Julian has released the files for the v4 drive system. This is an all new improved set up that he has been running successfully for a while now. Included are the STL files, a BOM, and instructions for assembly. See this Facebook post for more info:
https://www.facebook.com/groups/1033030753554654/posts/2394543410736708/
Or if you sign into this site, you can find more info here:
