Carbon Brush Size?

Anyone know how long the carbon brushes should be?

Started carving my last Christmas gift last night, and about 20 minutes in, the motor started slowing down sporadically throughout the carve, until it finally stopped, but the truck was still moving back and forth/up and down.

I gave everything a good cleaning and tried again this morning, but after maybe 5 minutes of carving, it did it again.

Took the motor out and removed the brushes, and both are worn down to about 1/4" (see below). I'm hoping the brushes are just worn down, and not an issue with a sensor or mother board. Have roughly 180 hours on the cut motor.

Attachment 85274

I believe they are 1/2" (.500) long. When mine started going (short) bad and the cut motor didn't come to a stop before it did the bob at the keypad side and cut into the part that it touches at the bottom. New brushes did the trick for me. When you order new brushes buy extra ones to help cover the shipping costs. May want to check for other parts recommended for small shipments just to keep on hand. Good luck

Here are some pictures.

I highly recommend you buy them from LHR.

For one, they are metric
Carbon comes in many flavors and hardness
The Wire Tether and Spring are important.

More than one user has gone to Ace Hardware for a almost match....

The result.. Carbon too soft wears too quick..
Tether too long and the spring got into the spinning parts...

Result... Buy Me a new Cut Motor...

We have years of listening to the results of sad cut motor brush stories...

Buy from LHR. And change every 250 cut hours when you change the 2 685ZZ Bearings in the Y Gearbox.

AL

Al, don't forget that the bearings have changed for the new machines, I still haven't gotten the size of the inner bearing (Larger) I just replaced my whole assembly with an old rebuilt I had. Has anyone got the specs for it?

Ordered new brushes, so hopefully that is the issue.

Thanks for the comments!

Well, I installed new brushes, but the motor still idles down to nothing a minute or so into the carve. Now what? :(

It could be a bad motor... The motor is 115 VAC so some have removed the wires at the cut motor safety switch and carefully hooked a power plug wire to the motor black and white wire. Then carefully plugged it in. If you would remove the motor from the machine be very careful the motor does not roll off the table winding up and shorting the wires in a big blast of electricity.... OR it could be a component on the X Termination board. The Motor Test will half split your troubleshooting.

Insulate the wire connections with tape... Only do this if you are comfortable working with live voltage. BE SAFE.

AL