Jump to content

Which balance staff for Omega 26.5T3 ?

mikepilk

By mikepilk
in Watch Repairs Help & Advice

 Share

Recommended Posts

mikepilk Distinguished Member

mikepilk

Posted
Posted

I've got an Omega 26.5 T3 (non-Incabloc) with both pivots broken on the balance staff.

There appears to be several versions available - Incabloc, normal, short, long. 

I've found Ronda 1855, 2796, 3880

Can anyone help as to which I need, or do I have to push out the old one and try to measure it ?

Link to comment
Share on other sites
Nucejoe Distinguished Member

Nucejoe

Posted
Posted

Are all dimension for the three you listed the same?  

Expectedly different size  rollers and H/S collets .....etc   . 

You will remove the staff anyway, the right choice/ requirments  can then be determined with certainty.

Regards joe

Link to comment
Share on other sites
Nucejoe Distinguished Member

Nucejoe

Posted
Posted
4 minutes ago, mikepilk said:

But with both pivots missing, and two of the staffs only 0.05 mm difference in length !

I might be able to do it on the width at the hairspring collet.

Right,  reffering to the model clockboy just posted, you also measure G the roller diameter .Though the pivot ligne( diameter) is not available to measure, other sizes are enough for selecting exact correct one.

Link to comment
Share on other sites
noirrac1j Distinguished Member

noirrac1j

Posted
Posted
1 hour ago, mikepilk said:

But with both pivots missing, and two of the staffs only 0.05 mm difference in length !

I might be able to do it on the width at the hairspring collet.

Measure as best you can. I purchased a balance from Balancestaffs.com and it was the wrong size. Its not their fault though...these older movements are difficult to source parts for. I looked up on J Borel and BestFit MATSYS and they both say 100/594 balance staff, but I can't fine the dimensions. If the Ronda is easier for you to get, then go with the 2796.

1.png.0e46a5b0bd0f1e45b93c616735831ed8.png

1461019129_Screenshot2018-10-20at3_06_47PM.thumb.png.a4409917b0df437ef6fbf7a758f27a92.png

 

  • Like 1
  • Thanks 1
Link to comment
Share on other sites
Nucejoe Distinguished Member

Nucejoe

Posted
Posted

Assuming the staff in the wheel you got was the correct one, Correct dimemsioms being the main issue,  the difference in pivot diameter 11.75 and 12 are not expected to produce beat error or problems of the sort, or even if we assume all the .05 mm difference in length is in section B, no fault is expected form that either.

I think larger J  forced into the wheel would have a roll in the wheel deformation, I am not sure though, perhaps experiences of Clockboy or OH comes to help and answer this. 

Inserting  any linge 12 pivot into the jewels answers some questions, for instance you can see the pivot end coming out of the reverse side of the jewel or not and how far it sticks out.

 All staff sizes are available,  further response coming in will help.

Regards joe

  • Like 1
Link to comment
Share on other sites
rogart63 Distinguished Member

rogart63

Posted
Posted (edited)

2796 is for incabloc is 327 long 

1855 non incabloc is 310 long

But there is also a version for 26.5 that is 1856 that is 332 long 

All in my Ronda book . The 3880 i can't find under Omega. 

Found this and hope it can help out as the dimension on the collet is different. Maybe you can figure out which one you need by measuring . 

https://www.ebay.com/itm/Omega-balance-staff-26-5-26-5T1-26-5T2-26-5T3-100-axe-de-balancier-Unruhwelle-/201826585959

Edited by rogart63
  • Like 1
Link to comment
Share on other sites
mikepilk Distinguished Member

mikepilk

Posted
  • Author
Posted
2 hours ago, rogart63 said:

2796 is for incabloc is 327 long 

1855 non incabloc is 310 long

But there is also a version for 26.5 that is 1856 that is 332 long 

All in my Ronda book . The 3880 i can't find under Omega. 

Found this and hope it can help out as the dimension on the collet is different. Maybe you can figure out which one you need by measuring . 

https://www.ebay.com/itm/Omega-balance-staff-26-5-26-5T1-26-5T2-26-5T3-100-axe-de-balancier-Unruhwelle-/201826585959

I found that on ebay too - that's why I mentioned the collet size.

Link to comment
Share on other sites
JohnR725 Distinguished Member

JohnR725

Posted
Posted

Bestfit online is nice but sometimes the physical books are nicer. So 594 is listed as non-Incabloc. Then the problem with finding the size of the staff is you have to have an idea of how long it is. So I've attached images for the 594 staff size and the equivalent balancestaff.com staff and its size. Then one of the problems with aftermarket replacement staffs even if they're made for a specific watch is they tend to vary a little by size. Usually there physically bigger to allow you to reduce things to fit. It's why the length isn't that important the pivots can be longer and then you can just shorten those. So it's always important with balance staffs to measure what you are taking out and comparing to what you put in to avoid unpleasant surprises.

Then because of the confusion I'm also listing of the Bestfit Incabloc number and its size just so you can compare to whatever. 

OME 26.5T3    100/594    STAFF/OME 26.5    BESTFIT BALANCE STAFF

OME 26.5T3    100/857    STAFF/OME 100    BESTFIT BALANCE STAFF  Incabloc

100/857
A  327
B  160
C 90
D 50
E 43

BF STAFF.JPG

STAFF 594.JPG

26.5t5 staff.JPG

  • Thanks 1
Link to comment
Share on other sites
mikepilk Distinguished Member

mikepilk

Posted
  • Author
Posted (edited)

I've just measured the staff.  I Haven't removed it yet, so had to use digital verniers instead of a micrometer.

