What should I do for my first attempt at changing jewels

[GregG]

I purchased a J Calame Robert wristwatch, and discovered that two of the crystals were broken, one on the third wheel, and one on the escape wheel.

I really would like to add this watch to my personal collection, so I'd like to replace the jewels, and I want to know what my best option is.  I already purchased a incomplete Seitz tool set a while back.  It's in rough shape, so I spent some time today polishing the surfaces to make sure the action is smooth, but I still have a lot of work to do.  Other than the main Seiitz tool, the set only included the pusher spindle and a handful of reamers (no reamer spindle though).

My other option is to buy a Chinese clone Horia tool, which includes 24 pump pusher/anvil pairs, for a total of $220 including shipping.  A few videos I've watched on YouTube have said that these are perfectly acceptable to use, so I'm not worries about the quality.

Which option should I go with?

Next: what nuances or technicalities should I know about the process of replacing a jewel?  Again, I've watched a few tutorials on the topic, so I know the gist of the process.

I suspect that as soon as I push out the jewel, it'll fall into pieces.  With that in mind, how do I pick the appropriate diameter replacement?  The same goes for the hole size.  I can measure the pinion size, but what amount should I add to that measurement to allow for acceptable sideshake?

Another watch I have has a similar problem, except worse.  The hole jewel in the balance is complete shattered and disintegrated except for a tiny leftover shard.  What do I do to measure the diameter of the jewel, and how do I properly size the hole for this?

Edited June 19, 2022 by GregG

[Paul80]

For the hole in the jewel size you can buy a guage but they are really expensive, normally over 200 for a used on on eBay, if you are careful you can use a micrometer, an ordinary engineering one should do if you have a light touch, again there are watchmakers micrometer but again they are expensive, as is everything with watchmaker in the title. A low cost thickness gauge should also work, just make sure you get one that can read down to 0.01mm rather than the cheapest which only go down to 0.1mm.

As for the outside diameter if the cracked ones can be held together you should be able to use the micrometer/thickness gauge, as for the smashed one, if the hole looks the same as the others try the same size as those are, if not you could maybe try different size drills as a bore gauge (the blunt end) to get you close then just broach the hole until it fits.

I would await a more knowledgeable reply first though.

I use the lowe ISH cost Chinese Horia clone  and never had any issues, not that I have used it a lot yet, mainly just moving jewels to adjust end shake but I foresee it having no issues if used to change a jewel.

Hope this has been of help

[GregG]

Hi Paul, thanks for the reply.  I've got a digital micrometer that measures out to 0.001mm. 

Regarding the watch with the smashed jewel, it's the jewel that belongs to the balance. If it was a regular arbor, then it wouldn't matter where I measured since the arbors are cylindrical.

But the balance staff is conical/tapered.  Where on the staff should the diameter be measured?

[Paul80]

Not sure with that one, you are beyond my limited knowledge already.

Hopefully one of the more skilled members will be along soon to enlighten us both regarding where to measure a conical staff, I assume near the thin end but you know what they say about assumptions

[Neverenoughwatches]

14 hours ago, GregG said:

I purchased a J Calame Robert wristwatch, and discovered that two of the crystals were broken, one on the third wheel, and one on the escape wheel.

I really would like to add this watch to my personal collection, so I'd like to replace the jewels, and I want to know what my best option is.  I already purchased a incomplete Seitz tool set a while back.  It's in rough shape, so I spent some time today polishing the surfaces to make sure the action is smooth, but I still have a lot of work to do.  Other than the main Seiitz tool, the set only included the pusher spindle and a handful of reamers (no reamer spindle though).

My other option is to buy a Chinese clone Horia tool, which includes 24 pump pusher/anvil pairs, for a total of $220 including shipping.  A few videos I've watched on YouTube have said that these are perfectly acceptable to use, so I'm not worries about the quality.

Which option should I go with?

