My team’s VEX-U robot is having an issue where if you put an electrical load on certain subsystems, the motors will begin twitching. As we have a competition on Friday, we would like your input. Here are some details about our robot:
- Four motor shooter (ports 2, 3, 4 and 5 not on a power expander), sensed by one rotary encoder
- Four mechanically and electrically separated parts of an intake plugged into ports 1, 8, 9 and 10, no sensors and not off of the power expander
- A four motor flywheel, signal from two ports on the cortex, Y’ed off to four ports in the power expander, ports 6 and 7, sensed by a rotary encoder. The shooter is currently controlled through a proportional controller with a feed forward term, it takes longer for the shooter to twitch if the proportional coefficient is reduced.
- A pneumatically actuated ramp, solenoid in port 7.
- When the drive starts twitching, we lose the entire drive and the intake motor plugged into port one, indicating that it is probably a problem with the breaker in the cortex.
- When we lose the shooter, only the shooter goes out.
- The issue is only evident when mechanical load is put on the system (the shooter turning on, changing directions quickly on the drivetrain)
- Our wiring is a bit of a mess but I insulated everything I could and the problem persisted, we will clean it up and post and update when that happens.
- The effected motors do not return to normal after a power cycle, again, indicating that a breaker is tripping.
- We have replaced the cortex and this did not help, we have not, but probably will replace the power expander.
- We are programming in PROS.
- Joystick and cortex lights do not change while the motors are twitching.
Thank you for any help you can provide, if you would like some more details, I would be happy to provide them.
UWM Panthers VEX-U