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I've rewound a few transformers, a couple of motors and a few of my GS stators over the years and these notes just represent stuff I've jotted down for my 79 GS1000. There's more sophisticated ways and materials to do all of this and great info is covered in "the stator papers" articles.
79 GS1000 - stator core stamped 037000 6R 1390 on the connection side, 037000 on the engine side. Core has 18 poles (6 poles per phase winding) and OEM is wound WYE with the center connection (neutral) not used. Core dimensions (bare core) are: 103.0mm O.D., 37.4mm I.D., 24.7mm width of pole at top, 16.7mm width of pole underneath top. There are 3 equal spaced mounting holes of 6.5mm approx.
AC VOLTAGE (measured RMS after rewind) - 14v @ idle/any 2 line-line connections (sometimes referred to as per phase though not correct when WYE wound) and 30v @ 3000 rpm (line-line as above).
The windings when disconnected and measured with a multi-meter should NOT show any continuity to chassis. If you see continuity (low resistance or any signicantly low resistance) you have a short circuit to ground (or one pending) that will reduce the output to near or unuseable levels (depending on where in the winding this has occurred). YOU MAY MEASURE CORRECT AC VOLTAGE in this condition from LINE-LINE and then wonder how come it seems to disappear when the rectifier bridge is connected!
For a WYE winding of 22 to 24 turns/pole (don't worry if this varies slightly) you'll need approx 22 ft of wire for each of 3 phases. What I use is Belden 8075 (1lb roll will just do 3 stators or 2 easily). Besides external electrical overload, the main cause of failed rewound stators (and other windings) is mechanical cutting of the insulation causing a short to ground. For this reason it's imperitive to: 1. Insulate the core where wire will touch completely, prior to winding and 2. Wind tightly but carefully so as to avoid unnecessary binding, crossing and chafing on sharp edges and 3. Make sure your soldered connections to the output (line) wires AND the center neutral connection are insulated with good tubing over top (must withstand extreme heat AND hot oil....no cheap rubber here).
Insulating paper or core covering can be cured epoxy, commecial "fish paper" or good results can be had with a good masking tape (this will be varnished when finished). See my pictures for an example using masking tape. A final coating of high temp epoxy (as detailed by others) or red insulator varnish such as Glyptol (a GE product) and allowing time to cure stabilizes your work against vibration failure.
RESIST the urge to wind more......a layer up and a layer down is sufficient for each pole. A third layer finishing at the top results in poor cross connection to the next pole and a 4th layer results in excessive power output (which is only partly used, the rest is dissipated in the stator itself!) and inconsistent winding/binding due to lack of space.
Leave 6" or so and start your winding, skipping 2 poles and doing the next etc until you arrive 2 away from your starting point.....leave a couple or 3 inches for neutral connection and continue to the next phase until done.
When installing the stator into the case, rotate it so that the soldered connections to the line leads are away from the bend up point......there's a single screw clamp available which I've variously used or not - be careful if using it as it can bite into wire or connections ruining your work. Carefully dress cross connecting leads between poles AWAY from the mounting holes (when done just bend away using a blunt object).....I've variously put insulator tubing on each cross wire but it''s more work.....not required if care is taken.
TRICKS OUT ON THE ROAD WITH A FAILED STATOR OR OBVIOUS LOW VOLTAGE....You should have some understanding of electrical circuits and theory here (You carry a multimeter with you don't you.....chuckling here....I do) Check your system DC voltage......if it's unable to charge the battery (assuming your battery doesn't have a shorted cell!) then switch off the headlight and retry....may get you home or able to run days and limited after dark. Disconnect and check line-line voltage and look for any line-ground voltage (a short in the winding). IF you see good line-line voltage but see voltage with respect to ground (a short to core), try disconnecting the ground wire of the rectifier and retest.....This causes a half-wave rectification and uses your short - see if your DC voltage is now higher.....this can get you home. If all else fails, disconnect the regulator and recheck.....you may find your problem or see an improvement (check at road rpm in neutral).....this may get you home (keep in mind that you may have to taylor your rpm to suit not causing an overvoltage condition).
