Best way to adjust positional variation in etachron systems

[ifibrin]

Does anyone have any tips on how to adjust the positional variation in etachron systems? Do you hack the watch and see where the hairspring lies between the two prongs of the regulator stud, at various positions (dial up, dial down, crown up, crown down, crown left, crown right) and make a calculated guess as to which direction to turn the regulator stud? Or do you have to reshape the terminal curve.

[JohnR725]

On 4/18/2022 at 4:20 AM, ifibrin said:

adjust the positional variation in etachron systems

I am confused with your question? Maybe it would be nice if you give an example of what you're dealing with.

 

 

 

[ifibrin]

I have an eta 2671 which has good amplitude, and can be adjusted to 280deg (dial up and dial down, +7s and +10s respectively) in the horizontal, and 260deg in the vertical positions. Unfortunately, while the crown up and crown down have good rate (-10, 0 respectively), the crown left and crown right are at -30s and +30s respectively. I thought it had something to do with the etachron regulator stud, but can’t get the positional variation between CL and CR to be below 1min.

[JohnR725]

4 hours ago, ifibrin said:

I thought it had something to do with the etachron regulator stud,

No that's not what the stud is for. You can cause timekeeping in position if you have an amplitude change but otherwise that's not normally What it's used for. The first link below has a little information on adjusting.

Then I have a PDF that you may find interesting the manufacturing information sheet for this watch. Unlike the technical communication which covers how to service the watch this has all the interesting technical specifications including the timing specifications. Then depending upon which grade you have it looks like you are Definitely out of timing specifications

4 hours ago, ifibrin said:

he crown left and crown right are at -30s and +30s respectively.

Is there any amplitude change in those positions? If for some unknown reason you had a severe amplitude change that might be a reason.

Because this is an older watch is possible that somebody has re-staff the watch and you have a poise error. Normally wouldn't have that screwless balance wheel if somebody put the Roller back in a different location that would give you a small poise error. Or if somebody tried the statically poise or even dynamically poise the balance wheel when it really didn't need that to happen that would also give you poise error. But otherwise you should be within the specifications of the information sheet unless there's something else going on?

So when you're in the positions on your timing machine of where you're giving the  timing problem are there any changes on the timing machine like is that amplitude would do this do the lines still looked nice and clean extra noise etc. otherwise it still keeps coming back to poise error which normally wouldn't exist on a screwless balance wheel unless somebody's played with it.

https://www.awci.com/watchmaking-excellen/hairsprings/

http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&0&2uswk&ETA_2671

ETA_2671_info.pdf

[ifibrin]

7 hours ago, JohnR725 said:

Is there any amplitude change in those positions? If for some unknown reason you had a severe amplitude change that might be a reason.

There’s no difference in amplitude between CL and CR; both are at a healthy 250deg to 260deg at 1hr after full wind. 

I am embarrassed to admit that there wasn’t such a huge difference between CL and CR about 10 assembly and reassembly cycles ago; I think I might have flipped the balance cock once since then, and had to nudge the terminal curve of the hairspring back into shape. The hairspring is now centered, and the terminal curve follows the regulator arm, but the CL and CR position is very out in rate.

 

I thought it might have something to do with the rotation of the etachron regulator stud, but rotating it in either direction slightly still doesn’t get the difference in CL and CR down. At this point, after your explanation, all I can think that is causing this is bent pivots, or a balance wheel out of round. Both seem unlikely since the pivots look good at 10x, and the balance wheel doesn’t appear to wobble when running. Maybe the hairspring is subtly deformed? But I can’t see that at 10x.

[Klassiker]

If you let the power down, so you are getting around 150 degrees or less in the vertical positions, what are the timings like?

[ifibrin]

Here is the rate and amplitude at low power. The very odd thing is that the rate actually slows down at low power.

Dial up

 

Dial down

 

Crown left

 

Crown right

 

Crown up

 

Crown down

Edited April 21, 2022 by ifibrin

[ifibrin]

Sorry for the late reply. Was playing around with my other ladies movement, a tissot 2700, and I have managed to destroy two hairsprings trying to get them flat. Finally found the time to go back to the 2671.

[ifibrin]

At full power

Dial up

 

Dial down

 

Crown left

 

Crown right

 

Crown up

 

Crown down

[JohnR725]

Thank you for the timing machine pictures. Often times when people give numbers they don't show the graphical display and sometimes it can look really bad and they think the numbers are right.

