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speed adjustment

j0ckser

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FIRST POST!
I have a Seth Thomas mantle clock, antique when given to my dad on his retirement in 1986. It has 3 springs: movement, hour chime, quarter-hour chime. I believe it is generally in good working order. However, I cannot seem to find the 'sweet spot' with the adjustment to get the clock to 'keep time'.

I know how to adjust it, but any tip or trick would be appreciated.

Also if some kind soul could direct me about model number or date of manufacture that may help others with tips.
 

eemoore

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FIRST POST!
I have a Seth Thomas mantle clock, antique when given to my dad on his retirement in 1986. It has 3 springs: movement, hour chime, quarter-hour chime. I believe it is generally in good working order. However, I cannot seem to find the 'sweet spot' with the adjustment to get the clock to 'keep time'.

I know how to adjust it, but any tip or trick would be appreciated.

Also if some kind soul could direct me about model number or date of manufacture that may help others with tips.
Did you try to post pictures ? Insert the pictures by using the "attach Files", found under your text.
 

wow

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How far off is it? Most American mantle clocks are adjustable to within 5 minutes in a week if not wound but once at the beginning. If you get it that close you should be happy. If you wind it twice a week you may do better. Wall clocks with longer pendulums can be adjusted much closer. If yours is Westminster it probably is a model 124. I have found they are pretty reliable if wound twice a week.
 

R. Croswell

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FIRST POST!
I have a Seth Thomas mantle clock, antique when given to my dad on his retirement in 1986. It has 3 springs: movement, hour chime, quarter-hour chime. I believe it is generally in good working order. However, I cannot seem to find the 'sweet spot' with the adjustment to get the clock to 'keep time'.

I know how to adjust it, but any tip or trick would be appreciated.

Also if some kind soul could direct me about model number or date of manufacture that may help others with tips.
We really need to see some pictures to know exactly what clock we are working with, but to what's already been said, I'll add this.

1) Typical American spring wound clocks tend to run a little fast right after being wound and a little slow near the end of the week. Stopping winding about a turn from wound tight may help

2) Don't try to regulate the clock on the fly day by day, rather wind the clock about 1 turn short of "wound tight" and let it run a full 7 days. Then after making a small adjustment, wind it again to about 1 turn short of "wound tight" and let it run another 7 days etc.

3) There is usually some backlash or slop in the rate adjustment device, so always make the last adjustment toward "fast". For example, if after a week the clock is a tiny bit too fast, and you want to adjust it 1/2 turn toward slow, turn the adjuster 2 turns toward slow then 1 and 1/2 turns toward fast.

4) If you find that your clock loses 6 minutes over a week, set it 3 minutes fast when you wind it and it should be on time midweek and 3 minutes slow at the end of the week. The max error at anytime during the week is now 3 minutes instead of 6 minutes.

RC

EDIT: We need to see the front of the clock and inside the back if the back opens.
 
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j0ckser

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How far off is it? Most American mantle clocks are adjustable to within 5 minutes in a week if not wound but once at the beginning. If you get it that close you should be happy. If you wind it twice a week you may do better. Wall clocks with longer pendulums can be adjusted much closer. If yours is Westminster it probably is a model 124. I have found they are pretty reliable if wound twice a week.
Ahha. Thanks for the speedy reply. I thought I could get to within a few seconds. Maybe I should count my blessings.
 

R. Croswell

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Ahha. Thanks for the speedy reply. I thought I could get to within a few seconds. Maybe I should count my blessings.
Yes, count your blessings if it even still runs 8 days on a winding. Probably should add that if this clock has never been rebuilt and has not been recently service, don't expect the accuracy of new clock from one with 100+ years of accumulated wear.

RC
 

eemoore

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Please suggest what you would like to see.
You asked some help on the make and model , and date of your clock. We need to see pictures of the clock ,the clock movement, and any identifying marks such as logos and serial numbers ,etc. These are usually on the back plate of the movement. You will probably need to open the back of the clock and take some close up pictures . Just as RC said.
 

j0ckser

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I should have separated my queries. I could not understand why you would need pics re the adjustment. BUT you do need them to ID the model/year. I'll post this weekend.
 

j0ckser

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Also the clock has been rebuilt - I broke the hour chime spring, so it should operate 'like new'. They said they set the time, but when I got it home it was off, and I've been 'playing' with it ever since. As I offered earlier, perhaps my expectations are too high. I'll keep that in mind as I work on the speed adjustment.