Next: what nuances or technicalities should I know about the process of replacing a jewel?  Again, I've watched a few tutorials on the topic, so I know the gist of the process.

I suspect that as soon as I push out the jewel, it'll fall into pieces.  With that in mind, how do I pick the appropriate diameter replacement?  The same goes for the hole size.  I can measure the pinion size, but what amount should I add to that measurement to allow for acceptable sideshake?

Another watch I have has a similar problem, except worse.  The hole jewel in the balance is complete shattered and disintegrated except for a tiny leftover shard.  What do I do to measure the diameter of the jewel, and how do I properly size the hole for this?

Eyup lads. A relatively easy and cheap way to  measure the jewel hole. Done under a scope, a fine smoothing broach inserted until full thickness of jewel hole reached, mark the broach depth and then measure the broach thickness at that point. 

30 minutes ago, Paul80 said:

Not sure with that one, you are beyond my limited knowledge already.

Hopefully one of the more skilled members will be along soon to enlighten us both regarding where to measure a conical staff, I assume near the thin end but you know what they say about assumptions

The pivot on a staff will be same thickness throughtout until it reaches the cone  ( conical staff ) . Hope this  helps chaps.

Edited June 19, 2022 by Neverenoughwatches

[Nucejoe]

On 7/22/2016 at 4:03 PM, sstakoff said:

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??

Check this  by member sstakoff ,  also vids on youtube  by member jdrichard.

Without special guage the task can get frustrating. 

And if you feel lucky get an assortment of jewels.

Good luck

[GregG]

Is there a typical amount of sideshake that you give the pinions/staff?  Because I could simply measure the diameter of the pinion out to 0.001mm, and then buy a jewel with a hole diameter to accompany the pinion + X amount of side shake.

Also, call me crazy, but does the underside of the center wheel bridge (2nd picture) look like a rubbed in jewel?

Edited June 19, 2022 by GregG

[Paul80]

It does look a little suspicious like lit might be, good luck with that one if it is

[GregG]

9 hours ago, Nucejoe said:

Check this  by member sstakoff ,  also vids on youtube  by member jdrichard.

Without special guage the task can get frustrating. 

And if you feel lucky get an assortment of jewels.

Good luck

Hi Joe, I did find that thread when I was initially looking for some info, and unfortunately, yes the tool prices are still outrageous.  Though instead of buying a $250+ gauge, I was thinking of buying some wires of varying gauge.  For example, wire gauges between 33 and 44 are:

0.18mm diameter, 0.16mm, 0.143mm, 0.127, 0.113, 0.101, 0.090, 0.080, 0.071, 0.063, 0.056, and 0.050mm.

Especially towards the end of that list, I have greater than 0.01mm resolution.  I might be able to have a makeshift jewel gauge by seeing what wires I can thread through the hole.

[Paul80]

For larger holes the blunt end of a micro drill makes a useful bore gauge.

Something like these.

https://www.ebay.co.uk/itm/154309135247?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=Vkmw649BTHe&sssrc=2349624&ssuid=cJqjENlHSBe&var=&widget_ver=artemis&media=COPY

Just double check the exact size with a micrometer or something similar.

They will do down to 0.3mm you my find sets that go even smaller, I have seen drills down to 0.1 but they tend to have a thicker shank so no use as a bore gauge.

 

[nickelsilver]

The jewel in the photo is rubbed in. Replacing it with another rubbed in jewel is usually a very frustrating exercise, even if you have a large stock of the proper jewels. Replacing with a friction jewel, trying to get it to seat and stay in the original setting, is very hard, as the friction jewel doesn't have a large enough bevel (usually) without modification, and the diameter is often rather oddball. Reaming it out to a standard friction jewel size would be OK, but even though this was promoted as a great thing back when friction jewels and Seitz tools became available, it can get sort of ugly looking. If you are lucky and careful, you can ream it open just to where the walls of where the old jewel sat, and get enough friction; otherwise you have to ream out the whole entire setting, checking that a new friction jewel large enough is available first!

