Fw: Motor faults and motor refurbishment

[David Halfpenny gmail]

Here's a thought from a member of another group.
Somebody had asked about replacement brushes for the DC motor on a Unimat
lathe, and since the C0 also has a DC motor I thought that passing these
tips on could be useful.

David

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Unimat Replacement Motor brushes

Hi,
Suggest a quick visit to any motor rebuilder, with the offending brushes in
hand.
I would be very surprised if they could not be replaced "off the shelf".
Will be much cheaper than than any Unimat part.

By the way, just another bit of info about brushes.
If you are required to have an Earth leakage Safety switch in your part of
the world you will find that you will have a problem with carbon brush
motors!
The dust from the worn brush will collect in the motor and will form a VERY
small leakage path to the casing (Earth)---result is that when you start
the motor, it instantly trips the safty switch---result no power! If this
happens to you, first course of action is not to the electrician, but
simply CLEAN the dust away. Without a safety switch the motor would keep on
running for years as the leakage is so small it has no effect.
This can happen to any brushed motor, so I hate to think how many
expensive repairs could have been simple clean up jobs!!!

Steve Greenhalgh,
Beijing