We’re a young middle-school team that uses V5 for competition. We have built the “Crunch” hero robot published by VEX, and are running the pre-installed default code in the V5 brain.
We’ve recently developed a problem, and have no idea what is happening. The lift arm suddenly became semi-frozen and “jittery” on the lift operation. The arm will raise a couple of inches, then stop, with a lot of vibration and jerking, if the lift control is held down. We have found that by repeatedly pressing and releasing the button, the motor will barely activate, lifting the arm by about a sixteenth of an inch every time it’s activated. Our high-school team has build the same robot, and experienced the same problem before we did. They replaced the motor, it worked fine for a bit, then started doing it again. They swapped out the brain, same results - it worked fine for a while, then started doing it again.
With my kids, almost the same story - we swapped out the motor, no improvement. We swapped the brain about 30 minutes ago, and as of this writing, it’s working OK, but…
Can anyone offer any insight as to what is actually going on here, and what might we do to correct the situation? Thank you!!