It’s not a real master caster but a 1” box tube copy of one I made and yes it’s a gear motor that runs it.
There are two timers and switches. One switch activates a timer & relay that when energized opens the circuit, stopping the gear motor while at the same time energizing the coil on the solenoid pouring the lead. When it times out, lead is stopped and power is returned to the gear motor.
The other switch/timer is to allow for cool down if needed.