Stalling a motor

[Yalib]

hi,
We are thinking about stalling the drivetrain motors in order to brake the robot on the bridge while balancing.. does it damage the motors or the battery?

[AllenGregoryIV]

Are you planning to run them against a physical stop to stall them? I'm not sure why you would want to do this. You can definitely hurt your motors stalling them for long periods of time. You will also consume a great deal of power doing this.

Look into PID position control for an electronic wheel lock that will not hurt your motors. Also teams have had success in the past with physical wheel locks. Such as Team 25's application of using a servo to push a pin into holes they drilled into their drive gears.

[Al Skierkiewicz]

Yalib,
I am guessing your real question is lost a little in the translation. If you are asking if you can add a short across the motor to prevent movement, the answer is no that is prevented through the rule...
[R47]
Custom circuits shall not directly alter the power pathways between the battery, PD Board, speed controllers,
relays, motors, or other elements of the Robot control system (including the power pathways to other sensors or
circuits).
The "brake mode" jumper on speed controllers does the same thing, legally. However, the brake is dependent on current flowing in the motor. When the motors are stopped, no current flows so the brake doesn't work either. There are ways you can actively lock the motors via software. This requires some accurate position feedback from the wheels or motors you are trying to lock. Performing a lock through software is legal but only takes place while the robot is enabled.
Electric solenoid actuators are legal this year. You can use them to hold mechanical locking devices (pins as above) out of the drive train and then turn them off to allow a spring return to drop the locking device into place in your drive train.

[Retired Starman]

Sounds like a possible use for those electric solenoids we can use this year!!!

Dr. Bob

Chairman's Award is not about building the robot. Every team builds a robot.