It’s actually a drawing machine. It’s built from two stepper motors I salvaged from come old CD-ROM drives. In its current incarnation, it has two pots each of which controls the movement of one of the two motors: for moving the pen up and down or left and right.
It’s great seeing students’ progress as they reach milestones on their projects. If you are a student or teacher and want to show off your classroom breakthroughs, pass them along in the comments or Make Flickr pool.
With Tom Igoe’s help, I figured out how the connections to the steppers worked. They are both bipolar steppers so they have four connections each. I measured the continuity to find which pairs of leads were connected to each magnet. Once I had this right, I plugged each of them into an h-bridge and then connected the h-bridge’s four inputs to the arduino and told the Stepper library about them.
In the Maker Shed: