tongue for a locking mechanism.

Figure 2 - Drawer slides fitted to base frame rails

The drawers were then drawn up on the sheet metal with a width to match the inside width of the drawer opening - drawer slide to drawer slide, depth, and height, to match the base frame - with suitable reduction for clearance.

The drawers were cut and folded using the previously described methods (clamped between tubing and angle-iron, bent over with bits of wood, and metal flatters)

Figure 3 - Drawers made and fitted to slides

After the mistakes were corrected, the drawers were shimmed up to the correct height for clearance, and holes drilled for the drawer slides. Bolts inserted, nuts tightened and all done.

The next step was to make some fascia sheets for the front of the drawers so the gaps around the sides for the drawers slides wasn't as obvious.. measure, drill, and pop rivet on.

The handles for the drawers are actually bus insulators from a switchboard I scrapped. A friend needed the breakers, and I disposed of the rest. The insulators were trimmed with the grinder, and then screwed in place to form the handles.

Figure 4- Drawer extended out to show the full drawer contents

As mentioned previously, the central slide rail was made extra long so a tongue protruded. This tongue was cross-drilled and a matching plate with slot was made from 4mm sheet. Locking the drawers is as simple as closing them both, then placing the plate over the tongue and slipping a lock on - illustrated here with a bolt.

Figure 5 - Demonstration of locked drawers

Writing this article doesn't do justice to these headaches these drawers caused... It's easy to blame my tools, but every one of the problems I had with these drawers actually highlighted something I'd read about, but luckily avoided thus far in the project.... metal stretch

If you're going to use the same methods I did for bending metal - clamping and hammering, be aware that the metal will stretch as you work it. I found the sheet metal stretched by about 4% over the length based on hammering in 4 bends... that doesn't sound too bad until you're trying to hold a dimension to within 2mm (about 1/16") so the drawer slides aren't tensioned in use.
The answer to the issue - test bends on scrap first, and clamp up tight to avoid shifting... the clamping is why I'd love to build a brake, but even then I'd still do test bends for high tolerance work.

Resulting drawer sizes...290W x 100H x 450D and 375W x 100H x 450D (11.5" or 15" x 4"H x 18"D)

NB - A note about scrapping photocopiers... The local photocopy guy gets paid $50 for each defunct/ old copier and they get shipped to India for refurbishment... For $50 I can bring home a photocopier which is nearly the size of my 6' x 4' trailer and salvage many heavy duty slides, at least 4 NEMA 27 or 34 Stepper motors (and several smaller ones), a few PSUs, shafting, bushes, pulleys, mirrors, etc. It takes about 6 hours to tear one down to the last nut and bolt if you use a cordless driver, but you get a treasure trove of useful bits - hence why the Indians want them. A bonus, you get to learn about how they are built, the engineering and tricks in their assembly and design.

Next installment.. most likely the top tray and control panel.. that will wrap up the mechanical construction.

Taig lathe cabinet - swarf gate and dump

2011-04-11T03:31:00.000-07:00

The reason for designing this cabinet with a drip tray with raised edges was due to the problems I used to have with things rolling off the flat board which was the prior base. Raised edges make it impossible to have things fall off, but make it harder to sweep swarf out.

Figure 1 - Swarf container on base board

Due to the loss of 100mm (4") of drawer width due to the tail-stock end E-stop, I had a "space" I figured I could fill with a container to catch swarf. I had toyed with making this tray for holding things like chucks, but the inspiration regarding a swarf dump made the most sense.

The angle iron base meant I could make the tray sit upon a piece of board which could use the angle iron as a track to retain it. The container was folded up as per the panel beating page, and then screwed to the board.

Figure 2 - Swarf container "in place", simply lift the handle up to remove the container

With the container built, the gate to dump the swarf needed to be made. A track was made using a pair of lap joints on each side of the gate piece.

The swarf gate was made from an old discarded lifting lug which already had a 45mm (1 3/4") hole in it, and simply had a piece of strap welded to it so the gate was accessible from the tail-stock side of the drip tray.

Figure 3 - Swarf gate resting in LHS track

The lap joint used to retain the gate was made two ways... the RHS one was simply a piece cut from the angle iron which supports the base sheet, whereas the LHS one was made of two pieces of 4mm scrap cut and welded together.
Both lap joints are tensioned by means of small bolts which pass through the base sheet, and drip tray and thread into the lap joint rails.

Figure 4 - Swarf gate half open

To demonstrate the effectiveness of the gate - the nuts are some 8mm nuts which have seen better days

Figure 5 - Swarf resting on closed gate

Figure 6 - Gate dropped into container below when gate opened

Figure 7 - Opening at top of swarf gate less than 45mm

The holes in the base sheet and drip tray were cut and filed so they were deliberately smaller than the gate opening - this prevents material hanging up in the gate mechanism.

Next installment - drawers (slides, lock, and construction)

Personal notes:
Still learning how to make this new O/S work, but at least I can start catching up on these articles
Took some time over the weekend to watch sessions from General Conference - very rewarding and inspiring.

Until next time....

Taig lathe cabinet - drip trays and panel beating

2011-04-10T05:28:00.000-07:00

This article covers the construction of the drip tray (first and second attempt) and touches on the panel beating methods I used

As mentioned in the article regarding the frame, the objective of the lathe base was to have a substantial piece of metal which was thick enough to support drilled and tapped holes, magnetic (for use of mag-based tool stands), and to help dampen noise. Thinking I could do this by building a drip tray out of 4mm steel, I made a tray by scoring and cutting the sheet, and then bending and welding it up.

Figure 1 - pieces of 4mm sheet scored and bent

Figure 2 - 4mm sheet welded up to form drip-tray #1

Figure 3 - resulting drip tray from 4mm sheet - distorted and not flat

BIG PROBLEM - the resulting tray buckled during welding and would not provide a flat base. no amount of cussin' or hammering would fix that. - on to Plan B.

Plan B was to use a thinner metal to make the drip tray, and then use a separate sheet to form the solid base floor. The frame was built to support this design, and the base sheet cut and fitted. From that sheet, all other measurements for the drip tray were derived.

The drip tray is made from colourbond "sign-white" - a thin sheet metal coated to prevent rust (some kind of zinc-aluminium coating) and coated in a bonded white paint - it's used by sign writers to make shop signs - hence the name. The other side is a pale grey colour, and this became the visible side since it was easier than trying to remove the old vinyl lettering from the white side.

My source of sign-white is a number of discarded signs which I obtained soon after moving to this town. The frames for the signs quickly became stock for building a myriad of doors, shelves, etc, and the panels have become door skins, guards, and a number of other tasks. This lathe drip tray commenced the use of the last full sheet.

Figure 4 - commencing the folding of the drip tray (#2) - forming the wired edge

Since I don't have a pan or finger brake (yet another project yet to start) , I improvised using tube and angle iron clamped together (often the tube was one side of an old table frame). The "mallet" was a piece of pine timber, and a piece of 2"x 1/4" flat bar was used as a flatter to help crisp up the edges. I formed up a wire edge for the edges of the tray where hands would touch by folding the sheetmetal around a strip of 3mm x 25mm (1/8" x 1") strip and hammering it flat with a mini sledge hammer.. after everything was folded up, this gap was then closed up to complete the wired edge.

Figure 5 - completed drip tray with wired edges for safety

This method of folding was used throughout this entire project - drip tray, drawers, trays, control cabinet - all fashioned with bits of tube or angle iron, 3 clamps, a piece of timber (with or without a flatter), and a pair of ear muffs to drown out the noise.

Figure 6 - completed drip tray and back board

Figure 7 - Rear view of back board showing overlap

Next article will cover the swarf gate and accompanying swarf drawer.
Still to come:
Drawers, electrical circuit, "home made" switches, control panel

Taig Lathe cabinet - base frame

2011-04-08T07:28:00.000-07:00

The frame of the lathe stand

The frame was built based a size calculated to permit the Taig lathe to be mounted with enough room to allow the mounting of a motor, space for changewheels, backgearing, control space for the leadscrew control, and any accessories I planned including a taper turning attachment and profile copier.

Figure 1- Base frame with headstock reinforcing

The overall baseplate dimensions became 500 x 850mm (20 x 33.5"). The baseplate became the core of the design with a sheetmetal tray built to sit under it with a lip coming up from the front and sides, and an extended lip coming up at the back making a swarf tray capable of containing swarf or coolant.

Figure 2 - Base frame with drip tray and top sheet

The frame was welded up from 20x20mm (3/4 x 3/4") angle iron, or tubing from the scrap pile.

Figure 3 - Base frame with backboard frame attached

The Taig lathe is a cantilever bed lathe with a foot under the headstock. To provide a strong stable mount for the lathe I welded a piece of 4mm (5/32") into the base. (shown in Figure 4) This means the lathe is mounted to 8mm (4+4mm) of steel, whereas the rest of base will have a thickness of only 4mm. I deemed 4mm as thick enough for magnetic bases, or drilling and tapping into, whereas I felt it prudent to have it thicker under the lathe foot, and for mounting the motor assembly.

Figure 4 -Base frame from rear, showing angle iron brackets for back board, and reinforcing sheet at headstock

The backboard for the lathe stand adds 560mm (22") to the height of the stand and runs the full width of 910mm (36"). The backboard is attached to the baseframe by some bolts mating the board to some angle iron brackets.(refer Figure 4)

The frame contains room underneath the baseplate assembly for drawers - the height of which is 100mm (4"). The drawer widths are governed by the spacing of the stiffeners added to support the plate under the lathe foot, and a small offset at the tailstock end to support the E-stop. The space behind the E-stop is used to house a "swarf drawer".

Figure 5 - Bare frame with drip tray and top sheet removed, backboard frame attached.

The frame has 2 fold-away handles attached for moving the lathe - these are located at each end of the base.

Figure 6 - The fold away handle at the tailstock end of the base frame

The backboard was clad with a sheet of polycarbonate approximately 6mm (1/4") thick (a salvaged shop display shelf when the local postoffice was renovated), and a piece of colourbond "signwhite" from a salvaged shop sign. The sheet of polycarbonate served 2 purposes:
a - the additional thickness stood the sheet of colourbond away from the frame at the bottom edge permitting the lip of the base drip tray to slide behind it - preserving the sealing of the tray assembly, and
b - the additional thickness added stiffness and "meat" to the backboard providing substance for screws to engage with, and to dampen any movement in the colourbond sheet.

Figure 7 - clad backboard - rear view.

A few other features are in the frame, but those will be elaborated upon during the articles describing what they support.
Overall dimensions - 710 (H) x 550 (D) x 910 (W) = 28" x 22" x 36"

some homemade tools - pin wrench and floor scraper

2011-04-07T05:41:00.000-07:00

The PC is now working (sorta) - the original motherboard died and took with it 2 of the hard-drives. A substitute motherboard was sourced on Ebay which should have taken the existing memory, CPU, graphics card etc... The motherboard was brand new, but over 5 years old. Basically it didn't last too long - failed in a different way and I was fighting a losing battle trying to repair this "on the cheap"
The "new" PC is simply a new motherboard ("Mainboard" as I was told by the sales guy) with new CPU, RAM and this also entailed a new OS since I exceeded the 4Gb of memory. I still have a few teething problems with my PCI SATA2 card, but I am working on it.

This article covers a few things I had to build during the outage on the PC.

Super Scraper
First is a tool for chipping cement off a concrete floor. There are floor scrapers available to taking plaster off floors, but this tool will remove tiles, cement, lino, cats, whatever you point it at. The secret to this tool is the heavy duty blade, coupled with it's weight.

Figure 1 - The super scraper leaning against the shed door

The blade is a bricklayer's bolster - a broad "chisel" which can be picked up in the discount tool stores for around $15. the bolster is modified by removing any rubber handle/covering, and then welding the handle to/inside a pipe handle of around 1500-1800mm (5-6') long. I deliberately choose heavy walled pipe for this job since you want a fair bit of weight in the tool. Since this one was made away from my scrap pile, a short length of thicker pipe was used to form a socket, and then a slightly thinner pipe was inserted to achieve the desired length.

Figure 2 - The head of the "super scraper"

The tool is used by simply sliding/ "driving" it along the concrete floor at an angle of around 45 degrees s the blade skims along the floor and the weight carves the "stuff" off the floor. A nice touch is to close in the other end of the pipe handle so there is no chance of cuts on any burrs or edges. It seems to self-sharpen as it wears on the concrete, but the bolsters tend to be pretty tough and don't wear that quick. This one was made to help a friend remove the leveling cement from under the tiles in his kitchen renovation. Prior to handing it to him, it was tested on the apron of my brother's shed where it removed lumps and cement dags with hardly any exertion.

