I’m trying to find an effective way to hold the slapper arm down so I can shoot faster in the match. I have tried using the vex ratchet and pawl and it wasn’t strong enough. I was wondering what alternatives you guys are using. Pretty much the same mechanism as most double catapults. It’s a 12 tooth driving a 60 tooth slip gear.
@Atomic Okay, I scrounged up This post and it has the best picture I have of it and an accompanying explanation. Here’s the picture from it for quicker reference.
Edit to add information:
There is an axle inside of those gussets constantly pulling down on the 6t sprocket. The way the ratchet spins, the axle holds the sprocket, and thusly the slipgear it’s mounted to, in place. Hence being effective.
So my team built a 2bc for states and we used 2 motors: 12t driving 36t that was on the same axle as a 36t slip gear that drove the 60t catapult. that was enough to use a pot to use a fire and draw back loop. aka the motors were strong enough for us.
It just depends on the application. If you heard it on here, it might’ve been me saying it. Others have had success with it, but I still would go for a ratchet as a backup to take some strain off of the (delicate and somewhat scarce) motors.
At the time, breaking a V5 motor was bad news because it was difficult and time-consuming to get a replacement. But now it’s not so bad, and I might consider risking it, depending on the gear ratio.
Basically we had a potentiometer on the catapult beam and a loop that drew back the catapult, then if I pressed button 6U it would run until the potentiometer returned to its original value. (the gear slipped) then it would run the motors until it reached that same set value, drawing it back and holding it there until the next button press.
I’m not sure how much this helps, but I’ve made some rlly effective ratchets by simply placing a sprocket at the end of the axle and then using screws to line up pillow bearings right alongside it. Then, I just slip a rubber band in and tension it the way I want to. One point of contact might not be enough to hold that force, but for me 2 is enough.