Jump to content

Recommended Posts

Posted

Hi all experts.

 

i have recently brought a seiko 6139 chronograph from Venezuela which wasn’t working at the time and I had tried to fix the balance but ruined instead. 
 

I have brought a donor movement to replace this whichh the balance on this movement was working fine and spining  freely.

 

now I have reassembled all of the movement and Serviced it. All wheels are working perfectly, the pallet fork is working as it should. However, when I then put the new balance on the movement. It doesn’t spin freely and doesn’t work as should. I have tried the pallet fork in both positions and the balance does nothing but struggle to spin freely. Can anyone advise. 

Posted (edited)

Without the pallet fork does the train run freely when you wind the mainspring?

As you have a spare movement......

Have you swapped the pallet fork and or its bridge? Try swapping the escape wheel as well.

Finally have you oiled the diashock jewel in the balance?

Edited by Melt
Posted

Check endshake on staff, if no endshake, both endstones might be pushing on pivots.

You can also loosen the stud screw 2 to 3 turns to release pressure on end stones.

if this did no good and you haven't check both the upper and lower jewel assemblies, you might have broken or very dirty jewel.

Third possibility is if something is rubbing, like hairspring runbbing on balance spokes or the cock, or pivot shoulder rubbing on jewel housing.

Good luck.

Posted
9 hours ago, Nucejoe said:

Check endshake on staff, if no endshake, both endstones might be pushing on pivots.

You can also loosen the stud screw 2 to 3 turns to release pressure on end stones.

if this did no good and you haven't check both the upper and lower jewel assemblies, you might have broken or very dirty jewel.

Third possibility is if something is rubbing, like hairspring runbbing on balance spokes or the cock, or pivot shoulder rubbing on jewel housing.

Good luck.

Correction: You can also loosen" THE COCK SCREW"   2 to 3  turns to release presuure on endstones. 

I had written "stud " instead of screw. 

Loosen the screw to a point that staff shows a bit of emdshake, nominally .02mm endshake is ideal.

If the issue turned out to be "no end shake" you might want to shim up balance cock or bridge to create some endshake.

 

  • Like 1
Posted

What Joe refers to is the balance cock( the part which holds the balance wheel), Just back off the screw a half turn and see if the balance starts up, Check the end shake of the balance wheel if it now runs shim the balance cock with a little aluminium foil (temporary )and re tighten the screw if it still runs  then the problem is lack of end shake. If that is the case the balance jewels/settings may need adjusting.

  • Thanks 1
Posted
17 hours ago, RyanGreerMcGilloway said:

I have brought a donor movement to replace this whichh the balance on this movement was working fine and spining  freely.

 

now I have reassembled all of the movement and Serviced it. All wheels are working perfectly, the pallet fork is working as it should. However, when I then put the new balance on the movement. It doesn’t spin freely and doesn’t work as should. I have tried the pallet fork in both positions and the balance does nothing but struggle to spin freely. Can anyone advise. 

I'm having a minor confusion here? So the first part you have a donor movement balances in everything works fine?

Then his service the watch but you have a reference to putting a new balance wheel in? So is this the balance wheel that up above was working fine or is this an entirely new balance wheel?

15 hours ago, Nucejoe said:

Check endshake on staff, if no endshake, both endstones might be pushing on pivots.

If I make the assumption that the donor movement balance wheel was working fine and that's still the same balance wheel after servicing it's not working fine then there's probably still nothing wrong with that balance wheel. But if you find when you're tightening the bridge screw for the balance wheel balance stops spinning it may be the balance  jewels if you took them out. It's usually not clear in the servicing guide but the end  stones have a curved surface and a flat surface. In some watches there actually a different thickness whether there on the one side or the other. you want to make sure that the curved surfaces out because otherwise that is a place you'd lose your end shake.

I am attaching a picture as that's always helpful hopefully.

Seiko balance jewels.JPG

  • Like 1
Posted

According to my Seiko parts interchangeability guide, the upper and lower cap and hole jewels are identical. Swapping them should not be an issue. There have been a lot of good suggestions made here. What does the balance do with the pallet fork removed? does it have good motion then? How about with the hairspring removed? It should spin freely. just some things to check. According to my Seiko reference on the 6139A, the chronograph adjustments can be a real beast to get right. make sure the time train is in good condition before starting on that.

Posted
On 12/17/2020 at 1:08 PM, RyanGreerMcGilloway said:

How can I unscrew this balance staff because I think that might be the issue. Just having the staff pressed down with nor movement in it

Sorry, I meant loosening cock screw, miswrote the word stud instead.

Considering that balance spun freely on other movement, staff pivots are alrignt.

Moving jewels as weasol says is actually prefered to shimming, seiko jewels are easy to move, I can move em without jewelling tool.   ?

