Re: Restoring Starter Armature

Posted by carla on March 27, 1998 at 13:35:45

In Reply to: Restoring Starter Armature
posted by Neil MacGregor on March 27, 1998 at 10:17:00

: I'm confused about restoration of the commutator.Some books say to undercut the mica separators after turning the commutator, while others say not to undercut.What's correct for the starter? Thanks in advance.
: Neil

neil, the old works manuals specified that one should always
undercut the mica in the com of a dynamo (generator) but
never undercut the mica in the com of a starter.

this is a standard practise of rebuilders generally, but i
can only theorise as to the reason why this is so

they might have found that , since the dynamo is running at
high speed at all times the engine runs, the copper segments
of the com would wear, causing a high mica condition to the
detriment of the brushes.

the starter, on the other hand, runs only briefly, with much
higher amperage, so a tendency may exist, were the mica
undercut, for the segments of the com to burr or deform
slightly, or maybe a bit of oil on the com, if it collected
in the undercuts, would carbonise from the heat generated
in the com, and conduct enough power to spark across between
the segments

that's what i've heard, whether its fact or folklore i can't
myself say for a certainty

hope this helps




Previous PageE-Mail Comment to WebmasterPost New MessagePrint MessageClose Window

© 1996-2010, Ahooga.Com

Anti Spam