[ksafin]

Originally Posted by Whippet

You *could* use an Andymark WormBox as the input on one of the shifter gearboxes, essentially preventing the winch from back driving. However, that would probably reduce the speed of the output to something too slow to be usable, so it would be necessary to replace the gears in the shifter to have no reduction, rather than the stock reduction used.

This would probably be the easiest way.

The strength of 3D printed parts is always in question, but given that AndyMark's wormgear gearbox uses plastic gears, you can probably CAD up some gear to do what Whippet is saying and have a 1:1 ratio.

Use 100% infill and ABS and it should be sturdy enough.