Incabloc spring problems 7750

[zrszach]

So I have a problem with a 7750.

I was removing and cleaning the jewel on the balance when the spring completely fell out. Now it seems almost impossible to get back in place, but I know it must be possible because it came out without pressing the setting or even bending it. 

I have seen some people talking about reinstalling incabloc springs, but not on a 7750. Nothing has helped so far. Any advice? It seems like the hinge side simply will not fit back in.

[HectorLooi]

Is this an original Valjoux 7750 or a clone?

The incabloc spring of an original 7750 is not easily dislodged. But the shock springs of a Chinese clone comes off with the slightest force.

There have been several post in recent years covering this problem. Do a search and have a read first.

[zrszach]

This is definitely a legit 7750. I have read people talking about this problem with clones. I have also seen many different ideas about how to replace the spring. Some say it will go back in, others say you have to press out the whole setting. 

[HectorLooi]

With Chinese shock springs, they come out easily and go back in easily. With genuine Incabloc springs, I'm afraid you might have to knock out the setting then fit the spring back in. But if you are lucky (or unlucky) the original Incabloc spring might have been replaced with a Chinese clone spring. Then you can try persuading the spring back into the hinge.

[watchweasol]

https://www.google.com/url?sa=i&url=https%3A%2F%2Fmb.nawcc.org%2Fthreads%2Ftechnique-for-fitting-incabloc-spring.124499%2F&psig=AOvVaw3sBedo1ehz5kyx5MuiQGzX&ust=1627809467576000&source=images&cd=vfe&ved=2ahUKEwicn_H5_IzyAhVKEhoKHc-oDsQQr4kDegUIARCjAQ        This is a link to NAWCC site where some one had the same problem and shares his technique.  May be of some use to read.

[clockboy]

I have re-fitted KEF springs but have never encountered a Inca becoming detached. However this is a vid that shows how the incabloc is fitted. As Hector states and the vid shows you have to remove the setting to re- fit.

 

 

[zrszach]

15 hours ago, HectorLooi said:

With Chinese shock springs, they come out easily and go back in easily. With genuine Incabloc springs, I'm afraid you might have to knock out the setting then fit the spring back in. But if you are lucky (or unlucky) the original Incabloc spring might have been replaced with a Chinese clone spring. Then you can try persuading the spring back into the hinge.

Any recs on a press for this? I don't have a jewel press currently, but I would want to get one that works for this setting as well.

[ifibrin]

6 hours ago, zrszach said:

Any recs on a press for this? I don't have a jewel press currently, but I would want to get one that works for this setting as well.

You may be able to get a second hand jeweling press with micrometer adjustment from ebay; new ones are quite expensive, costing above USD $500 for a good one (such as Horia), and may not even come with all the stumps and pushers which are about USD $150 for the cheapest...

Alternatively, and if you don't think you will be jeweling or replacing shock blocks frequently, you may find a local watchmaker to help you reinstall the incabloc for a reasonable fee, ideally below USD $50...

[ifibrin]

One other thing I would like to point out is that the reason the shock spring came out was probably because the factory endshake adjustment made the hinge slot very shallow and close to the surface of the mainplate. This means if you reinstall the shock spring again and the incabloc is in the same ideal endshake adjustment, the shock spring may come out again when you open it.

The only way to alleviate this is to put a small piece (pin head size) of rodico at the back of the incabloc where the shock spring hinges before unhinging the shock spring. Don't remove the rodico until the shock spring has been securely rehinged after removal of the jewels.

You may think "why not make the incabloc deeper in the mainplate?", but this is also a terrible idea because the endshake will probably be too little; the genuine ETA movements have had the endhshakes precisely adjusted.

[HectorLooi]

2 hours ago, ifibrin said:

One other thing I would like to point out is that the reason the shock spring came out was probably because the factory endshake adjustment made the hinge slot very shallow and close to the surface of the mainplate.

I doubt that very much. No self respecting factory would ever let something like that out of the front door. But if the balance had been re-staffed, that could be a possibility. 

More likely that the original shock spring broke and was replaced.

Could the OP provide a high magnification photo of the shock next to the Incabloc. 

[ifibrin]

14 minutes ago, HectorLooi said:

I doubt that very much. No self respecting factory would ever let something like that out of the front door. But if the balance had been re-staffed, that could be a possibility. 

More likely that the original shock spring broke and was replaced.

Could the OP provide a high magnification photo of the shock next to the Incabloc. 

I had a brand new eta 7001 where the shock spring also flew out when I unhinged the shock spring. When I looked carefully at the incabloc, the slit for  the incabloc hinge was almost exposed on the main plate. A number of other people have also previously reported incabloc shock springs flying out when unhinging them, which I imagine can only be because the shock spring can find its way out from the block slit if the block is not set deep enough in the main plate.

For some reason, this is more likely to happen for the incabloc on the main plate, not the balance cock. Suprisingly, the novodiac style shock springs are easier to work with as they come completely out easily and can be replaced with the right tool, not having to adjust the shock block.

Edited August 1, 2021 by ifibrin

[ifibrin]

From the NAWCC board: