You can see more thermal pictures in the general Mill-Turn thread, but my spindle is really noisy and runs much hotter then it should. I've also got some build quality concerns because the mounting face of it was messed up by the factory in order to 'tram' the spindle and the access hole for the pin is too small to actually do any adjustments.


I reached out to the guys who did the "how to build a CNC from scratch" thread, SkyFireCNC about getting a little higher quality spindle made. Their R8-80 spindle was almost the same size as the unit in the Mill-Turn and it comes standard setup for 6k rpm with optional 10k rpm bearings/balancing. It uses double angular contact bearings top and bottom instead of the single bearings in my Mill-Yurn. They also use an HTD style timing belt on their spindles, so I've requested a matching pulley for the stock motor with a 2:1 ratio. Right now my machine struggles/surges to reach the advertised 5k rpm (at the spindle) which is right at the ~120Hz/3600rpm upper limit @ the motor. The new 2:1 ratio should move the max rpm up to ~7k rpm without much of a drop in low-speed torque and with the timing belt, tensioning shouldn't be as finicky. I think it should fit between a 114-116 tooth 25mm wide HTD(5mm) belt.

I've also designed up a simple mounting system for SkyFIre's power-drawbar (QTC system) which I believe is compatible with the real Tormach (TTS) system. I'll be releasing my adapter design files on Thingiverse. It's already been published and licensed under the Creative-Commons-Non-Commercial-Share-alike terms.

Let me know if you're interested in participating in a group buy, there's already at least a couple others.