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SWCC Self-winding Type F - Various questions


Registered User
NAWCC Member
May 15, 2008
Here is a Self-Winding clock that raises some questions:

1. It appears that the friction clutch on the minute hand is too stiff and the synchronizaton coil is not strong enough to snap the minute hand back to 60. I can weaken the clutch action by loosening the minute hand retaining nut but this doesn't seem right. Is there some other adjustment here?

2. Running the synchronizing coil run on a higher voltage (4-5V) improves things. Is this proper?

3. When the synchronizing coil energizes and attracts its arm, how close to the coil heads should the arm get?

4. Picture 2 shows the minute hand reset arm, with a small hook pointing straight up. What's this for?

5. Picture 3 shows two fixed posts on the front of the front plate, below the seconds arbor. The larger one has a cross-drilled hole, as if something is missing here. What are these posts for?

6. Picture 4 shows what looks like an adjusting screw (but isn't) retaining the reset armature on its shaft. Is this just an ad-lib part?


self-wind-1.JPG self-wind-2.JPG self-wind-3.JPG self-wind-4.JPG

Tim Orr

National Membership Chair
NAWCC Fellow
NAWCC Member
Sep 27, 2008
Boulder CO
Good evening, Dave!

I can offer what I know and some opinions on some, but not all of your questions:

1 & 2 & 3: I would not suggest increasing the voltage. If it's not working right on 3v., something else is wrong. I doubt it's the friction clutch. I would suspect more likely the solenoid armature isn't adjusted quite right, binding, needs a little lube, etc. These things "clank" quite a bit when they synchronize, so if it's not doing that, I think that's where your problem is. Yes, I believe the armature should make contact with the magnets. That's what I think the "clank" is.

4 & 5. You have a part missing. I can't find a picture (and am too lazy to take the hands and dial off mine to make one), but you may be able to find one with a search of the BULLETIN archives. There is, if you will, a mating downward-pointing hook lever that engages the upward-pointing one you have. As I recall, it prevents synchronization from taking place if the clock is not within about 2 minutes of the top of the hour. I believe the second hand has to be within 20 seconds of the top of the minute. That mating hook hangs on the post with the pin hole and the other pin acts as a stop for the hook lever. The upper hook gets pushed out of the way so that the lower hook and semicircular ring can move down and sync the minute hand.

6. I believe this screw is simply to retain the armature on its pivot shaft. If you take it out, I believe you will be able to slide the armature off the shaft. It could have been held on with a pin of some sort or a cotter-style key, but I think they chose a screw. Good practice would dictate that a pin would have to be inserted from the top, and there's not a lot of room up there. A cotter key would work, but you'd have to bend it and unbend it for service. And, I've never seen a cotter key in a SWCC clock. These things were serviced by field techs, and they would have limited time, parts, and tools.

You might need some lube on that shaft. The spring that you can see on the left, attached to the armature plate (between the armature and the coils) might need adjustment, etc.

The best guy on this subject I know is Ken Reindel, President of Chapter 21 in Denver and who runs Ken's Clock Clinic. Website: Ken's Clock Clinic - Self Winding Clock Restoration & Products

Best regards!

Tim Orr
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