Quote:
Originally Posted by Kurt in NJ
Whem using a growler there is another test that is rarely mentioned, a output test, it's not as dramatic on a starter as a generator, the growler induces a alternating magnetic field, it can be measured as ac amps and each bar / winding can be checked, with a generator 10-20 amps, but with starter it is 2-5 amps, this will show the connections of the windings to the commutator
The Ford starter has hard copper brushes with high spring tension, this will wear the mica at about the same rate as the commutator bars, there are also starters with copper/carbon (much softer) brushes, these commutators are undercut
the original posters armature appears to be good in the commutator area, it has been turned, and though the turning wasn't carried all the way across it looks to good enough
I looked for a you tube video, but didn't find what I wanted, guess it is one I should make
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I like that test because it actually uses the generator/starter winding as the "secondary" winding of a transformer. Its probably more accurate than the "thin metal attraction" - the way its usually done, since it identifies EXACTLY which winding is open.
The downside and why it is not more frequently done is because by the time you fail the vibrating metal part of the test, you realize you're into rewinding the entire armature since almost no matter where the failure is, you have to first find the "last" winding done - and unwind from there - layer by layer.
And if you're like me, you ALWAYS find the failed coil on the "next to last" coil removed - or at least the second half.
"Random failures ALWAYS result in the maximum work/difficulty possible."
I think that's a Murphy sub-corollary.
The "LeJay Manual" is a good reference source for Model A generator/starter winding diagrams AND making your own ersatz Growler from a Model T generator/starter part.
https://www.scribd.com/document/3093121/LeJay-Manual
Plan 22
Joe K