Help with Seth Thomas mantel clock

[tyl]

Gentlemen - recently received a Seth Thomas mantel clock from wife's deceased uncle.   I am sure the clock has no value other than sentimental. However she would like for me to get it working again and I need help.

Pics are attached.

1) If I wind it clockwise it will start and run for a few minutes.  But winding it makes the minute hand move and I see no other way to set the hands.  It is also necessary to move the fast/slow window button before it will start ticking.

2)  The minute hand does not advance when the clock is ticking..  The hour hand will not move as if it is not pushed down tightly on the hour stem (assuming that is how it works).  I have tried to press it away from the clockface to free it up, then find a sweet spot to firm it down again.  No luck.

3)  The nut (?) securing the two hands - should it unscrew or is this a pressure fit?  If it screws down, how do I grasp it to unscrew it?

Or is this a lost cause?

Thanks for any help.

 

 

[watchweasol]

Hi.  Firts this is to get the movement out of the case to determine uts condition.  Assuming the hands are held on by a nut a pai4 of pliers will assist in its removal. Then the hands are removed. Place a polythene bag over the clock face and use two levers to lift the hands off. Then unscrew the winder ( opposite way to the wind usually anti clockwise). Remove the screws fron the case Bach and withdraw the movement. Then post pictures of the movement.

[AndyGSi]

I expect it's just gummed up.

It looks like the hands are just press fit and the knurled centre would be used to set the hands.

 

[tyl]

Fantastic.   A new project.  Thanks.  

OK; got it apart.  Pics attached.  The minute hand moves; the hour hand will not move even though the clock is working as I watch the mainspring.  If held perfectly straight it will work for quite some time; cant it forward or back and it will stop running.  

I can move the minute hand forward but the hour hand will not move even though the minute hand has seen two or three complete revolutions.  Feels like something inside is not connected to the hour hand. 

The hour gears on the front mesh fine.  The larger gear which fits over the main stem meshes with the smaller gear that apparently should be driven from something inside the front plate.  I have to guess there is a bad gear inside.

After removing the brass exterior case, I see that the fast/slow marker is slid completely to the left for fast.  It does not seem to move easily back to center using my finger carefully and I do not see any knob/screw to move it back and forth. 

So for now I am stumped.   It does look pretty clean inside.

Pics attached.

 

[tyl]

Follow up.  Clock ran all night.  I think the minute hand also moved.  However I removed it and it now will not fit securely on the stem.  

[watchweasol]

Hi. The min hand not fitting ?  How did you remove the hands?  Replace dial and hands and note positions wind up and re try. If nothing moves it’s time  investigate further as to why the center wheel is not being driven by the train.

[AndyGSi]

Can you confirm the minute wheel is rotating and it's just a hand fitting issue?

[tyl]

Used two levers gently to remove the hands.  Resolved - I determined that  without the wingnut winder attached the middle stem moves back and fourth maybe 1/8 inch; this was enough to prevent the minute hand from catching.  By trial and error I replaced the winder and the middle stem stopped moving; this forced it out a bit and the minute hand snapped on again - success.    The minute hand moves; the hour hand does not.  

Andy - minute wheel now moving; was operator error.

Minute hand moving; hour hand still not moving.  I did oil it yesterday and that may account for the fact that it now runs all day.

 

 

Attached are  better pictures of the interior mechanism with better light.

Edited February 15 by tyl
Add note

[AndyGSi]

46 minutes ago, tyl said:

Minute hand moving; hour hand still not moving.

The hour hand is just driven here so they need to mesh.

[tyl]

Understand.  They mesh fine.  Also there is no give here; the gears mesh and do not move.  No slack at all.

Edited February 15 by tyl

[AndyGSi]

So the minute gear rotates this which then rotates the hour.

I don't understand why if the minute rotates how this can't?

Edit

Unless it's 2 gears and the outer rotates but the inner doesn't?

