Bad balance jewel in ETA 813 movement

[bsoderling]

Hello,

 

Started to service an old watch with a nice dial and somewhat different case shape.

 

I think I managed to id the movement as an ETA 813.

 

Unfortunately it turned out that the base plate balance jewel is very poor.

 

I have studied Mark's videos on jewel fitting and it appears quite manageable...

 

But as I'm not keen on going chasing for a jewel setting tool, I'm wondering if my staking set , fitted with a mikrometer screw and a handle as can be seen in the photo attached, may lend itself to this purpose?

 

Even though the staking set isn't n the best condition, I think it's reasonably complete and I have successfully managed to swap out a couple of balance staffs using it.

 

I am grateful for any feedback and experiences here.

 

A thing that scares me a bit is the prospect of having to widen the hole for the jewel as I don't have the tools required for that either. I guess I'll have to cross that bridge when I come to it...

 

Any advice on using my staking set for removing and fitting jewels is appreciated.

 

 

 

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[wls1971]

Im pretty sure what you have is a combined staking and jewelling tool so it should be more than up to the job does it have a makers name on it.

[Chopin]

A bit off topic. Is that a microscope that you used to take that pic ? If yes what is it ?

[bsoderling]

The staking set is a K&D Inverto no. 18 and you are absolutely right, when I read a bit more carefully on one of the sites that show up when googling, it mentions that some were fitted with a friction jewelling add-on.

I got the set compraratively cheap from ebay with the seller stating that it would require some cleaning. And that was correct, all the stakes needed a long soak in some rust removing liquid and opening the wooden cover still lets out a very pungent smell :-)

I guess it's just to hammer away and see how it goes...

Regarding the blow-up picture, I use a very simple method; my iphone or ipad (this one was with the ipad) and a loupe of some strength held in front of the camera lens. Works surprisingly well.




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[FlyingWatchmaker]

That should work, what will be crucial is that the surfaces of the punches/supports you use are clean of rust, flat, polished and square..

Take note of the original depth of the flat surface of the jewel, punch out from the opposite side, and then be careful fitting the new one :-)

Tom

[clockboy]

You should be able to replace the jewel using your staking tool. If you purchase the correct size jewel there will be no need to re-size the original hole. 

[bsoderling]

Thanks for all support!

Regarding need for resizing hole, is there a general rule of thumb on the tolerance or mismatch allowed in the parts and/or measurements of these?

If anything I assume the jewel should be a tiny bit oversized to the hole?

Having spent most of my working life in measurement technology I know there's nothing as "exactly x mm's", there's a tolerance to every part and number...





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[rogart63]

Isn't that the jewel for the pallet fork?  Have a ETA 810 somewhere if that could help . Maybe even a complete mainplate.  But if you like to tinker with it anyway there is a set of jewels from cousinsuk and i am sure that at least one of them would fit.  

[bsoderling]

Hi rogart63,

No, it's really the balance jewel, I have attached a photo from the bottom side with the cap jewel plate removed. It's apparently one of these domed jewels that I understand are used for balances.

Let me see what I can find and achieve with parts from Cousins first. If that fails I will be pleased to get back with you for a potential spare. I believe you are Swedish as well, or...?




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[vinn3]

good work with the camera inovation.

[FlyingWatchmaker]

For sizing, jewel size is exact within 1/1000 I think, reamers are sized for a pressure fit (1/100mm undersized I believe) I'll see if I can find some examples.. ditto for holes, jewel sizes on packets are exact, pivots need to be sized to fit.

Tom

[FlyingWatchmaker]

Ok, my jewelling reamers have a marked size in 10ths of a mm, measured size is 0.01-0.015 under, for a pressure fit




Jewel diameter is marked as 200 (2.00mm), micrometer measures 2.000mm (vernier scale for 0 is on the top of the micrometer barrel, but spot on 0)



Tom

[rogart63]

How is it going with the jewels . I have gone thru my movements a little today. And have 2 ETA 810 . one of them was missing the balance jewel also. So i guess that is a common problem? Its strange as the balance bridge has a inca spring. 

[bsoderling]

Hi rogart63 and thanks to all for info reamers and hole/jewel sizes.

I haven't yet got round to work on that movement anymore. As it happens, I stumbled on an auction for an (almost) complete jeweling set from Seitz the day after I started this thread. And even more surprising I ended up winning the set for a seemingly very reasonable price. Now waiting for it to arrive and then to see where I can take this.

