Drill motor is attached to a screw shaft which moves a tapped cross bar back and forth along two horizontal rods.  The rods are bolted to four vertical legs that support the crane system.

A DC motor  is attached to a vertical screw shaft, connected to a tapped cross bar, which moves the comb up and down.

This is the two systems put together.  The box beneath the comb is where the spools will begin inside a six inch diameter circle.