Winches and alternatives to the modulox lunchbox?

[bs7280]

Our team has been pretty stuck this year on winches and on how to pull back a catapult. We originally wanted to go for a non-backdrive winch/gearbox with a clutch, that way we have total control over the power of the shot. We have decided that this is not necessary/reasonably possible, so we decided that we wanted to use the modulox lunchbox like in the robot in 3 days video. Of course they are out of stock now, so that is no longer an option.

So, Can someone please recommend an alternative to the modulox lunchbox, like the one used in the robot in 3 days video?