On Mon, 12 May 2014 01:18:03 +0000, Bob C
m wrote:

I have an old 12 volt 3 phase model railroad motor that has a dead spot
between two segments of the commutator.How can i fix it because to get a
replacement is almost impossible

No experience personally, but arent' such problems usually right at the
end of the wire, in this case where it connects to the commutator.

Is this Lionel? I do have experience with one of their commutators.
Although it was 55 years ago, I remember a lot. Actually what I
remember is that the commutator was a separate part from the motor,
though maybe not every engine was like that.