A Good Day

[chris mabbott]

I did a quick disassembly just to quell the curiosity..

So here goes..

[chris mabbott]

The click is present and functioning…

[chris mabbott]

AHA, here’s the problem, someone has stolen the pallet fork, except this is not the pallet fork type, it’s the long rectangular model that runs on three sides. Maan, I can’t think of the name for this type??

So there we have it, the problem has been determined, now how much should we charge the client?

[arutha]

Thanks for putting us out of our misery Chris.
I am sure you could teach me more about watches than I could teach you. I would love to spend time working on them and doing what you do but for every hour I steal to play with them a customers clock is not getting done. I used to put aside 1 day per week for my own stuff but I have been using that day to restore lathes and my own clocks ready for sale. I think once I have some of this stuff out of the way I will then be able to spend more time on them.
Paul.

My first reply to your post – @Arutha wrote:

1. Missing pallet jewel/jewels or complete pallet.
2. Missing any wheel in the train or one of the wheels has become un-riveted from its arbor.

[chris mabbott]

I would say that the prize goes to you Paul Good on ya cobba 😆 I think that means well done?

[chris mabbott]

A bit of good and bad news….. I had a Hampden 18s pallet in my stock, but the pivot size is too large

So I’m faced with the following…

1. Reduce the pivot size to fit the jewels
2. Replace the 2 rubbed-in jewels with larger hole size
3. Wait and see if I can find a proper match.

Decisions, decisions

---

>

[arutha]

I supose it depends on how fussy you are about keeping it original, as you well know with a lot of older watches now you can’t just phone a supplier and expect them to have the parts on the shelf. So if it were me I would first have a scout about to see if I could locate the correct part at a reasonable price. If I found that was going to be a problem I think I would be inclined to reduce the pivot size as if things went wrong it would be possible to re-pivot the pallet arbor. With bigger pivots and larger jewels I wonder if the increase in friction would cause any problems in getting the watch to run as it should?
Paul.

[chris mabbott]

Again, I agree, I hate like hell to “modify”, it’s my last resort, so I’ll probably do what I love to do, hunt

That’s a good point Paul regarding friction, but if we look at the formula to determine the coefficient of friction between two dynamic or static objects …

Ff = µFn whereas …

– Fr is the resistive force of friction
– μ is the coefficient of friction for the two surfaces
– N is the normal or perpendicular force pushing the two objects together
– μN is μ multiplied by N

Contact area is not a factor in determining friction between two objects, whether static or dynamic.
Friction is dependent on three factors..
1. The normal force between two objects in contact i.e. the component force perpendicular to the contact surface.
2. The specific materials involved which determines the coefficient of friction. in this case steel and mineral
3. Sliding with respect to one another, whether the friction is static or dynamic.

I’ve never seen in any of the equations involved in classical mechanics where the area of contact is taken into account.
So I would think that all things being equal, as in the alignment of the pallet to this particular movement, size of the arbor, shaft length in relation to determining the stones mating surface to the escape teeth etc etc… That it should work 😆

But like all things watch related, it will cause me blood, sweat & tears, not the band
Now I’m going to kill computer generated baddies on my newly arrived.. Wolfenstein New Order game Mwuuhuhuhuh 😈

[Author]

Posts