Ball Screw and Nut

A recirculating ball screw uses a series of balls between the threads of the nuts and the threads of the screw. These balls create a rolling (rather than sliding) contact between the screw and nut, making for very efficient power transmission. The rolling balls, however, eventually pop out one end of the nut and need a recirculation tube to shuttle them back to the other end of the nut. This is a working version that shows off how a recirculation ball screw works. It uses 6mm dia. airsoft BB's for the balls, but nut and screw are 3D printed. The transparent view of the nut above shows the spiral ball path and the internal recirculating tube. The screw is a little funky in that I flatted one side for printing. This creates gaps in the thread, but the gaps don't interfere with the ball recirculation, and only minimally reduce the load capacity.PrintingPrint in PLA. I used 0.2mm layers, which is fine for the nut, but with the screw printed sideways, it will be smoother with 0.15 or even 0