Cut Motor Help

[Carl H]

I was running the machine today and 80% through a 5 hour carve I heard the cut motor slowing down like it was under a heavy load. Then I got a z axis stall.
I removed the board. cleaned everything up and tried running the project again.
The cut motor did not spin the bit an the machine was oblivious to it.
I ran the cut motor test and that said the cut motor was running when it was not.

I have 281 hours on the machine and I am sure new brushes are in order.

I have a few questions.

Could it be a sensor?
Could it be a faulty board?
Could it be the switch in the cover?
I know this is no one esles problem but I have to get the order done by weekend.... ARGHHH

any help would be appreciated
Thanks Carl

[bergerud]

If you heard the cut motor slowing down and you have 281hours on the motor, it is very likely the brushes. It is not a sensor. It could be the x termination board but I doubt it.

Easy to check. Look at the brushes.

[Digitalwoodshop]

Yep... new brushes.....

AL

[Carl H]

Thanks I will check when I get home. I had brushes but I am not sure where I out them. Can someone give me the dimensions of the brushes so I can grab some locally. I live in Canada.

[bergerud]

The brushes are square when new. 12mm X 12mm and 6mm thick. If you do find brushes at a motor shop, make sure they are AC brushes. Brushes can be a little larger (1/2" X 1/2" and 1/4" thick) since they are easy to sand down. Make sure and switch the springs with your old ones.

[Carl H]

Thank you everyone. I got replacement brushes at a vacuum cleaner repair shop. Sanded them down to specs and the used the springs and caps from the old set.
Tested the motor and at first it ran at erratic speeds, Once I put the bit in and a load on it purred like a kitten. about 5 db quieter than before.
I also used the original board and finished the carve. I will post what I did on WIP.

Thanks again