Pivot advice

[StuartBaker104]

Hi,

I am working on an Edwardian Buren mantle clock. It has an 8 day lever escapement (probably a cylinder when new as the platform is not original).

One of the pivots on the first train wheel after the barrel is heavily worn.  I've never replaced a pivot before, but I do have an 8mm lathe with a tailstock chuck.

I could refinish the worn pivot, and need to bush the plate anyway, but I would probably end up at about 0.9mm diameter rather than the original 1.2mm which feels wrong.  However, under high magnification, I can see that the pivot has been replaced before and that there appears to be a harline crack along the whole length of the arbor, so I am anxious about applying any unnecessary force.

Advice please?

Thanks

S

[oldhippy]

Could you post a close up picture, I'd like to see the whole movement including the platform.

[StuartBaker104]

Best I can do with my phone. For scale, the plates are 3.5" diameter...

[clockboy]

I have never used these but they might be a way for this repair https://www.cousinsuk.com/product/clock-wheel-quick-pivots 
Looking at your pic I am wondering if you could turn the pivot down & then re-bush with the appropriate bushing. As shown on this site

http://www.masterclockrepair.com/clockmovtrestoration.html

James A. Lea also has some good vids on youtube

[oldhippy]

I would turn the pivot down first and see what it looks like; I can't see a hairline crack, what makes you think the pivot has been replaced? The steel on these Swiss clocks is good quality and quite hard, if it has been replaced it might not be as good; the main reason for wear in this type of movement is the powerful main spring as it is an 8 day movement. The platform is the original; you might be confusing it with the similar French drum movement that had a cylinder platform. I would also say it is later then Edwardian more likely from the 1930’s. You might be able to clean it up with a good pivot file and then burnish.      

[StuartBaker104]

Thanks Hippy, I will give it a try and see how I get on. I guess I have nothing to lose by refinishing the existing pivot. I was just worried that the smaller diameter would not provide a large enough bearing surface, or might snap.  As long as the pivot doesn't snap, then the only danger is faster wear and I have to service again sooner.

Clockboy - yes I have seen those, but never heard of anyone using them. Downside would be that I would have to shorten the arbor which feels just wrong.

As to the other questions and provenance...

I can see the crack in the arbor with a microscope but can't photograph it. I can also see a ring on the end of the arbor where a new pivot has been fitted, but again can't get a picture.

The clock came to me from my Grandmother about 25 years ago. I didn't have the money for such things back then, but she paid to have it repaired, and I know it had a replacement platform at that time. The (smaller) screw holes for the original are visible in the picture. My grandmother told me that the clock was originally a 21st birthday present to her brother. He was born in 1905, so that would date it to 1926... so you are right, a bit later than Edwardian - he died in 1910. I've never really thought about the dates before, I seem to recall that the repairer who fitted the platform described it as Edwardian on his invoice and it stuck in my head.

[oldhippy]

I can't see the screw holes (not with my eyesight) its a good replacement platform and quite early, it would keep better time then a cylinder. Just make sure when you re-bush that it has the correct thickness to the plate and the oil counter sink isn't to deep that way the wheel will rotate on a good part of the pivot.  

 

 

 

 

 

 

[StuartBaker104]

Thanks Hippy - helpful advice. Not sure when I'll get to this but will keep y'all posted.

[StuartBaker104]

Got this sorted over the past couple of days. The pivot ended up a shade under 1mm, but all is running well now and the old girl is back where she belongs.

Hopefully you can see that platform better now Oldhippy, and the old screw holes. I imagine the platform was rescued from another clock as there seems to have been no need to cut the top off it...

Thanks for the help

S

 

 

 

 

[oldhippy]

Good repair there. Yes I can see the old screw holes mind you that looks to be a good replacement platform and you have good setting for the regulator showing the tail to be center. Just one miner thing, the pin through the arbor, it would have been better to have twisted it into a form of S shape so it couldn't possible come out.