Grinder Spanners

Another tool I had to make was some replacement wrenches for an OLD 9" (230mm) angle grinder. This grinder is an heirloom, and is so old it doesn't have spindle locks or any form of softstart. This means the spindle torques up really fast, and this seizes the retaining piece on. I modified an old 7" pin wrench and 17mm spanner to undo the retainer in the past, but during some work the retainer became so tight the pinwrench failed during attempts to undo it.

Figure 3 - old wrenches alongside new wrenches - the ruler is 300mm (12") long

Figure 4 - old wrenches which failed

I made a new pin wrench using 1/4 x 1 1/4" flat bar with some grade 8 bolts filed down to make the pins. (4.6mm diameter on 28.1mm centres) The handle to this new pin wrench is twice as long as the original and once used the cheap modified 17mm spanner started bending. More scrap steel and I made a heavy duty 17mm spindle spanner.

Figure 5 - bolts used to provide pins in pin-wrench

Bonus Shop Tip - Cigarette Lighter Parts

Figure 6 - Disposable lighter found on road - cracked and empty

I walk the dog each day and often find discarded broken cigarette lighters. I usually pick them up and take them home to pull apart. What's worth having in a cigarette lighter?

Figure 7 - parts inside a disposable cigarette lighter

There is 2 springs and a "jet" which can be useful. The springs are a useful size for making detents in small tools, and the longer flint propelling spring is a size which is sometimes found in rifle ejectors. I've only started collecting the jets since I figure I can use them to solder into larger brass pieces instead of trying to drill such a tiny hole - useful for a burner in my project list.

Next articles will be the construction of the lathe stand.

Taig Lathe Cabinet - Motor Mount and unloader

2011-03-13T01:25:00.000-08:00

I'll start documenting the build of the lathe cabinet using those photos still on the card in the camera (the other photos will have to wait until after the PC is rebuilt)

The Motor Mount
The original lathe stand used a jackshaft mounted on a wooden slide-way for a clutch, and speed control was limited to the cone pulleys on the motor/jackshaft - and then the standard Taig 6 speed cone pulley.

The new motor system would have the motor speed controlled by a VSD (Variable speed drive) giving infinite speed control over the range of 0-100%.
I still wanted a clutch (unloader) so I looked at various designs used by others and cobbled up a version of my own.

The belt tension aspect of the motor mount is loosely based on a design shown on Nick Carter's website. (www.cartertools.com)
His design uses rods for alignment, and a threaded rod for adjusting the position of the moving member. My design uses slots cut in the mount for alignment, and a threaded rod for adjustment.
The basic structure is made of two pieces of 50x50x3mm angle iron (2" x2" x1/8") welded together to make a channel 100mm wide and 50mm deep (4"W x 2"D). the length of the pieces is approx 200mm (8")

I then cut 2 pieces of 50x50x3mm angle iron at around 300mm (12") long and cut slots about 12mm (1/2") from one edge. The slots were a clearance fit on standard 6mm bolts. (Slots were cut using drills to mark the ends, then 1mm cutting disc in between)

Corresponding holes were drilled in the piece made earlier in the description, and 20mm (3/4") bolts were tacked into place so the threads extended out through the slots.
End pieces were measured and made up to close out the end of the longer pieces, as much for stability, but also to support the threaded rod used for the adjustment.
The moving part is driven by a nut which was threaded in, and then tack welded to the underside of the moving part.Nuts spun on to the threaded rod, and welded in place became the thrust surfaces for the rod's action, and one nut was welded in place out the front of the unit for adjustment purposes.

Figure 1 - base of motor mount - sliding parts.

The pieces already described do not actually mount the motor, instead they provide a base which can be adjusted. The part which actually supports the motor is a hinged channel (cut from the side of some 100x100x3mm square tubing) so it actually 100mmwide, and 15mm deep.
A corresponding piece is fabricated from 4mm plate to sit atop the moving motor mount part made earlier, and to support the channel piece just described. The channel piece supports the motor by means of 2 slots cut in the channel at right angles to it's long axis - these permit adjustment of the motor position along it's shaft axis.

The channel is hinged onto the mount plate, and a cam is placed near the mount hinge to change the angle of the channel. The cam was built by cutting an approximate shape from 4mm sheet, then tack-welding a 15mm wide strip of sheet around the cam surface for wear reduction. The cam has a position where the "lifting effect" is stopped - this is the position where the motor is tilted back away from the headstock of the lathe.

Figure 2 - the built up cam which tilts the motor mount channel.

So the overall structure is:
the motor tilts forward and backward within a range of motion governed by a cam (35mm = 1 1/2")
which sits atop a sliding mechanism which adjusts belt tension over a range of 75mm (3")
The motor can also move along it's shaft axis by 25mm (1") via the slots its mounted in.

The cam is operated by a wire lever about 250mm (10") long located well out of the way on the LHS of the cabinet.

Figure 3 - completed motor mount assembly

A standard steel ruler pinched under one of the slide nuts was used to test the range of the tilt mechanism

Figure 4 - Motor mount system in the unloaded (belt tension released) position.

The recorded range of motion was approximately 35mm (1 1/2") between unloaded (no tension) to the loaded (tensioned) position.

Figure 5 - Motor Mount in the loaded (tensioned) position.

Why have the facility to drop belt tension via the lever?
#1 - ability to leave the lathe when not in use with the belt un-tensioned to prolong belt life
#2 - easier changing of positions of the belt on the 6 speed pulleys
#3 - less chance of driving the motor when moving the spindle by hand (new motor is a PM DC motor which would act like a generator if I spin the chuck by hand)

So based on this design whenever I change the belt, I would place the belt on the appropriate pulley range and push the lever up into the "loaded" position.
I would then use a 17mm socket to adjust the threaded rod and move the sliding part so the belt tension was where I wanted it.
Then I would use the lever to reduce the loading, and adjust speed ranges accordingly.

In testing, I have found the flat section on the cam is sufficient - I can "feel" it click in through the handle, and the tension stays constant during use.

Next couple of posts:
I have photos of the frame construction, basic sheet metal work, and the construction of the control panel i can access. It doesn't cover much of the control electrical system, but does cover the fabrication of the switches, and the panel-work itself.

Taig lathe cabinet - completed

2011-03-07T05:42:00.000-08:00

Today I took advantage of some time away from work during the public holiday to bolt the Taig lathe to the new stand.

Some history...

Figure 1 - original lathe stand

I bought the original Taig lathe from an amateur pyrotechnician in Brisbane in 2001 (or was it 2000?) The motor which came with it was a salvaged unit from a washing machine.

I modified the motor mount to retain the pillow block and 1/2" shaft, but mounted the motor and jackshaft on a set of sliding mounts which gave me a clutch in the form of a "belt unloader".

Figure 2 - motor mount and jackshaft on sliding mechanism

I put a drawer underneath the 18mm (3/4") MDF top sheet and used it this way ever since. In the meanwhile a removalist broke the jackshaft mounts, the motor board started a gradual twist (compensated for by inserting popsticks under the motor mounting), and the bearings in the motor started to fail.

Figure 3 - tail stock view of old stand

The motor controls (on-off switch) is mounted in the front of the white icecream container screwed to the baseboard - inside the icecream container is the start capacitor and the wiring out to the motor. - real high tech.

Over the past 5 years I commenced modifying the lathe by adding a leadscrew and halfnuts, converting the tool post and tail stock socket screws to thumb bolts, and building accessories.

Figure 4 - the conversion of socket screws to thumb bolts

So after essentially 10 years, this 12-14 year old lathe is getting a new cabinet and drive

That was the past - now here is the future...

Figure 5 - the new cabinet with Taig lathe in place

Electrical highlights
300W DC PM motor driven via a PWM VSD (Pulse Width Modulated) (Variable Speed Drive)
NVR and E-stop safety circuitry (No-Volts Relay)
4 switched GPOs onboard

Powered from a single 240VAC IEC power cord

Figure 6 - electrical cabinet

Mechanical features
Metal cabinet with enough "meat" to permit drilling and tapping accessories anywhere I want.
Swarf tray with gate in floor
magnetic metal base for DTI, etc
motor mount has a "belt unloader"
All painted up in "Bender gray" except the 4mm thick metal baseplate

The motor mount is loosely based on the Nick Carter design, but modified for my purposes with a cam operated unloader mechanism.

Figure 7 - the motor mount in the "unloaded" position

The control panel represented an interesting amount of work which will be covered in greater detail later. one of the fun parts was the logos and labelling - the frustrating parts was doing the wiring to a suitable standard which permitted easy construction, and repairs.

Figure 8 - close up of control panel

In all, about one month's work over weekends, and the odd day here and there (mornings during shift rostered days.) - estimated total labour time would be 100 hours
The wiring took about 3 days since I had to redo some of it when my neighbour offered some advice on how to make it better for someone else to fault find in.
Everything except the motor and some electrical components was either constructed, or salvaged - the out of pocket expenses were around $200, and a large chunk of that was for the power supply.

I will do up some articles which highlight the construction process, with focus on the various components/ skills, but in the mean time I'm going to enjoy using this "reborn" lathe.

Making some dolls houses (CBFT training aid)

2011-03-06T01:49:00.000-08:00

My ERT trainer mentioned once that as part of Compartment Fire
Behaviour Theory (CFBT) training, we can observe the phenomenons
(neutral plane, pyrolysis, etc) in a training aid called a "dolls house".

Figure 1 - cutting up the chipboard

A dolls house is made of chipboard and is nominally 400 x 400 x 400 mm in size with a door way cut in one side.
The plans called for 16mm chipboard, but all the local supplier had was 18mm - no difference, just means the internal volume will be slightly less... with thicker walls the burn may take more time before the house falls apart.

Basically I cut up 2 full sheets using a circular saw, and then nailed the pieces together to hold the bits together whilst the "liquid nails" (construction adhesive) set up.

Figure 2 - the doorway cut into strips which can later be broken up as cribbing

I cut up the left over pieces to make 6 small "tables" to simulate internal furniture, and the remaining timber was cut into small pieces to kindle the internal fire ( pieces called cribbing are all about 1/4" wide, and the full 18mm thick)

Figure 3 - open door to dolls house with "ikea table" inside

I also had to make a stand to place the completed dolls house at around chest level. I had a cast iron base from a large industrial fan which I modified to take a base for the dollshouse.

Figure 4 - completed stand with base for dolls house

During the construction of the stand, I had to undo a bolt on the stand which was slightly rusted - when the nut/bolt rust finally broke free, the spanner spun through and crushed my ring finger splitting the nail from side to side. Hurt like blue blazes, and bled like nothing I've seen in ages. After a few hours the bleeding had stopped and this is what it looked like...

Figure 5 - injury to ring finger

Job done as delivered to the trainer.

Figure 6 - completed houses and stand

Next posting/s should be the completed taig lathe cabinet, and construction articles.

Taig Lathe Stand/Cabinet - introduction

2011-02-05T05:31:00.000-08:00

The current project...
My Taig lathe has been residing on a sheet of 18mm MDF for the past 10 years. The sheet has a wooden drawer built in underneath it, and a clutch/ jackshaft system for speed control. I will put a photo up in this series of articles, but not yet, this post is more a "preview".

Basically the old base (lathe stand) works, but it has limitations and problems. Some of the problems are the result of a certain removalist, some the result of bad design on my part, and most are simply the result of cutting corners due to cost constraints. - whatever the reason, it's time to make things better.

I'll do up a series of articles covering the design and build (mechanical and electrical) later, but for now here's some progress photos and a brief note of some features...
Lathe stand/ cabinet features:
full length/width drip tray
2 lockable equipment drawers under the drip tray with full extension
removable swarf tray
swarf gate in drip tray for dumping swarf
removable back board
4 switched GPO's (power points) with MCB
adjustable motor mount with belt unloader (clutch)
fold in carry handles
magnetic base with enough thickness for tapping holes if needed.
enough room to permit/ support my planned projects (backgear, change-wheels, taper turning attachment, indicator bases)

Motor controls:
24VDC 500W PWM VSD with reversing switch
16-20A over current protection
NVR (No Volts Release) circuit with additional e-stop at tail stock end

Just waiting on the postman to deliver a few parts and this job is finished. The VSD cabinet (LHS rectangular section) contains:
500W 24VDC PSU (courtesy surplus parts online)
6800uF capacitor from a Seimens VVVF (for smoothing)
125mm fan (with some trickery in the ducting) for forced cooling
PWM circuit (with heatsinking)
control switches (Start, Stop, Speed control, reversing switch)
IEC socket with filter

DIN mount rail containing -
16-20A SFKOL overload protection device
NHP Terasaki MCB for isolating all 240VAC circuits
Industry standard relay mount and relay for NVR circuit
The DIN mounted components are accessible through the front panel (for resetting, or fault finding)

Both drawers are accessed from the front, on ball bearing slides with full extension - no excuse to have things lost in the back of the drawer again.

