The idea is simple. A plotter that hangs from a wall and draws on a UV-reactive surface with UV leds as the “paint”. Based on the characteristics of the UV-reactive surface, the picture will slowly fade and disappear over time.
Since I want this to hang from the wall, there are two ways I can do it. The way most people do it is with two stepper motors with a spool of rope connecting each to a center puck. I could go this route but I think it lacks a certain style in the mechanics and it lacks precision because you will, invariably, have to deal with a pendulum effect when changing directions.
While researching this project, I found CoreXY which works very similar to a drafting table rule. This stabilizes the center movement point while keeping the mechanics simple, and elegant.
So that’s what I’m building.
So far, I’ve ordered some pulleys from McMasters and the UV leds from Sparkfun. I’m still working on the design of exactly how I will put it together and most likely, there will be 3d printed parts involved, especially for the driving pulleys, I’ll probably design an interface piece for them.
Of course, I need to source the stepper motors. I’m also going to use the motor controller that I bought for the Chocolatabota since that will take longer to build and the drawbot is a great first step towards the 3d printer.