resetting window motor driven arm after each round

[Da Kid]

I have used cd search and looked other places but i can't seem to find a thread on this. since a window motor can't be backdriven we need a way to reset it after each round. we currently have this set-up for our arm.
A window motor is chained to the shaft with our arm on it. the arm is attached by having a metal tube slightly bigger than the shaft slipped over it with the arm welded to this tube. two bolts on each side of the arm go through the tube and the shaft to bind them together. The bolts will eventually be replaced with quick disconnect clips. these clips can be a quick fix for directly after each round by simply removing them but the shaft itself will still need to be reset before our next match. i know we can tether it in our pit and reset it that way but i'd prefer a mechanical fix since we might not have time to tether. i remember a time last year where we got done with a match, walked out of the arena, right past our pit, and we were immediately back in line for our next match. I read somewhere about a mechanical clutch but i don't know how that would be made or implemented
unfortunately our robot is bagged up right now but any help would be appreciated.