The removable back board supports the electrical circuits, and a tray for storing things during work - a work light will be attached to this backboard as well.

The range of travel in the "unloader" mechanism is shown here (the distance between the shaft and the vertical steel ruler - about 35mm (1.5")). The adjustable motor mount is shown midway through it's 100mm (4") of travel.

A photo from the tailstock end of the cabinet showing the tray mounted on the backboard - the rectangular holes visible in the slanting face are for the GPOs. The tray has a false floor and is sealed so the GPOs and cabling are protected. The GPOs were mounted in this manner (downwards sloping face) to provide easy access, but also make it impossible for swarf or coolant to fall into the outlet holes.

The materials used is basically salvaged sheet metal - some 4mm gal sheet for the load bearing areas, and sign-white (colourbond) for the rest.
The frame is a hotch potch of 25x25x3 angle, and some 25x25x1.6 square tubing.
All sheet metal bending (that worked - see future postings) was done using metal clamping with judicious use of hammers, wood blocks, and muttered cussin'
Most of the electrical parts are salvaged, however the power supply, and PWM section are purchased/ built - all other parts removed from salvaged equipment (even recycled some bus mounts from a switch board to make the drawer handles)

The techniques, design, and details will be covered once I get the main computer fixed (power outage cooked one of the bridges in the mobo - lost the O/S drive and a few other peripherals), and few other demands on me at this time

Next update will most likely be in two weeks time - the pictures are already taken, it's just time to type, format and upload.

shed PC cabinet, and electronics test gear

2011-01-15T06:47:00.000-08:00

another set of projects!!! - Yes I know - got more than enough on my plate as it is, but it is related (see end of this post)

I needed a PC in the shed for programming work. Given the lack of space, the easiest thing to do was put the PC in a wheel-able cabinet, and packaged in such a way to permit it to be collapsed as small as possible.

I'd rescued an old 3M overhead projector a couple of years ago, and the wheeled stand it came on... This stand, with a few modifications, became the PC cabinet.

The original stand had a top which was set approx 6" (150mm) under the level of the top vertical posts, and the 2 flip out leaves attached to the posts. I raised the top shelf to line up with the posts, and then closed in the underside on 3 sides with some old sheet metal. I took another piece of metal to work and bent it up to make a door for the fourth side.

The "front door" of the PC cabinet is the grey sheet of metal on the RHS of the picture - with black cloth tape covering the cut edges for hand protection.

The above photo shows the LHS leaf in the raised position - whereas the other photos in this article show both as lowered.

The PC is an antique (old celeron from memory) but it does what I need (runs the PICAXE suite of software). Network is accessible (if I run out the 15m patch lead) and the speakers, mouse and keyboard cabling is wrapped in a spiral wrap and pinned under the top shelf.

Currently (due to other projects) the most this PC does is play music for the shed area - the programming has been on hold for a few weeks now due to other commitments.

As part of the PICAXE work, I needed to rig up a 5VDC power supply for the breadboard and other circuit prototypes. Digging through my boxes of salvaged gear I found a near new 5VDC SMPSU. Using some scrap pexiglass, I fashioned up a board with the SMPSU encapsulated at the top. The scrap pexiglass had some bends in it already, and I used them to form the cover for the 240VAC section, and to mount the power switch.

It was a simple case of then bringing the 5VDC and COM rails out to the prototyping area by means of the terminal block. I also brought the mains Earth out as well. The colour code for the terminal positions is shown on the LHS of the cover.
LRF are applied on the bottom of the unit to stop the fixing screws from scratching up the top of the cabinet.

The unit fits nicely in the box with the other electronics bits.

Why PICAXE?
I needed something, and I was so out of date with my previous experience (6502, 8086, pic16f84) that I asked on the newsgroups what was the best to come back in with... the suggestions included Arduino and other systems, but PICAXE came through loud and clear as suited for what I'm trying to do...
I've a project to help someone who's eyesight is going. He's a machinist who's finding it hard to use a standard dividing head - I can't afford a "DivisionMaster" (excellent product designed by Tony Jeffree) so I'll try and build my own version (with several features not in the original - suited to the user's tasks) and bring my skills back up at the same time.
That is the story of my life so far - get an idea to do something, identify pre-requisite equipment and skills, acquire those, find there are more needed, etc ad nauseum.
Kinda the model engineer creed - "Build a jig to build a tool, to build a jig, to build a tool, to build a jig to build a project". In my case the lathe was bought to build a micro hybrid rocket motor, but the lathe needed parts so I started building parts, which meant I needed the furnace, which meant I needed to learn.... and on the story goes.
Don't take the above as a complaint - by the time I build that motor I'll have a fully equipped workshop, an amazing set of skills, and a very diverse set of experience - all I need is time... and patience... and space for junk... and money for bits... :)

welding helmet renewal

2011-01-15T05:42:00.000-08:00

I learned to weld (SMAW - aka Arc welding, aka "Stick welding") with a standard CIG "rockhide" full face helmet. You had to flip the helmet up and down to see whenever the arc wasn't running. Better than the handheld mask I used a few years later, but still painful to use compared to the newer "speed glass" style auto-tinting helmets. It's so much easier to weld when I can see the tip of the rod moving up to the point of the weld, instead of losing sight of it due to flipping the filter down

I bought a cheap helmet and used it for several years, and eventually it stopped working. Being the tinkerer that I am, I opened up the main unit and discovered a few things...

The helmet has a solar cell on it, and was advertised as never needing batteries since it charged from the sun. The batteries inside were 2 silver oxide non-chargeable button cells. My guess was that the solar cell reduced load on the batteries, but was never able to charge them. (Silver oxide batteries aren't rechargeable)

The other finding when I opened up the unit was that the nominal 6VDC across the 2 batteries was only 2.8VDC... I can hardly complain since they lasted seven years.

The rest of the circuitry is under the white "potting" used to protect the circuitry - I never disturbed that, just accessed the silver terminals which used to be spot welded to the original batteries.

Armed with that finding, I quickly fashioned up a 6VDC supply and connected it to the original battery leads (with the old battery removed) and tested the helmet - it worked.

The photo above shows the hole drilled through the back panel of the glass unit, and some flexible Cat5 cable led through for accessing the power terminals of the electronics.

A more permanent solution was made up...
The battery holders are from some cheap solar garden lights the dog broke
The cable is some flexible Cat5 patch cable
A number of holes were drilled in the helmet to affix the battery holders, and cabling.
All holes were then sealed over with some hot-melt glue, and painted over to block the UV from the welding operations.

Problems found with this solution:
Firstly the weight of 4 AA batteries sitting at my mouth level caused the front of the helmet to always hang down - rendering the friction locks at the headband useless - I ended up resorting to a short length of cord which runs from the top of the helmet to the back of the headband to stop that
The other issue I found was the attempt I made to have the power "switched", and removable - the 2 automotive crimps - frankly they proved more trouble than benefit. I'll cut them out and replace them with a soldered joint.

What else do I know about these units?
They don't like being dropped in quench buckets full of water
They don't like sweat dripping into them - day after stinking hot day
They can be replaced for around $30 via ebay (6shopriver is an example seller - no connection)

I don't consider the repairs I made to be a waste of time, they bought me some time so I could finish the job until I could replace the failing helmet. I will fully repair this helmet if possible and keep it as a back up.

shed tips - foaming tools, and disposable nozzles

2011-01-15T04:58:00.000-08:00

Foaming tools

Basically a number of tools come in either blow-mold cases, or metal cases with blow-mold inserts. The decision to use blow-mold is based on providing a close fit to the tools in the case, without the cost of the old style wooden inserts.
There is a problem with the blow-mold inserts - breaking down due to age and vibration. the plastic liner breaks down and cracks apart due to the weight of the tools and eventually becomes useless. Following the advice of those wiser people, I take the time to fill the backs of blow-mold liners so there isn't as much "give" in the liner, and the tools don't break it down as much (if at all)

The basic principle is to fill the voids in the back with something disposable and durable - currently I use expanding foam (the single expansion type, not the one which expands again when contacted by heat or water), but in the past I've used silastic (caulking sealer) bulked up with either sawdust, or scraps of foam, wood, or even general shed rubbish (broken hacksaw blades, etc)

Using foam
Access the underside of the blow-mold liner

fill the gaps with expanding foam

apply a sheet of heavy card (old filing cabinet suspension files) and weight it down until the foam cures

if you remove the card,you will find the foam pretty much filling all large gaps, but maybe missing some of the smaller ones - sometimes I refill them, other times simply leave them.

The photo below shows one weighted down liner, the other simply left uncovered and unweighted during the foam cure

As seen below, the unweighted one cured with large air bubbles under the foam, basically providing no support to the liner and the tools. The cut way pieces of cured foam aren't tossed away, instead they are pressed into the gaps, then refoamed and covered and weighted. As mentioned at the top of the article, the filling doesn't need to be anything flash, so offcuts of foam work fine.

I know people who use plaster for this some task - works well - my only concerns are the weight, and the holding of moisture inside the tool case.

Disposable nozzles for foam dispensing
The foam dispensing can nozzle - the sales guy from ramset told me that the expnding foam valve is a single function unit as mandated by the nannygovt - as a result I buy my can (local trade store) and collect up a handful of straws from macdonalds. I cut the supplied nozzle tube at 1" (25mm)

and slide the macdonalds straw over the original (shortened) nozzle tube - this makes cleanup much easier (throw the straw away, and blow out the short piece) - As long as I schedule all my foaming for one day, I can usually use up the whole can before the internally sabotaged valve locks me out of the can.

Upcoming posts -
New life for an old welding helmet, and the lathe stand/cabinet

still alive -barely

2010-12-17T01:42:00.000-08:00

this is more a message to say I'm still alive - apologetic for not updating this page recently. Kind of run ragged with work, community involvement, sorting out various issues (people, PCs, and other "interesting times")

I did get to use the Santa costume the other day, so already it's been used, and got good feedback.

Expecting updates/ progress over the next few months on the following projects:
MOT Spot welders
DTI stand repairs/ rebuild
Picaxe work
portable PC/electronics bench
I daresay there will be more (I've a "things to do" list of over 3 pages single spaced)...Updating this build log is part of it all.

Santa costume - hat and final - part 6

2010-11-03T06:15:00.000-07:00

The last of the postings regarding making the Santa costume...
The Hat.. Unfortunately the shots I took during the sewing of the hats themselves did not come out (still figuring out why) I made two hats, one standard traditional hat which is basically a cone with a circumference of 650mm (26"), and a height of 600mm (24"). The second hat was a experimental model which will be described soon.
Each hat comprised of a velour outer, a red poly-cotton liner, and fur trim at the brim, and a fur trim pompom at the top.

Figure 1 - hats - Experimental, and Traditional

The liner was simply a truncated cone of similar dimensions to the traditional hat (circumference of 650mm, and a height cut down to 300mm. If worn by itself, it would resemble an oversized cap.

The outer was sewn along the edge (right sides facing, then turn inside out to conceal the stitching), and then the fur trim stitched to the outer so the stitching was facing inwards. The liner was then placed inside, pinned and stitched into place to cover the seams for the attachment of the fur trim at the brim.

The pompom at the apex of the cone was handstitched on.

The experimental hat (combination hat and scarf) was patterned on the traditional conical pattern, but then at the 350mm height, the cone was changed to it had a total height of 1800mm (72"). This meant that the hat resembled a long tube of approximately 100mm (4") diameter for most of it's length, with a flare at the end which took the diameter out to 200mm (8") for the last 350mm (14"). All other aspects of the hat (including the liner) were unaltered from the traditional pattern.

Figure 2 - Pompom making - material, and octagon

So the pompom would match the fur trim used elsewhere in the costume, I made the pompoms from the fur trim. A square of fabric was cut - approximately 150 x 150mm (6" x 6") and the corners folded inwards to form an octagon. A heavy thread was loosely stitched in at each corner, and then around again bisecting each side making 16 points evenly spaced around the octagon. the thread was gently pulled up so the corners and sides pulled in, and the resulting hollow space was filled with assorted offcuts from the fur trim.

