CNC Mill motor stalling under load

[old-git]

Single phase, 230v Motor works OK when cutting small stuff in aluminium, but when attempting to cut deeper than a few mm or cutting steel it is very easy to stall the motor.

Brushes are worn but still making contact with the commutator.

Any ideas? Do motors wear out?

 

[T9 man]

Yes motors certainly do wear out OG. It may be just the brushes require replacing or the whole motor will need rewinding. There are loads of places who can do this for and usually with a turn around faster than you think. I use Sneath's in East London, not cheap mind you. There are cheaper people around and near you, make sure you have the motor details to hand as quite a few people have fixed overhaul prices.

As your going away very soon and for a while, now would be a good time to dismantle it and get it done so it will be ready for your return - no down time!

 

[old-git]

I was banking on you seeing this plea Thanks

I had thought of that but someone will have to store it for a month. I don't use it every day and I have a small manual mill if required.

When I get back I will compare new with repaired and go from there.

What wears out, other than the brushes? Is it a general breakdown of the coil insulation?

 

[T9 man]

The windings start to breakdown over the fullness of time unfortunately. You should also remember that although the brushes appear to be touching, they may well be wearing away at a different rate due to a weak spring behind them so electrical resistance starts to build up. You also need to check the small cable link that comes away from the brushes as they get dirty, some quite easily depending upon the design of the motor casing and it's environment.

 

[old-git]

Thanks. I will check during dismantling.