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Stud Removal Techniques For The Eta Chron System (Eg, 2824-2)


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Is there a video, or a detailed explanation for the proper way to remove the hairspring stud from the balance, as well as insert the stud back on to the balance bridge for the ETA Chron system, as found in a 2824-2 movement?

I know there is a special tool for this and it would be nice to see that demonstrated if nothing else than to see the force required, but also a way to do the detachment and reattachment if you don't have that special tool (as in my situation).

I tried pushing the stud back in between the forks with a screw-driver, which slipped and, well, that was the end of that. At least I had another complete balance and main spring assembly and do not want to kill another one.

Any help/pointers is greatly appreciated.

Sent from my iPad using Tapatalk

Edited by bytes2doc
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Need a pic to help.

If it is like most eta,s there is a small screw that needs to be loosened and then it pushes out with a bit of peg wood. However unless you are changing the hairspring or replacing the balance staff I would not remove.

If it has been removed I place the hairspring collet in a staking block hole that just fits the collet and present stud to the bridge with tweezers with one hand & tighten the screw using my other hand.

Thats my method anyway.

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Clockboy-the ETA Chron dose not have the screws.

Matabog - thanks, that is exactly what I was looking for. I ended up taking the stud out just as he demonstrated a few weeks back. Have you noticed if he has an example of placing that bugger back in? I don't want to kill another.

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I did a few (three) take out's and put back's just for fun on a scrap ETA2842 (from an automatic swatch). My big mistake was that when trying to rotate the regulating pins, I did it the other way and obviously I bent the spring :) But then I got to straighten it and make it work (and now I get to tell the story) - I mean I made it work, not made it work perfectly ;)

 

Anyway, my way of putting back the stud into that "fork" was: put it into position, with your left hand hold the movement holder (with the movement in it) and with the right hand use the back of a pair of tweezers (or other big, inelastic weight) to push it into the fork. Don't do it with the tip of the tweezers because it's somehow elastic and if it slips, you will break it again. You need controlled force. So rest you hand on the table and control your movement. I did it this way.

 

I hope you understand what I'm trying to say and also I hope it works for you too.

 

My advice, try to fix what you broke, from my point of view it's a treat. You work marvels when you have nothing to lose. Use superglue or shellac, if you have, to put the stud back if it fell out the first time. Try to straighten the spring, watch Mark's wonderful videos on that. Sweat a little on that hairspring. At the end it will be very rewarding, even if it doesn't work, next time you will get closer. If this is a hobby, this is the only way to learn.

Edited by matabog
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Ok got it wrong have not come across this one. I am guessing if you have not got the special tool a pin vice will do the job. The stud that did have me foxed for a while is the push fit stud such as in a EB8800.

Had to use my staking set to remove and install

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Just a little side note on this - a lot of watches (with the ETAChron system) I get in have this problem:

 

If you get a lot of positional error (sometimes by as much as 15secs/day differential) after service then check the index pin. If the hairspring is bouncing between the two pins then this 'could' be the cause of the positional error. Time and time again, I have turned the pins (from the top) until the inner pin is just touching (and effectively arresting) the outer coil of the hairspring, and with some tweaking, completely eradicated the positional error and getting a near perfect straight line in all major positions on the timing machine. 

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The method of fixing the hairspring stud has remained unchanged for at least 100 years and more like two hundred years, the old small screw method has passed the test of time with flying colours.  I  fail to see any advantage in this new fangled push in method unless it is to save the cost of one very small screw.  If it is to save the cost of the screw I would suggest their business is on a knife edge and that they look at more lucrative ways of making money such as starting a bank.

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@Mark:   In no way I want to contradict you, but the theory says that when the balance is at rest (with the pallets removed) the hairspring should stay between the regulator pins, right in the middle, with a very small room to spare (smaller then the thickness of the hairspring). It's exactly for this operation that the ETAChron system is so brilliantly good - you can center the hairspring between the regulating pins by rotating the end-stud and then minimizing the "room-to-spare" by rotating the regulator - this is presented very good here: http://www.timekeeperforum.com/forum/threads/adjustment-and-regulation.21105/

 

I got this info from some books that you recommended.

 

Again, I don't want to contradict you, I guess sometimes practice beats theory. 

 

p.s. I am personally waiting for a video on regulating the watch :D

Edited by matabog
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Absolutely - I agree with you 100%. The results are as surprising to me as I had always been taught as you have suggested.

 

Obviously in those cases where this has been required, the hairspring was out of centre and my turning the index has corrected this.

 

A more correct way would be to spend time adjusting the spring and the index until the spring is both central and contained central to the pins. Still - I have had good results either way with no noticeable drop in amp.

 

I have some good material for a video on regulation, this has been a popular request, so I will put something together asap. I will try to use my Timegrapher as it seems to be a popular piece of kit.

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I think that "regulating and adjusting a watch" is the next best thing after "building the watch". I also believe that there are so many things covered by this "regulating and adjusting", including shakes, oiling, etc aside from regulating pins distance and position...

 

So when I saw those hairspring-work-for-dummies I got my hopes up for more quality stuff... and here comes the watch regulating and adjustement (-for-dummies  :)) )

 

Thank you, Mark!

Bogdan

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