Figure 3 - Hollow created in pompom by pulling threads up

It was then pulled up tight and tied off resulting in a pompom which was about 65mm (2.5") in diameter. The heavy thread used to make the pompom and tie it off was left threaded to the hand needle during the previous steps, and then used to stitch the pompom to the hat's apex.

Figure 4- Pompom hand stitched to hat

Other accessories and costume tips.
A couple of shots of the bag which attaches to the belt for holding keys, mobile phone, lollies (candy), etc. Simply a bag made of velour offcuts, and lined in poly cotton - simple belt loops on the back for attachment
Figure 5 shows the interior view of the pouch with a mobile phone, and some car keys in it for the test.

Figure 5- Pouch on belt - interior view

Figure 6 - Pouch on belt, exterior view

The wig/ beard I purchased off Ebay for the costume - 100% polyester, and quite good fit, and shape. It cost about $30 to buy including shipping.

Figure 7 - polyester wig and beard set.

And lastly, some white zinc sunscreen paint... I've played Santa before for various groups (Church, charities, clubs) and seen many others play the part.. I have fairly thick dark eyebrows which show through on most wigs. If I apply a smear of the white zinc to my eyebrows, they whiten out as if I've aged 50+ years, and they don't look out of place. - It beats my old trick of gluing threads from cotton balls to my eyebrows with PVA (White) glue.

Figure 8 - White zinc sunscreen paint (with other unused colours)

Unfortunately we were unable to find a local source of the white zinc paint without buying it in a triple pack with the other bright colours... they'll get fobbed off at some future date, since we're not big fans of running around with fluro blue, or pink faces.

Next project things to document... MOT spotwelder progress, reviewing books, and progress on other projects.

Santa costume - belt - part 5

2010-11-01T03:51:00.000-07:00

Santa's belt

The idea was to use some near new automotive seatbelt material taken from one of the cars we'd cut up in training. Based on the that material, I designed a large brass buckle to suit.

Since I didn't have any suitable material to make the whole buckle from one piece, I decided to use some thin brass shim stock for the face of the buckle, and build the bulk of the buckle from thicker, but smaller brass material. Why couldn't I cast a buckle??? That's a story for another day....grumble and mutter.

I cut up the shim stock sheet to give me the shape I wanted, plus folding pieces to cover the joints.

Figure 1 - brass shim stock, and other material

I then cut up some 3/16 x 2" strip to give me the shapes I needed to fill in the back of the buckle. I then folded the shim stock up over the inserted pieces, and sweated it all together with soft solder. My torch is a Primus (Seivert) propane torch with a pencil tip.

Figure 2 - cutting the shim stock with a jeweller's saw

Figure 3- folding in the pieces prior to soldering

Once finished I tested the buckle only to find it didn't "grip" the material well enough to give me confidence. I considered adding a small barb in the buckle so it would grip, but figured it might pose a hazard. Determining the issue resulted from the excess clearance in the buckle openings, I drilled the buckle in four places and inserted some 1/16" stainless steel wire to close up the gaps. In fact it allowed me to double the material through the buckle, adding security and improving the appearance. The wire was cut from an antistatic dissipator from an old CO2 fire extinguisher

Figure 4- Buckle - Mk 1 - not suitable

Figure 5. Buckle Mk2 - with wires inserted

Figure 6. The good buckle threaded onto the belt material

I also made a smaller version of the buckle - reminiscent of a military buckle for capturing the excess belt length (tail as it were) - together they both hold the belt up nicely, and I need not fear the jacket coming open. (I started the smaller buckle while trying to think of a way to salvage the first buckle - thankfully I was blessed with some inspiration there... it would have been a shame to waste it.)

Figure 7. Both buckles on the raw material

Once it was all together, I noticed the seatbelt material would shine in certain light, and it looked distracting. To make the belt more consistent, I over-sewed it with 3 layers of black poly-cotton, and sewed rows of stitching the full length on 6mm (1/4") centres. This added a nice touch to the fabric, and allowed me to taper the open end of the belt making it easier to thread and prevent fraying.

Once the brass was polished up, the belt came out wonderful... the buckle adds a bit of weight, in fact the entire belt weighs in at around 1kg (~ 2 lbs)

Next installment - the hats.

Santa costume - pants - part 4

2010-11-01T03:22:00.000-07:00

let's wrap up the Santa Claus costume...

Pants - nothing spectacularly different there compared to the jacket - although there is one sewing tip worth pointing out...

Want inexpensive broad loom calico for projects? Look at Ikea. Ikea sells a quilt cover made of full width calico for about $8. That gives you 2 pieces of calico the full width and length of a QB quilt... in dollars per metre it's by far the cheapest calico I've ever found, even at the 900m width. Whenever I venture near an Ikea, a few of those quilt covers are always on the list, just for the cheap fabric. The SB cover is called "Bomull", I'd have to look up the QB sized one, but they're usually next to each other in the shop (says Des who hasn't been in Ikea for over 12 months...) IF it saves someone else money, it was worth putting here...

Figure 1. Cheap calico courtesy of Ikea

Basically the pants (I made two pairs) were made using the velour material and the patterns generated. I then lined the inside with the calico, and made a waistband of red polycotton.
The waistband has a drawstring channel in it, and suspender points.

Figure 2. Velour outer being pinned to calico liner

Originally the suspender points were simple tabs which the jaws of the suspenders could affix to, but during test wears I found the jaws would occasionally let go - to beat this issue, I added a small tab at the front with a button, and a larger tab at the back with a corresponding buttonhole. The suspender jaw grips the original tab, and then the buttonholed tab is fed through the loop on the jaw, and buttoned down so it cannot let go.

Figure 3 - original suspender tab

Figure 4 - buttonhole tab threaded through loop

Figure 5. Button tab visible

Figure 6. tab buttoned down for securing suspender

The fur trim added at the bottom has a band of seatbelt material added inside for weighting the cuff downwards, and accentuating the flare of the cuff so the boot is covered better. In the original test fit, the trim would ride up the boot and looked "dorky".. almost like Santa was wearing clamdigger pants. With the weighted trim, the pants naturally fall to the top of the ankle, and ride up only slightly when seated.
No trim is at the waist since it's under the jacket, and would make adjustment with the drawstring harder.

Still to cover... belt, and hats. I'll most likely wrap them both together just to get this documentation finished.

Santa costume - jacket - part 3

2010-10-07T22:22:00.000-07:00

The jacket was made by cutting out the panels for the back, front panels, and sleeves as per the pattern developed in part 1.

The lay of the fabric was maintained based on the arrows in the patterns. Once sewn together, the lining was made from standard polycotton (as used in making applique quilts) using the same patterns, and then placing it inside the jacket with all seams facing inside the jacket.

Photo 1 - cutting fabric from pattern

The collar of the jacket needed to stand up so any clothes worn under the jacket will not show, I decided the jacket collar needed some stiffening. I designed a flat collar which resembles a mandarin collar from the back, but lays flat as it comes down the front panels.
The stiffener material I used is some seatbelt webbing I salvaged from some of the road-crash training cars.

Photo 2 - Seatbelt and fur trim for collar and it's stiffening

I cut the seatbelt fabric to make the collar higher at the back, and tapering down as the collar crosses over at the front.

The liner was inserted inside the jacket outer, and pinned in place. This allowed for minor adjustments in fit, and the positioning of the internal pocket for the gloves which was sewn in place prior to joining the outer and inner together.

Photo 3 - Jacket outer and liner pinned together

I then stitched this into the fur trim and then stitched this into the layers between the jacket outer, and the liner. This was accomplished by turning the jacket (with it's liner) inside out, and stitching it all together, but leaving a turning area of about 300mm (12") unstitched at the back of the jacket.

Photo 4 - Fur trim pinned in place for sewing into jacket layers

Once the sewing was done, the jacket was turned "right side out" and the turning opening was closed by careful pinning and sewing. To reduce the appearance of the closed seam, I used a derivative of the bias tape method, where I sewed the fur trim to the outer, then reversed the lay so it sat properly and then over-sewed the seam with the liner held in place with pins, this concealed the stitching for the outer/trim seam, and allowed the seam for the liner/trim to be hidden in the seam of the first set of stitching - sorry no photos to simplify the description.

Photo 5 - the finished jacket showing the liner in place

The photo above (photo 5) is where I was trying to determine if a single width belt looked OK, compared to a double width belt.

The pants were made in a similar manner, but will be covered in another posting.

Santa Costume Finished - Part 2

2010-10-07T19:15:00.000-07:00

Well the santa costume is done...
There will be more parts put up to show how the costume was made - stay tuned..

The costume comprises:
1 - Jacket with cross-over front panels, internal lining, internal pocket (for gloves), shaped collar, fur trim
2 - Pants - lined, with drawstring and suspender tabs, weighted shaped cuffs, fur trim (2 pair made)
3 - modesty panel under jacket
4 - belt with brass buckles, and attachable "pouch" for lollies, keys, phone, etc
5 - Hat - 2 made, one traditional, one "special"
6 - Boots
7 - Gloves
8 - Beard and wig

There will be pages made for the pants, jacket, and belt so I won't discuss them here.

Photo 1 - showing the traditional hat

The boots are an old pair of structural fire boots (tread worn away to nothing) which I polished up and they're now in the costume set.
The wig and beard were a set I bought on E-Bay
The modesty panel is basically a large calico bib which I put on under the jacket - it's sole purpose is to prevent my shirt showing through the beard between the front panels of the jacket. Last year I went straight to a "santa run" from work and my bright "safety orange" work shirt was showing through the beard - not a good look for Santa. I deliberately wore the same shirt in these photos just to make sure the costume completely covered my clothes without ruining the look.
The belt pouch is simply a lined bag with belt loops which can be threaded onto the belt so Santa has an external pocket for stowing lollies (candy), keys, mobile phone, etc

Photo 2 - the costume

The hats were fun.
I'll probably do a page on the hats, but some of the photos didn't work out so there will be some gaps in the documentation.
Basically one hat is the typical design - about 600mm (24") tall, whereas the other is 1800mm (72") tall. The second one was a fun piece I made to try a theory about a hat also being able to be a scarf. Both hats were made from the same crushed velour fabric that the jacket and pants were made from, and used the same fur trim for the brim, and the pom-pom. Both hats are lined as well.

Photo 3 - Santa with the longer hat

Since Bender kept me company outside whilst I was sewing, it's only fair he gets to try on the hat...

Photo 4 - Bender modelling the scarf-hat

Since I don't have a large model of the Santa Robot, this will have to do...

Photo 5 - Santa and Bender - not menacing at all

I'll document the jacket, pants and belt over the next week (time permitting) and then get back to documenting (and working on) the MOT spotwelder, and a few other projects I'm trying to clear off the "to do" list.

Project costs (AUD):
about $80 for fabric
$30 for the beard and wig
approx 50 hours of sewing, metalwork, etc
maybe $10-20 for incidentals (power, threads, gas, etc)

The day after I completed this project my wife pointed out a costume for sale in one of the online clearance sites... the costume cost about $80 shipped, but it was a thin felt set - the type which only last 3-4 wearings before falling apart... I'd like to think this costume will last many many years so I hardly begrudge the costs in time or money.

A new project - a Santa costume - part 1 - pattern development

2010-09-19T05:02:00.000-07:00

Yes I'm still alive, and a bit stupid since I've added more projects to my "to do list"

Over the past week, I've attended a few callouts for fire and rescue, worked 5 days, and also attended a course (pump operations)
In the "spare" time I attended training for vollies, salvaged the shafting from 7 gas struts (see my earlier shed tip about that), and commenced this new project.

The Santa suit...
One of the fundraising activties carried out by the volunteer Fire and Rescue involves hiring out a "Santa" for local parties. Santa shows up in a 1950 Bedford fire truck (with original lights and siren) and is escorted into the party by a VFRS member... the kids love it, and it's fun work.
The santa costume worn by the volunteer is one of a few, some privately owned, and a couple owned by the brigade - after using one last year which was getting a little long in the tooth, I decided to make my own.

I bought the fabric through Spotlight, and made the pattern up myself.

This posting will discuss the development of the pattern.

Santa's outfit comprises a jacket, a pair of pants, a hat, and some trimmings (not to mention a jolly old fat guy in the middle)
This project will make the jacket (with internal pocket for gloves), 2 pairs of pants, a couple of hats, a belt, and maybe some spats (overboots)

I started the pattern development by grabbing some cardboard wrappers from whiteboards we bought at work - the large sheets of thin cardboard became my primary working material, and also protected the fabric from picking up stains from the trestle table I set up to work from.

I laid out my turnout coat on the cardboard and traced out the key dimensions of the arms, shoulder, waist, and inner/outer seams of the pants.

