[Bart Dring] is well known around these parts for Makerslide, the buildlog.net laser cutter, and a collaboration with Inventables for the Carvey CNC machine. They’re all popular projects and all very useful. This one, not so much. It’s a bipolar bot that doesn’t take itself too seriously, and this year’s build for [Bart]’s usual gonzo CNC machine for ORD Camp.
The Bipolar Bot – yes, that’s its name – is pretty much a SCARA bot. There are two NEMA 14 steppers in the joint of two arms, each of which are bolted to a bearing on a base plate with the other end holding a pen. That’s it as far as the mechanics go, but the software is extremely interesting.
The steppers are driven by an Arduino with the help of a tool that converts Cartesian Gcode to the bipolar Gcode the machine requires. There’s a bit of math involved, but nothing of note if you can code some trig functions
Right now the bipolar bot is busy drawing stuff that looks like it came right off a spirograph. You can see a video of that below.