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|
|Figure 2 - Hinges under construction - engaged|
|Figure 3 - Hinges under construction - released|
|Figure 4 - Hinges fitted - engaged|
|Figure 5 - hinges fitted - door released|
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|
|Figure 7 - Pin-wrench "key" under construction|
|Figure 8 - Finished lock - in locked position|
|Figure 9 - Finished lock in unlocked position|
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|
|Figure 11 - Pusher spring casing installed|
|Figure 12 - Pusher installation nearly complete|
|Figure 13 - Result of pusher on unlocked door|
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|
|Figure 15 - Assembled handle|
|Figure 16 - Completed field desk with all hardware|
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:
Trays and containers
- apologies for the number of photos - next time I'll do this as two articles.