Your workmanship is top notch. Any factory would be proud of a product that looks like that.

Have you already done all of the performance math for speed, acceleration, available cutting force?

I'm working on a spreadsheet for my own build. To try and determine the best pitch of ballscrew to use for the motors I have, and to account for possible future upgrades, including the effects of ballscrew and motor inertia. I've already been playing with this for rack and pinion. I'm curious if anyone else has done this that I can compare notes with.