Something wrong with our robot

  1. last week

    Rocket

    Jan 8 60466A

    We don't know what's wrong with our bot, because the bot works fine but everytime we compete with it; it starts to act up by stopping the left side wheels and the right side works but the left side stops and everything function just fine and we use all aluminum for the bot too and we have six motors powering the wheels and 2 motors for the ball shooter and 1 motor powering the ball intake and we aren't using v5 yet and we are using two batteries and a battery snap as well and the 6 motors for the wheels are high speed and when we are messing with it, it works fine but once we compete with it, it stops the left side and it even broke the breakers in the brain.

    @Rocket We don't know what's wrong with our bot, because the bot works fine but everytime we compete with it; it starts to act up by stopping the left side wheels and the right side works but the left side stops and everything function just fine and we use all aluminum for the bot too and we have six motors powering the wheels and 2 motors for the ball shooter and 1 motor powering the ball intake and we aren't using v5 yet and we are using two batteries and a battery snap as well and the 6 motors for the wheels are high speed and when we are messing with it, it works fine but once we compete with it, it stops the left side and it even broke the breakers in the brain.

    Punctuation is awesome :)

    It could be a hardware problem, an electrical problem, or a software problem. With reasonable gearing, 6 motors is plenty to run a normal chassis for two minutes, so you should probably test for each kind of issue independently.

    The most common hardware problem that causes stalling is friction. Take your motors off and give your wheels a spin. If they only free spin for a second or two, there is too much friction. You will need to diagnose what is causing the friction and fix it. (Usually a dead bearing flat or an over-tightened chain from my experience.) If the wheels spin for over 10 seconds, friction isn't the issue.

    It could also be a software problem. I'm not going to pretend to be an amazing coder, but there are plenty of them on the forum. Share your code :D

    And if it's an electrical issue, there's not as easy a way to diagnose it. If a motor is blown, that's easy enough to test for (just write a test program that spins each motor, one at a time), but the motors could be old and spinning at low power, there could be a physical problem with the PTC or the motor controller, or even with the brain. If it is an electrical issue and the motors are all working well, your best bet is probably just to replace all of the electronics on that part of the robot.

    Good luck!

  2. What gearing ratio do you have in your drive motors, and what external gear ratio are you using for your drive motors? If you unmount the motors from the left side of the drive, can you spin the wheels and have them continue spinning for several seconds, or are they hard to turn? Do any of the motors have frayed wires where the wire meets the motor casing? (Check inside of the rubber strain reliever, too. This can be done by carefully removing the back plate of the motor, then sliding the reliever up or down the wire a bit to see what it was covering.)

  3. callen

    Jan 8 Braintree, MA, USA

    Could possibly be static issues? If so, maybe try dragging a little metal?

  4. Xenon

    Jan 8 Long Beach, California 99999V

    code please?

  5. Add 2 motors to your drivetrain? Maybe you are stalling from pushing...

  6. meepmeepme

    Jan 8 Honolulu, Hawaii (Saint Louis ... 42700B/C

    Check if your axles are pushed in all the way. Happened to me too many times this season.

  7. Mark Finley

    Jan 8 Las Vegas, Nevada 6891B - Kep's Boys

    When you are testing it do you plug it into a competition switch? It could be something in the code format that doesn't work with the tournament setup.

  8. josh_siegel

    Jan 8 Davis, California 162A Mentor/Alumni

    Real quick off the top of my head: Test the motors, test the cortex, test the motor controllers, check to see if the wheel inserts are stripped, check the wire connections, check for frayed wires, test for friction, check that the axles are pushed into the motors, test that the wires are plugged in the correct direction, check the code for stupid errors. 6 motor drive should be either high speed on 4 inch wheels or turbo on 3.25 inch wheels with a light robot.

  9. Anomaly

    Jan 8 Answer

    @Rocket We don't know what's wrong with our bot, because the bot works fine but everytime we compete with it; it starts to act up by stopping the left side wheels and the right side works but the left side stops and everything function just fine and we use all aluminum for the bot too and we have six motors powering the wheels and 2 motors for the ball shooter and 1 motor powering the ball intake and we aren't using v5 yet and we are using two batteries and a battery snap as well and the 6 motors for the wheels are high speed and when we are messing with it, it works fine but once we compete with it, it stops the left side and it even broke the breakers in the brain.

    Punctuation is awesome :)

    It could be a hardware problem, an electrical problem, or a software problem. With reasonable gearing, 6 motors is plenty to run a normal chassis for two minutes, so you should probably test for each kind of issue independently.

    The most common hardware problem that causes stalling is friction. Take your motors off and give your wheels a spin. If they only free spin for a second or two, there is too much friction. You will need to diagnose what is causing the friction and fix it. (Usually a dead bearing flat or an over-tightened chain from my experience.) If the wheels spin for over 10 seconds, friction isn't the issue.

    It could also be a software problem. I'm not going to pretend to be an amazing coder, but there are plenty of them on the forum. Share your code :D

    And if it's an electrical issue, there's not as easy a way to diagnose it. If a motor is blown, that's easy enough to test for (just write a test program that spins each motor, one at a time), but the motors could be old and spinning at low power, there could be a physical problem with the PTC or the motor controller, or even with the brain. If it is an electrical issue and the motors are all working well, your best bet is probably just to replace all of the electronics on that part of the robot.

    Good luck!

  10. Rocket

    Jan 8 60466A

    @Mark Finley When you are testing it do you plug it into a competition switch? It could be something in the code format that doesn't work with the tournament setup.

    -We barely had the chance to test it

  11. @Rocket We don't know what's wrong with our bot, because the bot works fine but everytime we compete with it; it starts to act up by stopping the left side wheels and the right side works but the left side stops and everything function just fine and we use all aluminum for the bot too and we have six motors powering the wheels and 2 motors for the ball shooter and 1 motor powering the ball intake and we aren't using v5 yet and we are using two batteries and a battery snap as well and the 6 motors for the wheels are high speed and when we are messing with it, it works fine but once we compete with it, it stops the left side and it even broke the breakers in the brain.

    Ah yes, The problem my team ran into, You see here is your problem you must decrease the speed of your wheels to 90, You probably have them at 120, Our own cortex also broke it's breakers because we have everything run at 120, You need to have everything at 90 or have your ball shoot and intake at the max while your wheels are 90.

  12. TaranMayer

    Jan 8 Arizona 6142w

    @Rocket We don't know what's wrong with our bot, because the bot works fine but everytime we compete with it; it starts to act up by stopping the left side wheels and the right side works but the left side stops and everything function just fine and we use all aluminum for the bot too and we have six motors powering the wheels and 2 motors for the ball shooter and 1 motor powering the ball intake and we aren't using v5 yet and we are using two batteries and a battery snap as well and the 6 motors for the wheels are high speed and when we are messing with it, it works fine but once we compete with it, it stops the left side and it even broke the breakers in the brain.

    It happened to us - turns out the issue was a glowing red mc29. Check all your motor controllers, and do a complete rewire of the robot. Also, don't use ports 1 and 10 for drive motors.

 

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