Rotating Ballnut - design ideas

[Boyan Silyavski]

Jonathan, THANKS!

Great work and info!

As this rotating ball nut idea consumed my weekend and the whole last week, and i am sure much much more of Jonathan's time, here is the Sketchup file for all to use, if this is alright with Jonathan:

• rotating ball nut Jonathan design MYCNCUK.rar

Notes:
1. Every part is labeled , so can easily be found in internet
2. The bearings are recessed 0.5mm in the casing
3. The aluminum is 20mm thick and the bar can be 100x100, 100x90 or as originally 5"
4. Everything is tight fit / I still don't get it how the bearing casings are centered from both sides but hey, i am not a machinist yet :-)/
6. The clearing between the 2510/25.. nut and casing is 1mm
7. The clearing between rotating shaft and the ball screw is 1mm
8. The 2 retaining nuts actually are PACK OF 5 KM Series KM7 Locknut 35mm x 52 mm x 8mm FREE P&P | eBay as the thread will be 35mm
9. There could be small corrections of the lips that hold the outer and inner bearing racing rings, will update if necessary.
10. The motor is from Zapautomation 3Nm SY60STH86-3008B NEMA 23 STEPPER MOTOR, which i assume most will use for this job 8mm shaft