Figure 1 - using my turnout coat to start the tracing of dimensions

Figure 2. Adjusted tracing of the arm panel, and leg panel

Since I don't have any of that wide thin paper used for making patterns, and I'm not going to cut up my meagre stash of interfacing for a pattern I'll only use once in a blue moon, I decided to fall back on my old trick of using plastic sheet for the pattern material. (I have a stash of tranlucent builder's plastic used for covering gear during cyclones)

The plastic was laid over the tracing, and drawn through with a permanent marker (sharpie, Nikko, whatever your local term is). During this tracing, I made adjustments to the dimensions for cutting/ seam alowance, and changed the cut of the jacket to a more "universal" fit.

Figure 3. Tracing jacket back panel on to translucent plastic

The adjustments made to the pattern included making places for folding the fabric when cutting, and rearranging the seams for joining the arms so they had a natural fit when reaching.

Figure 4. marking on the arm panel plastic to show cuts, direction of fur lay, and number of panels.

Since I was planning on using a crushed velour for the main suit fabric, I had to mark on the lay of the fur (direction) so it looked proper when assembled.

Figure 5. Pants panel patterns.

The last part of the pattern work at this stage was to capture the notes regarding how the suit was to look and go together. Figure 6 shows the notes made regarding the fit of the jacket, placement of fur trim, and trimmings such as pockets and belt loops.

Figure 6. Pattern notes

The next installments will cover the making of the jacket, and belt - hopefully within the next 7 days I'll get the suit finished, then I'll get the documentation done.

Jeanie's Bottle

2010-09-10T04:30:00.000-07:00

I know, I know... I promised myself I'd keep this up to date, and regularly updated... plans of mice and men. Lots of things to blame, but ultimately it rests with me to update this record more often.
Over the past month I've probably spent a whopping total of 12 hours in the shed, and 4 of those hours was for someone else's benefit...

To partially redeem myself from the lack of updates, here is the documentation of a project I did 18 months ago (or so)

My wife is a fan of the TV show "I Dream of Jeannie".. for those with more money than I, you can purchase reproductions of the Jeannie bottle... I didn't have the money to spare so I looked at making one for my wife.

I started with some ceramic blanks purchased through Ebay - the original bottle was a glass bottle (Jim Beam 1969) modified and painted up by the studio, then after the success of the show, Jim Beam issued a regular run of the glass bottles for collectors - they go for around $80-100 USD on Ebay... the ceramic blanks cost around $25-35 USD each.

Figure 1. Ceramic bottle blanks

The blanks arrived (after some hiccups with post) and I primed and sanded them several times using automotive spray primer, and 600-800 wet and dry paper.

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Figure 2. Primed bottles in box

The bottles were stored in a cardboard box whenever the paint was drying, or not being worked on.. partly to prevent dust settling on the paint, but also to prevent the bottles from being seen by the recipient. Typically whenever I make a present for my wife (or children) I will make it in secret, and only give it to them once it's completed.

After suitable layers of primer and sanding, the bottle was spray painted with 2 coats of cheap gold spraypaint (for base colour), then 3 layers of metallic gold paint. The final coats of gold were supposed to be able to give me a polished gold finish - it came out more like satin over brass, but that was OK... the "original" bottle would have been enamel over brass, and that was the effect I was trying to achieve.

Then started the painting of the colours - I started with some thin coats of a translucent purple so the gold/brass could come through, then added opaque detailing.

Figure 3. Bottom of bottle showing base "gold" coat under translucent colouring.

My guide to colours and placement was a number of photos taken from the web, and a $5 painting/template guide I purchased on Ebay - Apparently there are about 5-6 different bottles shown on the show (Jeannie - Season 1, Jeannie - the rest of the seasons, then other characters) This paint scheme is the "Jeannie - Season 2 onwards" colouring.

Figure 4. Colours applied according to the painting guide

Adding the detail was painstaking at best. I've never used brushes so fine, and I never realised how much my hands shake when doing this kind of work. I had to rub back the work here and there, or paint over the occasional error, but generally it came out OK.

Once completed (or as close as I dared) I then started applying coat after coat of clear decoupage varnish over the entire thing to seal it all, and to add some slight gloss to the finish.

Figure 5. Varnish drying on finished bottle.

Once completed I wrapped them up for a Christmas gift. Below is the photo she took after unwrapping them. Everything we own is photographed for insurance purposes, and typically on our kitchen table.

Figure 6. Finished bottles as unwrapped.

One day I'll figure out how to make and fit a Barbara Eden in the bottles, but until then, I'll continue working on making my own (and my wife's) wishes come true by hard work instead of a "blinky head nod".

The paints were predominantly "Jo Sonia" glass paint, and folk art paint, and the spray paints were those left over from model rocketry.
Hours to "build" was in the order of 50-60 hours of work, plus about the same again waiting for paint/ varnish to dry.

Projects coming up:
MOT spotwelders, indicator stand repairs, taper turning attachment construction, lathe stand/motor construction just to name a few.

Shed tips - free shim steel, and parallels

2010-08-22T04:03:00.000-07:00

just another post to prove I'm alive, and trying to live up to my commitment to publish up the things I find useful, hoping someone else finds them useful.

Another "free" tip - shim steel
The anti-theft widgets I find inside PC software, DVDs and other packages often looks like a small rectangle. Inside is normally 3 pieces of incredibly thin steel - suitable for shimming tool bits up to 1/4" wide.
After several years of cutting these things open, only to fight with the sticky tape inside, this is the easiest way I've found to open the widget.

Figure 1 - the "unopened" widget

Using a sharp knife, slice the case near the bottom flange

Figure 2 - opening the widget

Remove the strips which you can easily - there may be one at the bottom under another layer of sticky tape - leave it at this stage

Figure 3 - the removed pieces, and one still in the case (under tape)

Cut the end off the rectangular plastic, as close to the end as possible

Figure 4 - sliced tape so the last piece can be retrieved

Insert the point of the blade between the tape and the shim, and then slice back into the tape to cut the top off for at least 1/4".
Remove the remaining shim, discard the rubbish.

Result - Three pieces of shim, without any glue residue, or creases.

Bonus Tip - "free" parallels
an oldie but a goodie
Salvaged bearing races make good parallels, particularly for packing on the mill or lathe.
I took the time to dismantle a stash of saved bearings which were not worth saving (sand in the races)
Someone suggested drilling out the rivets holding the cage together - easier said than done, and it cost me a 4mm HSS drill - not again.

Figure 5 - old bearings too rough for use - destined to be dismantled

What I did was use on of my punches to drive the cage towards one side (punched in the gap between 2 balls) so the cage was deformed to the other side, then flipped the bearing and struck it back - I repeated this about 2 times and the cage broke at the point of the flexing. Using the point of the punch, I levered the cage material up, and then started winding it around the points of some pliers - most of the time the metal tore at the rivets, sometimes it broke, and all I'd do is commence from the other side and eventually all the cage was removed.
Then it was simply a case of pushing the balls all to one point in the races, and the inner race was able to be persuaded into the side without balls to drop away freely.

Figure 6 - a collection of free parallels for packing on the lathe.

Each bearing yielded 2 races with perfectly parallel sides, and a number of ball bearings which get filed away for use in detents, etc.

Speaking of detents - I pick up old disposable cigarette lighters whenever I'm out walking the dog - people are forever dropping them on the streets when they run out, or become damaged, The mainspring (the one pushing the flint up) is the perfect size for making/ replacing small detent springs (and extractor springs for rimfire bolts) - just another excuse to bring home junk, then pull it apart and file the parts.

What's on the horizon?
Webpage wise - I'll push to continue reviewing and recommending books - I can do that with little to no shed time.
Shed wise - Added 2 more projects to the "To Do" list (the "do to" list is at 12 major projects, and 23 minor projects and counting) - first is a couple of MOT spot welders (wound the first transformer last weekend), the second is building a electronics device to semi automate gear cutting... there are commercial offerings out there which do this, but the ulterior motive in this is getting my microprocessing skills back - I'm an Electrical/ Electronics engineer by training, but I spend more of my leisure time doing mechanical fitting - the irony has not escaped many people, especially myself.

Scrounging up materials - tips, etc

2010-08-09T05:59:00.000-07:00

I am alive – I’ve just been burning the candle at each end, the middle, and a few other places. Mostly work demands due to a sudden change in my shifts, but one thing upon another and I haven’t had as much time, or energy, to sit down and update this site.

I did get to do some cleaning in the shed on the weekend just gone, and as part of that I photographed these two useful tips.

Firstly I need some STRONG steel rod for a couple of upcoming projects. One source of high tensile rod is the rod in a gas strut. I always keep my eyes open for any of these being tossed out, and I opened another 2 on the weekend in front of the camera. NOTE: opening these can be dangerous – I take precautions, but don’t blame me if you get hurt doing this!!!

Figure 1. Gas struts as recovered from being tossed out

The cylinder is filled with pressurized gas and oil. Near the end where the rod comes out there is some crimping which acts like a seal/ travel stop. I dress in appropriate PPE ("Personal Protective Equipment - in this case - ear-muffs, face-shield, leather apron) and work with the grinder and cut area pointed away from me. The first longitudinal cut in that area will suddenly release the gas and oil – I point that in a safe direction and let it vent out. Then once vented, I cut 3 or 4 longitudinal cuts for about 20-30mm above the crimped line. This allows me to remove the rod with it’s piston/ seals captive on the end.

Figure 2. Longitudinal cuts through crimped area to allow piston and seals to be pulled out of cylinder

I then grind off the peened over section of rod, and remove the piston/ seals from the rod.

Figure 3. Showing the peened end of the rod in the piston

The result is a strong, straight length of high tensile steel which has a polished surface. I now have 4 of these rods, one will be used to make the mast/pillar for the magnetic DTI base, another for my upcoming taper turner project, and the other 2 (matched pair) will be set aside as candidates for a Z axis slide in my CNC mill project. The photo below shows the 2 recovered rods on the RHS of the grinder.

Figure 4. Salvaged high tensile steel rods.

A useful tip I picked up from one of the contract firms I saw at a worksite…
We all have had a retractable steel tape measure break on us from time to time, I used to throw them out when I realized I “never get around to fixing them” – Not anymore.

Figure 5. Broken 8m tape measure

Instead I now open them up carefully

Using some heavy duty scissors (good tin-snips will do here as well) I carefully cut the measuring tape into useful pieces

Figure 6. Opened tape measure and snips

Since Oz is a metric country, most tape measures will have meters (with or with out imperial markings on the other side) so I cut the tape on the multiples of 1 meter.

Figure 7. Tape cut on meter markings

The resulting pieces are used as “disposable” yard sticks – useful for taking to messy places, using at the welding table, etc.

Figure 8. Seven 1m "yard sticks" made from one broken tape measure

I keep a stash of them threaded in the frame of the shed door – always there ready for use whenever I need a ruler for measuring something.

Figure 9. About 15 yard sticks threaded in the door frame of the shed.

I have 2 broken tape measures I haven’t cut up yet “in storage” for my CNC mill – these will be affixed on the sides of the axes for quick positioning/ verification under jog/ MPG control.

If I have time, I’ll put up the account of the other salvaged/ scrounged useful junk I worked on during this weekend’s clean up. (free shim steel and “free” parallels)

Time - it always comes back to that - a question of what to do with the limited amount you have each day...

Reprint Popular Mechanics sets, and other Algrove gems

2010-07-01T06:04:00.000-07:00

As part of pointing out useful books and references, I'll start with one of the two biggest sets I have.

The Popular Mechanics "Shop Notes" books have been read now, cover to cover at least twice, and I fear the number of bookmarks in the books make them lean when stacked.

I saved up and bought the reprint set through Lee Valley tools a few years ago, and have used some of the methods and ideas in there at work from time to time - a wonderful reference.

The link to the set is here, and currently costs $165 USD. You can buy the books in sets of 5, or as individual books, so budgeting can be eased. I cannot recall the exact shipping charges to Oz, but I know it was quite reasonable considering the number of books.

Each book is roughly the same size at 240mm x 165mm x 15mm (H x W x T) although the thickness does vary a little with some books being 12mm thick, and others at 18mm thick. The books are all black and white reprints, and of excellent quality and reproduction.
The picture below is from the Lee Valley page noted above.

The reprint series is printed/ published by Algrove, and some of the books are listed on Amazon such as this. It's your call how you like to buy books, but with the above information and links, you should be able to find the books.

If you can afford it, there are two other sets of books well worth looking at from Lee Valley (not saying the rest aren't good, but these are ones I can reccomend based on reading them...)

