[dez250]

The 120-amp marine style breaker is not designed for what we use them as. When we use them as an on/off switch and continually they wear out and can fail quite easily. The main spring that keeps them "engaged" is less than a 1/4" long and weighs only a few grams, will fatigue quickly. If you welded the nut on this to a bolt, I would suggest not only to swap it out for a new one, but also check for chassis grounding, especially with use of the Banebot 775 motors.

Many recent production 775 motors have been found to have a case short, which leads to chassis grounding if the motor is mounted directly to a metal frame. We found a team that showed no signs of damage to their robot this past weekend in DC that was chassis grounded through a 775 and had all ready competed at a prior regional with this issue existing. After going through their five 775 motors they had in stock, only two were not case shorted.