What tool for measuring jewel holes ?

[wls1971]

Hi,

I have a lecoultre inline banjo type 8 day clock cal.250 that needs a new jewel fitting. What tool do I need to measure the diameter of the jewel hole ? Or can I just measure the pivot on the wheel and use that measurement ?

 

Wayne

[sstakoff]

I have a jewel hole gauge and a pivot gauge similar to these:

 

The problem is that these are VERY expensive tools. You can also measure the pivot using a micrometer. You will need a jewel with a hole slightly larger than the pivot. Of course you also need to know the measurement of the outside diameter of the jewel in order to make sure it can be fit into the plate or chaton. You may need to ream the hole to a larger size. You will need a jeweling set for reaming and pushing in the new jewel. Are you certain that the jewel is friction fit??

[wls1971]

Hi,

Thanks for reply,

The jewels in the clock are mostly friction fit, I have a favorite jeweling set so have means to fit a new jewel.

I shall search ebay and try and find gauges like the ones you have shown, the clock will probably go on the back burner for a while until I can source a suitable gauge,

 

Wayne

[sstakoff]

You may be better off measuring the pivot and then ordering a selection of jewels around that size. This may be significantly cheaper than buying the gauges. The hole gauge like the one pictured usually sells for about $300-500 when I've seen them. And the pivot gauge around $150-$250. Ouch!

[wls1971]

I think I may opt for saving and buying the gauges, I have the outlook that if I don't use them enough I can always resell them later.

I bought the jeweling set for £40.00 thinking, that it may be useful one day so I now have a project to use it on, I have been practicing on old movements pushing jewels out and resetting so think I will be able to manage the job( famous last words).

I shall keep my eyes peeled and hopefully I can source them at reasonable prices,

Many thanks for your help,

 

Wayne

 

 

 

[szbalogh]

Well, i would make my own gauges

http://www.tp178.com/jd/watch-school/3/ws3a.html

Or You just turn down a piece of brass that fits in the hole and then measur with micrometer.

Edited July 23, 2016 by szbalogh

[VWatchie]

On 7/23/2016 at 8:25 AM, szbalogh said:

Well, i would make my own gauges

http://www.tp178.com/jd/watch-school/3/ws3a.html

Or You just turn down a piece of brass that fits in the hole and then measur with micrometer.

I'm afraid the link has transformed into a spam link!?

[jdrichard]

Sent from my iPhone using Tapatalk Pro