Edited February 15 by AndyGSi

[tyl]

Need to look. 

[watchweasol]

Hi it is possible that the drive wheel has come loose on its arbour and free wheeling.

[tyl]

.

Thanks for your help.

Sounds reasonable.  Here is what I have found overnight:

1) clock runs

2) minute hand sometimes moves, sometimes does not.  It moved for 35 minutes then stopped at number 7 even though the clockworks was still running.  I tried to duplicate but since then it will not move.

3) the hour hand can be moved by turning the large left outside gear, the one with a very small gear attached in the middle of the larger gear.    

4) the minute hand will move using the knob at the rear but the hour hand will not move.  After removing the hands and the hour center arbor gear, I can tell the the very small gear attached to the minute arbor is loose.  Although it meshes with the gear necessary to move the hour hand, it is absolutely loose.  

I believe this is the problem.  I tried gently pressing it down the minute stem but nothing would catch.  How do I tighten up this gear?  Not sure why the minute hand does not move all the time.

 

Again thanks for your help.

[AndyGSi]

27 minutes ago, tyl said:

How do I tighten up this gear?

We need to see how this is fixed through the plate? Is it just riveted?

27 minutes ago, tyl said:

Not sure why the minute hand does not move all the time.

Have you tried running with just the minute hand and not the hour pinion as this could be what's causing it to stop.

[watchweasol]

If it’s come loose and can’t be tightened as is the only answer is dismantle the clock and investigate why it’s loose and why it will not tighten.   Or fix the pinion by some other method, wouldn't recommend glue.  Removing the center arbour and running the affected area between two files would likley provide a key for the pinion.

[tyl]

From my very last picture I believe that you can see that the front and back faceplates are bolted with three bolts and a nut on the rear.  Can also be seen on pics #12 and #14The front appears to be threaded and the bolts screw slightly through the faceplate.

 

Will try running the minute hand only.

 

OK - confirmed.  Minute hand not moving.  Arbor-pinion??  not sure what these are but there is about 1/32 inch slack; I must push it from the back to make it stick out enough for the minute hand to pop on.

Reconfirm - it is moving now after I pushed the arbor back and felt a faint tactile metallic connection.

 

Thx.

Edited February 16 by tyl

[watchweasol]

Sounds like a loss of friction on the pinion and center wheel.  It will probably work loose again with use, but woth a try at this juncture.

[tyl]

Are you suggesting that I try to force the gear backwards on the arbor if it is just a friction fit?  Tap it with a hammer?

Edited February 16 by tyl

[nevenbekriev]

On 2/16/2025 at 12:34 AM, AndyGSi said:

So the minute gear rotates this which then rotates the hour.

I don't understand why if the minute rotates how this can't?

Edit

Unless it's 2 gears and the outer rotates but the inner doesn't?

There is a crack where the arrow points

OP, the internal clutch of the center wheel probably is loose too

[AndyGSi]

8 minutes ago, nevenbekriev said:

There is a crack where the arrow points

OP, the internal clutch of the center wheel probably is loose too

Good spot.

[tyl]

Yes, I see it.  Also report that the minute hand stops of its own accord at about the 7; have tested this several times.

What to do now?

 

Appreciate the help.

[nevenbekriev]

You have to disassemble the movement and clean all the parts - it is dirty on the pictures. Then take a look at the central wheel - the clutch must be tightened.

I would try to file the walls of the crack of the small wheel (to enlarge the gap by cutting or filing) This will allow to close the hole by bending as to close the gap. Hopefully, when pressed back, the wheel will stay firm enough on the shaft.

[tyl]

Disassembly probably above my pay grade.  If I need to remove much more than the faceplate, I am probably doomed.  Makes sense that the crack just keeps widening and this defeats an attempt to secure it by friction to the arbor.

What would be used to file - is there such a thing as a file string like there is a similar saw for tree limbs?

[nevenbekriev]

Silversmith's saw can be used