All my Drawbot boards arrived from the fabricator today. Time to go by a bigger magnifier and get to building!
This is the communications board that converts USB to RS-485.
This is the board for the pen carrier. It takes RS-485 in, and drives a servo to accomplish the pen up/down.
And this is the winch board. It takes RS-485 in, and drives a 2 phase bi-polar stepper motor.