Ballscrew articulation, has anybody had success?

Has anybody replicated a 'port block' style of milling machine?

More info?

Didnt think they used this on cnc machines, but I guess you can get a whole 120 degrees outta it so not bad. I figured control would be something linear like (ballscrew travel/total degrees)/steps per mm

tommy, it looks like centroid has a 5 axis mill that uses linear ballscrews for rotary motion, like those fancy laser adjustment stages.

Thats if I understand it correctly. I havent seen any diy implementations before but my interest is piqued now.

Ok, that explains a lot.
A balscrew and some good bearings can get pretty good tolerances compared to cheap gearboxes, so that might be one of the reasons for using this.

It would need some maths in the kinematics file to convert linear motion to the final angle, but it seems simple enough.

I think this is cooler: