On Jul 21, 11:08 pm, "William Wixon" wrote:
hey, i have another question if anyone would like to reply. i posted "OT
commutator wear" on 6/24/07, finally got around to working on this inverter
again. removed the armature (to bring to a electric motor shop) to get the
slip rings smoothed out and saw these (two, one on each end) blobs of what i
assume is JB weld on the windings. my first thought was one of the previous
owners put them on there to disguise damage or to cover up a jerryrig repair
job (is it possible to solder broken armature wires?). my second thought
was maybe they were applied at the factory to balance the amature. i have
no idea. asking you guys.

http://www.frontiernet.net/~wwixon/a.../armature2.jpg

i was taking this inspection/repair job one step at a time, was reading the
service manual, procedure for disassembly, one of the steps was to
"...remove printed circuit board..." i was poking and prodding, "...printed
circuit board, printed CIRCUIT BOARD...." finally it dawned on me there
was NO printed circuit board. (one of the) previous owner removed the
printed circuit board and simply crimped together the wires that went to it.
THAT was a very depressing discovery/realization. BUM-MER. replacement
printed circuit board goes for like $230 but they told me it's an older
model and i'll have to get the "conversion kit" that goes for $430, fukkin'
bummer.

thanks for all your previous replies and thanks in advance for any info
y'all would like to impart.

b.w.

Don't know what those blobs are. All the armatures I've seen balanced
were done by drilling in an automatic jig. I'd think it would be
tough to balance just by sticking some random-sized epoxy blobs on
there, and I don't see any signs of filing. It doesn't look like the
windings are soldered into the commutator, just punched. This CAN
cause problems under load later on. Another thing I don't see is any
form of winding restraints at the ends. Usually there's some form of
ties(ribbon, straps, string!) to keep the windings in place so they
don't come loose at speed. This seems to have been abandoned on cheap
imported stuff, one reason the older motors are still out there
kicking while the newer stuff ends up in the scrap bin. The
commutators really don't look bad on your example, can't really see
the slip rings well enough to comment. Hope the output is worth it,
you can get 2 KW solid-state inverters now for well under $200.

Stan