Barrel to right on arbor?

[Stevelp]

Hi everyone!  So recently after reading an article about excess friction in the barrel/arbor assembly affecting amplitude I’ve been testing the fit between the 2 without the mainspring installed.  So to test it I assemble the barrel and arbor without the mainspring installed and secure the arbor in a pin vise.  Once secured I blow the assembly with a blower.  According to the article and from what I’ve experienced the barrel should move freely on the arbor from the wind made by the blower.  I’m working on my first Omega movement, an 865 and this barrel assembly does not move freely at all.  So I’m just curious if anyone else does this, and being my first Omega I’m not sure if this is maybe normal for them?  To me it makes sense it should be fairly free to rotate.  Any thoughts on this?  And if it’s not the norm any recommendations on remedies?  I’ve seen some procedures to increase end shake with the staking set.  Any input would be greatly appreciated!

[saswatch88]

54 minutes ago, Stevelp said:

Hi everyone!  So recently after reading an article about excess friction in the barrel/arbor assembly affecting amplitude I’ve been testing the fit between the 2 without the mainspring installed.  So to test it I assemble the barrel and arbor without the mainspring installed and secure the arbor in a pin vise.  Once secured I blow the assembly with a blower.  According to the article and from what I’ve experienced the barrel should move freely on the arbor from the wind made by the blower.  I’m working on my first Omega movement, an 865 and this barrel assembly does not move freely at all.  So I’m just curious if anyone else does this, and being my first Omega I’m not sure if this is maybe normal for them?  To me it makes sense it should be fairly free to rotate.  Any thoughts on this?  And if it’s not the norm any recommendations on remedies?  I’ve seen some procedures to increase end shake with the staking set.  Any input would be greatly appreciated!

Did you properly clean/lube the arbor prior to testing?

[Stevelp]

On the previous ones that I have tested I’ve always done them dry but maybe that’s something I should do with this one.

[saswatch88]

3 hours ago, Stevelp said:

On the previous ones that I have tested I’ve always done them dry but maybe that’s something I should do with this one.

Yes you should and makes no point in doing testing on parts and movements if they haven’t been cleaned, inspected, and serviced

 

Edited February 18, 2020 by saswatch88

[Klassiker]

Never had the privilege to work on an Omega, so I can't say for sure, but why would they be different? The arbor and the spring still need room to move freely in the barrel.

Are you talking about this article:

https://adjustingvintagewatches.com/testing-mainspring-barrels/

There are some good tips in there about what the causes could be and how to remedy them. As long as you have cleaned everything thoroughly, I cannot see a problem with testing dry. Better than testing with a viscous lubricant on the parts, in my opinion.

[anilv]

Clean the holes in the barrel and lid properly, lightly oil and test. I usually move it with my finger and see if it spins. Usually the problem is too much clearance so that the barrel rocks a bit on the arbor.

Also check the barrel installed in the movement (with or without mainspring) and see if you can rock it. Too much rock and the barrel will bind up.  Usually its because the barrel pivots are worn, there are bodges to get around this but thats another story.

Anilv

[nickelsilver]

Normally this check is done clean and dry, but clean and oiled is OK too. Ideally it should move with a blower but just moving it by hand will tell you if it's free. You need some endshake, not excessive, and as said above it shouldn't have too much "tilt", this is a sign that the holes need to be closed.

 

If holding with a pinvice you have to watch that the pinvice isn't influencing things. I prefer to capture the ends of the arbor in the flats of stout tweezers.

[Stevelp]

Klassiker that's my thoughts exactly thinking there should be no difference from one brand to the next.  Yes that is the exact article that I was referring too, lots of good info in there for sure!  When I am at the point of doing this test, the parts have been pegged and put through the cleaning machine and inspected so I'm fairly confident in the fact that grim would not be a contributing factor in this case.  Nickelsilver that looks to be a much better way to do the test than what I was doing, thanks for the advice!  I can rotate the barrel by hand but there is resistance when I do so.  Maybe I should assemble it the way it is and check my amplitude reading.  That way I can have a feel of what may be too much and what may be acceptable for future projects.

[nickelsilver]

Do you have endshake? It is unlikely (essentially impossible) for the holes to become tight over time, but it is possible for the cap to sit too low in the center, zapping the endshake and causing drag.

 

If you're motivated to do it, it would be interesting to see what your amplitude is as is, then after correcting the barrel.

[rodabod]

Check the barrel on its own. If it's ok, then add the centre wheel. If those spin freely when meshed, then check that they turn smoothly when under torque by applying drag to the centre wheel while turning the barrel. If it becomes "lumpy" then you possibly have a depthing issue due to side-shake.

[Stevelp]

I was home for lunch and was able to check for some end shake and I feel absolutely none.  I also tried to hold the barrel and arbor in my tweezers like you have pictured nickelsilver and I was not able to hold it tight enough to keep the barrel from turning the arbor with it.  So I would feel pretty confident that the cap may have been moved in the wrong direction. 

[Klassiker]

Check for flatness of the barrel lid and the housing. Sounds like one or both are dished inwards.

[Stevelp]

Hi everyone, sorry for the silence over the last few days.  So I was finally able to sit down at the bench and spend some time with this.  I ended up adjusting the lid of the barrel and it feels much better.  Things now move freely with a puff of the blower!  

[VWatchie]

On 2/25/2020 at 3:55 AM, Stevelp said:

Hi everyone, sorry for the silence over the last few days.  So I was finally able to sit down at the bench and spend some time with this.  I ended up adjusting the lid of the barrel and it feels much better.  Things now move freely with a puff of the blower!  

 Well done and thanks for starting this thread, it's been very informative!

I'm in the process of trying to figure out why a Unitas calibre 6325 of mine has too little amplitude so I'm definitely going to look into this.

[VWatchie]

So, I have now tested the "free running" of the mainspring barrel around the barrel arbor (Unitas 6325) using the techniques described in this thread, but unfortunately I'm having a hard time determining whether the "free running" is free enough or if I should or need to take some sort of action. I thought perhaps those of you following this thread might be interested in my thread (where I've also recorded a couple of videos) on this topic which stems from trying to locate the cause of a way too low amplitude. I'd really be interested in your opinions and thoughts! If so, perhaps a good starting point in my thread would be here, so hopefully I'll see you there!