About this 3D model

Also known as Do-nothing machine, bull-shit grinder or ellipsograph. http://en.wikipedia.org/wiki/Trammel_of_Archimedes This unit works pretty well but you may need to adjust the tightness of the screw to get the best motion...not too tight or loose...just right! Assembled with three #4 3/4" pan head screws. https://www.youtube.com/watch?v=ohRI3R9_0nY