How To Rewind an Alternator

Step 2 Ripping out the Old

I'll start off with the caution.
The wiring varnish/shellac has sharp edges, so be careful when removing the old windings.

The original windings were 13 turns of 1.2mm dia and I reduced the wire diameter to 0.75mm in order to double up on the windings, fitting in 30 turns in each stator slot. This is an attempt to increase the voltage which has the benefit of generating 12V at much lower rpm's.
In their designed for application, alternators generate 12V at about 2000rpm and higher. This is totally impractical for a windmill whose blades might only turn at 300 ~ 700rpms.

TIP of the Day
...take note  of the original style of windings as well as the start and end connect positions, in order for the new rewound stator to match up in the original position.

This stator 4 coils of 13 anti-clockwise turns for each of the 3 phases, so we need to keep a similar format in order for the rewound stator to fit.

Comments

[Oorspronklikheid]

To make ripping out the old coil easier you might try turning your oven on max and putting the stator inside it to melt of the enamel.

[databoy]

I worked in the electrical industry. Placing the stator in an oven to melt the enamel will not make any difference. There is a wedge in the slots to hold the windings in place. Professional re-winders do not re-use the old copper. They just cut one side of the winding and tap out the windings. Professional re-winders use a bench form to wind the new windings then drop the windings into the stator slots. Then they use a wedge to stop the windings moving. Sometimes the wedge is just a thick piece of insulation.

[honorman]

Sorry, If it was taken from my post to reuse the old wire, of course this would never work, (dead short) plus cheap workmanship.

Also this was in the early 1950's that this man did this without any fancy jigs or maybe one he made, because he did take the motor back inside to his work bench to rewind it.

Its likely he learned this trade from someone else. this was small town Mayberry back then, 2000 people.

I then spent 12 years myself in electronic trouble shooting, later in life, then 33 year building New Homes

[Oorspronklikheid]

i got the idea from a company that regarly rewind motors in exess of 100KW(wich is kind of smal to them), so i thought it might work here too

[petercd]

Just a tad over the top? :) I was tempted to use a heat gun, but didnt know if it'd be a stuffup. Guess it could be kinda tricky pulling hot wire and perhaps too much heat could warp the stator plates, some of them have a varnish between them.

[honorman]

When I was a kid there was a man that did rewinding of motors as a business in my brothers electrical shop, he would build a fire outside (like a camp fire) and put the old winding on the fire to burn out the enamel, then tear out the wires when cool. and take it to his work bench and rewind the motors. this was in the 1950's