4 hours ago, ifibrin said:

rate actually slows down at low power.

Usually when the rate slows down as the amplitude decreases it's an indication that the regulator pins are too far apart.

Not sure where to get anything out of this next request but I'm going to requested anyway. Low amplitude dial-up and dial down and eight crown positions not just four. I'm hoping maybe we'll see something that I'm not seeing now. 

[ifibrin]

5 hours ago, JohnR725 said:

Usually when the rate slows down as the amplitude decreases it's an indication that the regulator pins are too far apart.

Isn’t the distance between the pins of the etachron regulator fixed? Not sure how to adjust the distance of that. Now that I think about it, I did open up the prongs of the etachron regulator with a sharp razor blade to remove the balance wheel and hairspring for inspection, then close the prongs with steel tweezers after I re-installed the balance wheel. But that only affects the very tip of the prongs?

But the issue with CL and CR was already there before I checked the balance wheel and hairspring.

I do think it has something to do with the balance wheel and hairspring though, because the positional variation was fine about 10 practice cycles of disassembly and reassembly ago. Maybe something got twisted taking it apart and putting it back together? These movements are really tiny and a good way to build dexterity.

 

5 hours ago, JohnR725 said:

 Low amplitude dial-up and dial down and eight crown positions not just four.

I can’t release power in the mainspring via the click and stem in the 2671, since the click and click spring are combined in the 2672 as a flimsy piece of brass spring. It’s risky to lift the tab on the brass spring since it might break the spring, so I have to wait until the amplitude drops sufficiently by itself as the watch runs out.

Edited April 22, 2022 by ifibrin

[JohnR725]

56 minutes ago, ifibrin said:

Isn’t the distance between the pins of the etachron regulator fixed?

 really should be better instructions out there and maybe they are I'm just not finding them. What makes the system interesting is there's lots of various adjustments more than a regular system.

The regulator pins can be opened. Then you center with the stud so they hairspring is in the center. Then you close but not super tight need to be closed but not tight the needs to be a little breathing room.

So that means you can open up the pins and have horrible isochronism because the pins are too far apart.

Then don't worry about letting the power off just wait until watch runs down to around 200° hundred and 80 would be nice about their.

Just had to expand the search in the computer found a PDF that will be helpful.

seiko etachron.pdf

Edited April 22, 2022 by JohnR725

[ifibrin]

4 minutes ago, JohnR725 said:

Then don't worry about letting the power off just wait until watch runs down to around 200° hundred and 80 would be nice about their.

As far as I can tell, the other 4 vertical positions (CUL, CLD, CDR, CRU), are in between the CU-CL, CL-CR, CD-CR, CR-CU positions, and the traces are all stable, with no noise or although signs of escapement issues. This is at the intermediate wind level.

I’m not sure if it’s due to the regulator pin spacing since the issue arose before I opened the regulator pins to remove the balance wheel.

[Nucejoe]

This guy adjusts for ischronism.

ifibrin should be able to readjust the regulating pins after replacing the hairspring. 

[Klassiker]

From the results you posted so far (verticals at low power) I think I can see a heavy spot at around 11 o'clock. The in-between positions suggested by John should confirm that. If it was mine, I think I would spot-drill the rim very lightly at the heavy spot, and see what difference it makes. Closing the gap in the regulator pins would be my first move though.

[ifibrin]

That's useful to know! Its still a mystery to me how the positional variation developed. The original difference between CL and CR was less than 20seconds, and I didn't mess around with the regulator stud when I noticed it in one of my practice disassembly-reassembly rounds with the movement.

Hypothetically, would a slightly bent pivot, or a subtly deformed hairspring be able to show the same positional variation error as this? Visually, both the balance pivots, and the hairspring appear fine at 10X magnification. In such a hypothetical case, what would the effect be of removing weight from the balance wheel rim to correct? Would it achieve the same result?

I'm just finding out more information first, I don't think I have the confidence to attempt such repairs at my current skill level, after all, the movement still works. I have already ruined two hairsprings from a Tissot 2700 trying to correct minor issues in positional variation/ out of flat so I think I will hold off further balance wheel manipulations for the time being.

