Foundry "Robot" - part 2

Following on from "part 1".. the tilting joint (located under the main sleeve joint) is comprised a small pipe/bar joint atop the spigot joint.
The photo below shows the pipe welded to the top of the spigot joint, and the two cheek pieces holding the bar...

Photos of tilt joint in action - from one extreme...

To the other extreme...
The dust cover was also shown is those photos protecting the sleeve joint, and it's bearing shells. There is also a carry handle visible - I put it there since when I first moved the robot, I'd let the spigot joint open, and carry the base as a separate piece form the top... now they are always together with a hook, which is disengaged after movement.

The gripper...
Basically I designed this to be fully adjustable. By changing the "fingers" I can change what it picks up.
The fingers have a full range of movement between two extremes, shown below...

Above was "fully open", now this is "mostly closed"...


I say "mostly" closed since the finger design prevents further movement, but the mechanism permits more movement.

The gripper consists of some major parts - all of which are visible in the photo above.

a - The actuator and bell cranks -square pipe at low left and flat bar bolted to it, up to and including the small plates which tilt between the pincers

b - bolt on "fingers" - held to the bell cranks via 2 of 1/4" bolts - the angle iron "pincer" shapes with the small length of flat bar at the end near the bell cranks

c - nose piece - it's the small piece of round pipe visible protruding from the end of the square pipe... the nose piece actually includes the last inch of square pipe (removable)

These components allow the gripper to work, and be modified to suit the crucibles in use. My pipe crucibles have a "tang" which I use to locate them, and the nose piece mates with that. If I use a ceramic crucible, the nose-piece is swapped for one resembling an up-side-down letter "L" which locates the top rim of the crucible, and the fingers are broader, and more curved.

The next part will show the controls, and a test drive of the robot

Foundry "Robot" - part 1

I built a furnace/ foundry for casting in Aluminium, Brass, and Bronze. (more details on that later) - to manipulate the crucible, I looked at a number of options, but this.. is what I ended up building and using.
It's all home construction - tools used was welder (arc), grinder (grind, and cutoff discs), and miscellaneous hand tools.

The "robot" is not a real robot (powered with a form of control), but rather more a mechanical machine which I control. (yes I won't split hairs over semantics - compared to the robots at work, THIS doesn't count)


The distance between the operator, and the gripper is 3.0m (10'), and there is no lifting required, except to assemble and relocate. All "lifting" is done on a counterweight system, and my own body weight is used to my advantage.
Following over the remainder of this page, and the next pages will be photos of the robot, and text explanations of the mechanisms. All steel sizes are as much a reflection of my stockpile, rather than calculated engineering recommendations - in fact everything I write should be taken with the usual legal indemnities/ waivers applied. - in other words, if you don't know what you're doing, and aren't prepared to wear the consequences, don't use anything I've done help you qualify for a Darwin award.

Overview of the "robot" - open gripper facing camera.
The crucible is on the ground in the shot above - the pipe is 2 1/2" OD for the main beam.
Now some detail - working from the bottom up...
The spigot joint (Slew)...

The spigot joint is made of three lengths of pipe, two the same diameter, and the third a slip fit inside the first two. The bottom pipe, and the central (internal) pipe are welded together, with a washer across the top of the internal pipe. A steel mouse ball is placed on top of the washer, and the third pipe is dropped over the top of the whole lot. Inside the third pipe is another ppe with a wisher, so the bearing surfaces are the two washers, with the mouse ball between them. The three bits of pipe form a spigot joint for rigidity, and the ball/ washer bearing for friction reduction. The legs on my robot fold up, but that's a personal choice.



The top joint is complex - please bear with me.
On the top is a "sleeve" joint, complete with bearing shells (made from pipe halves), to provide a rotational, and sliding joint. The photo below show the bearing opened on the LHS and the upper bearing shell moved to the left. Obviously the whole bearing assembly is greased up in use.

The shells are tightened via the wingnuts at the lower edge of the photo, and normally there is a dust cover over the entire sleeve joint.



The other major axis of movement is the tilt joint located under the sleeve joint. It's hard to photograph, but it's simply a short length of pipe mounted across the top of the spigot joint pipe, and a slip fit bar running inside the pipe, welded between two "cheek" pieces (shown as yellow in the photo below.


Part 2 will show more of the joint, and focus on the gripper

Bender's Beard - or is it Flexo's?

Fans of the show know Bender has a beard, but "never wears it". When we first meet Flexo, the key visual difference between Bender and Flexo is the beard.
To make a beard... When I was making the eyelids for Bender, I tipped any leftover putty into a quick cardboard mold I made.

The mold was basically a triangle, with a thickness of around 42mm (1 3/4"). Since it was done as two pours, I placed a magnet inside with it's poles facing the base of the triangle, between the first, and second pour.

Once cured, I cut the mold apart, and then cut the triangle section apart to form Bender's beard - as seen below.

The followed a lot of filing, and adjusting so the magnet poles were exposed, and the triangle cleaned up so it was even, and had sharp lines at the edges. Once happy with the look, I primed the beard as shown...

Originally I painted it the same light gray as Bender's body and head, but my darling wife pointed out it looked wrong. I checked the disc again, and sure enough it was too light (She is always right, but don't tell her I said that...). The beard needed to be darker than the colour of Bender's extensomatic arms, so I gave it a shot of the Zinc-It.

Front view...

Three quarter view...


