Fantastic, the structure looks like simple and useful.
I want to do a machine that shapes disks to use in the cover of tank used in trucks that transport water.
Can you post more photos that show the machine structure?
The motors are actually fairly small, I can't find the specs for these just now but they are about the size of 2 tuna cans, and standard 200 steps/rev. They are very strong though, magnets have improved since my mill was built. They are each geared down 4:1 to a 5tpi 25mm ballscrew.
The bearing blocks, rails and ballscrews are all from HiWin. The stepper driver is a RoutOut unit similar to the one on my mill. It didn't need to move quickly, just steadily and accurately.
The wood stuffed under the rail was to damp a vibration which occured periodically as turning progressed. The setup lacked rigidity and if I was to do it again I'd fabricate a rail based on some of the 20" hot finished steel CHS we use here, and probably filled it with concrete. We also experienced resonance in the tool and were forced to adjust the spindle speed to dial it out. It was quite a job. I needed a good long sleep afterwards.
Afterwards we removed 600kg of swarf from the pit.
Chrisjh - Both techniques are still in use, we spin ours but larger sizes are hydroformed here and in the US. Stretch forming is also widely used, it works for the bigger segmented reflectors. Composites are also widely used but they have problems all of their own.