[nixiebunny]

My cohorts came up with a nice way to make the winch safe for our surgical-tubing powered shooter. We use a VexPro shifting gearbox, with one speed converted to neutral by removing the three balls from inside its output gear.

We only allow the software to shift the winch to neutral right before firing it. So it will be in gear when idle, such as after the match ends. That way, when the cocked shooter's trigger is released by hand, the winch cable will back-drive the motors through the gearbox, which absorbs a lot of energy and releases slowly and safely.

We've tested it and it works.

We will work on making it easy to visually determine if the gearbox is in the right gear. We may add a flag to the shifter so that it looks red when it's not safe.