Jump to content

Bunn Special stopping in Pennant Down

jdrichard

By jdrichard
in Watch Repairs Help & Advice

 Share

Recommended Posts

jdrichard Distinguished Member

jdrichard

Posted
Posted

Quick Question. Just serviced a 24 Jewel Illinois Bunn Special Pocket Watch. It now has an amplitude of 260 deg, however, it stops when placed in Pennant Down position. It has a right angle escapement. Any hints?

D73FB8DE-42EF-459B-B3DF-A3B368C24572.jpeg

AEE24639-CB84-43A0-B20F-2C5098CC3579.jpeg

D9448D90-E0E5-45FB-8425-555DB00DA841.jpeg

  • Like 1
Repivot Member

Repivot

Posted
Posted (edited)

Based on the position of the stem to the pallet, pendant down would place the balance above the pallet. My guess would be to check the interaction of the fork and guard pin with the roller table and jewel. There could be enough play in the pivots that the guard pin is touching the roller table, but only in that position. Or that the jewel doesnt have sufficient corner clearance to enter the fork, again only in that position.

Edited by Repivot
  • Like 1
WellAdjusted Member

WellAdjusted

Posted
Posted

Agreed. I have worked on many of these, and when the watch fully stops when the balance wheel is directly above or below that pallet, the issues you've heard are almost always the reason.

  • Thanks 1
WellAdjusted Member

WellAdjusted

Posted
Posted

Although it probably isn't the fault in this case, a chip in the edge of a balance hole jewel can cause this behavior as well.

It happens when the jewel is intact enough for respectable amplitude dial-up and dial-down and in most vertical positions, but in one vertical position the pivot falls into the chipped area, causing it to stop.

WellAdjusted Member

WellAdjusted

Posted
Posted

Those full-plate watches can be a trial. (I have an Illinois 18s Model 2 that is giving me fits right now.)

You might consider removing the hairspring, replacing the balance, and then observing the watch. The movement will still send an impulse to the balance in the good positions, and it is easier to see how the guard pin and roller are interacting.

Some of the old-time repair books called this "running in half-time" and recommend it for troubleshooting after a balance staff replacement.

 

jdrichard Distinguished Member

jdrichard

Posted
  • Author
Posted
12 minutes ago, WellAdjusted said:

Those full-plate watches can be a trial. (I have an Illinois 18s Model 2 that is giving me fits right now.)

You might consider removing the hairspring, replacing the balance, and then observing the watch. The movement will still send an impulse to the balance in the good positions, and it is easier to see how the guard pin and roller are interacting.

Some of the old-time repair books called this "running in half-time" and recommend it for troubleshooting after a balance staff replacement.

 

I like your name by the way:)  I have done this before where the top of the palate fork was rubbing against the bottom of the roller table.  I have also observed the action in my microscope.  Will try that out...

Again thanks all.

  • Like 1
nickelsilver Distinguished Member

nickelsilver

Posted
Posted

I wouldn't touch anything until I was sure it was working toward a solution. It could be that the guard pin is rubbing in that position, but why? Did it get bent, or is something else causing it to rub? It plays an important role in the safety action of the escapement, maybe bending it fixes your pendant down issue, but then the escapement unlocks when it shouldn't in other positions.

 

For sure vertical guard pins are very sensitive. One thing they are renowned for is wedging against the roller table when they have too much freedom. So do you move it closer, or further away? Just randomly trying things is like praying for abundance- you might get an abundance of mosquitoes!

  • Like 1
  • Haha 1
Nucejoe Distinguished Member

Nucejoe

Posted
Posted
43 minutes ago, jdrichard said:

ALL Exceptional advice.  Very hard to see on a full plate watch.  Would you recommend i adjust the guard pin?

Hi jd, as equipped as you are, I was expecting a video of the roller table and guard pin in action.

I imagine adjusting the guard is easier than painting the roller with ink to check it for signs of rubbing in PD versus PU position.

Wont this full plate let you check side shakes?  

Have you check staff pivots and jewels for wear? 

Do you see a sign of guard pin having moved or bent?   

Has the fork been replaced?    I guess you don't know if it ever run with this fork.

 

jdrichard Distinguished Member

jdrichard

Posted
  • Author
Posted
1 hour ago, Nucejoe said:

Hi jd, as equipped as you are, I was expecting a video of the roller table and guard pin in action.

I imagine adjusting the guard is easier than painting the roller with ink to check it for signs of rubbing in PD versus PU position.

Wont this full plate let you check side shakes?  

Have you check staff pivots and jewels for wear? 

Do you see a sign of guard pin having moved or bent?   

Has the fork been replaced?    I guess you don't know if it ever run with this fork.

