He's added a fourth axis

[GeorgeD]

Deep groove ball bearings are intended to work only with radial forces and not with axial forces.

Metal shielded bearings are more efficient over rubber sealed as rubber sealed has more friction.

[GeorgeD]

Hi Irving,Ross

These tapered roller bearings are for the Lathe spindle as I'm aware the Deepgroove are not satisfactory for the lathe spindle.
This is common to the Mini lathes and the deepgroove come standard with the mini lathes.

[Smiler]

Got to admit here that I have built this very 4th axis. I use it on a router and have cut oak, beech and Iroko, it works perfectly well with a 6:1 reduction and a 3Nm stepper. Although the materials I have cut are a little harder than cheese, and I intend to try PVC an HDPE soon, you'd be mad to think of using it to cut metals.

It cost more to build than buying a rotary table and converting it; even given I am in the happy position of getting the main shaft, backplate and ally plates etc for free. I used my router to machine the plates and the lathe at work to bore the backplate for the chuck and it STILL cost more than a bought solution but I'm happy as it was a good excersise.

Jeff.