I have a Hammond clock with a "dead" motor. I understand the Telechron synchronous motors are interchangeable with the Hammond Type B, but there is no point in my purchasing a fresh motor, if my coil is "fried" I measure 400 ohms through the coil. That seems high to me, but on the other hand, It isn't completely open, so perhaps is normal for these coils. Does anyone know what normal resistance should be for a Hammond coil from the pre- Hammond Instrument Company (1938) days should measure?

David, Post a picture of the clock motor. I have worked on this one with some success.

Here's a 'before' picture.

A quick search directed me here:http://sound.whsites.net/clocks/ocm.html

"Most old clock motors should measure somewhere under 1K ohm."

I finally got around to taking a photo of the motor. It is labeled Type C. If it matters, the number stamped on the coil is 3416. I suspect that is probably a date code.

After reading your response, I did a little more research online, and have concluded the reason someone (probably my grandfather) cut the cord to this clock was probably because the insulation is all hardened inside the cloth. I have ordered some new cloth covered power cord online, and intend to wire this thing up, and see if it is a "fuse blower".

I grew up in a family of Westinghouse electrical engineers, and have been messing about with radios ever since I was about six or seven years old. So I know how to keep from getting myself "high-potted", and have the proper meters and such for safe testing. (Even when UL would highly disapprove):-)

Well - I took a chance ad reattached a fresh wire to it, with a new plug. Held my breath and plugged it in. NO smoke, and no explosions, which I took to be a good sign. So I spun the little starting knob. It ran for about a minute and a half or so, then stopped, so I did it again with the same result. After several similar attempts, with similar results, I got disgusted and pulled the plug.

There is a lot of other businesss going on around here right now, but I figure my nesxt step is to remove the coil from the works, and take a look see at the pivots, and install bushings as necessary. IF that does not solve the problem, then I suppose I shall have to "bite te bullet" and remove the solder plug, and slosh out the motor. I am hoping that will not be necessary, though.

David, The symptoms you describe parallel what I went through with mine.
One thing you might try to narrow down the problem... Take the motor off and warm it up enough to get the oil inside running freely. Then give the gear a spin and see if it turns more freely than when it's at room temp. You should see a noticeable difference.

That motor is not at all difficult to service. I tried to remove the solder plug by de-soldering, but ultimately had to drill a small hole where the plug is located. After you gain access, you can then flush the old oil and replace. Not difficult, just takes a little time. I flushed mine with WD-40, (you could probably use brake cleaner too) 2 or 3 times and then blew it out with compressed air. You need to be careful when doing so, as you can distort the aluminum. Just need to be sure you've got all of it out before adding fresh oil. I added oil, blew it out and then added more.

I think your coil is fine. And I doubt any re-bushing work is necessary.

Well. yesterday I disassembled the clock and ran all the parts and pieces (not the motor or the coil, of course) - through my ultrasonic cleaner. The wheels and pivots were filthy, but after everybody was a sparkly clean, I put the wheels back in and watched the pivots as I spun it back and forth. I didn't see any noticeable major wear. And the fingernail test didn't disclose any ridges in the pivots, nor could I see any nastiness through a 15X loupe. So it looks like I am going to have to attack the motor. I am leery of using compressed air from my compressor, so I am going to buy a can of compressed air. I suspect there is less chance of bulging the housing with that than using the "spritzer" from my compressor.(Its set at 100 psi) I don't like WD-40 - it leaves a film that is the very devil himself to remove. But I have plenty of acetone and plenty of naphtha and plenty of alcohol. and I hav4e a glass syringe that I can fill with those things to flush out the motor. For the net few days, my evenings are filled with big band and theater work, so It will probably be sometime next week before I can get back to the clock repair bench. I'll keep everyone posted on my progress.

Sounds like you're narrowing it down. Keep us posted.

Finally got around to messing with it a little again this evening. Decided before I got too excited, I'd try warming it up to see if that helped matters any. Put it in my toaster oven, set on 200 degrees for an hour, and then tried it again. It spins more freely, and coasts after I spin the pinon, but when I put it back in the clock, it still wasn't happy. SO, the next thing is to bite the bullet, and slosh it out with some solvent, and put fresh oil in it.

So far, your experience mirrors mine. I'm pretty sure when you clean and lube the motor, it will solve the problem. The fact that it runs free and smooth after warming it up would indicate to me that's all it needs.