79 GS1000 - stator core stamped 037000 6R 1390 on the connection side, 037000 on the engine side. Core has 18 poles (6 poles per phase winding) and OEM is wound WYE with the center connection (neutral) not used. Core dimensions (bare core) are: 103.0mm O.D., 37.4mm I.D., 24.7mm width of pole at top, 16.7mm width of pole underneath top. There are 3 equal spaced mounting holes of 6.5mm approx.
AC VOLTAGE (measured RMS after rewind) - 14v @ idle/any 2 line-line connections (sometimes referred to as per phase though not correct when WYE wound) and 30v @ 3000 rpm (line-line as above).
The windings when disconnected and measured with a multi-meter should NOT show any continuity to chassis. If you see continuity (low resistance or any signicantly low resistance) you have a short circuit to ground (or one pending) that will reduce the output to near or unuseable levels (depending on where in the winding this has occurred). YOU MAY MEASURE CORRECT AC VOLTAGE in this condition from LINE-LINE and then wonder how come it seems to disappear when the rectifier bridge is connected!
For a WYE winding of 22 to 24 turns/pole (don't worry if this varies slightly) you'll need approx 22 ft of wire for each of 3 phases. What I use is Belden 8075 (1lb roll will just do 3 stators or 2 easily). Besides external electrical overload, the main cause of failed rewound stators (and other windings) is mechanical cutting of the insulation causing a short to ground. For this reason it's imperitive to: 1. Insulate the core where wire will touch completely, prior to winding and 2. Wind tightly but carefully so as to avoid unnecessary binding, crossing and chafing on sharp edges and 3. Make sure your soldered connections to the output (line) wires AND the center neutral connection are insulated with good tubing over top (must withstand extreme heat AND hot oil....no cheap rubber here).
Insulating paper or core covering can be cured epoxy, commecial "fish paper" or good results can be had with a good masking tape (this will be varnished when finished). See my pictures for an example using masking tape. A final coating of high temp epoxy (as detailed by others) or red insulator varnish such as Glyptol (a GE product) and allowing time to cure stabilizes your work against vibration failure.
RESIST the urge to wind more......a layer up and a layer down is sufficient for each pole. A third layer finishing at the top results in poor cross connection to the next pole and a 4th layer results in excessive power output (which is only partly used, the rest is dissipated in the stator itself!) and inconsistent winding/binding due to lack of space.
Leave 6" or so and start your winding, skipping 2 poles and doing the next etc until you arrive 2 away from your starting point.....leave a couple or 3 inches for neutral connection and continue to the next phase until done.
When installing the stator into the case, rotate it so that the soldered connections to the line leads are away from the bend up point......there's a single screw clamp available which I've variously used or not - be careful if using it as it can bite into wire or connections ruining your work. Carefully dress cross connecting leads between poles AWAY from the mounting holes (when done just bend away using a blunt object).....I've variously put insulator tubing on each cross wire but it''s more work.....not required if care is taken.
TRICKS OUT ON THE ROAD WITH A FAILED STATOR OR OBVIOUS LOW VOLTAGE....You should have some understanding of electrical circuits and theory here (You carry a multimeter with you don't you.....chuckling here....I do) Check your system DC voltage......if it's unable to charge the battery (assuming your battery doesn't have a shorted cell!) then switch off the headlight and retry....may get you home or able to run days and limited after dark. Disconnect and check line-line voltage and look for any line-ground voltage (a short in the winding). IF you see good line-line voltage but see voltage with respect to ground (a short to core), try disconnecting the ground wire of the rectifier and retest.....This causes a half-wave rectification and uses your short - see if your DC voltage is now higher.....this can get you home. If all else fails, disconnect the regulator and recheck.....you may find your problem or see an improvement (check at road rpm in neutral).....this may get you home (keep in mind that you may have to taylor your rpm to suit not causing an overvoltage condition).
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