Motors quitting

Dear Vexers,

Why do my motors stop working when I push against mobile goals? The motors are connected to a power expander that is connected to ports 6 and 7. Is there any way I can fix this? Also, why does my robot quit working when I push against something stationary like a wall? How can I fix this? Does this have to do with the amount the battery is charged?

You are tripping your motor’s PTCs

These links should help.

Your motors are stalling because you’re asking more of them than they can do. They will DEFINITELY stall when you push on something like a wall – the motor internal gears are trying to turn, but the wall is preventing that from happening, and so the motor cuts out before it damages itself. Please see these 2 posts: