How does a drag brake work?

[dmcchaser]

I'm wondering how a drag brake on a brushed motor works.
I understand the function and why one is recommended, I am curious about how it works electrically.
I'm still running the stock axial speed controller, or I would hook it up to the oscilloscope at work and find out for myself.
My best guess is that it just flips the polarity back and forth really quick. But it seems like that would cause weird twitching.

If anyone has some info on this, I'd love to hear it.

[CrawlinClodKiller]

I bet it just basicly applies brake slowly, hence drag brake. The braking I imagine is done by reversing motor power to a certain point, like going in reverse does. Of course it doesn't go into reverse as that would make any since. I am just guessing though, and am not sure how to explain what I am thinking.

[ThunderVP]

ESC brushed motor brakes work by shorting the + & - poles of the motor together. As the motor spins while shorted, it generates current in the armature windings creating an opposing magnetic field to the fixed can magnets. As the RPMs slow down, the brake force also decreases. At rest the holding power is minimal until the motor starts to rotate again.

This is how the Punk digs, and do it yourself MOA digs work by using a switch or relay to short the motor.

[CrawlinClodKiller]

That's what I was sort of trying to explain. I will respond with ya that's it.

[dmcchaser]

Interesting. I should be able to simulate that on the bench by shorting a motor and attempting to spin it quickly.
Looks like I have an experiment to try when I get home.

[EddieO]

Drag Brake is an ESC setting that applies brake when you are off throttle....you can adjust this on most speed controls.

Holding power is completely different.....

As is rolling resistance...

But for whatever reason, in crawling......they have all been shoved under the term of Drag Brake...

Later EddieO

[ThunderVP]

Originally Posted by dmcchaser

Interesting. I should be able to simulate that on the bench by shorting a motor and attempting to spin it quickly.
Looks like I have an experiment to try when I get home.

You got it now.

Try spinning the motor by hand unshorted, then short it, you will notice a change in the resistance. The faster you try to turn it, the more it will resist. This is also a simple way to test the magnets in a motor. Compare the free spin and shorted force of a silver can motor to a good 540 with high end magnets and it will be night and day. Then try it with a colbalt magnet motor. The harder it is to turn, the stronger the magnets and more torque the motor will have if windings are the same.

[Jamis17]

If one of you guys, figure a way to hack, a esc to make a home made break, please PM ME PLS.