Kitchen Clock Mainspring

[dc2daylight]

A friend asked if I would look at a kitchen clock that he inherited. It is one with a wind up alarm built in. It appeared to just need to be cleaned and oiled so I did so. The clock now runs for 4-5 days keeping perfect time and then quits. The mainspring appears normal as in not shortened. Is it normal for these clocks to run only for a few days?

[Scottie-TX]

No, that is not normal. Often they will run eight, nine, or more days.
1. Mainspring FULLY wound? (You cannot overwind it)
2. Mainspring interfering with another wheel as it expands between the plates?
3. Performance of escapement - excellent recoil and overswing ? Or pendulum activity feeble, labored.

[dc2daylight]

The Mainspring is fully wound and it is not interfering with another wheel. Strong running escapement. I'll take a picture of it wound down.


No, that is not normal. Often they will run eight, nine, or more days.
1. Mainspring FULLY wound? (You cannot overwind it)
2. Mainspring interfering with another wheel as it expands between the plates?
3. Performance of escapement - excellent recoil and overswing ? Or pendulum activity feeble, labored.

[shutterbug]

A couple of possibilities:

One, as Scottie mentioned, the spring stops have been removed or broke off and the spring is pushing against one of the arbors as it runs down.

Two, you missed a bad bushing when you had it apart and it's hosing the movement when the spring loses power.

You didn't mention your experience level, so I'm guessing the latter :) Did you disassemble the movement when you cleaned it?

[R. Croswell]

dc,
There’s not a lot of information here to go on and Scottie and Shutterbug have already mentioned the obvious. Maybe you can shed a little more light on the problem. You say the clock rings for 5 days and that it runs strong, but how is it running at say, 4 ½ days? That is, does the pendulum start to swing less and less over the five day period so that it is noticeably less on the 4th day and finally quits on the 5th day?

If there’s nothing actually binding the movement, like the spring expanding against an arbor, then I would suspect a power problem. That is, either the movement is requiring too much power, or the spring is not able to provide enough power after 5 days running. Either way, I believe you need to take the movement apart, completely apart, including removing the springs. Check for rough and/or bent pivots, and excessively worn pivot holes. As previously suggested, a damaged, poorly fitted, or dirty pivot will cause a lot of extra friction.

Check the springs carefully. Are they rusted, rough, dry, or coated with dried up oil? There’s no absolute rule, but when you lay out the springs from a clock like this, if they don’t expand to about 6 inches or so, the spring may be “tired” or “set” and no longer able to sustain power for a full 8 days. You say the springs do not appear to have been shortened. Did you measure them or come to this conclusion because the end looks “factory made”? It’s not uncommon to find old clocks that have had incorrect springs installed. Did you lubricate the springs, and if so, with what?

Some pictures might help, along with dimensions of the springs – thickness, width and length (don’t try to uncoil the last few turns). I believe that if you take the movement completely apart and reclean everything, and carefully inspect the pivots and pivot holes, and the spring, you will easily identify the problem.

Bob C.

[harold bain]

Some kitchen clocks are thirty hour clocks. If this one is, then 4-5 days is exceptional performance. Most 8 day clocks of this type should run for up to 14 days on a full wind, if in good mechanical condition.

[shutterbug]

Harold makes a good point. How wide are the springs? 3/4" indicates an 8 day clock. 3/8" would be a 30 hour variety. If it is a 30 hour movement you can be quite happy with your repair :)

[dc2daylight]

I finally was able to return to the shop and look at teh mainspring on teh kitchen clock more closely. It is 3/8" wide and 0.18" thick and estimated 30 to 40" long. After 4-5 days the clock stops and inspection shows the mainspring appears to be fully unwound hitting on the nearest arbor. So what I am going to assume is that this is a 30hour clock and it is working as designed. Next question is: If I were to try to put a 96" long spring in, would it enable the clock to run longer (looking for 8days)

[harold bain]

No, that would not work. 30 hour clocks have different gearing from 8 day clocks. The spring size is only part of the reason it is a 30 hour clock. It would still hit that arbor after 4-5 days. It is doing well to get 4-5 days on a wind.

[Willie X]

The spring you describe sounds more like a one-day, but if you have a
one-day that will run for 4 to 5 days, this would be unheard of (at least by me). A photo of the movement would help. I'm guessing that you may have one of the smaller (novety type) 8-day movements.

Willie X

[dc2daylight]

Thanks guys. All of the research that I've done is telling me this is a 30 hour clock. I'm going to declare victory and give it back to my friend.

John in Seattle

[burnz]

Wow--if you are getting 4 to 5 days out of a 30 hour clock---I would ask the friend if he wants to sell it---lol!

Do you have a photo of this clock?