Drivetrain problems


#1

Hi guys we have a problem with drivetrain. After 30 seconds of turning the left site of drivetrain is just dying. Video with problem - https://youtu.be/7Se69cJUctA
Both sites are absolutely simular but only right is working correctly. It also isn’t about the weight because we had the same problem when we removed everything else from robot. Problem is also not about the motors - we’ve already checked them.
Picture of drivetrain below (just to prevent issues wuth left/right in the picture - the working site has shaft encoder and problematic doesn’t.
photo_2019-03-14_22-39-44


#2

Try to switch around the ports you’re driving it with. Also, just write a simple drive forward code and try to see if the problem persists.

It could be that you’re tripping a PTC, but I’m not sure why one side would burn out first. It’d have to be varying friction.


#3

So the first thing I notice is that a lot of your build isn’t square. a couple of the pieces are at a strange angle when they probably shouldn’t be. Over time this will add small amounts of friction that the small cortex motors won’t be able to handle. On the left side of the chassis the C-channel is leaning left slightly. I would recommend that you go and make sure everything on your chassis is either parallel or perpendicular except for a few small exceptions.


#4

^^^^^^^^^
I assumed it was just the angle of the picture (mine have also been distorted over the forums), but I think that this may be right. It’s most likely the friction. But if not, try to swap out the Cortex or change around the ports.


#5

Check for a bent shaft . This could happen because the frame is not square (as mentioned), particularly the third beam from the right. If all the beams that the shafts go through are not parallel, then the shaft must bend to fit. Bent shafts are high friction and will cause the motor to stall.

Also write a program to test each motor separately. You do have two motors connected to the same wheel. It may move fine with only one motor, but that will cause the other motor to stall quickly.


#6

The base definitely seems like it just has too much friction. You want to make sure that everything is 100% square and solid. If pieces can move around, you want to add some support to those so they can’t bend out of place. Even slight distortions or misaligned axle will cause immense amounts of friction.


#7

a good rule of thumb is that without any motors attached, the wheels should be able to spin freely.


#8

A good test you can try is the ten second spin test. If you disconnect your wheel from your axel and the rest of your drive train, you should be able to spin it and it will keep spinning for at least ten seconds. Anywhere below that and you can determine that it’s somewhere on that axel. If not you problem is somewhere else.