Will keep you posted on the progess. Will likely take some time though.

Your comment about inca on the 810 made me curious. My 813 certainly has no shock protection at all.




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[FlyingWatchmaker]

For movements like these, the ebauche was often supplied with the option of different shock settings, end stones etc... there could be 10 different variations of cap jewels on train wheels, different bridge configurations etc.. it's what keeps things interesting (and frustrating at times..)

Tom

[rogart63]

On 10/7/2017 at 8:34 AM, bsoderling said:

Hi rogart63 and thanks to all for info reamers and hole/jewel sizes.

I haven't yet got round to work on that movement anymore. As it happens, I stumbled on an auction for an (almost) complete jeweling set from Seitz the day after I started this thread. And even more surprising I ended up winning the set for a seemingly very reasonable price. Now waiting for it to arrive and then to see where I can take this.

Will keep you posted on the progess. Will likely take some time though.

Your comment about inca on the 810 made me curious. My 813 certainly has no shock protection at all.




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See if i find it. 

[bsoderling]

Took another step today...

My jewelling set arrived and looked fairly decent even though a couple of items were missing and if/when I need them I will have to get a few reamer replacements as at least one looked more like a corkscrew... :-)

But the very nice thing was also that the seller had included a bunch of glass tubes with balance jewels and guess what, one of them was exactly the one I needed, diameter 0,9 mm & hole 0,11 mm! And furthermore, this dimension was one of the few obsolete ones in the Cousins list.

After running through Mark's video on the topic again I managed to push the jewel in place. I have attached a photo of the new thing and just have to hope I got the depth precise enough as it wasn't entirely easy to feel when the pusher was sitting exactly on top of the old jewel and note the micrometer setting.

Will now continue with the cleaning and assembly and a few prayers that the movement will eventually run.

I'll keep you posted on my further challenges...




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[rogart63]

4 hours ago, bsoderling said:

Took another step today...

My jewelling set arrived and looked fairly decent even though a couple of items were missing and if/when I need them I will have to get a few reamer replacements as at least one looked more like a corkscrew... :-)

But the very nice thing was also that the seller had included a bunch of glass tubes with balance jewels and guess what, one of them was exactly the one I needed, diameter 0,9 mm & hole 0,11 mm! And furthermore, this dimension was one of the few obsolete ones in the Cousins list.

After running through Mark's video on the topic again I managed to push the jewel in place. I have attached a photo of the new thing and just have to hope I got the depth precise enough as it wasn't entirely easy to feel when the pusher was sitting exactly on top of the old jewel and note the micrometer setting.

Will now continue with the cleaning and assembly and a few prayers that the movement will eventually run.

I'll keep you posted on my further challenges...




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That great work.

Found mine 810 btw. It doesn't have a  jewel in the mainplate. It was the inca bloc piece that was missing  Looked about the same but have a thread for the screw also. 

Edited October 13, 2017 by rogart63

[bsoderling]

To round this one off...

I had the movement cleaned and assembled and was happy to see it start up immediately.

A quick tuning on my Ipad timegrapher gave the response below. Some beat error (that I will leave as is) and what I hope is a decent amplitude.

I would really like to learn more about amplitude as I often have problems getting this to where I understand it should be, in spite of swapping main spring, cleaning, oiling etc.

I attached a couple of photos of the watch ( no glass, will have to get a replacement). What caught my interest was the to me somewhat unusual case design and a nice looking dial for the age of the watch.

Thanks for all the support I'm getting in this nice forum!





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[clockboy]

Looks good. I am not familiar with the "Ipad timegrapher" but the odd stray dot you are getting with the reading might be because the beat is out. A bit of tweaking to reduce this and it could well be a great job done. 

[bsoderling]

Hi Clockboy,

I am really a newbie in the art of timegrapher plot interpretation and you may well be correct. The app that I use (works on both iPad & iPhone) seems to work decently and the presentation is nice as such. I must assume the weak point is the microphone, it uses the one built into your regular hands-free set.

The app has served me well for my capabillity, but maybe I should treat myself for an upgrade :-)

If there are other users with experience and hints on the usage of this app, I would be happy to hear it!



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[clockboy]

I have noticed with a Timographer the sensitivity always has to be turned down when regulating a pin lever movement because they just generate a lot of noise not related to the escape.