Threadless Ballscrew in Motion

thingiverse

The 'threadless ballscrew' 3D-printed design is put to the test, specifically measuring the slip when traveling over smooth rods. The ballscrew's suitability for open-loop control with or without position sensors is also assessed, revealing low backlash as a positive feature. The essential geometry of tilted bearings was designed in OpenScad and further edited in Tinkercad for added details. 3D-printing and CNC-machining were completed at FabLab Zurich. In a test run, the final position accuracy was impressive at ~0.1mm, but disturbances caused slippage. Open-loop control reliability is questioned, prompting curiosity about others' experiences with similar builds. Future work includes adding springs to fastener screws, refining the OpenScad script, and considering aluminum construction for the part. Required materials include smooth 8mm rods (hardened steel preferred), six roller bearings 625 (16mm outer diameter), six M5 screws and nuts (20mm), six flat washers (M5), two M5 screws (25mm) for fasteners, and four M4 screws and nuts for base plate mounting.