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I have an old orphaned pocket watch movement of unknown type/maker; with a jewel in need of replacement.  It's on the train bridge, and it's for the 3rd wheel.  I got myself a Seitz jewel setting tool and I've popped the jewels from a 10-movement lot (steampunk) purchase on ebay.  I was able to place the jewels in small "lots" by OD. 

I will take the depth measurement from the train bridge, then pop the broken jewel out.  Without having an inside micrometer; would using a reamer (not turning it, just for sizing purposes) be a rational way of determining the size of the hole in the mainplate?  Hope that was clear.  This is just in case the existing jewel doesn't come out in one piece. 

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45 minutes ago, SparkyLB said:

I have an old orphaned pocket watch movement of unknown type/maker; with a jewel in need of replacement.  It's on the train bridge, and it's for the 3rd wheel.  I got myself a Seitz jewel setting tool and I've popped the jewels from a 10-movement lot (steampunk) purchase on ebay.  I was able to place the jewels in small "lots" by OD. 

I will take the depth measurement from the train bridge, then pop the broken jewel out.  Without having an inside micrometer; would using a reamer (not turning it, just for sizing purposes) be a rational way of determining the size of the hole in the mainplate?  Hope that was clear.  This is just in case the existing jewel doesn't come out in one piece. 

So guessing the seitz set didn’t come with the jeweled pivot sizer. These are hard to come by. I would say trying anything you can to get the correct measurement will work if you don’t have the right measuring device. But i would say you could also measure the pivot with a digital caliper and If you had the matching wheel to each jewel on parts movements you could compare the pivot sizes but you already removed them all. And I would check end and side shakes after your selected jewel is installed. A little more play is allowed on the train then the balance or escapement.

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1 hour ago, SparkyLB said:

I have an old orphaned pocket watch movement of unknown type/maker; with a jewel in need of replacement.  It's on the train bridge, and it's for the 3rd wheel.  I got myself a Seitz jewel setting tool and I've popped the jewels from a 10-movement lot (steampunk) purchase on ebay.  I was able to place the jewels in small "lots" by OD. 

I will take the depth measurement from the train bridge, then pop the broken jewel out.  Without having an inside micrometer; would using a reamer (not turning it, just for sizing purposes) be a rational way of determining the size of the hole in the mainplate?  Hope that was clear.  This is just in case the existing jewel doesn't come out in one piece. 

I'm not an expert, but that is definitely what I would do!

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Thank you kindly to both.  Forgot to mention, I have a JKA Feintaster so I know the jewel ODs.  If luck prevails, I'll have several correct OD jewels from which to choose, and I'll try the 3rd wheel in the pivot hole for side shake.  I'm happy to hear that there's a bit more wiggle room with sideshake for the train wheels. 

And no, Saswatch88, the Seitz unit lacked a jeweled pivot sizer.  But now this is something that I can look for--now knowing the name.  I started a thread about a week ago about this.  I was calling them pin gauges.  The absolute smallest pin gauge I could find was .060", or 1.5mm, far too large for our work. 

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You could also measure the pivot diameter using your JKA Feintaster (congrats on having such a fine tool!), but beware that when you get below about 0.12mm there's a real risk of forming flats on the pivot. I guess the safest and most convenient way to find the diameter of the pivot hole is to use a Seitz Jeweled Pivot Gauge (not "sizer") as seen in the below picture. They come up on eBay now and then but are unfortunately often very expensive. If you can get one for around $200 you'll be pretty lucky. I think you might find this thread interesting.

s-l1600.jpg

Edited by VWatchie
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1 hour ago, SparkyLB said:

Thank you kindly to both.  Forgot to mention, I have a JKA Feintaster so I know the jewel ODs.  If luck prevails, I'll have several correct OD jewels from which to choose, and I'll try the 3rd wheel in the pivot hole for side shake.  I'm happy to hear that there's a bit more wiggle room with sideshake for the train wheels. 

