4th axis brake enquiry

[Voicecoil]

They look like a top bit of kit - accurate to about 0.1 degree if I've read the Ondrives data correctly.

[m_c]

I just remembered I bought a few of these a few years ago. Very high quality wormscrew mechanisms. Might be worth a tryout
Rino Ondrives Worm Gear Reducer 30:1 Vexta Nema23

They're certainly worth trying.

They look like a top bit of kit - accurate to about 0.1 degree if I've read the Ondrives data correctly.

Looking at the OnDrive website for Nema mount version, it looks like you can get either an 8 arc minute, and a 30 arc minute version, which is 0.1333, or 0.5 degrees.
It all depends what kind of accuracy is needed. 0.5 deg works out about 1.3mm of movement at a 300mm diameter. Off course the 0.5deg figure is the worst case scenario.

[marbles]

Just out of interest i've knocked up this manual trunnion positioner to allow me to 5 faces foamboard up to 750x400x200mm. Ideally yes this would all be automated one day with the OnDrive Rino units I have but in these COVid times i'm doing a temp improvisation with what i've got in the workshop to test the proof of concept. Hopefully one day this will be a fully automated unit with amazing holding torque and a brake but for now just got to test it works. Watch this space for an update.

I should point out the top plate is attached to the foamboard with jumbo helical insulation screws and that plate is mounted to a 360 deg turntable, which should allow for quick changeover of stock. I have afterall got 144, 5-sided parts to mill!!