.... and realised that the roller and collet diameters (G and K above) the same for all the staffs !

My measurements are collet 49, roller 41.

I found this on an ebay ad :

image.thumb.png.d1809f59798538aca6d6d06d992b074b.png

If 2796 and 3880 are only for Incabloc, then it's got to be 1855/6. And from the collet sizes, it looks like Ronda 1856 is the one ?

 

 

 

Edited by mikepilk
Link to comment
Share on other sites
noirrac1j Distinguished Member

noirrac1j

Posted
Posted
21 hours ago, JohnR725 said:

Bestfit online is nice but sometimes the physical books are nicer. So 594 is listed as non-Incabloc. Then the problem with finding the size of the staff is you have to have an idea of how long it is. So I've attached images for the 594 staff size and the equivalent balancestaff.com staff and its size. Then one of the problems with aftermarket replacement staffs even if they're made for a specific watch is they tend to vary a little by size. Usually there physically bigger to allow you to reduce things to fit. It's why the length isn't that important the pivots can be longer and then you can just shorten those. So it's always important with balance staffs to measure what you are taking out and comparing to what you put in to avoid unpleasant surprises.

Then because of the confusion I'm also listing of the Bestfit Incabloc number and its size just so you can compare to whatever. 

OME 26.5T3    100/594    STAFF/OME 26.5    BESTFIT BALANCE STAFF

OME 26.5T3    100/857    STAFF/OME 100    BESTFIT BALANCE STAFF  Incabloc

100/857
A  327
B  160
C 90
D 50
E 43

BF STAFF.JPG

STAFF 594.JPG

26.5t5 staff.JPG

Yes I like physical books myself, but it's hard to beat online reference tools for convenience. Great, You found the measurements for 100/594! One thing you mentioned is the fact that many aftermarket staffs tend to vary, but keep in mind not everyone has a lathe or Jacot tool to shorten a staff or reduce a pivot--not trivial!

J

Link to comment
Share on other sites
mikepilk Distinguished Member

mikepilk

Posted
  • Author
Posted
On 10/22/2018 at 5:08 AM, noirrac1j said:

Yes I like physical books myself, but it's hard to beat online reference tools for convenience. Great, You found the measurements for 100/594! One thing you mentioned is the fact that many aftermarket staffs tend to vary, but keep in mind not everyone has a lathe or Jacot tool to shorten a staff or reduce a pivot--not trivial!

J

The 100/594 looks almost the same as Ronda 1856 - length 330 v 332, collet/roller diameters only 0.01 difference. 

I'll go for which ever I can find.

I don't have a lathe, but do have a Jacot tool, so can only do minor adjustments.

  • Like 1
Link to comment
Share on other sites
 Share
Go to topic listing


  • Recently Browsing

    • No registered users viewing this page.

  • Topics

  • Posts

    • joelcarvajal
      Gamblin Gamsol for cleaning?

      By joelcarvajal · Posted

      Thank you all for the replies!  Very informative! True enough, the Gamsol took some time to evaporate and does leave a residue. So not all naphtha are created equal!  Need to find alternatives then. i was able to try Hexane recommended by Alex and it seems great.  I wonder what the cons are?
    • GuyMontag
      1972 Bulova President "E" Sea King 11ACACB movement

      By GuyMontag · Posted

      Yeah, I saw that in the tech sheet but I don't see how it can be adequately cleaned with the friction pinion still in place. I've accidentally pulled the arbor right out of the wheel once when I used a presto tool to try and remove it. Mark shows how he does it with the Platax tool. Those are a little too pricey for me so I got one of these from Aliexpress and I just push down on the arbor with the end of my brass tweezers. That usually gets it most of the way out and then I just grab the wheel with one hand the and the friction pinion with the other and gently rotate them until it pops off. Probably not the best way but it's seemed to work for me so far.    
    • Zedster
      Movement inserted from crytal side

      By Zedster · Posted

      Thanks, Jon Sounds like a plan. Obviously I'll have the face on so do you think gripping with the holder will create any problems, but I will check in the morning to see how feasible it is but I assume it only needs to be lightly held. As for holding the movement instead of the holder won't be possible in this scenario as one hand will be puling on the stem while the other pushes the spring down. That was my initial concern is how the hell can I do this with only one pair of hands. All the other times I've had to remove the stem hasn't been a problem, apart from the force required to release the stem from the setting lever, but now I need to fit the face and hands its sent me into panic mode. If it had the screw type release things would be a lot simpler but that's life 😀   Another thing I will need to consider is once the dial and hands are fitted and the movement is sitting in the case I will need to turn it over to put the case screws in. I saw a vid on Wristwatch revival where he lightly fitted the crystal and bezel so he could turn it over, is this the only option or is there another method?      
    • nevenbekriev
      Main spring

      By nevenbekriev · Posted

      Hi Jon, do You think that relation spring torque - amplitude is linear? I would rather guess that the amplitude should be proportional to the square of the torque. I had once idea to check it, but still haven't.
    • ManSkirtBrew
      1972 Bulova President "E" Sea King 11ACACB movement

      By ManSkirtBrew · Posted

      I did not. I thought about it, but I had cleaned it in my ultrasonic, and the tech sheet shows lubricating it in place already assembled, so I figured discretion was the better part of valor. Although since I have to depth the jewels anyway, maybe I pull the pinion off to rule it out 100% as part of the problem. Do you know if there's a safe way to do it? I don't want to use a puller because it would push down on the plane of the wheel, and that seems like a Bad Idea. I thought about using a roller table remover, but I don't think I have a hole stake pointy enough to push it down.
×
×
  • Create New...