basically, the purpose of ratchet is just to stop the gear from turning back.
There are many ways of doing that. My teams had even used just a simple piece of metal (angled at the correct direction) to just stop the gear from turning back.
The pic attached above is the best close up shot that we have.
there was a period when the high strength gears were not gripping or sitting nicely with the 12-tooth pinion.
not sure if they have improved the quality, but we put 2 low strength gears together ever since then.
Amazing robots I was very impressed with the double catapult, this inspired our team to make one of our own (which we discovered to be quite difficult) Overall amazing job.