2 Way Ratchet Mechanism or 'Mungomotor'

I was thinking of a way to remove the Z-axis motor from a RepStrap machine, and instead use the X-axis to ratchet the boom up and down by traveling to its extremetries and \'pushing\' a ratchet mechanism.

Pushing the red frame from one end will turn the captive nut by 90 degrees, pushing the other end turns -90 degrees. This would result in a distance of around 0.3mm travel on a standard M8 thread.

It may also be usable as a mechanical stepper motor with the frame driven by a solenoid and