Process

However, I didn't know how to go about making the device, and spent many hours thinking about different possibilities before a friend who has been a fabrication mentor in the past suggested that an excellent resource was right under my nose: the Etch-a-Sketch patent, filed in 1959. This was a great piece of advice. With the patent in hand, I did not need to create a novel way of moving two rods in parallel remotely; all I had to do was adapt the existing old method of doing so to my purposes.

I went through a trial-and-error process of building the device, with many, many failures along the way. Major difficulties included: tensioning the cables properly, affixing cables firmly to each other with improvised hardware, measuring cable run lengths correctly to match the bus stop installation, and tweaking the perpendicular rods so that they would lie exactly perpendicular to each other at all times and not bind in the 3d-printed junction block. I had a very hard time finding a device that could reliably cut the cable I was using, which made threading the newly cut end through the cable housing extremely laborious. Additionally, I found myself approximately 2' short of cable when all was said and done; I needed to twice modify the cable housing (involving unthreading and rethreading the cable) to adjust for the discrepancy. I tried to add a feature where a piece of paper with a drawing on it could be rolled out and ejected so the user could keep it; this was just too hard in the time I had and I abandoned that effort. Ultimately, I installed a pencil as the writing implement in the prototype device, which wasn't especially satisfactory. I substituted in a crayon which somehow was also very unsatisfactory. Many things didn't go to plan and I had to change course repeatedly throughout the fabrication process!