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Seth Thomas Speed Adjustment

armyguber

NAWCC Member
Oct 8, 2019
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I have a speed adjustment issue with a Seth Thomas Westminster mantle clock.

The speed adjustment is a tripod spring mounted on top of the clock’s balance wheel. Shifting the tripod legs to the right speeds the clock; to the left slows it. A brass nub on the balance wheel slides in a groove on the tripod that limits the range of the speed adjustment. I now have the nub at the full extent of the ‘faster’ setting but am still losing about five minutes per day. What can I do? IMG_6482.JPG IMG_6479.JPG
 

wow

NAWCC Member
Jun 24, 2008
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This usually indicates a power problem in the time train. It probably needs cleaning, bushings, and pivot polishing.
 

Wayne A

NAWCC Member
Sep 24, 2019
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How much total rotation of the balance are you getting stop to stop? Rotation around 360deg on full wind would be ideal.
If the rotation is looking good depending on what weights you have in place perhaps you can just relocate some. I've done this by relocating weights from the center spoke to the rim to get one regulated. THIS may help.
 

Willie X

Registered User
Feb 9, 2008
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army,

Often when these clocks are running slow, something is slightly dragging against the balance wheel. The fork can be dragging against the rollers, or the lower table can be twisted. This twist will cause the little overbanking tab to scrape against the inside (or outside) edge of the lower table. These defects can easily be heard with a good beat amplifier.

My next guess would be that the balance assembly has been in the ole ultrasonic cleaner. US cleaning will 'etch' the steel floating balance spring. This will cause a decrease in the springs thickness and thusly a slow rate.

Willie X
 

Bruce Alexander

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Feb 22, 2010
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Willie? Good the see you. Welcome back!
 

Willie X

Registered User
Feb 9, 2008
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Thanks Bruce wow and all the other clock peeps who left the kind words in my message box ... I'm feelin th luv. Willie
 
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shutterbug

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Oct 19, 2005
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We have been worried about you, Willie! There's even a thread about you :) Glad to see you back!
 

Dick Feldman

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Sep 1, 2000
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I have a speed adjustment issue with a Seth Thomas Westminster mantle clock.

The speed adjustment is a tripod spring mounted on top of the clock’s balance wheel. Shifting the tripod legs to the right speeds the clock; to the left slows it. A brass nub on the balance wheel slides in a groove on the tripod that limits the range of the speed adjustment. I now have the nub at the full extent of the ‘faster’ setting but am still losing about five minutes per day. What can I do? View attachment 634012 View attachment 634013
The clock you are working on has a floating balance escapement.
Those were mostly trouble free unless someone messed with them.
When they are/were tampered with, the problem usually is not with the balance but with the movement itself.
The balance assembly is usually a victim rather than the cause of the problem.
I know, it is the thing that moves, it HAS TO BE the problem.
Floating balances have not been in production for many years.
(The use was discontinued due to a patent dispute, not because they did not work)
Clock movements are machines and will wear just as any other machine.
Movements of that era produced with floating balance escapements have been around long enough to fail due to wear.
Probably three movement lifespans have passed since those were last available.
Before attacking the balance, I would suggest you solve any wear problems in the movement.
My bet is that once the rest of the movement is in good shape, the balance will work just fine.
I tried to enhance your photo to find a manufacturing date code but the photo is too foggy.
If you would like to know when the thing was made, please let us know what is stamped on the rear plate of the movement.
My best regards,
Dick
 

TooManyClocks

NAWCC Member
Feb 6, 2019
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Thanks Peter,
I checked the list a few days back and when I saw all the kind words in my private message box, I quickly decided to make another comeback. :)
Willie
You have been missed by all of us! Like the others, I’ve worried/wondered what happened to you. Good to see you back!:)

John
 
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Lynsey

Registered User
Nov 7, 2019
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Willie!!!!!! We all were so worried about you. Now, listen. Don't do that again, sheesh! We are so glad you are back!!! Stay happy, stay healthy and stay in touch. Your absence created a huge hole here in the forums, which no one else could fill.
 

shutterbug

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NAWCC Member
Oct 19, 2005
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Armygruber, I'm in agreement with Dick. The cause of the issue is probably not the balance. One way to know for sure is to remove the balance from the movement and test it free standing. If you turn it one full turn and let it go, it should rotate back and forth for a couple of minutes. If it does, the issue is elsewhere. You can remove the balance without worrying about exploding springs or other calamities. Just be careful with it so you don't injure it as you remove it ;)
 

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