Guru
Joined: 26/07/2007
Location: AustraliaPosts: 1686
| Posted: 02:04pm 07 Jul 2010 |
Looks like a starter motor I rewound out of a big grader a few years back.
It can't see any reason why the pro's couldn't rewind it easily. Those string ties part way up the armature look to mean that the slots aren't captive slots,.. hence the need for the tiedown. Should make it very very much easier to rewind.
It appears to be single turn wave winding, same as a starter motor. The only tricky bit I found was getting that "twist" at the output end right.
If you don't pretwist your wire to the right angles, you will never get the last 10 slots in. If you get it right, it is a doddle, and you wonder what all the fuss is about (took me 2 days to work out the right angle and find success... I'm a slow learner.), but I had the captive slots, (and I had to make the copper bars from 3 in hand 2mm wire) so I could not place them in the wide slots like that one appears. (mine all had to slide up the slotlength)
I'm not sure I would blame the advancing just yet, unless perhaps that motor was wound advanced, and your extra 6 degrees was then over the top advanced... but that's unlikely, as it would mean very poor reverse (unless your using the gearbox for this). I would expect that type of motor to be designed to perform well in either rotation. If it was better one way than the other, it may well have been biased already.... like a vacuumme cleaner motor. They are already near 2 full segments or so advanced. They will burn out in reverse if you rewire the fields to go backwards.... unless you shift the brushes about 4 segments back at the same time.
I agree with Bob, something did not do those field shoes any favours...... I'm more inclined to blame the worn brushes for messing things up.
If you lose one, you run on 2. You then draw the same (or usually much worse) current, and get less power out....
More in and less out = burn out... and thats not talking about the physical damage the copper wires in the dying brushes are doing dragging and spot welding onto the armature.... and possibly bits lodging themselves in between the armature and the field shoes.... maybe that explains the copper bits that appear to be stuck to the shoes in the pictures.
Not pretty at all..... now I will have to go out and check mine.
My few thousand Kms have all been done in the paddocks.... It won't be so embarrassing when the cows see me push it when the time comes.
......oztules
Village idiot...or... just another hack out of his depth