If you’ve followed Hackaday for a while, you might know that all ball screws don’t have threads. While ball screws are uncommon in 3D printers, they show up pretty often in CNC machine designs.

Keen-eyed readers will recall [Andy]’s recent scratch-built ball screw build, in service of some top-secret, hush-hush project related to world domination and total subjugation of humanity.