blind alley

[brianw]

I wonder if any of you know this feeling….
I bought an old French mantel clock with the front facing exposed escape wheel and pallets.
The clock was a mess and the pallets missing so I took it all to bits, cleaned, burnished the pivots and put it all back together making sure all the wheels lined up with their corresponding manufacturers punched marks etc.
I turned up two new steel pallet pins and started everything ticking, but it stopped after a while. I didn’t have the original pallet pins, so assumed I had got the diameter of the new pins wrong and made some more with a slightly smaller diameter.
Once again the clock ticked away for a while, then stopped. So I made yet another set of pins, smaller still and, guess what, the clock ran for a while and then stopped.
By this time I was starting to doubt my ability (and my sanity) and was wondering if I really did enjoy this new found interest of mine. Then the penny dropped. There was something wrong with the chiming that was stopping the clock, not the pins.
I checked out the chiming train and everything was exactly as it was supposed to be, except, it would sometimes chime as soon as the rack dropped at the warning point. I looked very carefully and figured that the punch mark on the pin wheel was in the wrong place. I turned the wheel a couple of teeth and now the clock works fine and doesn’t stop.
I’ve learned some lessons. First, don’t focus on one thing to the exclusion of everything else, the fault might be elsewhere. Second, don’t always blindly trust punch marks, work it out for yourself. Third, you learn the most when things don’t work.
I’m new to clocks and I have learnt a lot from this clock and seeing the clock ticking merrily away and keeping good time has helped restore my confidence.
I spend an inordinate amount of time getting this clock to work.
I’m hoping that some of you have experienced the same frustrations and know exactly how I feel.

[bernie weishapl]

Brianw I think we have all been there at one time or another. Sometimes I find myself with tunnel vision even today after over 30 yrs. I remember some years ago I had a similar situation where the clock stopped after running for 3 to 5 minutes. I was sure it was the verge depthing. I don’t know how many hours I spent adjusting them up and down to no avail. What I finally found was the lever that lifted to set it to strike on the hour and half hour had a bad spot on it worn in it. I took it apart, filed, cleaned it up and polished it. It has been running in my house now for over 30 yrs. I have cleaned and oiled it 3 times during that time. So yes we have all been there and yes when you finally find the problem it is one of those slap the forehead and say duh moments! 😆

[willofiam]

@brianw wrote:

you learn the most when things don’t work

ABSOLUTELY!!!
did you figure out how to determine the pin size for a pin pallet, also referred to as a Brocot pin pallet escapement? William

[brianw]

My book tells me that the diameter of the pins should be less than the distance between the tips of the teeth on the escape wheel, but not too much less or they will be unable to generate enough impulse to keep everything going.
I tried three sizes and they all seemed to work. Good practice on the lathe…..
It’s reassuring to know that there are others out there who have experienced the same difficulties as me.

[arutha]

Hi brian, i have done quite a few french clocks now and you are quite right to no longer trust the pucnh marks, over the years wheels may have been swapped from other movements or replaced with new wheels, some of these movements don’t even have the punch marks. Its good to understand how it works and well done for turning up the new pallets, what method did you use for removing the unwanted steel on the pallets?
Paul.

[brianw]

Hi Paul,
Your comments on the punch marks are interesting. I assumed it was just a mistake that was made when it was first assembled. I learn something every day.
I turned up the pins with silver steel, then filed most of the flat with the pin still in the lathe then held the pin in my hand and filed the rest because I found it easier to keep it flat that way.
I took some advice from a book and turned a small lip in the middle of the pins so that it was easier to get them to stay vertical when fixing in place with shellac.
I then heated to red hot and dropped in water. Then polished with a fine slip and finally burnished. The flat bit was the easiest to get smooth, the curved, not so easy.
All in all a lot of work, especially given that four of the pins were not needed. Still, I’ve got some spares now, so next time it will be easier.
Brian

[arutha]

Nice explanation This is a job I have yet to do, all of the french clocks I have done have had the anchor type pallets until today I did my first Brocot style pallets. Fortunately they were in good order. Daryn can make these out of synthetic ruby when needed on visible escapements, just something to bear in mind if you ever get stuck for a set.
Paul

[daryn]

Gotta watch out fer them Friday afternoon punch men !

[daryn]

It’s real stone Paul , not synthetic, it’s just grown by man rather than naturally formed , which makes it more affordable and less likely to have floors , I can’t remember the firm I got it from must’ve been fifteen years ago, I do remember they made focusing lenses and prisms from it for big laser equipment,I bought off cuts from around the edges of the growing tube , primarily for chronometer locking stones n impulse jewels etc.
Good strong stuff!
Daryn

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