Ronda staff as replacement in Pierce 103

[bsoderling]

Hi again....

 

Need to pick your brains on balance staff replacements.

 

So I have another one of these Pierce 103 movements to work on, this is the 3rd so far. I start to know them when I see them :-)

 

This one has a broken balance staff and I have learned the hard way that microns count in this area. The 103 was apparently fitted with several different staffs and the one coming closest to the measurements I take on the broken one is Ronda 2028.

 

BUT... there are still small differences.

 

I measure the part where the roller sits to 0,45 mm (Rn2028 - 0,44mm) There's a photo attached showing where I measure.

 

The part for the hairspring collet I measure to 0,52 mm (Rn2028 - 0,50 mm)

 

Will anyone with experience out there take a guess wether my roller will stay on or fall off the Rn2028 considering that the Ronda staff appears 10 micron less in diameter?

 

In a larger context I suppose my question boils down to how trustworthy these Ronda staffs are as replacements as I suppose they were a kind of 2nd source and not "orignal parts" ?

 

 

 

 

 

 

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[bsoderling]

Correction....

The photo is actually showing the poition along the staff that gives me the 0,44 reading i.e. Only halfways on the part where the roller sits.

Here's another picture showing the 0,44 mm position:



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[matabog]

I am sure you can squeeze the collet. About the roller, just try it and see how it goes. I think you can squeeze it also, but in a staking tool.

Just don't use superglue!

[bsoderling]

Hello matabog,

As you say, there's probably no better alternativ than trying it out.

I have used my staking set with a hollow stake to tighten a collet. Worked fine.

Not sure it's possible with the roller though...?

Superglue can be tempting sometimes but I'll do my best to stay away from that stuff :-)




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