70mm Level Winding Device utilizing Diamond Ball Screw (includes CAD links)

https://www.youtube.com/watch?v=1SsxRlJ4dqc

This is a 90mm wide (~70mm travel) level winding device utilizing three 4.5mm steel BBs in a ballscrew-style diamond-screw self-reversing configuration. There is the screw shaft (with 8mm axles for use with standard 608zz skate bearings) an inner and an outer nut as well as the base. tolerances on all pieces are quite tight, as this is a rotating mechanism, print and post process with that in mind.

Although I have found it to work quite well in testing, it IS possible, due to the design, for the nut to reverse direction before the end of travel, to "short stroke" as it were... If anyone has knowledge of how to prevent this from happening I'd love to know the secret!

check out the "experimental latching inner nut" I have not tested it extensively, but it seems to work =) It may require some filing to get the smoothest functionality while still latching the ball direction adequately. added a version of the latching nut with a flex/spring mount for the detent

There is a 3mm screw hole designed to hold the inner and outer nuts together, but I found the interference fit was tight enough that I didn't really need to use it. It's there if you need to though.

I've added public links to the Fusion 360 files for this project. check 'em out!

https://a360.co/2OATcrr <-- Support Frame

https://a360.co/2Oxupo8 <-- Main reversing screw and nut

adding Google Drive link with .f3d and .step files: --->

https://drive.google.com/drive/folders/1A8JmW9I8pBIonfZHxG-oSolNn4eYNayM?usp=sharing