welding positioner, rotating table

[radom]

I was thinking about building small bench type welding positioner for a long time but when I found this big lathe chuck for cheap I changed my design a bit
I made the positioner that I can insert 80mm pipe through it, although chuck have through hole of 100mm
this limitation is only because I already had the materials and could make bearing housings on my small lathe
there is also a trust bearing directly under the face plate
I mainly tig weld so the speed is quite slow around 1,2rpm max, it's 12v dc motor with pwm speed controller
ideally you would have worm drive because it's self locking but I couldn't find one at the time, maybe I will change that in the future
motor, sprocket and ground wire are isolated from the frame (small sprocket is mounted on nylon shaft)