And no, Saswatch88, the Seitz unit lacked a jeweled pivot sizer.  But now this is something that I can look for--now knowing the name.  I started a thread about a week ago about this.  I was calling them pin gauges.  The absolute smallest pin gauge I could find was .060", or 1.5mm, far too large for our work. 

The one VW sent is it their other kinds besides seitz. hard to find complete without missing jewels, they also make a gauge that is the slide in type kinda like a mainspring gauge. It’s a metal plate with a slit in it and you take the pivot and slide it down till it stops and that will take you the pivot size and can gauge the jewel size needed. I have one but I don’t have it right now to send a picture.

Edited by saswatch88
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2 hours ago, VWatchie said:

You could also measure the pivot diameter using your JKA Feintaster (congrats on having such a fine tool!), but beware that when you get below about 0.12mm there's a real risk of forming flats on the pivot. I guess the safest and most convenient way to find the diameter of the pivot hole is to use a Seitz Jeweled Pivot Gauge (not "sizer") as seen in the below picture. They come up on eBay now and then but are unfortunately often very expensive. If you can get one for around $200 you'll be pretty lucky. I think you might find this thread interesting.

s-l1600.jpg

Yes.  That's the one I saw on eBay right after I read the first two replies.  I see that quite a few jewels are missing.  I see the utility of this tool for finding the size of a pivot on a wheel or pallet, but as mentioned, I can get the pivot diameter with  my JKA.  I could be barking up the wrong tree here; but I was puzzled by what to do if I have some jewels, and they'll fit in the main plate, but I don't know if the pivot hole of the jewel is the correct size.  Is there a set of gauges made for this purpose?  Or, perhaps am I approaching this unlike most do?   

 

2 hours ago, saswatch88 said:

The one VW sent is it their other kinds besides seitz. hard to find complete without missing jewels, they also make a gauge that is the slide in type kinda like a mainspring gauge. It’s a metal plate with a slit in it and you take the pivot and slide it down till it stops and that will take you the pivot size and can gauge the jewel size needed. I have one but I don’t have it right now to send a picture.

Thank you.  Yes I'm familiar with the graduated taper-typer tool. 

Other than the Bergeon tool with the 3 tapered pins that a jewel is slid onto and read wherever it stops along the pin--I haven't seen anything else to measure the internal diameter of the jewel's hole. 

I don't think I want to know how much that Bergeon tool costs. 

 

Thank you both again.  :)

 

 

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VWatchie, thank you ever so much for those videos.  While I am quite satisfied with my new re-jeweling tool, it seems I am missing quite a few stumps.  I see the size of the stump is quite significant, lest the mainplate no be held perpendicular to the pusher/reamer. 

I'm learning quite a lot here. 

I've taken all 3 or Marks courses, and am quite satisfied with the progress I'm making.  It's guys like you who make the experience that much easier. 

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14 minutes ago, SparkyLB said:

Yes.  That's the one I saw on eBay right after I read the first two replies.  I see that quite a few jewels are missing.  I see the utility of this tool for finding the size of a pivot on a wheel or pallet, but as mentioned, I can get the pivot diameter with  my JKA.  I could be barking up the wrong tree here; but I was puzzled by what to do if I have some jewels, and they'll fit in the main plate, but I don't know if the pivot hole of the jewel is the correct size.  Is there a set of gauges made for this purpose?  Or, perhaps am I approaching this unlike most do?   

 

Thank you.  Yes I'm familiar with the graduated taper-typer tool. 

Other than the Bergeon tool with the 3 tapered pins that a jewel is slid onto and read wherever it stops along the pin--I haven't seen anything else to measure the internal diameter of the jewel's hole. 

I don't think I want to know how much that Bergeon tool costs. 

 

Thank you both again.  :)

 

 

I bought vintage one off eBay for $15

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10 hours ago, SparkyLB said:

Yes.  That's the one I saw on eBay right after I read the first two replies.  I see that quite a few jewels are missing.  I see the utility of this tool for finding the size of a pivot on a wheel or pallet, but as mentioned, I can get the pivot diameter with  my JKA.  I could be barking up the wrong tree here; but I was puzzled by what to do if I have some jewels, and they'll fit in the main plate, but I don't know if the pivot hole of the jewel is the correct size.  Is there a set of gauges made for this purpose?  Or, perhaps am I approaching this unlike most do?

