Whilst waiting for my CNC controller to arrive, I had a rummage around in my junk box and found an old worm wheel gearbox.... Ahhh, CNC rotary table ? I had a look on Youtube and found another guy had done this mod and he mentioned his issue with backlash and requirement of a brake. I was looking round and spotted the hydraulic brake on an old mountain bike. OK might be over kill for this, but the principle is sound. How to implement this in 3D printed parts.
Body is easy, just a couple of blocks bolted together and attached to the gearbox somewhere. Next came the brake pads, as they aren't stopping the disc from spinning they just need to clamp the disc. Lets see see how contra rotating splined inserts will hold up, they can be operated from a small pneumatic cylinder/bellows or solenoid is my thinking. Anyone got any thoughts on suitable bellows for simple operation, bit like in a barograph.
Anyhow, some sketching later and I have this as a starter. Now it could easily be machined, but if the printed brake pads work it's such a quick solution even if they wear some. The disc will most likely be a small circular saw blade machined down or hard drive disc. As drawn the pads move 0.5mm with 45 degree movement on the arms, they will probably need a return spring to release the pads.