The first other suggestion is the "Boy Mechanics" series - it's a set of four books, each the size of a novel. They remind me of the books my Dad had when he was young, all about things boys can build from timber, salvaged materials, etc.
UPDATE!!! - Whilst checking for the link I found this set is being discontinued and is heavily marked down!!!! A shame, but don't miss out. The link to the series is here through Lee Valley

The picture is again from the Lee Valley webpage. Some of this series can be bought for a similar (discounted) price from Amazon like this.

The last set of books I grabbed from Lee Valley was the "Bull of the Woods" books. They are a series of machinist orientated cartoons. There is a similar cartoon in the old Model Engineer magazines about "Chuck, the Muddle Engineer", but the "Bull" series is more serious, but just as funny. The books are the size of a Reader's digest, and each cartoon is a single frame, one per page. Here is the link from Lee Valley, and the picture below.

I did find a listing for one of these reprint books on Amazon, but I won't insult anyone by posting the link.. the "sellers" wanted $222.80 USD for the one book new... compared to the $3.95 USD ea at LeeValley, you can see why I don't bother linking the listing.

These books represent a valuable archive of knowledge and ideas from the period of time when machines were powered from shafts and belts, and CNC and computers were unheard of, HSS was a new thing, and even electric motors were a rarity.

The Popular Mechanics set includes gems such as how to turn a pulley of 28" diameter on a lathe capable of only 16", or how to lift several tonnes of line shafting up into the shaft hangers without using a crane - the list goes on and on... If I had to choose only one set from the three mentioned here, this would be the set. I hope my own children will learn from the sets as much as I have.

NOTE: Just a general note about the postings discussing books. Where possible I'll provide links to purchasing the books, and try and provide options. Typically Amazon will carry the books at the best price, but there is the odd, rare occasion where it's cheaper elsewhere, or amazon doesn't carry the books. In those cases I'll provide links, and comments to that effect - it's nothing against Amazon (goodness knows they get enough of my money as it is), but I try to stretch my money as far as possible, and presume others have the same limitations...

Still alive - ingot trays

2010-06-28T05:36:00.000-07:00

Sorry this posting has been late in coming... I've several previous projects to document, so the fact I haven't been in the shed is no excuse for not writing.
I'm currently putting the finishing touches on the design for the backgearing of my Taig lathe. I built and installed a leadscrew (with halfnuts) about 18 months ago, and the intent was always to add change-wheels and a spindle gear to drive it. I stopped working on that (temporarily) while I figured out how to drive the leadscrew, and get the speed ranges I was seeking - the backgearing evolved from that, and now it's practically completed in it's design (Got more parts for it today), I'll start construction of it this weekend.

It's kind of ironic when I think of it... I bought the lathe so I could build a hybrid rocket motor. I didn't start that because I wanted to bring the lathe up to spec with what I wanted. That meant I had to build other tools (furnace, etc), which created more needs, and on and on it goes. Now here I am, 10 years later, and the rocket motor still isn't built, and even if it was, I can't use it in this area.
Not that I regret the journey, but it is a long road which could have been considerably shorter (time wise) if I had the money to begin with. I guess it's part of the ME (model engineering - not narcissism) sickness that every project means more tools, jigs, projects, etc

Let me introduce you to one of the projects spawned out of another project, which was built to build another project...... The ingot trays from my furnace.

The furnace (another set of pages yet to come) can hold crucibles of up to A30 - in other words 30lbs (~14Kg) of molten aluminium at a time. In "smelting mode" it can melt as fast as it can be fed (I've gone as fast as 100lbs per 10 mins) limited only by how fast the molten aluminium can be captured.
To handle excess molten metal (from smelting or casting) I built up 2 ingot trays - one small, one large. Both are made from salvaged 3"x3"x1/4" angle iron.
The small tray has lengths of 12" making the finished ingots a triangle shape with sides of around 2.75" x 2.75" on the sides (4" across the long edge) and 12" long
The long tray is made of the same angle iron, but the lengths come out at 22" - this is too long for my crucibles, so I put a removable "breaker bar" in the tray to mold in a weakened break point in the longer ingots.

The photo above shows the removable bar in place in the large ingot tray - the bar is held in place by 2 1/2" pins which rest in the short lengths of pipe welded to the sides of the tray. (pipe visible at middle of front edge of tray)

The photo below shows how the bar has "wedges" welded to it which do not come to the bottom of the angle V, but leave a 1/2" gap at the bottom for the flow of molten aluminium. The sides come to within 1/16" of the side walls. Once cold, the resulting ingot can be snapped in half by a sharp rap on the concrete floor.

The photo above also shows the angled end on the LHS - the RHS is cut square, but the LHS has about a 15 degree slope to it to aid in the removal of the cooled ingots. The RUST is left in place to act as a "mold release" to prevent the aluminium from sticking to the tray.

The photo above shows the gaps mentioned at the bottom of the angle, and the slight gaps on the sides. All the welding is done on the outside, so there is minor narrow gaps here and there in which aluminium will freeze, but these don't seem to cause issues, and the minor loss is negligible.

Moving the trays whilst hot proved to be harder than originally thought. Originally I used hooks and wire loops, but found the trays would catch on irregularities in the concrete floor, plus I worried about the heat from the trays causing issues with the concrete floor. My sand traps didn't make the movement of the trays any easier (to put it politely) so I looked at making wheels for the trays. What I came up with is shown below...

The photo above shows the "wheels" I fitted to the ingot trays. These are simply short bolts with their heads welded to the inside of the tray with the shanks pointing towards the middle of the tray. The bolt then had a number of wide washers slipped on the shaft, and then a nut wound on and captured with a wire threaded through a cross hole to stop the nut coming off too easily. Four of these were welded on each tray so the wheels worked along the long axis of the trays. The existing wire loops (handles) were retained, and the trays moved quite well over concrete, and sand traps.

As you can see, these trays don't need to be "babied"... they sit out in the weather, and are ready for use whenever they're needed since the rust helps release the ingots.
The height of the rays is so slight, they fit under the furnace drain hole to catch any crucible failures, (or smelting mode), and the wire loops are long enough to permit one tray to be lead in under the furnace without disturbing the other tray - making swapping from one tray to the other seamless, without spills.

All welding was done with my CIG stick welder, and the original cutting of the 3x3 angle iron was done at work on one of the bandsaws.

What would I do different if I built more? I'd probably make the trays only take 3 ingots at a time, instead of 4 to reduce weight. I'd make the ingots all the same size, instead of maximising use of salvaged metal. I'd learn how to do internal fillets so the trays didn't have small internal seams.

I've a few other projects already completed to document, so I'll try and get them done, even if the current projects aren't getting the progress I want them to have.

not forgotten, just flat out

2010-06-07T21:46:00.000-07:00

I haven't written lately due to other demands on my time and energy.
Generally I'll try and publish based on the current projects, or projects I've already completed, and have documentation for.

Because of the various demands on my time and energy lately, I haven't done anything in the shed except some minor cleanup and salvage - hardly worth reporting yet, although what was salvaged will hopefully prove quite useful.

What's taken my time? - work, church, responding to emergency calls, some training, helping people with various problems, listening to people's problems, etc.
What's taken my energy? - pretty much as above - I actually find the emergency responding quite fulfilling - gives me a sense of making a difference. Listening to people's issues, and trying to help them overcome the same issues which have been in place for years and years can be quite draining.

So sorry about the rant - this post is more just a simple "I'm still alive, and I will post something of value soon" message... we all have problems - we all know people with problems.. some are there to be fixed, some to learn from, some to endure...

What's on the radar?
repair of the magnetic base indicator stand.
repair of a broken mitoyo vernier height guage
design, construction, and use of a taper turning attachment for a taig lathe
adaptation of taper turning attachment to profile copying attachment

I think that's about it - more plans than hours in the day - situation normal.

Sharpening sticks - an alternative to stones for razor edges

2010-05-16T05:48:00.000-07:00

A recent email ad from Amazon about sharpening gear jogged my memory about documenting my own sharpening systems.

I have a number of sharpening systems I use, and use them based on what I'm sharpening, and how much shaping of the edge is required.
The systems I use for aggressive removal of material from the edge, centre around the typical stones used in most workshops and homes. A friend from wayback taught me to use babyoil on the standard carborundum stones favoured by butchers and handymen. The lighter oil carried away the metal flakes, and did not clog up the stone as it dried. I have a few "inherited" stones which are sticky and almost tar-ry in feeling with old oil soaked into them.
I also have some water stones such as this, which I use from time to time. My first water stones were actual carborundum stones, but instead of using oil on them, I used water as the lubricant. I eventually purchased a few proper water stones, but only use them occasionally.

I also have some diamond plates. I don't like calling them stones since they resemble plastic backed plates of metal, with the diamond material bonded to the metal. I occasionally use them for aggressive removal of metal, but find they can be too aggressive, and leave deep scratches. Admittedly the plates I have aren't as good as the ones in the link above, but they look similar. I think mine were some cheap chinese knockoffs, so the "fine" is more of a "medium", etc. They have their use, but I don't use them for honing an edge.

I used to be heavily involved in model rocketry, and would still be if it weren't for the firebans in this area. One of the tricks I learnt in model rocketry was the concept of mounting disposal scalpel blades into permanent holders, and then resharpening them as required. I cannot recall the webpage which introduced this concept, but from memory it was one of the HO scale sites.
The sharpening method the site used was perfect for such small blades, and I used it every since for all size blades.
The main premise of the system presumes the blade shape is already correct, and all that is required is to refine the cutting edge whilst preserving the angles. A selection of "wet and dry" carborundum paper is obtained in a number of grits - I used 400, 600, 800, 1000, and 1200.
I obtained some timber of size 35x12 (1 1/2" x 1/2") DAR (Dressed All Round) and cut it into lengths of about 350mm (14"). I cut strips from the wet and dry paper, and glued them to the wood strips using rubber cement. The photo below shows a number of these sticks with the size written on them with a permanent marker, and a 3/8" hole drilled through the top for hanging.

The other side of the stick has another size glued and labeled to it... except the stick on the right. An observant reader will notice 2 sticks with 400, and 1200 grit paper attached. Part of this was due to the even number of sides, and the odd number of papers (including the RHS one), but the main reason for the duplication is the heavy work 400 grit gets early in edge refinement, and the regular use 1200 gets for touchups. These two grit sizes get more work than the intermediate sizes, so they are duplicated. I still use the intermediate sizes, so will not give them up.

The right hand stick has a strip of leather glued to it (again with rubber cement). The leather was cut from a discarded belt, and has then had rouge rubbed into it. The rouge was standard cheap Tripoli, nothing fancy. The leather strip becomes a strop to polish away any fine scratches in the sharpened edge, and to remove any burrs or "wires" I recharge the Tripoli every now and then, but the amount is uses is almost negligible.

So how is this system used?... The tool to be sharpened will need to have it's edge geometry already formed by some other means. I use stones if minor rework is required, if major rework, then it's power tools to the rescue (grinder)
Once the edge geometry is correct, and all deep scratches are removed by use of a stone (or extra fine diamond plate), I will use the 400 grit stick to start sharpening the edge. I usually choose to hold the stick stationary, and move the tool, but sometimes it's easier to move the stick over an edge.

As the appearance of the edge improves, I will switch the sticks to the next grit up, working from 400, through 600, then 800, and to 1000, and then 1200 grit. By the time I've gotten to 1200 grit, the edge is not changing in shape, but merely becoming smoother, and almost "frosted" in appearance.

The photo above shows a cheap garage sale knife on the 1200 grit stick. Lubricants can be used with these sticks since the paper is designed to withstand moisture, and the rubber cement was chosen for the same reason. Eventually the sticks may warp, but since I dry them after use if I wet them, I've never observed any significant warping - these sticks were made over 10 years ago. The only lubricant I've used on these sticks is water.

The photo below shows the mirror finish on the edge of a knife after using the leather strop.

The above knife was one I found laying on the road when walking to the train station several years ago. The tip had been broken away, and the edge bellied out in that area. (I suspect it had been used to twist something open, and the tip broken off as a result.) I reshaped the point using a grinder, and put a tanto style chisel point on the blade. After some work on the stones, the point, and edge of the blade had a useful blade geometry, and fairly pleasing lines. After using the sharpening sticks on it, the cutting edge (with it's mirror finish) extends from point to ricasso in a width of around 2mm (~1/16") As a knife, it's a rough cheapie which suffered a hard life, but now resides in my workshop as a general utility knife and can cut most things I point it at.

