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400 day clock


Salman

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I'm a newbie learning to fix a 400 day clock that I just bought from a friend. I have a problem with a broken suspension spring. Can someone help me with thickness and length of suspension springs for kern & sohne clocks? I can't fix, because I don't have the manual I need This is my 400 day clock body shape, seen from behind Thank you in advance

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Hi  What you have got is a kern and sohne clock .  Can you post apicture of the backplate face on as I am trying to locate the plate in the 400 day guide.and the position of the pallet bearing and escapement inspection holes  coupled with the logo position amd the winding s quare dont seem to fit any images. also what is the measure ment of the back plate.    It could be units 12A   12B   12c   or  unit 118       Kern standard uses .0036 so to be sure a square on picture would help a great deal.

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I'm afraid this is the best picture I can give at this point. But I can't wait to fix it soon. Because this is a new experience for me.

Maybe next time, I'll post a better picture, of course after confirming the size of the backplate

Besides that, I also can't find a picture of a clock that is exactly the same as it, on the internet. To ensure its originality so that I can restore it to how it was

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Don't worry too much about finding the exact match in the book. I checked the 10th edition and I can't find an exact match. I fixed my first anniversary clock before I got the book. I think the images of the specific suspension wires have become a little blurry after so many revisions and reprints of the book.

You can measure the old spring with a micrometer to determine the thickness. The length can be determined by attaching the pendulum and checking that it is able to rotate freely without rubbing against anything. Then getting the correct position of the crutch might be a little tricky. It will take a bit of trial and error to get it right. But even if you follow the pictures in the book, some tweaking of the position of the crutch is necessary to get good amplitude.

I know @oldhippy will be probably be frowning when he reads this.

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1 hour ago, HectorLooi said:

Don't worry too much about finding the exact match in the book. I checked the 10th edition and I can't find an exact match. I fixed my first anniversary clock before I got the book. I think the images of the specific suspension wires have become a little blurry after so many revisions and reprints of the book.

You can measure the old spring with a micrometer to determine the thickness. The length can be determined by attaching the pendulum and checking that it is able to rotate freely without rubbing against anything. Then getting the correct position of the crutch might be a little tricky. It will take a bit of trial and error to get it right. But even if you follow the pictures in the book, some tweaking of the position of the crutch is necessary to get good amplitude.

I know @oldhippy will be probably be frowning when he reads this.

Actually I really want to do that. By doing a little experiment on the clock. It's just that when I think about replacing the suspension spring, a lot of questions come to my mind.

How long is the spring required?

How flexible is the spring?

Spring material that does not break easily when moved to rotate the pendulum?

And some adjustments to the position of the crutches as you stated above😔

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2 hours ago, Salman said:

Actually I really want to do that. By doing a little experiment on the clock. It's just that when I think about replacing the suspension spring, a lot of questions come to my mind.

How long is the spring required?

How flexible is the spring?

Spring material that does not break easily when moved to rotate the pendulum?

And some adjustments to the position of the crutches as you stated above😔

The new spring will longer than required, you will have to cut it to length. Although the spring is elastic, it does get deformed and kinked quite easily, especially when the pendulum is relatively heavy. Even the weight of the upper suspension block and the crutch alone is enough to deform the spring. The spring has to be handled with utmost care.

Actually, from your photos, I can see that the old spring still has the crutch attached. You can mark the position of the crutch and use that as the reference for the position.

Good luck and don't be afraid to ask if you have any problems.

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I’ve just finished one here, be very careful of the torsion spring ok, ( suspension spring )they are very apt to being bent or twisted.
Once bent or twisted they are useless and you’ll need to order another. If you order a horolover one then they do come with blocks and forks attached at the correct height. 
If you intend to work on these then the horolover book is essential, so well worth buying it now as it has a Q&A section and so much info in it.

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2 minutes ago, transporter said:

If you intend to work on these then the horolover book is essential, so well worth buying it now as it has a Q&A section and so much info in it.

 correct. for the price the information is brilliant. well worth the money as is the adjuster tool for the block as it allows fine adjustment of the upper block.

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