Motor tripping or stalling?

Hi friends
We are currently having an issue regarding the motors stalling/overheating, we are not sure. About two weeks ago our robot performed fine and had no issues but now we do. We have a 6 motor high speed lift on a 1:5 external gear set, 4 motor direct high speed base, and a piston claw.

Here is our motor setup.

P1 Lift Left Front
P2 Base Left Back (Power Expander)
P3 Base Left Front (Power Expander)
P4 Lift Left Back
P5 Life Left Bottom
P6 Base Right Front
P7 Base Right Back
P8 Lift Right Back (Power Expander)
P9 Lift Right Bottom (Power Expander)
P10 Lift Right Front

Recently, as we are practicing the base motors on the power expander side stop working while the base motors directly into the cortex still continue to run. At first we thought it was just a bad power expander, so we replaced it two times and it still didint work. We are pretty sure our wiring is correct but the reason we say stalling/overheating is because we arent sure if the motors are actually stalling our because of stress, or because we are drawing too much current out of a breaker. We find this frustrating because it worked perfectly fine until now and we arent sure how to fix it. We haven’t done any major maintenance on it in about a week, because everything appears to be in good and now loose screws on the robot. Is this problem caused by breaking circuits, over stressing the motors, mechanical issues? Any tips or suggestions would be greatly appreciated.

Try not to have 4 motors on the power expander. Especially since sometimes u run lift and base.

From our testing, the power expander will trip faster than the cortex. Try this config:
P2P7P5P9 on power expander. That should be easier for it. Unfortunately, the only motors on the cortex will ALL be running at the same time, which can we super hard to manage.

Could you elaborate more on that? I’m not entirely sure what you mean by not having 4 motors, wouldn’t that just load up the other circuits?

Okay, i’ll try this config, unfortunately i don’t have direct access to the robot currently but ill definitely give it a try.

He means the Power Expander trips at a lower Amperage/Wattage/Voltage than the two cortex breakers

We had something like this, and I fixed the problem by connecting four of the lift motors to the power expander (one motor per port) and the other two running off of the cortex (but not on the same PTC as the drive, ports 1-5 and 6-10 have different PTC’s). Our lift doesn’t use high speed motors, but it is still capable of getting objects in the far zone. We have yet to have problems with it overheating, even after running non-stop for 30+ minutes. Another thing that might help, allow the lift to come back down slowly. Don’t use motor power to make it go down. Also try to avoid allowing the lift to come down too fast, as this can add energy into the motor and can cause it to overheat. How are the gears and motors arranged? This might also be a factor. Ours is set up like in the picture below. The gears to the side of the large gear is spaced so that if there is too much resistance, it will start to slip so that your motors don’t overheat. If you continue to have trouble, please contact me and I will try to help as much as I can.
Screenshot 2017-03-06 at 3.24.47 PM.png

As what I can tell, the left side of your lift is on the CORTEX, and the right side of your lift is on the expander. It is best to put one sub-set on one power source instead of putting it on different batteries. If one battery is dead, practically both your drive and your lift will fail. But most probably your lift will fail the easiest compared to the drive.

I, personally, suggest that you put all lift motors on the expander and the rest of the motors on your CORTEX. The lift is what consumes the most power out of your entire robot because it is practically under heavy load almost always.