Rotating Ballnut - design ideas

[Jonathan]

Hi Jonathan,
have you seen these bearings, which are meant for the purpose?

No, I hadn't spotted that. I see they've used bearings with a higher contact angle than most angular contact bearings, as that allows the bearing spacing to be lower for the same stiffness. I don't think this is too big a concern with the rotating ballnut bearings, as they are oversized compared to the bearings one would use if spinning the screw.

I've just finished making three more rotating nut mounts for someone who spotted the video on YouTube who's making a large machine with two SFE2525 ballscrews and one SFU2010 ballscrew. I simplified the design by changing the housing for a block machined from 4" square aluminium bar, and a separate piece cut on my router for the motor mount.


Some pictures:




A video, feedrate displayed assumes connection to 25mm pitch ballscrew:



Drawings:

RotatingNutSimple.zip


Feel free to copy or modify the drawings and use them to make your own or get the parts machined by your favorite company... I don't mind.