Compact Slapper Ratchet

I am not using rubber bands. I’m using a double looped latex tubing loop. Is it better to use rubber bands?

Depends on how it’s used. For a puncher I think rubber bands are better, but for catapults or slappers latex is a good option. Personally I always had trouble replicating tension when I need to replace it. That however isn’t my point, I was curious about how much stress the motor hold is under. If it’s constantly fighting the tension of the tubing because of the hold it can stall your motor out pretty fast. Now if you tried it and it works, then you can’t argue with success, but I wouldn’t feel comfortable with using the hold. I also put off making a ratchet for a long time cause I thought it was gonna be challenging, but it was actually one of the easiest things to build for my bot.

I’m going to see because i only need to hold it down for 20 seconds max. Probably more like 5-10 secs.

As I said, can’t argue for success. Good luck.

I would personally use rubber bands. (As I assumed would be used) It’s just really easy to swap out rubber bands because the tension is almost always the same as the old(broken) rubber bands, given a bit of pre-stretching beforehand.
But, whatever works for you. I always expect everything on my robot to break, so I try to make most things somewhat easily interchangeable.

True. Theoretically you could have smaller sprockets on there and the effect should be the same.
It doesn’t add much width to the puncher itself

Your puncher should be able to work at least with 100 RPM cartridges at a 1:1 gear ratio. The puncher should have the efficiency to handle that. Theres no need to do a 1:5 gear ratio at all, also if youre spending the money to use sprockets as a ratchet might as well buy one online.
If youre building a slapper and need a ratchet for the slapper, put the ratchet right on the gear of the motor, as the ratchet is capable of handling torque a motor can turn. I would suggest potentially screwing lockbars onto the ratchet just to ensure that the ratchet will last through the stresses at worlds.

Oh I got a 12 tooth gear as a pawl to work, it fully works now.


glad to hear it!