Router Rotation Direction

[Cobra]

Jim it is a universal motor and you can indeed change the direction of rotation. Unlike some tools which are designed to run in both directions this router will likely have a leading commutator brush angle which gives it better performance in the normal direction. If it is reversed you may notice a bit more sparking at the commutator, although it should not be excessive.

These motors have two field coils and the armature. Power comes into one field coil (#1) terminal out of that coil (#1) to a brush(#1). The other brush(#2) goes to the terminal of the second field coil(#2) and finally the other terminal goes to neutral.

You essentially want to swap the two terminals going to the brushes. So field coil #1 goes to brush #2 and field coil #2 goes to brush #1.

I am at the rv park enjoying a rainy day and don't have access to make a sketch.

David

Thanks for the directions David. I got at it today to give it a try.
First time effort to reverse a motor. Electrical is not my comfort zone!
Got the motor apart fairly easily and could see the field coils and the brush wires.
I was thinking that I was going to have to unsolder the brush leads and move them but when I took a closer look, the brushes were spring attached to the brush housings.



Unscrewed the field coils from the frame, popped the leads of the brush holders moved them to the opposite side and reassembled. Easy right? Not so fast.
Must have flipped the field coils over when I was messing with the brush attachments. Damn thing is still going the same direction. They good thing was that it still worked!




Took it all apart again and got smarter this time. Marked the orientation of the coils, swapped the brush leads and re-assembled.
Worked! Rotating in the opposite direction. Seems to run just as smooth as original, no sparking on the brushes.
The speed is exactly the same as the original orientation. Settled in at 32,000.

Thanks again David. Your directions were spot on.

Jim

 

[David S]

Jim thanks for closing the loop.

I worked designing power tools for the largest consumer power tool company in the world for 30 years. Universal and DC motors were my thing..among myriad other awesome things.

I am glad it worked out. Did you notice what kind of fan it had?

David

 

[Cobra]

Jim thanks for closing the loop.

I worked designing power tools for the largest consumer power tool company in the world for 30 years. Universal and DC motors were my thing..among myriad other awesome things.

I am glad it worked out. Did you notice what time of fan it had?

David

The fan is a cast aluminum piece that seems to work just as well in the other direction.

 

[David S]

Jim do you happen to have a picture of the fan so we can show the difference between axial and radial fans for future discussions.

David

 

[Cobra]

I didn't take one today but I can get a shot tomorrow.

 

[Cobra]

Jim do you happen to have a picture of the fan so we can show the difference between axial and radial fans for future discussions.

David

Hey David. Got a chance to take it apart again this morning.
Here's a couple of shots of the fan.




Thanks again
Jim