Hello! Our catapult has been working well, and consistently launching triballs into a pool next to the opposing goal. However, when we got to our first tournament, the catapult had almost half the power, and had about a 50/50 chance of even crossing over the bar. I’ve been tinkering with the catapult for a couple hours now, and it’s very arbitrary as to when it works and when it doesn’t. My speculations are that it’s a faulty motor, but I feel that if that were true, the catapult would never work as intended. So my second guess was a banding issue, but even if I don’t change the banding, the cata will sometimes stop working. I’m a little lost now, but I think the issue has something to do with the way we put the triballs into the catapult. So, any tips on how I can modify the design to make the catapult more consistent? Thanks!
We just switched out the motor base, but there was very little difference in the results. I have no way currently to test if the cartridge is the error, however, as I don’t have another cartridge.
The brain reads 100 RPM. When I test it with the catapult, it reads 1.1 Nm of torque… I don’t know if that’s correct for a cata, but the motor cannot handle that much torque.
what our team did was that we got a small gear, then a medium size gear, and then a large gear. I don’t work on mechanics a lot, but it seems that the design we chose prevent overheating of motor, and our cata is pretty consistant.
Adding on to what @evarikkad_thecoder said, you should gear down creating more torque, and shave off more teeth from your slip gear. Another thing is that you should keep the placement of the triball consistent, make sure your match loaders know how to put it. You can also try changing the orientation of the triball.
If it worked fine before, its probably not an issue with your gear ratio (also my team’s cata has less torque and it works fine). Because you replaced the motor and it still didn’t work it’s probably a friction problem, my guess is something got bent at your competition and now it rubs, adding a lot of friction. Try checking for anything that could have bent and unbending it
Thanks everyone for your help! I was in the process of trying to see if any parts were an issue, as per iseau’s soloution. Apparently the catapult had received so much use that the HS bearing flats had been chafed to the point where they weren’t even adding support.
You can use ball bearings which vex sells, (kinda expensive, but a more long term solution) but if u have the budget or already have them, they’re great and the HS axles fit right into the bearing.
if ur ratchet is banded try banding it with less force, but yes, ratchets will slightly slow down ur cats. But it shouldn’t be slowing it down significantly enough to cause an issue
I did not see a rachet in previous photos you sent. It could be the type of rachet. You might want to try using a sprocket, a standoff and a nylon spacer for a rachet if you aren’t using that already.
