Thread: Discussion Removing old windings?
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Old Aug 20, 2012, 06:17 PM
jackerbes is offline
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Jack
USA, ME, Ellsworth
Joined May 2008
18,083 Posts
Quote:
Originally Posted by vtdiy View Post
Thanks flydiver. I've made all my wires exactly the same length. That will help as a check.

The first layer does seem to always take 5 turns neatly, but the second layer and third start getting difficult to keep absolutely straight. I can pretty easily re-count the first layer, if I forget where I am.

I just was thinking if I could put a very thin vertical strip of cellophane or paper after the first layer, I could at least re-count the subsequent turns on top of it if I lost count. After a tooth was done I could maybe pull the strip out.

Right now it's too hard to distinguish (with my eyes, at least) the first layer from the second, if I try to re-count.
I generally know the turns on the first layer when the arm gets full, then as I lay turns on top in the "V's" of the first layer. I say the turn number aloud to myself three times, once as it starts across the top, again as it goes down the side, again as it crosses the bottom, and a fourth time as it comes back up the other side. Then I am ready to up the count and start the the next turn.

I use a 3rd hand to help keep the tension even as I work. I put a close fitting dowel through the stator so it has a short handle on each end and am actually rolling the stator up the lightly tensioned wire more than I am winding turns onto a stationary stator.

I use a plastic stylus sanded to a blunt chisel shape to push the turns back against each other, and the stylus and a APC prop blade to press the slightly bulged turns back against the sides of the stator arms. That last is particularly helpful when the winds on two adjacent arms start crowding each other and the wire does not want to pass down between them.

Then there are the "money turns". Those are the last turn or two at the bottom of the "V" when the winding is crowded by the adjacent arm. For that one, you want to sand the end of the wire to smooth rounded (not sharp as cut) shape and poke it down into an opening in the strands and push it through. And when that opening is snug you can use a smooth jawed pliers to "milk" down and through in small increments, then grab it from the other side and pull it through.

The photo shows a money turn associated desperation measure. I take a large T-pin (smooth as glass, slightly blunted tip) and push it through the crowd of wires at the bottom of the "V" and then remove it. That creates an opening that I can milk a strand of wire down and through by shouldering the other strands aside slightly.

When you are pulling a money turn snug make sure that the half loop formed by the last 1/2" or so is not diagonal to the other turns or twisted. Twist it back so it is parallel to the other strands before you pull it down snug or you run the risk of pulling a tight little knot into the wire. That little knot is a heart breaker, cannot be straightened and is an almost guaranteed broken wire if you even try. Get one of those and it is starting over with new wire time!

The second photo shows the money turn strand pushed through, pulled down, straightened to parallel so as not to throw a knot, and ready to be pulled down snug.

And the third photo is thaqt D4023-850 rewound with 18 AWG, 13 turns, in a LRK wind and ready for termination. It is a testimonial to how the LRK wind allows you to really pack a lot of copper around the arms when you only use half of them.

Jack
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