I built a rotary welding table using a recycled motor drive assembly from an old filament winder. The stepper motor, motor driver, chain drive system and chuck were all salvaged from the dumpster.
The system uses an Arduino paired with a potentiometer to control speed and two switches to control ON/OFF and direction.
The table makes it super easy to maintain consistent weld beads on circular weld joints, especially when performing repetitive welding operations.