No, not as far as I'm aware. If you have an existing jewel with (a known diameter but) an unknown pivot hole diameter I guess the only way would be to drop the jewel on to the pivot and then gently manipulate the jewel with your tweezers to get a feel for the side-shake. Anyway, it's just an idea which I've never tried so I don't know how well (or badly) it would work. Hopefully someone else is more informed or have a better/more correct method for determining the diameter of jewel holes.

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Pin gages (sometimes called plug gages) are used to measure small holes. Some watch tool makers and supply houses offered small sets back in the day, they often were in 0.02mm increments so not particularly precise but will get you close. Cary is the main maker of these tools in Switzerland but a box of 50 in 0.01mm increments is about a thousand bucks... Of course you can find them secondhand but they still command a high price. Many watchmaking schools used to have students make a set of pin gages from about 0.05mm up to around 0.25mm. You see the sets on Ebay sometimes, usually in nice little trays with holes for the gages with the school name and each gage numbered by size.

 

As for using a reamer to measure the hole in the plate- for jewel holes, Obama was a German watch tool maker that made a tapered pin gage, like a long precise smoothing broach. The taper pin was in a handle which had a scale on it, you put the jewel on the taper, retract the pin until the jewel touches the end of the tool, and read the size. You can approximate the same thing if you have small smoothing broaches: slide the jewel on the broach, then press it into pithwood (fat side of broach first) until the jewel sits on the wood. Remove jewel and measure broach where it exits the pithwood. You won't be precise within microns but pretty darn close. So yes, you can use the same technique for finding the hole size in the plate.

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11 hours ago, nickelsilver said:

Pin gages (sometimes called plug gages) are used to measure small holes. Some watch tool makers and supply houses offered small sets back in the day, they often were in 0.02mm increments so not particularly precise but will get you close. Cary is the main maker of these tools in Switzerland but a box of 50 in 0.01mm increments is about a thousand bucks... Of course you can find them secondhand but they still command a high price. Many watchmaking schools used to have students make a set of pin gages from about 0.05mm up to around 0.25mm. You see the sets on Ebay sometimes, usually in nice little trays with holes for the gages with the school name and each gage numbered by size.

 

As for using a reamer to measure the hole in the plate- for jewel holes, Obama was a German watch tool maker that made a tapered pin gage, like a long precise smoothing broach. The taper pin was in a handle which had a scale on it, you put the jewel on the taper, retract the pin until the jewel touches the end of the tool, and read the size. You can approximate the same thing if you have small smoothing broaches: slide the jewel on the broach, then press it into pithwood (fat side of broach first) until the jewel sits on the wood. Remove jewel and measure broach where it exits the pithwood. You won't be precise within microns but pretty darn close. So yes, you can use the same technique for finding the hole size in the plate.

I had to read that second paragraph a couple of times but that makes good sense.  I know home depot sells brass round stock; and this would be a great project.  I have no cross slide apparatus, but I have a lathe, a tool rest and several gravers.  I can make cylinders and turn down the ends and sneak up on the diameters, so to speak.  It will take some doing, but this hobby seems to be all about time.  You folks are generous with your knowledge--and that's so very important for an old craft to remain viable.  Thank you again.   

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You might also find this previous topic of interest too: https://www.watchrepairtalk.com/topic/13033-where-to-buy-jewel-holes

Quoting myself! : Whilst measuring the outside diameter of your jewel to find a replacement with a micrometer is good there may be times when you want to double check or where the jewel is shattered. I usually do this kind of thing using known precision drill bit diameters. Since the OD of jewels is typically in 0.1mm increments (0.8, 0.9, 1.0 etc.) then you can double check an evacuated jewel hole's size with a reference drill bit.

You can pick up micro drill bits sets quite easily on a site like ebay.

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