Talon Speed Controlers

[golucky66]

I was wondering if anyone out there has played for the brake and coast function on these controls? My team was wondering how well the brake function of the talon on a CIM motor.
But has anyone played with this function yet?

[cgmv123]

The brake function shorts the leads of the motor together. You're effectively generating opposing current when you turn the motor. Because of resistance and friction, it's able to be overcome, so it isn't a perfect brake.

[GeeTwo]

While I haven't tried it with Talons specifically, I have seen a definite difference between the two cases just playing with the motors not under power and shorting them out. Since the resistance is constant and the voltage generated is proportional to the rotational speed, the amount of energy dissipated should increase with the square of the rotational speed. That means it will probably be pretty good at getting the robot from full speed down to a crawl (though the motor will heat up as it absorbs the energy!) but it won't be so good at resisting a slow steady force.
I have considered using shorted-out motors as a brake to a catching device for just this reason; if we don't need all of our allowed thirty pounds of manufactured parts for spares, we may look at this as a post-stop-build project.

[RobotDoktor]

The Talons on our drivetrain are set on brake and it stops on a dime when you let off throttle. If you are trying to keep the CIM stopped against a constant force, like in a winch, it might not work so well.