The Bipolar ORD Bot at Buildlog.Net by Barton Dring:
This was built and programmed gonzo style in about 2 evenings. The sole purpose is to spark conversation at ORD Camp 2015. The machine uses two polar axes to create the motion. It is running off stock grbl 0.9g on an Arduino. It runs standard gcode that is mapped to the polar coordinates by a post-post processor
Check out the video after the break.