Edited April 23, 2022 by ifibrin

[nickelsilver]

On 4/22/2022 at 5:13 AM, ifibrin said:

 

I’m not sure if it’s due to the regulator pin spacing since the issue arose before I opened the regulator pins to remove the balance wheel.

It could be the regulator pin spacing, along with the centering of the spring between them. If the spring isn't fully centered, and is favoring one side over the other, in different vertical positions gravity can cause it to then stay away from one side more and favor the other even more, which will definitely show up in the timing. Get them as close as possible with still a gap that allows you to see the spring bouncing from one to the other, check the centering with power off, see that the spring is centered, then with a slight agitation of the balance that it does bounce from one to the other.

[ifibrin]

15 minutes ago, nickelsilver said:

It could be the regulator pin spacing, along with the centering of the spring between them. If the spring isn't fully centered, and is favoring one side over the other, in different vertical positions gravity can cause it to then stay away from one side more and favor the other even more, which will definitely show up in the timing. Get them as close as possible with still a gap that allows you to see the spring bouncing from one to the other, check the centering with power off, see that the spring is centered, then with a slight agitation of the balance that it does bounce from one to the other.

Do you check the centering of the hairspring in the regulator stud, in the horizontal dial down position only, or do you have to look at the centering in all horizontal and vertical positions? I assume that if the hairspring isn't centered between the prongs of the regulator stud, then you have to rotate the regulator stud slightly? And if rotation of the regulator stud doesn't center the hairspring quite enough, then you have to bend the hairspring slightly so its centered? Assuming the hairspring is now in the middle, what is the best way to close the gap between the prongs safely in a controlled manner? I'm concerned that just grasping the prongs of the regulator stud and pressing them together will close them too tightly and pinch the hairspring. Lastly, I notice that the regulator stud in the Seiko system is just a slot cut in the stud, as compared to the etachron system where there are two fine prongs which can be opened and closed.

Thanks for all your help so far, I really appreciate it. Sorry if what I am asking is a bit long-winded, I just want to be clear.

Edited April 23, 2022 by ifibrin

[nickelsilver]

Twist the stud to center (the adjustment will be very small, unless the spring was bent at the stud when manipulating before), twist the pins to close the gap, like in John's post above. You don't want to squeeze or pinch anything, that's the advantage of the system, both Seiko and ETA. There are tools to fit the shape of the tops of stud/pins, but you can twist them with (well dressed) stout tweezers.

[ifibrin]

7 minutes ago, nickelsilver said:

Twist the stud to center (the adjustment will be very small, unless the spring was bent at the stud when manipulating before), twist the pins to close the gap, like in John's post above. You don't want to squeeze or pinch anything, that's the advantage of the system, both Seiko and ETA. There are tools to fit the shape of the tops of stud/pins, but you can twist them with (well dressed) stout tweezers.

Do you mean that the prongs of the etachron regulator stud are open, and should not be closed to stop the hairspring from falling out? Meaning to say, if the hairspring stud is released, you can easily lift the balance wheel off the cock without having to further open the prongs of the regulator stud?

[JohnR725]

To understand what nickelsilver Is saying look at the link below it has lots of nice pictures

https://www.awci.com/watchmaking-excellen/hairsprings/

 

[nickelsilver]

26 minutes ago, ifibrin said:

Do you mean that the prongs of the etachron regulator stud are open, and should not be closed to stop the hairspring from falling out? Meaning to say, if the hairspring stud is released, you can easily lift the balance wheel off the cock without having to further open the prongs of the regulator stud?

Ah- yes, you will usually need to open the pins very slightly to get the spring out if removing, and close them after replacing. What's important is that they are parallel. Then all adjustments are made by turning the pins (and/or stud).

[ifibrin]

This is the best photo I could get of the regulator stud with my iPhone.

[nickelsilver]

Looks nicely centered, now twist the regulator pin block to close the gap about twice as small and see what you get on the timing machine.

[ifibrin]

14 minutes ago, nickelsilver said:

Looks nicely centered, now twist the regulator pin block to close the gap about twice as small and see what you get on the timing machine.

Would it be correct to say I should turn the regulator stud in the direction that the inner prong of the stud (the prong on the inner radius, less distance to the pivot hole) so that the inner prong will be closer to the hairspring stud? That is the impression I get from the awci article.