Rewinding Cutout Relays

[awander]

Hi Everyone:

I am a new member to the forum; my friend Alex recently bought an A and I have been helping him work on it.

I recently started rewinding Harley Davidson(Delco-Remy) cutout relays, and documented the process on a couple of bike forums I belong to. I'd like to do the same for the A cutouts, especially what it would take to rewind the fine winding on burnt out relays.

I wondered if anyone had any burnt out relays laying around? I nee at least 2 or 3 so that I can disassemble them, count windings, etc. I'd like to document the rewinding/rebuild process on teh forum.

thanks,

Andy

[leo]

Hey Andy, I have some experience with your topic, I've opened over a dozen original cutouts recently and found all of them have a bad inner winding. Specifically the inner winding tests 0 on an ohm meter instead of 50. Have you looked at one of these yet? The inner winding is almost hair thin and wrapped around it separating the layers of winding is a thin paper almost like onion skin which just disintegrates from being old. Send me your address and I will send you a couple.

[awander]

Hi Leo:

PM Sent!

Thanks,

[awander]

Thanks to a couple of members here, I have some dead relays that I am working on.

At first glance, these things appear to be very well made. Even compared to the Delco-Remy relays I have rebuilt, these have some "extra" features:

-each "wrap" of the fine(shunt) winding is separated/insulated from the wraps below and above it by a piece of "onion-skin" paper.

-the stationery contact is easily adjustable by loosening 2 screws-this requires bending the contact bracket on the D-Rs.

I also noticed a feature that I have not seen before. On the D-R relays, the connection to the fine winding is done using a piece of braided wire, soldered to the end of the winding, and captured underneath the tape of paper wrap on the winding. this relay uses a tripled loop of the winding wire itself, which seems like it would work at least as well.

Finally, I have seem one way in which the D-R relays were superior, from the standpoint of a rebuilder. On the D-R relays, the core, which carries the spool and the windings, is attached to the relay frame using a threaded post and a nut, while the Model A relay has the core riveted to the frame. I think I have found a way to remove it and re-rivet it; that remains to be proven, though.

Andy

[leo]

Andy, have you been able to determine what is the most common form of cutout failure when it comes to the small windings? When I sent you the three cutouts I had already tested about 16 and found them all to have shorted small windings, couldn't find one that would give me 50-55 ohms of resistance, just '0'.

[awander]

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Leo, that is strange, I tested those 3 and I do measure between 45 and 48 ohms on all of them. One of them had one end of the winding disconnected, though.....

I'll be sending a rebuilt one back to you soon(as long as things continue to go well)

Andy

[dumb person]

Looking at rewinding a cutout now, i see heavy windings, i guess lighter ones are inside. How critical is the correct winding of the fine wire? Not sure where i could get fine wire but if some transformer from a transistor radio was a close fit i might consider using it without having to wind wire & paper for a month & 3 years on rainy sundays.

[Tom Wesenberg]

Originally Posted by dumb person

Looking at rewinding a cutout now, i see heavy windings, i guess lighter ones are inside. How critical is the correct winding of the fine wire? Not sure where i could get fine wire but if some transformer from a transistor radio was a close fit i might consider using it without having to wind wire & paper for a month & 3 years on rainy sundays.

I'm not sure of the guage of the fine wire, but it's long enough to have 50 ohms. I don't think you'll find enough copper in a small transistor radio to wind it.

[Kurt in NJ]

Even though I have rewound releys, magnet coils, armatures and had acess to the wire and a winding machine I took the easy route, I drilled the reley frame and pressed in a used diode from a 60s mopar alternator, 40 years of use so far---same for the generator, it is one of the few modifications that doesn't need other modifications to support it,and results in increased reliability.

[larrys40]

Andy,

I have rebuilt/serviced many original cutouts. I believe the exciter coil ( small wire) is 47 ohms...Usually the problem is they lose or have a cold solder joint ( or bad solder joint) at the base solder joint. You can see it easily in looking near the large coil and see the small wire solder joint. I have disassembled over several hundred of these over time. in drilling out the rivets for the coil structure you have to be sure to preserve the small fiber washing that is the spacer to the sheet metal structure that is sandwiched between the coil unit and the lower and upper gaskets. The gaskets were obtainable.. or at least I know if you call walt bratton you can order them in bulk if not in the catalog. I usually ordered 25 or 50 at a time. I would never spend time rewinding them.. .as they are way to plentiful. find another one. The time is not worth it. Usually if they ohm out OK the problem is the points need to be faced and surfaced, and the air gap of the coil needs to be set ( when points are closed). These are all adjustable. Use a digital ohm meter to ensure that there is or almost no resitance in your contacts and posts when points are closed. Of course you should get you 47 ohms on the exciter coil between generator side and base ( when soldered and connected well.

The biggest challenges are opening the case and keeping the feet undamaged. You know what to do there if you've had them open. Only open feet cutouts are Model A, all closed are 32 and later or service replacements. Repro cutouts are junk.. The originals function great onced serviced properly. I know some folks have done well with diodes. Personally I don't like them as they are heat sensative... but then that's how the alternators function. I used to by these for around a $1. They are still there or if it's really nice I will go to $5. Not as plentiful as they use to be as people just pitch them. The days of folks saving and dragging the small parts to the swap meets is almost behind us.. unfortunately.
Good luck!

Larry S