This is a welding positioner I built recently.  Well actually completed recently.  I used a treadmill motor run through a 100:1 speed reduction gearbox to turn the table.  It will turn as slow as 1/4 turn per minute.  Of course the Redneck plastic tool box was used for the electronics.

I machined the spindle with the 5mm pitch thread to allow me to screw on the flat table or a three jaw chuck.  On the flat table I machined circular shallow groves to help align the part to center.

There is a handle on the back side of the table that I just have to lift and swing down the support leg to put in several locations to allow for horizontal welding.

The arm rest slips into the 50x50mm uprights to allow for me to use either hand for welding which I do quite often.

The table rotation direction is reversible also.

It looks quite funky because I sprayed with with phosphoric acid in preparation for painting which obviously isn't done yet.