Workshop 88 had a table at the Southland Mini Maker Faire in Mokena on 8/22/15.  Jim’s drawbot string plotter made a “big” hit, standing 6 feet above the table and drawing poster-size images.

The drawbot, a junkbox project inspired by Bill Paulson, is driven by a couple of $3 steppers from American Science and Surplus, some cheap H bridges and an Arduino clone.  Software is free from Makelangelo.com.  It does the heavy lifting math to convert from X-Y coordinates to the “inches of string” coordinates the polar geometry imposes on its steppers.  In addition to accepting normal X-Y gcode, it can take a jpeg image and use the traveling salesman algorithm to generate a single path reflecting the darkness of different areas in the image as it’s doing in the picture above.  Such a path is ideal for a plotter that doesn’t have pen lift capability.  Yet.