Thank you all for your help. Much appreciated.
 
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R. Croswell

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I could not understand why you would need pics re the adjustment.
Various clocks use different means to adjust the speed. Depending on the type of adjustment method, there are a few issues that can cause erratic speed adjustments. For example, if your clock has an adjustable pendulum, turning the regulator nut at the bottom of the pendulum toward slow may not change the rate if the pendulum bob is sticking on the supporting rod. If you have a gear driven regulator at the top of the pendulum suspension spring (many Seth Thomas clocks do) I would have said make sure the gear is actually turning, they sometimes come lose. Some of these regulators move the suspension spring, others move a set of "chops" to pinch the spring at differing locations. I would have said to check how the suspension spring is attached and is it being pushed out of position by the rate adjuster. As you can see, we can't see what type of regulating system your clock has unless you post pictures that clearly show these parts. Therefore, we can only provide generic answers and guesses.

RC
 

wow

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Well, you have a Sonora chime clock. You said it had three springs so I assumed it was a Westminster with a 124 or other movement. Yours has a separate movement that is just for the quarter hour chimes. The upper movement is a common ST movement that has a wire tha extends down to the second movement to trigger the chimes. The mainspring in the chime movement is huge and very powerful.
Do a search for”Sonora Chime” on this forum and you will find all kinds of info.
 
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Willie X

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The rate adjuster appears to be jammed in the max fast position. Is the clock running fast? Willie X
 

j0ckser

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BTW, my lady has a finely tuned musical ear, and says the bells are flat. Are they tuneable (if such a word exists)?
 

j0ckser

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Well, you have a Sonora chime clock. You said it had three springs so I assumed it was a Westminster with a 124 or other movement. Yours has a separate movement that is just for the quarter hour chimes. The upper movement is a common ST movement that has a wire tha extends down to the second movement to trigger the chimes. The mainspring in the chime movement is huge and very powerful.
Do a search for”Sonora Chime” on this forum and you will find all kinds of info.
Please explain: 124 movement, ST movement.
 

wow

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Please explain: 124 movement, ST movement.
One of the most common Westminster chime movements is model 124. They also made other Westminster chime models. Yours is more rare and collectable. I have never heard a Sonora chime bell set that was flat. They are tuned perfectly to the four notes of the Westminster tune. Overtones are produced when the tune is playing and cause dissonances which may sound flat to your lady. I don’t think the bells are flat, though. Make a video and let us hear the chimes.
 

eemoore

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Also the clock has been rebuilt - I broke the hour chime spring, so it should operate 'like new'. They said they set the time, but when I got it home it was off, and I've been 'playing' with it ever since. As I offered earlier, perhaps my expectations are too high. I'll keep that in mind as I work on the speed adjustment.

Thank you all for your help. Much appreciated.
Now that you have posted pictures, just what were you" playing" with to try to adjust the rate.? Just curious; is it running accurately now?
 

j0ckser

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Now that you have posted pictures, just what were you" playing" with to try to adjust the rate.? Just curious; is it running accurately now?
I say 'play' because I'm not entirely sure that what I'm doing is correct.

I am using the double ended key into the s-f hole. I turn the key counter-clock to slow it (I think), and clockwise to speed up (I think). When I make an adjustment (1 'click') in either direction, there seems to be no change. When I make a full turn, there is a noticeable change, but I usually do that in frustration, and the clock definitely speeds up, or slows.

I'm definitely a newbie, so technique tips are in order.
 

eemoore

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Perhaps 'click' is a poor term, but as the horizontal gear moves the vertical gear, there's a small sound. I used click for want of a better term.
It sounds like you are doing it correctly. Go back and re-read the post #5 by RC. These clocks are never going to be as accurate as a quartz clock
or a long pendulum clock but should be pretty good. A little adjustment of the time occasionally is normal ( in my opinion). Glad you have taken an interest in keeping this clock ticking ! Best of luck.
 

shutterbug

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Regarding the bells, I don't think I'd try adjusting the tuning on them. The bells on mine are in tune, so perhaps one of hers was replaced at some time? Those bell nests can be purchased, but are very expensive.
 

