Jump to content

Barrel in pocket watch slanted by about 5 degrees, could that contribute to low amplitude/non-running?


Recommended Posts

I was finishing up a fusee pocket watch, and fixed a problem with the fusee cone, but I am experiencing issue with low amplitude/the watch barely running. 

I noticed that the hairspring was out of flat and rubbing against the balance cock.  Fixed that issue as well by gently manipulating the hairspring according to this video, but the low amplitude/non-running issue was still present.

The fusee was fully wound, so I tried to let out the power before doing any more diagnostics.  I took out the escape wheel to let it quickly dump the power.  I know this method is frowned upon, but I find it less risky than removing the third wheel and rotating the movement to unwind it.  The fourth wheel began to spin up to a high speed, as expected, but then stopped.  It only ended up winding the fusee chain back around the barrel by about ¾ to 1 full rotation.  The chain still had plenty of tension, and the cone was mostly wound, but otherwise the movement was completely stopped. 

Then I noticed that the barrel is tilted by about 5 degrees.  The sideshake on the pivots didn't seem unusual when I originally reassembled it, so I observed the actual body of the barrel, and thought that it looked warped.  I put it up against a straight edge, and noticed that there are high spots, and low spots where the light can shine through.  Does a deformed barrel sound like it could be the culprit here, and if so, how would I correct it? 

IMG_20241005_161104.jpg

Link to comment
Share on other sites

Nop, You are digging in wrong place. If the chain had tension, but the train didn't spin, then search the reason in the train. Tilted barrel can be the problem if the bottom of the barrel is rubbing on the 2nd wheel table and some of the teeth has cough firmly. Then You will have the train stopped, but there will be free play in the mesh between 2nd wheel table and 3rd wheel pinion. And, it is good to inform what kind of fusee movement You are talking about. I can guess that this is english lever full plate one, but then how exactly did You remove the escape wheel?

PS As the question is about tilted barrel and lo amplitude - yes, but only if the barrel is rubbing somewhere - like the upper plate (barrel bridge), or 2nd wheel table, or fusee wheel table. If there is clearance above and under the barrel and it doesn't touch anything, then it can be tilted but no problem of that.

Edited by nevenbekriev
Link to comment
Share on other sites

On 10/5/2024 at 10:21 PM, GregG said:

I was finishing up a fusee pocket watch, and fixed a problem with the fusee cone, but I am experiencing issue with low amplitude/the watch barely running. 

I noticed that the hairspring was out of flat and rubbing against the balance cock.  Fixed that issue as well by gently manipulating the hairspring according to this video, but the low amplitude/non-running issue was still present.

The fusee was fully wound, so I tried to let out the power before doing any more diagnostics.  I took out the escape wheel to let it quickly dump the power.  I know this method is frowned upon, but I find it less risky than removing the third wheel and rotating the movement to unwind it.  The fourth wheel began to spin up to a high speed, as expected, but then stopped.  It only ended up winding the fusee chain back around the barrel by about ¾ to 1 full rotation.  The chain still had plenty of tension, and the cone was mostly wound, but otherwise the movement was completely stopped. 

Then I noticed that the barrel is tilted by about 5 degrees.  The sideshake on the pivots didn't seem unusual when I originally reassembled it, so I observed the actual body of the barrel, and thought that it looked warped.  I put it up against a straight edge, and noticed that there are high spots, and low spots where the light can shine through.  Does a deformed barrel sound like it could be the culprit here, and if so, how would I correct it? 

IMG_20241005_161104.jpg

A 5 degree tilt from the barrel's plane is generally thought of as maximum allowable when considering a watch that is not fusee, but i think I would be more concerned about the barrel rubbing something.

  • Like 1
Link to comment
Share on other sites

Sorry for the late reply.  It's actually closer to a 3/4 plate movement than a full plate movement, so the bridge for the escape wheel and pallet fork are exposed.  I think the barrel was rubbing against the top or bottom plate.  I noticed that when I loosened the screw that was above the barrel, it freed it up and it moved a little bit.  I'll do some more digging this weekend.

Link to comment
Share on other sites

Took some photos this past weekend.  Looks like the pivots inside the barrel are jacked up and rotated.  Tried hammering it flat but that didn't work.  Going to lathe turn a tool that can cover the whole bottom face and give it a little more gentle persuasion.

When the dial and movement plate are screwed together normally, the barrel fouls against them, making it unable to move.  Once I unscrew it a little it gives it enough clearance to rotate freely.

IMG_0098.jpg

IMG_0097.jpg

IMG_0096.jpg

Edited by GregG
Link to comment
Share on other sites

Did you replace the cap in its original orientation? Generally one can expect things to go together and line up regardless, but on old stuff the barrel cap is usually indexed, with a mark or sometimes a "divot" indicating the orientation. If the exterior of the cap is eccentric to the hole, getting it out of orientation can show up as a barrel tilted on its arbor.

 

If there's no indication, the cut in the lid is usually placed in line with the hook in the barrel. I do this even on modern watches and clocks, just because it was how we were taught.

Link to comment
Share on other sites

30 minutes ago, nickelsilver said:

but on old stuff the barrel cap is usually indexed, with a mark or sometimes a "divot" indicating the orientation. If the exterior of the cap is eccentric to the hole, getting it out of orientation can show up as a barrel tilted on its arbor.

Well I've learnt something. 

  • Like 1
Link to comment
Share on other sites

Well, in the fusee barrels You shouldn't put the lid in wrong position as the hole in the barrel where the chain hook goes must be exactly against the cut place in the lid. If not, the chain hook may not get in place.