 

For sideshake, generally about 0.01mm is correct. If a tiny watch with 0.07mm pivots, you'd want less, like 0.005mm, for larger pivots like a center wheel it can be a bit more. If checking pivots with a micrometer, be very, very careful to use the lightest touch possible, as the mechanical advantage of the fine pitch thread and the hard (often carbide) faces of the mic anvil and spindle can put tiny flats on the pivot. If checking very small pivots there's really no replacement for a jewel gage.

[RichardHarris123]

2 minutes ago, nickelsilver said:

The jewel in the photo is rubbed in. Replacing it with another rubbed in jewel is usually a very frustrating exercise, even if you have a large stock of the proper jewels. Replacing with a friction jewel, trying to get it to seat and stay in the original setting, is very hard, as the friction jewel doesn't have a large enough bevel (usually) without modification, and the diameter is often rather oddball. Reaming it out to a standard friction jewel size would be OK, but even though this was promoted as a great thing back when friction jewels and Seitz tools became available, it can get sort of ugly looking. If you are lucky and careful, you can ream it open just to where the walls of where the old jewel sat, and get enough friction; otherwise you have to ream out the whole entire setting, checking that a new friction jewel large enough is available first!

 

For sideshake, generally about 0.01mm is correct. If a tiny watch with 0.07mm pivots, you'd want less, like 0.005mm, for larger pivots like a center wheel it can be a bit more. If checking pivots with a micrometer, be very, very careful to use the lightest touch possible, as the mechanical advantage of the fine pitch thread and the hard (often carbide) faces of the mic anvil and spindle can put tiny flats on the pivot. If checking very small pivots there's really no replacement for a jewel gage.

What is a rubbed in jewel? 

[nickelsilver]

10 minutes ago, RichardHarris123 said:

What is a rubbed in jewel? 

Some good info including a video from member szbalogh in this thread: Replacing a balance jewel

[Nucejoe]

Just replacing a rubbed in  jewel. 

Vid by Mark.

 

[GregG]

2 hours ago, nickelsilver said:

The jewel in the photo is rubbed in. Replacing it with another rubbed in jewel is usually a very frustrating exercise, even if you have a large stock of the proper jewels. Replacing with a friction jewel, trying to get it to seat and stay in the original setting, is very hard, as the friction jewel doesn't have a large enough bevel (usually) without modification, and the diameter is often rather oddball. Reaming it out to a standard friction jewel size would be OK, but even though this was promoted as a great thing back when friction jewels and Seitz tools became available, it can get sort of ugly looking. If you are lucky and careful, you can ream it open just to where the walls of where the old jewel sat, and get enough friction; otherwise you have to ream out the whole entire setting, checking that a new friction jewel large enough is available first!

 

For sideshake, generally about 0.01mm is correct. If a tiny watch with 0.07mm pivots, you'd want less, like 0.005mm, for larger pivots like a center wheel it can be a bit more. If checking pivots with a micrometer, be very, very careful to use the lightest touch possible, as the mechanical advantage of the fine pitch thread and the hard (often carbide) faces of the mic anvil and spindle can put tiny flats on the pivot. If checking very small pivots there's really no replacement for a jewel gage.

 

3 minutes ago, Nucejoe said:

Just replacing a rubbed in  jewel. 

Vid by Mark.

 

Hmmm, this repair might end up being more trouble than it's worth.

I like the idea of reaming it out to update it to modern standards, but...

From a few other posts I saw, friction jewels are straight-walled, whereas rubbed in jewels are beveled to allow the metal or be rubbed over it.  I don't have the tools to grind down a jewel.  And even if I did, I'd probably mess it up a few times before I got the hang of it, and those little suckers are expensive!

FWIW, the watch is working surprisingly well given the amount of dirt and debris in it, so I guess the broken jewels aren't affecting it too much.

Thoughts?

