I ran my first test this past week of the drawbot! It was a fail and success: the circuitry and software is running as it should, but there is a problem with the steppers driving the wheels. I’m pretty sure there isn’t enough torque at the current gear ratios I have in place. I’m going to try to add a third wheel and secure the steppers (this test was with tape holding the stepper mounts in place); hopefully this will reduce the amount of resistance the bot is currently trying to push.
This chassis is made from the hardware frame of a very old projector headed for the trash. I trimmed it up on the bandsaw and added L brace support.
As you can see from the picture, the steppers have a gear attached to them that’s attempting to drive each wheel independently. This will enable the drawbot to execute G-code commands that will draw a picture. The electronics hardware includes: an Arduino Uno, 12V battery, 2 nema 17 motors, 3 A4988 motor drivers, and a RN-42 bluetooth module. I can currently send commands to the motors, but they don’t like something about how I’ve setup the gears. Next on the agenda: a third wheel, secure steppers, then test again!