How do those winch-loaded shooters work?

[Mr_I]

Originally Posted by Jeffy

This is I think the 3rd time I have tried to figure out that linkage, and it clicked, I get it, and realize how simple it really is. It does require a non-backdriveable transmission though, correct?

While a non-backdrivable transmission will do the trick, it can be done without. If you consider how the linkages work, when the main sprocket is at the "ready to fire" position, there is very little force driving the sprocket either forward or backward. If you use a position sensor that can stop the sprocket at this "ready" location, the sprocket won't move until you say "fire!" and push it just past this point.