Willie X

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If she has perfect pitch, the bells may well be flat as they were probably tuned by ear (not a standard) long ago. This does not mean that they are out of tune. If she hears a bell within the set that has a flat tone, that's another matter all together but it still may not be the bell itself at fault.

Note, bells are difficult to tune, even by bell makers. If someone volunteers to tune your bells, run like the wind. :)

I don't think anyone dated this clock but most were made around 1915.

Willie X
 

shutterbug

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I've know people with "perfect" perfect pitch, and others who can identify a note, but can't tell if it's right on, sharp, or flat. The first type would be really bothered by most chimers ;)
 

JayKosta

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The 'speed adjustment' is done by this mechanism -
by changing the length of the flat spring that suspends the pendulum.
The 'sled' that surrounds the flat suspension spring rides on the threaded rod - it should move upwards to make it run slower, and down for faster.
Perhaps movement of the 'sled' is not working because the large flat-headed screw is too tight and is binding.
 

Willie X

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The screw is supposed to have a shoulder. This together with the brass cup washer is supposed to place a slight tension between the slide and the rear plate at all times.

The slide is near the top but not jammed as I first thought. Willie X
 
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j0ckser

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I want to thank ALL who contributed to this thread. Many comments are very helpful. I will now wind the clock twice weekly; that may keep the time setting. At the moment it is consistently off by 10 seconds fast. I'll take that.
 

R. Croswell

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I want to thank ALL who contributed to this thread. Many comments are very helpful. I will now wind the clock twice weekly; that may keep the time setting. At the moment it is consistently off by 10 seconds fast. I'll take that.
10 seconds in 24 hours is not bad for a clock this, but this clock has no seconds hand, so how did you determine it was off by 10 seconds? If you are going by when it strikes, that can be a little off. The first task is to verify that the clock responds to rate adjustments. and you seem to have done that. There is always a little slop or backlash in the adjusting mechanism, so turning the key one "click" in the opposite direction from the last adjustment probably isn't actually changing the rate at all. Try to keep the drive gears under tension. For example, your clock is a bit fast, so move the key one click toward slow and wait for the clock to respond, then another click etc. but always going toward slow. If you overshoot the target and the clock is now slow, one click toward fast will have no effect because of the slack in the adjustment mechanism. Then turn the key a full turn toward fast, then back off one click less than a full turn toward slow. The adjuster will now be moving toward slow again with no backlash.

It can help if you give the pendulum a little tug downward after each adjustment to make sure the suspension spring is seated in the upper support (an adjustment toward "fast" can sometimes push the suspension spring upward).

I suggest that you make a graph showing the minutes (or seconds) fast/slow over a full 7 days without making any adjustments to the rate. You are chasing ghosts trying to make instantaneous adjustments throughout the week with the mainspring at various percent wound. Start the week fully wound (minus about one key turn) and set the clock. The goal is to have it end the week as close as possible to the actual time of day. You will likely find that it gains a few seconds during the first few days, settles down mid-weel, and begins losing a few seconds near the end of the week as the spring runs down. Then take a look at your graph and determine how much too fast it was at the fastest point on the graph. Divide that number by 2 and next week, set it that much slower than the actual time of day. Your clock will now be a bit slow early in the week, a bit fast mid-week, and a bit slow at the end of the week, but the actual error from the correct time of day will be about half as much than if you set the fully wound clock to the exact time of day to begin the week.

The time section of this clock is basically a Seth Thomas # 89 movement with modifications to link to the chimes unit. +/- one minute per week is considered pretty good for this movement. Some may even say +/- 5 minutes over a week is acceptable.

Regarding the flat bell tone, as I understand it, a bell does not have a true fundamental pitch but rather produces a complex set of harmonics that sounds like a specific musical note. Perhaps your true pitch listener is listening for something that isn't there. Bottom line is does the set of bells have a pleasant sound together, or does it sound like something is "wrong". Attempting to tune the bells is opening a can of worms. I agree with others, OK to change the position that the hammer hits the bell, and make sure the hammer tips are all in good condition.

RC
 

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