Help with Seth Thomas mantel clock

[MikeEll]

It was my pleasure to help.  I took plenty of pics while I was working on it, will post those a little later for anyone interested.

Edited April 9 by MikeEll

[tyl]

Mike - I just realized that the forum members including myself might be interested to know how you let down the mainspring.  Reading back through these posts it looks like no one exactly knew how to do it.

 

Thx.

[MikeEll]

11 hours ago, tyl said:

Mike - I just realized that the forum members including myself might be interested to know how you let down the mainspring.  Reading back through these posts it looks like no one exactly knew how to do it.

 

Thx.

Of course.  OH did comment what needed to be done using a stiff wire or similar. The following procedure needed to be done while the half plate was in position, as this is what prevents the click components falling apart and self-destructing the clock. Every clock with a mainspring will have some sort of ‘click’ arrangement to prevent the spring from simply unwinding as you wind it.  On your clock there are two mainspring barrels allowing it to run for 8 days or so with relatively small mainsprings.  The barrel ratchet wheels both engage with a shared intermediate gear attached to the winder.  You can see the click in the picture (see red), which is held between the main plate and half-plate (removed in this pic), and is itself spring loaded from the other side of the main plate to keep its teeth engaged.  To release the main spring power you need to securely hold the movement as you’ll need both hands free, or find a helper.  Fit the winder and apply just enough wind to lift the click (see red arrow), then insert a slim screwdriver or stiff wire to hold the click away from the ratchet wheels (see blue line).  This is the risky part where you mustn’t let the winder go.  Gently unwind as much as you are able to do safely,  probably only a single turn of the winder key if you are lucky, then remove the wire allowing the click to re-engage.  Rinse and repeat until no more power remains.

I discovered quite a few issues that needed to be sorted.  Obviously the wheel had been destroyed when the click let go, but there were also damaged teeth on both barrels.  I simply replaced these from a donor movement we were lucky to find.  The center wheel arbour was bent, and most of the brass bushings had cracked and come loose, along with the cracked center wheel pinion/gear that had the crack in the earlier pictures.  I think this is a design flaw in the clock, they really should have used steel for those parts.  I used the replacement center wheel with good bushings, then for the pinion/gear I opened up the crack with a fine file and soft-soldered it up.  Finally I closed up the central hole of the gear with a staking set to get a good friction fit on the shaft.

The other problem was I think there was a missing dial washer, which allowed the hour wheel to lift out of position, preventing the hour hand from turning.  I replaced that with a domed washer.  All that and a thorough clean and service, and she’s up and running.

I’ll upload more pictures when home at the weekend, the internet connection is crap in the hotel I’m in.

 

 

 

Edited April 10 by MikeEll

[tyl]

Got it.  Way over my pay grade.  The clock is keeping time perfectly and we have it in a place of honor.

Thanks again for all your help.

Here is a pic of the back of the clock.  Just beautiful

[MikeEll]

It’s a beautiful object isn’t it.  

[tyl]

Thought I had included a pic of the front.  

[MikeEll]

On 2/14/2025 at 6:24 PM, tyl said:

 

 

 

And how it looked previously…

Edited Friday at 05:52 PM by MikeEll

[MikeEll]

A few more pics….

The steel rule shows the position of the dial when fitted to the clock case.  You can see the dial washer I’ve added. Without that you can see how the hour wheel could move excessively allowing its teeth to disengage.  That’s one of the reasons the hour hand wouldn’t turn.

The cracked gear from the minute wheel, opened up with a file and soldered…

 

the central bore was closed up a little with a staking set to give it a good friction fit.

Stripped, ready to clean.