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Location: Missouri
11-01-2018, 03:53 PM
(This post was last modified: 11-01-2018, 05:49 PM by Stwood_.)
(11-01-2018, 03:08 PM)Info on the I nternet Wrote: The DW 705 and 708 (most all Dewalts) use an electrical brake to stop the motor. This is usually another winding in the motor that is connected to the primary motor windings when the switch is released. The primary motor becomes a generator because of the collapsing magnetic field in the primary windings. The electrical energy goes through the switch (and brushes) to the brake winding to slow or stop the motor. I'd inspect the brushes, and replace them if they are worn. If not, then I'd replace the switch since it controls the starting and stopping. If that fails to correct the problem, the only items left in the brake system are the field and armature.
I've removed the handle covers and blew the surrounding dust out of the switch and that has cured 2 of my Dewalts. I also checked the wire connections while there. So not really sure what fixed them, but the brakes started working again.
Steve
Mo.
I miss the days of using my dinghy with a girlfriend too. Zack Butler-4/18/24
The Revos apparently are designed to clamp railroad ties and pull together horrifically prepared joints
WaterlooMark 02/9/2020
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(11-01-2018, 03:08 PM)Roly Wrote: Most miter saws use dynamic braking where the motor becomes a generator when voltage is not applied. Easiest thing to check are the brushes, make sure they are free and not worn out. A dirty commutator could also be a issue or the switch itself that applies a short or load when it is shut off. I know it is counter intuitive for the brushes to be the problem but check them first. Roly
Roly,
"Dynamic Braking" who knew. When I did a search I found a ton of info. Not knowing what to call it was the problem. That is why having human beings to talk to will never go out of style.
I may try checking the brushes. Easiest first.
I'll circle back with results.
Thanks
Mark