Hey! So our team just finished our worlds rebuild. It’s a meta bot with 2 air tanks and weighs roughly 20 pounds. We are running a 6 motor drive with a 5:3 gear ratio on 200 rpm motors, for a final rpm of 333. However, our motors get hot to the point that we can climb/barley move in literally 3 mins and 30 seconds. Anyone have thoughts on what might be going on? Wheels are free spinning for over 20 seconds and our base integrity is very strong as well. Any help is greatly appreciated!
20lbs seems like it’s too heavy. are you using screw joints or axles on wheels?
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Axels. And last year we had a 13 pound robot on 600 rpm and that could go for a very long time…
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How many gears are in the gear train? If it’s really long, that might be the issue. Just because individual wheels can spin for a decent length doesn’t there is still friction.
Also, what size wheels? I’m assuming 3.25. If it’s on 4" wheels, that may be too fast.
The weight sounds okay for a 6 motor drive. I had a 21 lb robot with a 6 motor 257 on 4" wheels this season and was totally fine (could drive for 2 hours and motors would barely be warm at all.
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True, the gear chain is fairly long, but we focused on friction reduction during the build and made sure everything was as smooth as possible. The wheels are 4in. I realized we used our old brain which was on a super old OS, and updating it seemed to make it a bit better. Thanks for the advice!
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4” wheels on 333 rpm, on a 20lb robot is pushing it, even on 6 motors. might want to give a more reasonable ratio a try, like 280 or 257.
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Were you testing your bot with or without goals? If you were testing it with then that would partially explain why your robot heats up faster than a 13 lb robot at 600rpm in previous seasons as not only is your robot 20 lbs but the goals themselves are heavier than previous season field elements adding to the weight of the robot.
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333 on 4 inch wheels in the first place with mobile goals is pushing it. from my experience 280 will work well 7:5 200rpm motor cartridge
you could either change the ratio, or you could switch to 3.25 wheels as thats what 333-360 requires to not overheat
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