I am doing VRC, and my robots drivetrain will not drive straight. I changed my controller controls to two different joy sticks, one for turning, and one for back and forth, but it still won’t go straight. I also used lubricant on both sides but it didn’t seem to help. When I turn the wheels with my hand, I notice that the left side has a little more friction than the right, but I left space in between so that it won’t have that much friction and so that I can still wiggle the wheels and gears back and fourth. Is there anything I can do? I have a four motor drive. Is there something I could do with the program? I don’t currently have one. Thank you!
Check if your drivetrain is square. This means, check if each c-channel is actually parallel. An easy way to test this is to take off the gear and/or wheel on the axle and individually check the free-spin of each axle. If the free-spin isn’t good, loosen the screws that hold the c-channels in place and use a 90º level to ensure that they are parallel before tightening those screws again. If the free-spin feels “notchy” be sure to check if you overtightened the bearings. If possible, I would highly recommend using screw joints as those provide much more tolerance for free-spin.
If you are still running into friction issues, take off each motor (having hot-swap motors helps a ton with this) and check if the gear cartridge and motor are running with minimal friction.
This process may take a deceptively long amount of time so be patient and good luck!
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You could attach potentiometers to your drive shafts and make motors going faster than others slow down accordingly.
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Your could also look and see if there are the same Moder cartridges and or one of the motors could be dead.
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check if your drive train is completely straight and there is no friction and there is plenty of space for wiggle room. Check your motors, shafts (if they are bent or not) and your overall shape. Teams have had problems with their c-channels bending inwards, or their drivetrain bending because of uneven parts
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Sometimes it’s just a bearing flat that is sitting funny and causing friction on the wheel shaft.
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Last season our team had the same problem, and we arrived to the conclusion that was strain in the drivetrain. A few days before of that problem we built a new estructure in the top of the robot, and this one was generaring strain in a few whells of the drivetrain. That meke that some whells were allways in contanc with the floor, and the ones with strain were in the air.
The solution for our problem was mesuaring with a spirit level all the c-channels. Some of them were not completely straight, the spirit level indicated that they were slightly inclined. If you don’t have a spirit level, there are mobile applications that, despite not being as precise, can get you out of trouble.
This solved the problem for our team, I hope it does the same for yours.
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Don’t use potentiometers, those don’t have a full 360 degrees reading. You will want to use encoders or rotation sensors.
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Sorry, I was writing this in a rush, you are indeed right.
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Thank you guys so much for all the help! After lots of debugging and reading over these replies, I did a few things and now my drivetrain can drive really straight. I changed my motors to hot swap motors, and it turns out that one of my shafts connected to the front right motor was bent causing it to not be in the the cartridge 100%, and maybe only 60%. Good luck this year!!!
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always is a bent shaft lol
POV you accidentally used that bent shaft for a 3600 rpm flywheel and it starts walking
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