Edited June 20, 2022 by GregG

[Nucejoe]

 Broken jewel can eat into the pivot so you wouldn't want to let the watch run and your sure to get just what you asy " a mess" if you try fitting  a rubbed in jewel without the right tools and experience. So looks like this watch would have to wait for a while to get fixed. 

What kind of amplitude are you seeing? 

Regs

[GregG]

24 minutes ago, Nucejoe said:

 Broken jewel can eat into the pivot so you wouldn't want to let the watch run and your sure to get just what you asy " a mess" if you try fitting  a rubbed in jewel without the right tools and experience. So looks like this watch would have to wait for a while to get fixed. 

What kind of amplitude are you seeing? 

Regs

It's been disassembled now, so I don't remember what the amplitude was.  I would estimate 180*.  Granted I'm not saying it's running well, I'm saying it's running well considering it's condition.  It was keeping ok time however, albeit too slowly.

[GregG]

16 hours ago, nickelsilver said:

The jewel in the photo is rubbed in. Replacing it with another rubbed in jewel is usually a very frustrating exercise, even if you have a large stock of the proper jewels. Replacing with a friction jewel, trying to get it to seat and stay in the original setting, is very hard, as the friction jewel doesn't have a large enough bevel (usually) without modification, and the diameter is often rather oddball. Reaming it out to a standard friction jewel size would be OK, but even though this was promoted as a great thing back when friction jewels and Seitz tools became available, it can get sort of ugly looking. If you are lucky and careful, you can ream it open just to where the walls of where the old jewel sat, and get enough friction; otherwise you have to ream out the whole entire setting, checking that a new friction jewel large enough is available first!

 

For sideshake, generally about 0.01mm is correct. If a tiny watch with 0.07mm pivots, you'd want less, like 0.005mm, for larger pivots like a center wheel it can be a bit more. If checking pivots with a micrometer, be very, very careful to use the lightest touch possible, as the mechanical advantage of the fine pitch thread and the hard (often carbide) faces of the mic anvil and spindle can put tiny flats on the pivot. If checking very small pivots there's really no replacement for a jewel gage.

I think at this stage, reaming out is my only realistic option.  I measured the diameter of the entire setting and it's 2.15mm.  The diameter of the pivot is 0.195mm.  There's no choice for 0.205mm internal jewels, so would I settle for 0.2mm internal diameter?  And the next standard ream size up from 2.15 is 2.29mm.  That would land me at 2.3mm x 0.2mm.  I found this size on Ofrei (https://www.ofrei.com/page942.html "Seitz 30712 Jewel 20/230") and on Jules Borel (http://www.julesborel.com/products/Seitz-Flat-Jewels-with-Cylindrical-Hole-30712/Seitz-30712-20-230-Flat-Cylindrical-Hole-Plate-Jewel).  Though interestingly, the item is listed as discontinued on Cousins.  Does that mean Ofrei and Borel are selling old stock?

[nickelsilver]

If you checked the pivot with a micrometer and got 0.195mm, it will be almost certainly too close for a 0.20mm jewel; Seitz jumps by 0.02 increments from 0.20mm, so go for a 0.22mm, it will be fine.

 

I don't know what the situation is with Seitz. I have the impression it might be defunct and everybody is selling old stock, but at the very least, it seems they have reduced the offering of sizes.

[GregG]

1 hour ago, nickelsilver said:

If you checked the pivot with a micrometer and got 0.195mm, it will be almost certainly too close for a 0.20mm jewel; Seitz jumps by 0.02 increments from 0.20mm, so go for a 0.22mm, it will be fine.

 

I don't know what the situation is with Seitz. I have the impression it might be defunct and everybody is selling old stock, but at the very least, it seems they have reduced the offering of sizes.

Thanks Nickelsilver.  Looking at the reamers, a thought occurred.  If I ream past the cutting edge into the cylindrical portion of the head, I will be removing the beveled edge on the top of the setting (see first picture in OP), correct?

