I think the original idea was to use metal baking trays because we both had seen these and the rolling carts that hold them used in restaurants. Aside from being expensive, I decided against this because the metal trays are conductive and while helpful for ESD reasons, would likely cause a short when testing electronics.
The next thing that came to mind was a lunch tray. I didn’t know much about these so I just shopped-around for something inexpensive to start with. I found these 16”x12” gray plastic trays for about $2 each and gave them a shot.
Takes you back to elementary school, doesn’t it?
When they arrived they were smaller than I expected and I thought this would be a problem, but it turned out to be the opposite. The size of the tray created enforced a maximum “grain size” on any individual unit of work, which had the effect of conditioning me to break larger projects into pieces that would fit on single trays. This also encouraged a modularity that would allow me to switch between projects more easily.
This project (the transmaterializer) is starting to push the envelope of what one tray can handle…
Another happy accident with my choice in trays was the angle at which the “sides” of the trays lies. This makes it very easy to pick-up small components by sliding them over and up the side (this makes them great for LEGO as well).
Hard to get a picture of this but you get the idea.
Part of the original design was the idea that a project could be “paused” quickly and easily by picking up the tray and sliding it into a slot on a shelf. The project could then be just as easily resumed by pulling it off the shelf. This might seem simple and obvious, but if you’ve ever worked on a project on a nice big workbench you know that the work will quickly expand to consume the entire surface, and if you need to work on something else the process of making space without disturbing the previous work is a time consuming and delicate business. The tray system reduces these “task swaps” from minutes or hours to seconds.
Of course this only works if you have somewhere to put the trays. I spent over a year failing to solve this problem because I couldn’t come-up with a custom design I wanted to build, and I also couldn’t find an off-the-shelf option that fit the trays I picked (I even considered starting over with new trays). Eventually the mess got to me and I decided to just build something so I could get some space back in the lab.
1”x4”x8’ pine boards kept the project on the cheap side.
So…many…cuts…
So…many…screws…
What I settled on was an 8’ rack built essentially like two simple ladders connected face-to-face. The rungs are spaced so that the lip of the tray is held but the sides and bottom can hang down. It was the simplest design I could come up with using dimensional lumber and no fancy tools (no table saw, radial arm saw, dado blades, etc.)
Test fitting the trays in the finished rack outside. 8 feet is really tall…
The hardest part of the build came from the difficulty finding perfectly straight lumber. I worked around this as best as I could and in the end it was good enough to get the job done. If (when?) I do it again, I might try something different just to avoid the sheer number of cuts and screws that this design required.
Finished rack in its permanent home at KGL.
Overall the system works extremely well. I’m tempted to get more trays and build another rack, but limiting myself to the ~30 trays I have now keeps the number of in-flight projects to a somewhat reasonable level so maybe I better stick with that for awhile.