I keep mentioning blade and edge geometry. I've got a couple of books I've read which discuss how to sharpen tools, knives, etc. Both books shown below have their strengths and flavour.

The Razor Edge Book of Sharpening by John Juranitch
This book is good at explaining what to do, how to sharpen common tools, and has some good pictures covering methods, and testing an edge. John is quite vocal about how simple sharpening should be, and illustrates the gaining, and protection of edge geometry well.

The Complete Guide to Sharpening by Leonard Lee
Leonard Lee is a name most woodworkers know from the company "Lee Valley Tools". This book covers the finer detail left out of the preceding book (John Juranitch), and discusses some metallurgy, and the effects of edge geometry on certain tasks, and the effects it has on finish, effort etc. The other main appeal of this book is the demonstration of sharpening methods for common, and some "not so common" tools.

To some up, John's book is good for homeowners looking for some skills in sharpening, Leonard's book is for workshop folks looking to understand and maximise the ability of their tools. I cannot recommend one book over the other, and instead took advantage of the bundling deals amazon seems to run when buying both books together.

Everyday First-Aid kit - gloves and portability

2010-05-16T02:15:00.000-07:00

Personal protection during emergency response is the first priority of all responders. After all, it's no good responding to an incident, and becoming a casualty as a result.
Training, exercises, shared experiences all help prepare a person for protecting themselves... and there are also procedures to help (S.O.Ps cover things such as equipment, PPE, and biological protection)

I've attended a few incidents where my first responsibilities have been more of a firstaid/ medical response, as opposed to rescue, or fire. All of these incidents have been motor vehicle accidents (MVA), and the ambulance service has not arrived prior to fire and rescue personelle. The first MVA I worked at, I forgot to wear nitrile gloves under my leather gloves due to the tunnel vision of responding. The discussion with leadership afterwords brought the training home hard. Since then I've prepared some disposable gloves and store them in my helmet for protection.
I purchased some strong disposable gloves (shown in photo below) and sorted the gloves out into pairs.

I then rolled (from the fingers to the wrist) the gloves to exclude as much air as possible, and placed the rolls in some ziplock bags. The photo below shows two pairs of gloves, in the bag - one pair on the left, the other on the right.

The gloves do settle down over time, and the bags never seem to seal 100% against air, but dust, sweat and water don't seem to get in the bag, so that's what's important.

I got to thinking about those incidents, and came to the conclusion that I would be wise to make up a small firstaid kit. The professionals I work with use the large "Thomas packs", but for my duties and daily roles, this would represent overkill, and would be beyond my current experience and training. My criteria for the kit would be:

1 - small enough to sit on the front seat of my car, and not be in the way of passengers, or work activities.

2 - able to be placed either on my shoulder, or around my waist , thereby keeping my hands free for scaling stairs, ladders, or other paths to an injured person.

3 - contain the essentials to maintain life for the time needed for a fully equipped ambulance to arrive (estimated at 20 mins - worst case)

The intention was to be able to provide resuscitation, observations, and rudimentary bleeding control for a casualty until the ambulance arrives, or until I expect to "run out of steam".. and based on my previous experience, I'd been totally worn out after 20 mins of providing full CPR.

I purchased a "bum bag" off one of the airsoft sellers on Ebay (Note to US readers... "Fanny pack" isn't the term in Oz.. means something totally different here). I wasn't too worried about colours, but went with the typical OD green so dirt stains wouldn't be as noticable. This particular bag had a strap which could be moved from a waist strap, to a shoulder strap, which added appeal for what I was trying to accomplish.

I added a "hard shell" security case I bought from another seller, and filled it with bagged gloves (3 packs, each containing 2 or 3 pairs of gloves). The security case simply clipped on to the strap/belt.
Since the photos were taken, I've added a smaller "pouch" on the side of the bag between the bag and the glove case. This pouch holds a pair of 7" shears for cutting clothing, etc.

The bag as purchased from the airsoft guy has a number of pockets (one on the front, plus one on each end, and the main big section in the middle). I basically put a resuscitation mask, and my observations notebook (with a pencil) in the front pocket (as shown below).

Some standard bandages (not a huge selection, I'll prioritise their use on assessment of the scene), and a selection of bandaids were placed in the middle pouch with a mylar sheet (Space blanket)

A number of safety pins were pinned on the straps dotted around the bag, and some pens were clipped in convenient locations (The aforementioned pencil is my backup).

The downloadable pupil chart mentioned in the previous post has been laminated, and a copy is taped inside the obs notebook, and a strip version is loose in the front pocket.
There's still some room inside the kit, but I won't fill those spots until I have some more experience, or insight on suitable items.

Most of the time I carry my torch, and a Leatherman with me. Between those, and this kit, I'd like to think I'm more able to help others than I was previously.

I've used the Leatherman a few times at incidents and been very impressed with how well it's worked. I ended up procuring a second Leatherman after the loss of my first, and deliberately choose the Charge model for the hook blade, and the intent of using it to cut seatbelts.

I'll do up another post someday about Leathermans (and other multitools), but simply put...

I've owned several pocketknives over the years, some I've sorely missed, others I'd rather forget. I've yet to use a Leatherman I didn't trust, but certain models seem to suit my needs better than others. My previous favorite was the heavy Core model, and upon it's loss, it was replaced with the Charge ALX. I've tested the Charge TTi, Wave,Surge, Fuse, and SuperTool300. They all have their features and purpose, and none has failed to impress me. I've also evaluated a few other multitools for use... I won't mention names, but one particular unit was so bad to hold and use, I couldn't even give it away at the end. My current everyday Leatherman is the Charge ALX, carried in the old nylon pouch from the Core on my belt beside the Fenix LD2 torch. I have a backup Charge TTi in my turnout gear, with a LD20 torch.

Bladesmithing is one of my interests, and once I get the forge finished (yes another project to document) I'll get more into the forging of blades (instead of my previous "stock removal" projects), but I'll still carry the Leatherman.

ERT/ EMS/ EMT torch and pupil gauge

2010-05-11T19:40:00.000-07:00

I use the Fenix LD2 as my current "every day" torch - it's no longer available and has been replaced with the better LD20 (click here for the amazon listing). The torch has multiple power levels, and can be switched between them quite easily (some via the push button at the rear, others through turning the bezel)
The main appeals of the LD2 series is that the battery life is great compared to the brightness, and the torch is nearly indestructible.(These comments are compared to the 4 other LED, and 3 bulb torches I used in the hunt to find a torch which fulfilled my needs at work) The battery life (in the lower power modes) is amazing, the only problem I've found is stopping other people from "borrowing" it.

I was trying to find a torch for my first-aid kit, and was looking hard at this type of torch. (image taken from a medical supply mob in UK) to clip on my kit, but most I could find contained sealed battery setups, and would be treated as disposable. Not an issue, but in my case the torch might only be needed a few times and the last thing I need is to find the heat has deteriorated the battery.

The main difference between the torch I carry everyday (in lowest power mode), and the medical torch is the pupil gauge printed on the side.
So my solution (for now) is to make up a pupil chart, and have it sitting in my observations notebook, and a strip copy laminated and carried in the pack.
Googling for a printable pupil chart was interesting... millions of hits, but the only one I found I could download was a PDF Neurological diagnosis flowchart. To make the chart more useable to my needs, I captured the chart from the PDF, and then pasted it into a BMP (Bitmap). Then it was a simple case of copying parts of the image and pasting the pieces in the arrangement that suits my needs.

The BMP file is shown above, and you can download the bitmap chart here

I copied the BMP into a word document so I could print it out at 100%. Download the printable chart here as a word document, should anyone else need this file for similar purposes.

I'll be posting some details on my first aid kit soon, I've built the kit to reflect the incidents I've attended, and what I think I need for responding when I arrive at those incidents. The kit is built from parts purchased on Ebay, and taken from my supplies of kits at home.

Customised Meter Case - & musings

2010-05-08T06:35:00.000-07:00

Before I get into this little project, I just want to say how happy I am Daria is finally coming out on DVD. I've bough the various box sets issued over the years by various companies, but all of them were simply DVDs cut from the "Sarcast-a-thon" showing, complete with the original music, and various station markers, and glitches.. but still Waaayyy better than nothing. But come 11th of May 2010, MTV is releasing the Daria DVD box set - still no news on the music, but again - better than nothing. I'll be buying my copy from Amazon due to the price - Here

The other musing was trying to pick a suitable photo for my profile. There was no way on earth I was going to put a photo of myself up there (It's offend the internet spirits for sure) so I was thinking about suitable "archetypes" I could use... some of the candidates included "Q" (Desmond Llewellyn) - from the James Bond franchise, "Tobermory" from the Wombles, Macgyver, Eeyore, and Alastair Cookie, and I even considered Erik (the Phantom of the Opera), but then I kept coming back to this one choice.... This man displays all the qualities and attributes I'd associate with - quick witted, intelligent, inventive, and a great many other characteristics I wouldn't dare include on a resume such as devious, megalomaniacal, and unassuming dress sense. He's Graeme Garden from the Goodies - if you missed out growing up with the Goodies in your life, take the time to get some episodes and see what the fuss was about. If you know the Goodies, you'll know and love "Graybags", even if you associate more with Bill or Tim.

On to the project...

I use a Fluke 179 DMM (Digital Multi Meter) as part of my work, and carry a number of leads, clips, and spares for the meter. One of my co-workers had a case which had the meter on one side, and the spare leads on the other, but I could not find anyone offering the case, and he'd had it for years. I got sick of carrying two cases to jobs, and so decided to make my own case.

I started with a CD wallet for the local Kmart store (big variety chain store - viz Target, or WalMart). The wallet had a zipper around three sides, and a "clam shell" design based around a firm material covered rubber. All up the case was about 50mm (2") thick when stuffed with cardboard.
The CD wallet is shown below...

I removed the CD sleeves, and salvaged the velcro strips used to hold the sleeves in place. I purchased two "cheap and nasty" pencil cases ($1 each) just to get cheap zips, and purchased a cheap roll-up cutting board for the plastic ($3 for 4 boards). The fabric is from some old work shirts that had become too ratty to wear in the shed.
I sewed up a "pouch" to sit above the meter which holds the spares for the meter (fuses, battery, holding clip)

The divider which holds the meter to the LHS (Left Hand Side) of the case is a piece of the roll-up cutting board sewn into a sleeve of cotton fabric. The salvaged velcro is used to secure the meter into the case. The spare space on the RHS of the meter is used to roll the connected leads in for easy use.

The contents of the top pouch are shown below... the brown wire is the K thermocouple used by the Fluke meters for measuring temperature.

The RHS of the CD wallet was separated from the meter section by a panel made from more cutting board plastic encased in another cotton sleeve. The panel is retained by a fabric hinge stitched in the middle of the wallet (White lines of stitching in photo above), and held in place with a velcro closure on the RHS edge. With the velcro closure opened, the panel can swing over the meter to reveal...

The spare leads are vecro'd in pairs to the top section of the panel. The thin black velcro was the last of the velcro salvaged from the original CD wallet.
The pouch sewn into the lower half of the RHS shell contains the spare tips, and probes. The pouch is a simple sewn pouch with another "pencil case" zipper for a closure.

The entire meter case took about 2-3 hours to make including the cutting, sewing, and hand stitching the pouches in place. I've now been using the case in the field for about 6 months and had no complaints about how well it's met my expectations.

A few sewing notes...
threads were typical 100% polyester threads used for normal sewing.
Sewing needle was a normal Smetz universal needle (#15 from memory) and it handled the three layers of cotton, plus the 1mm of cutting board plastic fine.
I used my Toyota sewing machine for this job since it is my current "work horse" machine. I have an old Elna "Air electric", and a Husky 4 thread overlocker, but those only get used when needed.. the Toyota is my "day to day" machine.

I'll post a review on Daria once I have it my hands!!! - Come on Amazon...

"free" pegboard - shed tip #1, and magnets

2010-05-02T00:06:00.000-07:00

A useful shed tip which saved me some money when I first set up my shed here. I know many people who adore the look of pegboards, with all their tools neatly silhouetted on the board, easy to see what you have, and if anything is missing.
Personally I'm not too fussed on having my tools on display (seems hypocritical after posting about tooling - bear with me), but I do like having commonly used tools in a location that is easy to get to quickly.
When I set up my shed, I considered pegboard, but it's not cheap. I then came across the idea of using an old hollow core door.
These doors get tossed out all the time around here as homes are refurbished. I grabbed some for use as trestle tops, and I took one of these and screwed it to the shed wall, effectively cladding that section of the wall with the door. The door is screwed on horizontally, and flush with the wall top.

