So, I tried making a ratchet for my first ever catapult. I tried a high-strength 36-tooth gear as the screw would go against. But for some reason, it didn’t work for some reason. I tried a sprocket but didn’t work either. I want the ratchet to hold down the catapult as loaded and ready to shoot for match loads and for during the game. This is my first time making a catapult.
It’s not the code, but the entire robot build for the catapult isn’t working. I’ve tried a screw in a shaft collar mounted to the Cata build and it’s being pulled by rubber bands tensioned. I don’t get it why it doesn’t work!
Can you send a picture?
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I didn’t take a picture when I had my robot. I’ll send a picture tomorrow, but I think I figured out the problem. I was using a 36 High Strength Gear instead of a 12-tooth metal gear. I’ll try it out tomorrow and i’ll send a picture.
Specifically where is the ratchet. Is it in front of the cata gear?
When we had a cata on our bot we had a red 100rpm 11 watt motor driven 36 tooth gear that was stripped 12 teeth running to a like a 72 tooth gear and on the same shaft of the stripped 36 tooth gear we had another high strength 36 tooth gear and we used a standoff on a shaft in front of the high strength gear and it was tensioned back by rubber bands and when our stripped 36 rotated it slipped after bringing the cata back far enough and it would go back into position. However the ratchet was not able to rotate the other way because of the rubber-bands and however far we rotated the catapult back, unless it slipped, the ratchet being tensioned on the gear would hold it in place.
it’s on the outside rather than the inside because I never planned to have a ratchet involved with the cata, so I put it on the outside.
I understand! We did try at one of our comps with the cata still on to do what your describing and we only had room to do it from the outside and it also didn’t work for us. It later ended up just being the position of the ratchet and it just couldn’t get enough tension. So to make it work on the outside, I’m assuming you have a gear or sprocket on the same shaft as the slip gear so just try doing what I described by having it in front of the gear lowered down a little and tension it with rubber bands going in the backwards direction from the ratchet and at a downward angle
I really don’t know what else you could do without me seeing it though.
Happy to help though!
Instead of a 32-tooth gear, should I use a 12-tooth metal gear instead? Would there be any difference and how strong should the screw be tensioned? Should I wrap it around more than 2 times? I’m about to get to my robot so it would be good to know what to use instead of not knowing.
Yes! I recommend using a 12 tooth metal gear for the ratchet considering the wear that the ratchet screw would make on a regular gear or high strength 32! Also tension the ratchet screw with like two rubber-bands and double them up like wrap them over each other for more tightness!
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I was not aware that VEX now makes 32-tooth gears, good to know.
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I must’ve gotten it wrong, but we both meant the 36-tooth gears. If you look at the V5 gears page, it shows a 24-tooth metal gear to 36-tooth high strength. " Gears - VEX Robotics"
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So sorry!! Meant to say 36
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(post deleted by author)
Wesley,
This is a good example of what I am talking about here. The user already realized they made a mistake& corrected themselves. Your post does not provide any additional content to the conversation occuring. Please work to improve your posts’ content moving forward.
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