Do stock electric brakes normally not work in reverse?

[Cate&Rob]

howson
Internal drum brakes are a unique thing. The brakes "SELF ACTUATE" partially as the top of the shoe in the direction of rotation comes in contact with the internal of the drum. In and IDEAL situation, the shoes would actuate at opposing ends. Meaning: Going forward, the front shoe top would contact the drum and the bottom of the rear shoe would contact the drum.

This is exactly what happens. If you watch the attachment to Howard's post, you can see the actuation of the top of the front shoe, followed by the bottom of the front shoe pushing out the bottom of the rear shoe. Ted's attachment shows the top of the rear shoe being pushed out first in reverse.

Rob

[Lonestar]

Does the speed of the rotation of the wheel have anything to do with how much braking force is applied? I've wondered if even though the magnet should adhere to the drum when voltage is applied, will a slow spinning drum really allow the shoes to be expanded with same force as if you are going down the road at 50 mph.

[Jlawles2]

Lonestar I think braking force is controlled by magnet strength. As voltage is increased the holding force of the magnet is increased, which increases friction, thus more force applied to the end of the arm. Ideally at 0 movement of magnet to drum the force at the arm will be the highest as static friction is higher than dynamic friction.

[Scott'n'Wendy]

Does virtually nothing in reverse. Crank your controller to max and back up. What happens? On my trailer.... nothing. Go forward, instant lock up.

[Yoda]

Does virtually nothing in reverse. Crank your controller to max and back up. What happens? On my trailer.... nothing. Go forward, instant lock up.

Yep that's exactly what happened - was using the manual control (max gain) for the pull test.

[Scott'n'Wendy]

Yep that's exactly what happened - was using the manual control (max gain) for the pull test.

And that's the way it is designed to work. No one expects you to be doing more than one or two mph backing up.