That'll be it for a while.. Bender is pretty much complete. I still want to do up a bottle of "Ole Fortran" for him (does anyone else remember FORTRAN?... I can still remember coding in FORTRAN 77 and FORTRAN 90 - first language I ever used which didn't have a "print" statement of some description.)
I digress... I want to do up a bottle of booze for him, and try and recreate the kids' drawing from the orphanarium. At that point, Bender will definitely be finished.

The suggestion has been made that the next project should be the Robot Devil... I'll admit he looks great, and would be a challenge. I think I'll hold off for a while - never a shortage of jobs to do, and I'd like to document some of my other projects.

Bender starts smoking.

To make a cigar for Bender.... Ideally it shouldn't fade, and should look reasonably "realistic", or at least as real as Bender does.
I started with a short length of 20mm (3/4") electrical conduit, with a magnet taped into on end.
I also grabbed some empty chip packets (Samboy BBQ) for the orange colour, and the "sparkly texture"


To simulate the burning/ glowing end of the cigar, I cut the chip packets up to get 50mm (2") wide strips of orange material, folded them lengthwise so no silver showed, and rolled them into a tight roll to place inside the end of the conduit - shown below.


I then rolled a wider strip around the outside to cover the end of the conduit, and taped this in place. The rest of the chip packet was then folded into itself to form a 60mm (2 1/2") wide strip, and wrapped around the conduit to widen the middle portion of the cigar. I then wrapped the whole thing in tape to form the cigar shape, and leave the orange exposed.


Once the taping was finished, I painted it Brown, and let it dry. The photo below shows the painted cigar drying - stuck by it's magnet to a cabinet.


I then added the black spiral lines to the cigar using the gridding tape (see article on teeth) and gave the cigar to Bender - he seems to enjoy it.

Next article will cover the beard.

Bender gets emotional - part 2

As mentioned previously, Bender displays emotions via his eyelids, and to a lesser extent via his teeth - specifically the horizontal lines. To that end, I made some extra teeth panels when I first finished the heads, and reserved three of them for "emotional effects" - this page documents finishing two of them.

The teeth panels are simple rectangular panels cut from colourbond offcuts. Colourbond is a common roofing, and fencing steel, about 0.6mm (about 25 thou) thick, and quite "springy"... it'll crack if you attempt to put a sharp bend in it since the way it's shaped hardens it considerably.
This springy-ness is used to hold the panel inside Bender's head - as shown in the photo below.


The two "ears" bent into the teeth panel make it easier to spring the teeth panel into a tight curve to insert and position the panel.

Knowing how difficult it'd be to mask up some nice curves, I acquired some of the adhesive tape used for putting gridlines on whiteboards and tried using that to make some wavy lines (Bender's "error" teeth pattern) - it worked OK.

A second line added..



I also tried some sharper wavy lines to recreate Bender's look when shocked - that didn't work as well since the tape couldn't turn sharp corners without puckering. I ended up pulling it off and creating the shocked lines with black paint free handed on to the panel.


Here is the finished panel installed in the spare head - "error"

And the "shocked" look...
Next installment should make Bender happy - he gets his cigar, and a beard he "never wears".

Bender gets emotional - part 1

For Bender to display emotions he usually has his eyelids change, or his teeth change (horizontal lines only)
To make some eyelids for Bender I cut up the eye molds I'd used - made from Christmas decorations. In the photo below, you can see two halves of a Christmas decoration which were used for eye molds, and one still complete decoration.

I removed the eye-plate (with eyes) from the spare head, and using a discarded plastic tag, made a dam for the putty. I cling wrapped the eyes and plate to prevent the putty from sticking, and positioned some cut decorations on the eyes with their centres at 1:30 for the "sad" look, and at 10:30 for the "frown" look. I magnet was placed at the top between the eyes, and a piece of metal was placed for a handle into the putty before it cured.

Once the putty had cured, and the dam, and cling-wrap removed, the resulting eyelids were filed, carved and generally cleaned up. In the photo below, you can see them stuck (via their magnets) on a metal cabinet.

Once painted black (to match the interior of the eye shroud, and eye-plate, the eyelids were tested. The "frown" first...
Then the "sad" expression...

The next installment of this build log will cover the other emotional accessories I built, teeth plates.

Bender Gets Religion

Given that smoking isn't something I encourage in our house, I thought it fair to give Bender a good behaviour. He was quite well behaved when he had religion in "Hell is other robots" so I made him a Robotology symbol.

I started by drawing up the symbol, tracing around a 20cent piece for the dots, and scaling everything else so it looked in proportion.



I then traced it onto a piece of sheet aluminum from an instrument case in the scrap bin. To trace the design I painted the aluminum with cheap white paint (for contrast), and coloured in the back of the paper with the design with red pen, I then went over the design from the front, transferring the red ink onto the white paint. I then went over the marks with the red pen to contrast it better.



The shape was cut out with shears, hacksaw and filed to shape. I then primed the shape, and glued some magnets to the back with rubber cement.

A second coat of primer on the front to smooth any drips, and soften the edges a little


I then sprayed the symbol with a "cold galvanising" spray called Zinc-It. It's a CRC product one of the boilermakers from work put me on to. My Dad used to have a paint on version he used when making gates, so when I was given a can of spray zinc, I use it on all my work where I want it to last. Here I only used it for the colour, and the fast drying aspects. - The finished result...



One well behaved Bender

Next installment.. eyelids