Peg board works by having a 6mm (1/4") masonite board, pre-drilled with holes, mounted with a 1" (25mm) gap behind it for hooks to pass through.
A hollow core door is a sheet of 5-6mm masonite, with a 1" gap filled with a light honeycomb of cardboard, and then finished with another 5-6mm sheet of masonite. The whole assembly is edged with a solid wood frame which is around 35-50 (1 1/2 - 2") wide... other than the pre-drilled holes, the hollowcore door would pass for pegboard on a frame.

The photo above shows the door, with holes drilled anywhere I want them, things screwed to the door, things hanging off it... lots of options.
Once the door is mounted on the wall, I simply started screwing things to it, corner brackets for heavy duty hooks, blocks of wood for holding squares or saws. I can drill holes where ever I want for hooks, the tail of the hook simply crushes the internal cardboard if it's in the way.

Another thing which is good about the doors is that I could screw hard drive magnets to it where ever I want. I dismantled a number of harddrives over the years - mostly for collecting material for the furnace, but I also salvage useful components such as platters, magnets, and bearings.

The magnets get used for all sorts of things, but one common use is for holding things up. The photo below shows magnets screwed to the door and labelled for the hammers they hold.

I've yet to find a hook I'd trust for holding up my sledge hammers, but is easy to remove, or replace the hammers on. The photo below shows my club hammer attached to the wall via the magnet.

I'd show a better picture of some of the other things hanging on the wall, but it's hard to get a decent photograph through all the mess in the shed.

The magnets also get used for holding charts to the roof of the shed. I ran out of wall space in my shed pretty quick. Between shelving, door, tool storage, and a bench, the walls seemed to disappear pretty quick, so I stored my thread/ drilling charts on the roof. I simply covered the charts in contact, and then used some magnets to attach the corners to the roof.

So shed tip #1 - free pegboard by using hollowcore doors, and drilling your own holes where you want them, (as you need them, etc)

Bonus tip - save hard drive magnets for use for holding tools to walls, etc. I use one magnet for a 35lb sledge hammer - they are dynamite for holding, clamping, etc - and free for minimal labour.

Indicator stand - magnetic - disassembly

2010-05-01T22:52:00.000-07:00

I obtained a very damaged indicator stand (magnetic) which was to be thrown out. The damage includes the lack of the main post, all clamps, and the magnetic base is damaged by the loss of the front plate, switch lever, and some dings.
Below is a picture of what a complete stand should look like, with an indicator on it (picture taken from the Amazon listing for the Grizzly indicator/ stand set). I will rebuild the damaged one back to this level of usefulness, and use it with my existing indicator.

Before I can repair the damaged unit, I need to disassemble it, determine what needs fixing/repair, and then proceed from there. This page will cover the disassembly, another page will be written up to cover the rebuild once I've done it.

Since the front panel was already missing, I simply removed a brass lock screw from the side, and tried to remove the magnetic core from the internals of the base. I found the only way to achieve this was to tap the corner of the base on a block of wood, with the open end downwards, and use momentum of the core to pull it out (similar to a kinetic puller if you're into reloading) Once out, the pieces were laid out as shown below...

The pieces are: (from left to right) remains of actuating lever, magnetic core, spacer ring, base.

The base is a metal component, a singled piece, but it's made of four sections. All of these sections are visible in the photo below. The two sides (bulk of the base) are made of a cast iron, separated by a brass section about 5mm (3/16") thick. The final section is a zinc/epoxy shield which covers the hole at the back.

The brass separates the two iron halves, and effectively "breaks" the magnetic circuit between the two halves.

The magnetic core resides in the hole in the middle. The core comprises a strong magnet, with some pole pieces to direct the magnetic flux across the axis of the core. Some bonded plastic flanges are located at each end, and these plastic end pieces have a square hole molded in for turning the core.

The above photo shows the core with it's endpieces (the one on the right has a spacer ring fitted), whereas the photo below shows the square hole in the end for turning the core...

The spacer ring is to prevent the magnetic core actually contacting the interior of the base during normal operation. The diameter of the core is measured at 0.8mm less than the diameter of the hole it rotates in. The spacer ring is measured to centre the core in this hole, and this gives a rotating clearance of less than 0.5mm between the magnetic pole pieces, and the base.
The small gap is designed to offer minimal attenuation to the magnetic flux, but still permit rotation of the core. The base is designed (with the brass strip) to offer two flux paths from one side of the core to the other...
One path is through the iron side, through the magnetic material contacting the base, and then back through the other half - this path is the path which "grabs" whatever the base is sitting on.

The other path is where the flux flows within the same iron half - the flux path is vertical, and splits, with half of the flux circulating in the left hand iron side, the remaining flux in the right hand side.

That pretty much covers the internals of a magnetic base, and roughly how it works.
To repair this stand I'll be doing the following:

a - Machine a front spacer ring
b - Build a new actuating lever
c - Build a face plate to hold the lever
d - Build a post including mounting threads, washer, locknut, etc
e - Build the clamps, bars, etc to connect the indicator to the post.
f - Paint/ finish the components

As always I'll photograph as I go, and document after it's done with comments and findings.

Homemade Anvil - RR Anvil - Part 2

2010-04-26T02:35:00.000-07:00

Part 1 talked about a home made RR-anvil which I designed, and had built with a lot of assistance from some of the guys in one of the workshops at work.

As mentioned in part 1, the issue is to stop the ringing by thickening up the web, and helping transfer any forces from the table to the base.

In an article in one of the 1920-ish shop notes from Popular Mechanics the article talked about making anvils from I-beam and thickening the web by bolting a piece of wood on each side of the web... based on that idea I made a number of pieces of 1 1/2" reinforcing steel which fitted between the rail head and the base plate of the rail.

I then cut another set of pieces which would sit between the underside of the table, and the base.

The next step was to cover the reo-bar. I used some scrap 4mm galv sheet I had kicking around. It welds easy enough, and is thick enough to stand some abuse.

The pritchel hole at the back of the anvil needed to be protected from whatever I did, so I cut up a piece of pipe to make a hollow in the back of the anvil so the underside of the hole would always be accessible.

The sheet metal shroud covered all the reinforcing bar sections welded in underneath the head, and table. Since the rail is made of high carbon Japanese steel, and my welding capabilities didn't seem to like that too much, I ensured mechanical locking whenever possible to make everything sit properly. Knowing that this would not suffice in the long run, knowing the welds made to the rail would crack under repeated hammer strikes, the next step was to fill the gaps so the reo-bar would not move under any circumstance.

The shroud was completed, with just a simple plate (about the size of a credit card) left unwelded at the back.

I obtained from the local tyre place a few bucketfuls of lead tyre weights, and melted them down using a wok burner, and one of my furnace crucibles. I could have used the furnace, but was concerned that over heating the lead might create fumes. I used the furnace when I was melting aluminium, brass and bronze since there wasn't significant issues with fumes... I was not as familiar with lead (I'm not a fishing guy who makes sinkers), so did not know how the fumes went with excessive heating. The wok burner was slower, but I figured there'd be less in the way of fumes.

Using the foundry robot, I picked up a 7L crucible of molten lead, and poured it into the gap between the shroud, and the internals of the RR-Anvil, effectively filling the gap. All surplus molten lead was poured into one of the ingot trays I use when pigging aluminium.

The lead was allowed to cool, and the final plate was recessed into the lead, and welded in place, effectively sealing in the lead. A test with the hammer and it was sweet - no ringing at all.

Here is a photo of the painted up anvil showing the recess under the pritchel hole...

And a side view of the painted anvil...

Yes, the final weight now exceeds it's original weight by more than 100%. The anvil started at 26Kg (57 lbs), and now weighs over 55 Kg (121 lbs).
The slots cut in the base web are for securing the anvil down on a wooden base, and the wonderful "imperial plum" purple paint is one of my garage sale paints I use to paint up things that need protection. I've left the top faces unpainted since it's unlikely the paint would survive the use of the horn, cutting table, and main table.

Now the anvil is finished, I've already found it too small. I've used it for a number of small jobs and for those purposes, it's fine. But once I start pointing bladeware, or other items longer than 8" at it, the table is too small. I've considered welding a larger table on top, using the existing table as a weldment anchor. I have some 2" plate here which could be used, but I'd be back at the workshops to have it cut and welded on the big machines.... I only have one small piece and I can't afford to replace it if it's spotted by a boss.

For now I limit my work in size, and am on the hunt for a decent size anvil. I'm playing with a "false table" idea to allow larger work, but that's had to take the back seat for other projects lately. The "false table" is effectively an extension of the "third hand" concept used by some smiths... a set of light gauge supports are used to retain, or hold the work on the anvil, but they aren't actually part of the anvil. All striking would still occur on the anvil, but the false table would permit me to ensure the work was level, and flat when it is on the table... still in Mk2 testing....

Homemade Anvil - RR Anvil - Part 1

2010-04-26T01:45:00.000-07:00

Anvils are one of those things which can be "home made", or totally unorthodox, but it's hard to make a cheap home made anvil which is good, and matches the traditional pattern.
The biggest issue with home made anvils is mass, and "ringing". People tend to make them too light, or out of materials which ring. The first anvils I made were made of material which was too soft, and would scar when I attempted to flatten coat hanger wire on them, let alone anything substantial.

I was given access to a source of rail offcuts, and so was able to grab a number of lengths of rail ranging from 200-1200mm (8" - 48") in length. Since oxy cutting is not in my list of proficient skills yet, I asked one of my friends in the workshops to cut the rail for me. I also provided a sizable piece of 1-1 1/2" plate and marked up a "table" to be cut at the same time. Payment for getting the cutting done was to supply additional lengths of rail offcuts so other anvils could be made.
Sounds good, and it was... the problem was some of the "bosses" spotted my anvil in the workshop whilst it was being cut - each time the bosses would spot it, they'd claim it. The workshop would then start another one for me, and another boss would walk through. By the time I got my anvil, all the heavy plate was used up, and I had refilled the rail offcuts bin at least twice. I don't relate this story to criticise the workshop - far from it. I relate it to show that most people who work with metal like the idea of having an anvil, but would rather someone else made it. If I could afford the purchase and shipping on a commercial anvil I'd have bought one..instead I made one.

To reduce the demand on the workshop, I only asked them to do what I couldn't easily do at home, or to do what was considerably easier (and more efficient) to do with the machines at work.
I asked them to rough cut the rail with the oxy, and to cut the table from the 1 1/2" plate with either oxy or plasma cutting.
I asked them to drill a pritchel hole in the table of a minimum of 1/2" diameter.
I asked them to weld the table to the head of the rail, with appropriate overhangs, clearances, etc as per the drawings and templates I'd supplied.

From what I understand, the guys who'd made my anvil were apprentices tasked by the tradesmen between jobs. I am led to believe that the two apprentices ended up making at least 8 anvils prior to mine, and had at least another 4 to complete after mine. After all that, I'd have expected them to be cutting corners, and generally sick of making something, only to have a boss claim it. When I collected my anvil, I was most pleasantly surprised with how much work they'd done over and above what I'd asked... all the finish grinding was done, there was practically nothing left for me to do other than a few minor alterations.

Below are pictures of the anvil I ended up with. I'll point out the features and the reasoning behind them.

The feet are deliberately cut so they are under the tip of the horn. I read on one of the blacksmithing sites that when someone builds a RR-Anvil (Rail Road Anvil), that by making the base extend under the horn, the force from strikes is transmitted to the base better, and is less likely to cause issues through the web.

The table ended up slightly smaller than planned due to the loss of materials. The table is roughly 150x200x19mm (6" x 8" x 3/4"). A section of bare rail head had been left uncovered for the cutting table.

The table is welded to the rail head on all four sides. I don't know what the trick is the workshop guys used, but their welds to the high carbon rail have excellent penetration. When part 2 comes along I will be able to tell you that nothing I tried worked anything as well as what the workshop guys did.

The RR-Anvil (Mk 1) weighs in at 26 Kg (57 lb). Is it heavy enough?
Does it work?

I tried the anvil and found it rings like the proverbial bell. I don't know if the original anvils I tried to get made turned out, but with some perverse pleasure, I really hope the ones claimed by the bosses also ring as badly. It's mostly the thin web through the middle of the rail section which causes the ringing, so odds are all the other anvils made will also ring.

The way to reduce the ringing is to increase the mass of the web. Some people accomplish this by wrapping the web in chain.

I tried it, but no luck. It still rang badly - subdued slightly, but still quite uncomfortable.

Part 2 will cover how I got rid of the ringing, and ended up with a very serviceable, albeit small anvil.