 

Wont this full plate let you check side shakes?  

Answer: Yes i can check the side shake and I did...all looked good.

Have you check staff pivots and jewels for wear? 

Answer: I did make a cleaning video and did check all jewels with my microscope and all looked good.

Do you see a sign of guard pin having moved or bent? 

Answer:  Did not check the guard pin as there was no obvious issue...but that may be the guilty party.  I am hoping I dont have to take that full plate off again as getting the pivots in the holes with a 24J full plate is almost impossible. Took be 30 min of frustrating nudging the last time.

Has the fork been replaced?

Nucejoe Distinguished Member

Nucejoe

Posted
Posted
2 minutes ago, KarlvonKoln said:

Man, judging the interaction between roller and lever fork and guard pin.. on a full plate watch!  My sympathies. 

yes I agree.

  Jd makes some real tough to capture videos, shows upclose how he makes staffs, I thought  a close up vid of roller table- guard pin should be easy for him. oh well. 

I am certainly not for messing with the guard pin unless he has solid reason to.

1 hour ago, jdrichard said:

Wont this full plate let you check side shakes?  

Answer: Yes i can check the side shake and I did...all looked good.

Have you check staff pivots and jewels for wear? 

Answer: I did make a cleaning video and did check all jewels with my microscope and all looked good.

Do you see a sign of guard pin having moved or bent? 

Answer:  Did not check the guard pin as there was no obvious issue...but that may be the guilty party.  I am hoping I dont have to take that full plate off again as getting the pivots in the holes with a 24J full plate is almost impossible. Took be 30 min of frustrating nudging the last time.

Has the fork been replaced?

ya, you nudge one pivot in and two pivot slide out.

Repivot Member

Repivot

Posted
Posted

In my world, checking these things on a full plate means using a mirror or holding the movement over my head or some awkward contortions like that. But it can and needs to be done from time to time. Good lighting helps. Eventually the problem shows itself. 

What I do prior to installing the balance is test the pallet under low power. Is the guard pin straight? Does the fork come to a lock equally on both sides in relationship to the hole of the balance jewel? If not, there needs to be an adjustment to one of the banking pins. These two checks go a long way in addressing any issues between the balance and pallet.

Let us know what you find.

 Share
Go to topic listing

  • Recently Browsing

    • No registered users viewing this page.

  • Topics

  • Posts

    • RichardHarris123
      New forum member, new learner

      By RichardHarris123 · Posted

      Hello and welcome from Leeds, England . No idea about Citizen but someone will advise soon.
    • watchweasol
      New forum member, new learner

      By watchweasol · Posted

      Hi Chris and welcome to the forum, The hands and knees is by way of the rite of passage, we have all done that at some time or another.   Added a bit of citizen gen plus the T Z glossary Citizen Technical Information.pdf TZIllustratedGlossary.pdf
    • Leonid
      Rolex cal. 3135 issues

      By Leonid · Posted

      By the way, I opened my watch, looked under a magnifying glass, there is simply no grease, the screws are without traces, the slots are intact.I think it's just a matter of maintenance.there are no rotor marks on the body. And to remove the strap from yours, just press on the 1st side,and slightly move the strap, then on the other side and it will come off.
    • chrisG
      New forum member, new learner

      By chrisG · Posted

      Hi My name is Chris. Just started trying to learn about watch and clock repair as a result of repairing my fathers old 1890s police station clock (about a year ago). The clock was Ok, but having graduated to pocket watches and then wrist watches, despite the really excellent stuff on Youtube, I am struggling a bit.  As a retired engineer, I find the engineering exquisite, but a bit on the fiddly side.  I have done a few practice watches with a little success but failed a few, but have had success with Seiko 7005s, 7009s etc, but have just attempted a citizen 5430.  Nightmare.  My wife thought I had found religion as I spent so much time on my knees with my eyes to the floor looking for springs.  Got through that and found that the balance is shot.  Trying to source one or something that will fit from the citizen range has me totally perplexed.  Tried Ebay, Cousins etc without luck.  Any advice as to alternatives that will fit or alternative sources would be gratefully received.
    • Klassiker
      Typical and max diameter of faceplate for 8mm WW lathe?

      By Klassiker · Posted

      Agreed, this is puzzling. Can you ask questions or inspect the lots before bidding? My Boley & Leinen Reform face plate is dia. 95mm exactly. It's possible that 4 inches is a slightly too large approximation, but why then make the distinction to 3 11/16 for the sake of 8mm? If the larger ones are truly 4" then they will clash with the bed, but then I have no idea which 8mm lathe would take them. All 8mm lathes have spindle height 50mm or less, as far as I know. The spindle height is, as you say, standard 50mm for W.W.
×
×
  • Create New...