Also, I'm assuming I can use a pump pusher to help center the bridge under the spindle when removing it, but how can I make sure I keep the piece steady when I attach the reamer?

[nickelsilver]

18 minutes ago, GregG said:

Thanks Nickelsilver.  Looking at the reamers, a thought occurred.  If I ream past the cutting edge into the cylindrical portion of the head, I will be removing the beveled edge on the top of the setting (see first picture in OP), correct?

Also, I'm assuming I can use a pump pusher to help center the bridge under the spindle when removing it, but how can I make sure I keep the piece steady when I attach the reamer?

Yes, you will pretty sure remove all the original sink around the top side of the jewel. 

 

In theory the reamers are self centering, and you don't really worry about holding the part firmly apart from keeping it from turning. In reality, when opening so much, first- it's often necessary to use several reamers to get up to final size; second, in all the material removal it's possible that things wander a bit. I know a very highly reputed watchmaker who regularly opens up mainplates and bridges for bushings for barrels in watches; I asked if he has issues with losing hole location, and he said it simply isn't an issue. Personally, if it's a critical location (near the escapement in a small watch for example), I will use a faceplate in the lathe, center on the original hole, and bore using a cross slide to open up the hole. I usually take it right to correct size for the jewel, but I might get it close and finish with a reamer.

[GregG]

1 hour ago, nickelsilver said:

Yes, you will pretty sure remove all the original sink around the top side of the jewel. 

 

In theory the reamers are self centering, and you don't really worry about holding the part firmly apart from keeping it from turning. In reality, when opening so much, first- it's often necessary to use several reamers to get up to final size; second, in all the material removal it's possible that things wander a bit. I know a very highly reputed watchmaker who regularly opens up mainplates and bridges for bushings for barrels in watches; I asked if he has issues with losing hole location, and he said it simply isn't an issue. Personally, if it's a critical location (near the escapement in a small watch for example), I will use a faceplate in the lathe, center on the original hole, and bore using a cross slide to open up the hole. I usually take it right to correct size for the jewel, but I might get it close and finish with a reamer.

Thanks.  Let me know if my process for this would be correct.

1. To measure the headspace for this, I'd check the micrometer position when the pump (or flat?) pusher is resting against the bottom face of the jewel, and make a note of it.
2. Turn the bridge over, and push out the old jewel from the top.
3. Ream out the setting as needed.
4. Insert the jewel into the hole from the underside, and press it in until the micrometer position matches what it was in step 1.

[praezis]

Essentially right.

However; I removed a whole setting once in my beginning for a press-in jewel (key wound pocket watch). It worked, but the much too big jewel looked soooo ugly, I never did it again!

Frank

[nickelsilver]

Something you can do when you have a lathe is make a "false" setting. You bore/ream out to the perimeter of the original sink, then make a bushing to fit, with a bore for a friction jewel that's about the same diameter as what was visible of the old rub-in jewel. Cut the sink so it hits the border where the bushing meets the bridge/plate.

 

It's quite invisible, especially if you have german silver or brass for different color bridges- if the watch warrants it you can also plate the bushing. This is also useful for rub-in balance jewels just to be able to fit available jewels in what might be an otherwise too large opening.

[GregG]

27 minutes ago, nickelsilver said:

Something you can do when you have a lathe is make a "false" setting. You bore/ream out to the perimeter of the original sink, then make a bushing to fit, with a bore for a friction jewel that's about the same diameter as what was visible of the old rub-in jewel. Cut the sink so it hits the border where the bushing meets the bridge/plate.

 

It's quite invisible, especially if you have german silver or brass for different color bridges- if the watch warrants it you can also plate the bushing. This is also useful for rub-in balance jewels just to be able to fit available jewels in what might be an otherwise too large opening.

An interesting possibility, if I'm understanding it correctly.  However, I think I should at least get 1 jewel replacement under my belt before I start techniques like these.