OP, What You should do is to remove the spring from the barrel and assemble it exactly as it looks  in the photos. Then grasp the arbor with something and rotate the barrel. This will show if the barrel is not true or the arbor itself is not true. If the barrel rotates true, then the arbor is the reason for the tilting. If the barrel doesn't rotate true, and this is so much that rectifying is needed, then the best option is to make new lid that will compensate for the barrel being not true. If this is to be done, I will give further instructions what to do.

  • Like 2
Link to comment
Share on other sites

1 hour ago, nickelsilver said:

Did you replace the cap in its original orientation? Generally one can expect things to go together and line up regardless, but on old stuff the barrel cap is usually indexed, with a mark or sometimes a "divot" indicating the orientation. If the exterior of the cap is eccentric to the hole, getting it out of orientation can show up as a barrel tilted on its arbor.

 

If there's no indication, the cut in the lid is usually placed in line with the hook in the barrel. I do this even on modern watches and clocks, just because it was how we were taught.

I have to double check the lid.  I do remember seeing an index mark on some part of it last night that I didn't expect to see one.  I don't remember if it was the lid or not.  Why would they have created them where orientation is necessary?  Or was it a limitation of the fabrication technology available at the time?

42 minutes ago, nevenbekriev said:

Well, in the fusee barrels You shouldn't put the lid in wrong position as the hole in the barrel where the chain hook goes must be exactly against the cut place in the lid. If not, the chain hook may not get in place.

OP, What You should do is to remove the spring from the barrel and assemble it exactly as it looks  in the photos. Then grasp the arbor with something and rotate the barrel. This will show if the barrel is not true or the arbor itself is not true. If the barrel rotates true, then the arbor is the reason for the tilting. If the barrel doesn't rotate true, and this is so much that rectifying is needed, then the best option is to make new lid that will compensate for the barrel being not true. If this is to be done, I will give further instructions what to do.

Will do.  Thank you.  Though I should mention that the barrel did not have the mainspring in it when I took the picture.

Edited by GregG
because I felt like it
Link to comment
Share on other sites

The barrel may have been roughed out, then later machined for the lid (for example). That would open the possibility of the lid mating surface not being perfectly concentric with the barrel hole. A lid would be fabricated, fit to the barrel, then the barrel centered up in the lathe, lid fit, and hole bored. They had techniques to center up stuff really well, but it's time consuming so they might cut corners on lower end stuff, or if there was a way to make a certain eccentricity a non-issue.

 

Some books show boring the mounted cap and barrel in the same operation.

  • Like 1
Link to comment
Share on other sites

The barrel is only distorted when the cap is installed.  I tried the cap in various degrees of rotation.  Best case scenario it is distorted but still spins around the arbor.  Worst case, it completely locks up against the arbor and won't spin at all.

IMG_20241015_192459.jpg

IMG_20241015_192601.jpg

Link to comment
Share on other sites

5 hours ago, GregG said:

The barrel is only distorted when the cap is installed.  I tried the cap in various degrees of rotation.  Best case scenario it is distorted but still spins around the arbor.  Worst case, it completely locks up against the arbor and won't spin at all.

IMG_20241015_192459.jpg

IMG_20241015_192601.jpg

Do you know yet if its the lid or the barrel with eccentric  holes or both ?

Link to comment
Share on other sites

Actually, there is no matter if the barrel is eccentric or the lid. The idea is to make a lid that will compensate for the eccentricity of the barrel, no mater how big it is. Making a lid is much more simple than making a barrel.

OP, so You need to make new lid. The idea is to turn one with the same sizes, but with no hole. The new lid must firmly snap in place on the barrel. You must  do on the lid's periphery the same cut place as on the old lid and remember to put the lid on the barrel in only one and the same position - with the cut place to cover the hole for the chain hook in the barrel. Then, You need to grasp a big rod in the lathe and turn it's face to look like this

10.png.261f36154ecb25c8e14a013e0adafbef.png

The 'pivot on the top must fit the hole of the barrel.

Then You fix the barrel (with the new lid placed) with shellac on the face of the rod as shown here.

11.png.39f378b2eb2cf2708f4f4626a3ad9071.png

The rod here is in red, the barrel is green and the lid is yellow.  The idea is the down side of the barrel to lay well on the face so it will rotate true. If there is some axial wobble of the cylindrical part of the barrel, it is no important at all.

Then, the lid has to be drilled and the hole enlarged to fit the arbor pivot.

 

  • Like 4
Link to comment
Share on other sites

The barrel should sit straight to the barrel bridge and to the bottom plate, if not then the wear in the barrel hole is to great so check the hole for wear and check the arbor to but as the arbor is made of steel which as you know is harder then brass it is most likely the barrel, this can also affect the spring inside the barrel causing rubbing and wear.   

Link to comment
Share on other sites

Yes, I'm subscribed to this guy on YouTube and had seen this a few weeks back.  I know it doesn't apply to this particular watch, but if I wanted to re-make a barrel with teeth, how do I know which cycloidal profile cutter to choose?

Link to comment
Share on other sites

IMG_20241015_192459.jpg

It is clearly seen here that the side wall of the barrel is broken, thus no wonder if the barrel is distorter when the lid is put in place.

You need to replace the barrel, so now is the time to make one.

The answer to the 'interference' question is simple: decrease the lid diameter until it snap fits well to the barrel, or increase the diameter of the place in the barrel until the lid snap fits well in it.

  • Like 2
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.



×
×
  • Create New...