 

Posted

Hi all I think I have finally discovered the error with the balance. It wasn’t the balance itself. It seemed to have been the pallet fork. Now, I’ve purchased a NOS pallet fork for the same movement and I’ve come Across another hurdle, whenever I Place the fork in its jewel and the bridge on top and screw into place. The forks snaps as it should a few times and then seems to jam and I can’t figure out why. This is the course to the balance not turning. The wheels work perfectly when the forks not in place as well

Posted

Do you have enough end shake on fork arbour?   if yes; 

I would keep nudging the fork to snap until it jams there ink mark the escape teeth and the pallet in contact with the teeth.  If it kept jamming on the same tooth, that is where the fault is, most likely a defective tooth, perhaps dirty.

One you have ink marked the tooth, you might put the oscilator-cock assembly back on, shake to run the oscilator at low wind, see where it stops.

Good luck and happy Christmas.

 

  • Like 1
  • Recently Browsing

    • No registered users viewing this page.
  • Topics

  • Posts

    • You shared this test with me a few months back on a Hamilton project and so I had checked this watch to find the pins were still equally spaced. Their screw slots were undamaged and very tight hard to move so maybe no one has messed with them before. I can't work on it much today but I did measure the fork slot again and it seems like 0.44 is the right size. I measure the jewel that had been installed at just 0.42. would an undersized too narrow impulse jewel impact the impulse drastically? I ask because I have had it at a state where flipping the fork manually with a tool would unlock some of the time, but the balance was never capable of unlocking.
    • This was what I was afraid of. The movement is not one of the generic black square modules. Remove the movement from the clock and try prying it open very carefully, without breaking the plastic tabs. The plastic might be brittle from age. Clean the wheels and check the battery contacts for corrosion. Check the PCB for bad solder joints. Take plenty of photos along the way.
    • One of the problems with trying to Photograph Phils things are that his enjoyment was building these things so they tended to E falls on what will see if I can find some earlier pictures or any pictures I wasn't even sure because I was looking for that specific picture for somebody else and even it got the last version and that would have been the last version. You will note that he put the indexing on something that he could unscrew it or whatever and it can slide back out of the way so the rest of the lathe can be used as a lathe. With the lathe cut are actually coming down from the top I was there once where he demonstrated how to cut a pivot with the setup it was really beautiful. Older set up if I remember it's not a worm gear assembly in the thing in between the stepping motor and the holding block I believe this particular one was like a 100 to 1 gear ratio. Earlier version with watchmaker's lathe. Even looks like he is the watchmakers bed and then switch to something he made. Then I do have other pictures and things of the rotary stage in use. In the raw so if you tube videos here is an example of one were somebody's mounting a three jaw chuck. At one time there were available on eBay they were not cheap but if you're patient like I was I found one cheap on eBay. After you watch the video it look at his other videos he is a whole bunch of other examples of the same rotary stage. That I do know there are other pictures examples and possibly videos you just have to track them down. One of the minor issues of finding this particular tech sheet for the unit is I believe it was a custom manufacturer and the company change their name but I remember the new name here's a link to the company https://www.ondrivesus.com/rino-mechanical-components                
    • Escapement adjusting always interesting and depending upon the reference always confusing. Okay maybe it's not always confusing but it does lead to confusion. I have a PDF below it's actually a whole bunch of separate stuff including a hand out that came from a lecture that's on you tube. Then from that we get this image Consequences of doing things especially if you do things out of order or you do things for the wrong reason. Oh and even if the watches working I made the mistake one so showing my boss how tweaking the banking pins on a full plate on the timing machine made the amplitude get better and now he thinks that's what they're for and I don't think a fully grasped exactly what horn clearance means. Consequence of doing things. Notice what it says about opening and closing the banking pins and total lock? So yes I've had that on a full plate where it won't unlock at all and that's the banking pins or a combination of things basically. So banking pins unfortunately get moved. One of the ways to tell if it's been moved is the look straight down at the end of the fork with the balance wheel removed. Power on the fork push at the one side look at it push it to the other side also look at it and compare anything with the center reference the balance jewel and see if both sides of the same. No guarantee after the same there in the right place but at least are the same typically when people play with things one side will be way off from the other because they had no idea what they were doing at all because of course it's a full plate and you really have to paying attention and even then there's still hard to do. Then the other thing that comes up like it shows below is people often adjust the banking pins to do all those other things as opposed to horn clearance which is all that it's therefore and maybe bonus Guard pin clearance although you're supposed to deal with the guard pin is a separate thing like single roller gets bent in Or out or sometimes physically gets moved in and out. Some full plates older escapement's typically pallet forks held together with screws and you can actually unscrew and move the entire assembly in Or out more complications to deal with.     Escapement handout wostep nscc.pdf
    • If he was much younger and some sort of sports player it wouldn't be a problem. They would be in there and doing surgery and he'd be back on the field in no time. Unfortunately when you get older little things are bad and big things can be really bad so not good at all.
×
×
  • Create New...