amplitude

[Graziano]

Hi all ,an old watchmaker friend of mine he is 76 and still goes to work as a watchmaker everyday . Imagine his knowledge .Anyway on with the topic . As you all know sometimes when you service a watch it doesn't matter what you do the amplitude would be nice another 5 or 10 degrees higher .Peter (that's his name ) told me to get an old piece of ladies watch mainspring and cut it about 2 inches long and wire it to a piece of pegwood leaving an inch hanging past the end .Get a hold of the pallet fork with a holder of some sort ,tweezers will do if your steady enough and burnish inside of the folk where the impulse jewel makes contact . This works amazingly as it polishes the inside and gives an uninterrupted smooth passing of the impulse jewel .Takes a bit of time  but it works . I wanted to make videos of him doing some great stuff and upload but he won't let me Anyway give it a shot .

[jdrichard]

Hi all ,an old watchmaker friend of mine he is 76 and still goes to work as a watchmaker everyday . Imagine his knowledge .Anyway on with the topic . As you all know sometimes when you service a watch it doesn't matter what you do the amplitude would be nice another 5 or 10 degrees higher .Peter (that's his name ) told me to get an old piece of ladies watch mainspring and cut it about 2 inches long and wire it to a piece of pegwood leaving an inch hanging past the end .Get a hold of the pallet fork with a holder of some sort ,tweezers will do if your steady enough and burnish inside of the folk where the impulse jewel makes contact . This works amazingly as it polishes the inside and gives an uninterrupted smooth passing of the impulse jewel .Takes a bit of time  but it works . I wanted to make videos of him doing some great stuff and upload but he won't let me Anyway give it a shot .

Sounds like a good trick


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[Graziano]

3 minutes ago, jdrichard said:

Sounds like a good trick


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Hello jdrichard ,give it a crack , its amazing the difference it makes

[rodabod]

This does make me wonder about pallet refinements on some watch calibers. 

On fancier JLC calibers, they use a common pallet which is interchangeable with the pallets used in the same family of movements. But they finely polish and chamfer the edges to remove material where it is not needed. I always thought that this was purely to lighten the pallet fork to reduce inertia in the escapement and to improve aesthetics. But now I’m wondering if they did provide an improved surface inside the horns. I’m currently working on a Cal 488 with modified pallet, so will compare under a microscope....

[nickelsilver]

I work on a lot of old JLC movements, tending toward the smaller and thinner but also up to small clock size. They tend to have a very good finish inside the fork slot, even if the beveling on the non-functional areas is rudimentary. However, it's not uncommon to see (with microscope) a faint or even significant "dent" where the roller jewel smacks the slot, and touching this up does usually help. Seems worse with the old triangular roller jewels.

 

Mainspring as a burnishing tool is good technique. Even with thin spring though there can be very little clearance for the spring/burnisher with the guard pin so be careful!

 

Some of those old JLCs also have very high lift angles, like 56, 58, even 60.

[jdm]

3 hours ago, nickelsilver said:

 

Some of those old JLCs also have very high lift angles, like 56, 58, even 60.

What's the implication off that?

I should read some book. Promise, I will.

[rodabod]

If the lift angle is great, then it implies that the escapement is possibly less “detached” or has a larger amount of drop. Or, more broadly that the balance spends a longer time interfacing with the pallet fork during a cycle. 

It’s hard to speculate why it may have been designed in a particular way, but I’d welcome hearing any comments. 

In terms of the 1948 dated cal 488s which I’ve worked on, they achieve ruler-flat rate with negligible positional variation when running well. I believe that the balances would have been specially adjusted for this caliber. Otherwise they look the same as what you’d find on a Cal 450. 
 

I’ll need to pay more attention to the condition of the slot by the sounds of things.