This winch tows hang gliders from the ground to up to 2500 feet. I assisted the owner of this winch in it's initial designs and manufactured some critical parts for its level winding mechanism.
Simple MathCad calculations to determine the pressure on the drum.
For any spool winding string it is important to shift the winding evenly across the spool. This is achieved by using a gear and chain system and a link which can shift the winding pulleys back and forth across the spool.
The installed piece for the level winder.