Can't remove a wheel to release the main spring (Old Junghans)

Discussion in 'Clock Repair' started by Alberto Walker, May 28, 2020.

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  1. Alberto Walker

    Alberto Walker Registered User

    Mar 13, 2020
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    Hi, could someone give me a hand?
    I am from Spain - Alpujarra / Granada and a clockmaker student.
    I am taking apart this very basic Junghans movement to wash and grease it, but this wheel (see photo please) does not allow me to remove the main wheel with the spring. I'm stuck because I don't know what tool or procedure I would use to remove the star wheel from the axle without damaging the plate or axle.
    Should I wash the parts together in this case trying to unroll the spiral, clean it and grease it?
    Thanks in advance!
    Alberto Walker

    IMG_20200502_142014.jpg IMG_20200502_140056.jpg
     
  2. Grant Perry

    Grant Perry Registered User

    Jun 5, 2002
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    Hi Alberto,
    I see this is your first post here, so welcome.
    First, if I were dismantling this movement, I would have let the mainspring down before taking the movement apart. Do you have a let down key set (see pic)? Letting it down before dismantling the movement allows you to take the power off the spring in a controlled manner without needing any special tools, but you would need to use a let down key, or a similar tool to control the power during the let down.
    Now that you have dismantled the movement, your best option to unwind the mainspring may be a mainspring winder. Do you have one?
    Can you provide a top down picture of the center wheel? Is there a spring washer on the top that can be removed? If you move the mainspring clamp so that it is not resting on the lantern pinion, I think that you should be able to remove the great wheel.
    Grant

    let down.PNG
     
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  3. THTanner

    THTanner Registered User
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    Jul 3, 2016
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    The spring appears to have been let down into a C clamp, but I cannot see the loop end. Can you also provide a photo that shows the loop end?
     
  4. Grant Perry

    Grant Perry Registered User

    Jun 5, 2002
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    Yes, I think you are correct as it would have been removed from the post attached to the bottom plate. He will still need to remove the spring from the c-clamp to properly clean the spring though. Looking at his pictures, from what I can see, I think the center wheel can be removed by pushing out a pin and removing the spring washer first.....but I think we need a better picture.
     
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  5. Uhralt

    Uhralt Registered User
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    Sep 4, 2008
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    You need to remove the pinion on the center wheel. I think that's what you called a star wheel. There are different ways to do so. one is to use two paint can openers from opposite sides from under the pinion to pry it off. If there is insufficient space between pinion and plate to get the can openers underneath the pinion, you can support the plate with a crow's foot located under the plate on top of the wheel and carefully tap on the arbor with a small hammer and a piece of hardwood to protect the arbor. Once the pinion is off, you can remove that wheel and the main wheel with the spring.

    Uhralt
     
  6. Grant Perry

    Grant Perry Registered User

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    you are probably correct Uhralt, but I would still recommend seeing a full picture of the top of that gear before recommending a solution for removal.

    Capture.PNG
     
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  7. disciple_dan

    disciple_dan Registered User
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    Mar 10, 2016
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    I think Grant is on to something. If the wheel on the center arbor is removable you could get the great wheel off without removing the pinion on the front.
     
  8. R. Croswell

    R. Croswell Registered User

    Apr 4, 2006
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    I agree, Grant is correct, that large center wheel and detention spring should came apart to allow the main wheel to be removed. If you want to completely disassemble the movement do as Uhralt advised in post # 5. I'll just add that the small pinion will usually pry off easier if heated for a few seconds with a butane torch.

    RC
     
  9. Royce

    Royce Registered User
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    Alberto, I would like to also extend my welcome. My approach would be the same as Uhralt's in post #5 as I believe this would be the easiest approach both for removal and re-installation.
     
  10. Alberto Walker

    Alberto Walker Registered User

    Mar 13, 2020
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    Hello Grant. Many thanks for your support.
    Yes, I have used the let down tool and put a C-clamp to catch the spring. What I don't have yet is the Mainspring winder. It is out of stock in all the vendors I have been looking for. (I mean the Ollie Baker style). If you know somewhere or someone who has one to sell (new or used) I will be very grateful. I am aware that I will need that machine to disassemble and wash the spring and lubricate it.
    Alberto

    IMG_20200529_173141.jpg IMG_20200529_173048.jpg IMG_20200529_172919.jpg IMG_20200529_172730.jpg
     
  11. Alberto Walker

    Alberto Walker Registered User

    Mar 13, 2020
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    Hello Royce, Thanks for your replay. I've uploaded some more images hope they are useful
     
  12. THTanner

    THTanner Registered User
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    I think the best option is to remove the pin and tension spring on the front of the wheel (T2) and take it off to remove the great wheel and spring.

    You can put a bit of pressure down on the spring and should be able to slip the pin out quite easily.
     
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  13. David S

    David S Registered User
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    Dec 18, 2011
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    I think that is a crimp to secure the collar holding the tension spring. Best to remove the pinion I think.

    David
     
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  14. Uhralt

    Uhralt Registered User
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    That's what I believe to see too.

    Uhralt
     
  15. shutterbug

    shutterbug Moderator
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    Oct 19, 2005
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    You wound the spring up and released it into a clamp, so you can use the movement as your mainspring winder. Put what you have back into the movement plates. Then wind the spring until it releases the clamp and let it down slowly. It should unwind outside the plates. If any of the four holes need bushing of course, you'll have to remove the wheels ... but with the spring out of the equation it should be easier.
     
  16. R. Croswell

    R. Croswell Registered User

    Apr 4, 2006
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    Yes, some are made that way. I agree, best to remove the small pinion as previously described.

    RC
     
  17. Alberto Walker

    Alberto Walker Registered User

    Mar 13, 2020
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    Hello Shutterbug moderator. You will not believe that I was just thinking about doing something like that. Because I don't have enough knowledge to remove the pinion and the large main spring wheel does not have a pin to remove, but it is crimped. I agree that if some bushings need to be replaced, I will have no choice. It is really exciting that so many experts help me in my first post (and so fast) it is a very pleasant experience!
    Thank you very much to all.
     
  18. Alberto Walker

    Alberto Walker Registered User

    Mar 13, 2020
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    Hello again. Thanks to all for the help. I have cleaned, assembled and greased. And it works well! 72 continuous hours :)
    I stretched the spring by hand (it is small) before assembling the movement and cleaning it with WD40. I removed some rust and greased it.
    Kind regards from Spain!

    Junghans_OK.jpg
     
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  19. shutterbug

    shutterbug Moderator
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    Well done, Alberto! Congratulations on your first successful repair. Now you're hooked, so we look forward to the next adventure :D
     
  20. Alberto Walker

    Alberto Walker Registered User

    Mar 13, 2020
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    Helllo again, and thank you very much for your prior help.
    I can't find an Ollie Baker Mainspring Winder anywhere. Neither Europe nor the United States. Well I saw a K&D 128 MAINSPRING WINDER NO. 52641 looking around and I would like to know your opinion, considering that I am only a Clockmaker student.
    (Use should be to repair mantel and wall clocks, not watches.
    Should I wait another couple of month as Merritś or Timesavers told me to stay in the wait list?
    Kind regards from Andalusia / Spain!
     
  21. shutterbug

    shutterbug Moderator
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    Oct 19, 2005
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    This one might serve your purposes until you can find the one you want. You might even decide it's worth keeping ;)
     

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