Expert: Kenneth Saunders - 3/6/2008

Question
QUESTION: How do you let down a mainspring in a clock and why do you have to use a winding tool before you reinstall it?

ANSWER: open spring older American clock? more modern spring in a barrel?
is the clock going to be completely dissasembled? What brand of movement are we dealing with and why are you letting it down? thanks

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QUESTION: I have two clock I would like to work on. One is a 400 day German Anniversary with a spring in a barrel and the other works is a Korean open works. The spring is broken in the Korean and is running down so then I can remove the spring but I thought you just put a spring in and would with a key. If I need a winder where can I get one?

ANSWER: Ok- to wind down - you can use a key and hold the click ratchet pawl out of the way and unwind it a 1/2 turn at at time. you can get a 1/2 inch diameter piece of metal pipe and cut a slit in the end about 1 inch long and put it over the end of the clock key and do the same only in one smooth move by holding the pipe and letting it slip in your hand till it fully unwinds. They also make "let down" tools that do the same.

New springs come wound up and held with wire or a C shaped "keeper" so you may be able to mount the spring as it comes, re-assemble the clock and then wind up the new spring more and then remove or cut what is holding it as it cam from the supplier.

check out the photos (click to enlarge them):

http://www.timesavers.com/catalogmain2.asp?ProductID=14203%2C20053%2C15687%2C100

The 400 day can be a real pain to remove by hand and winders for barrels are expensive - maybe remove cover and add some lube instead of removal???

---------- FOLLOW-UP ----------

QUESTION: Ken: The problem I ran into on the 400 day clock is that when you remove the back plate of the works the spring unravels and could possible damage parts. Can you give me tips on the proper proceedure?

Answer
If this is the ONE 400 day clock that does NOT have the spring inside a seperate round spring barrel like here :
http://www.clock-keys.com/CART/images/22987.JPG

then you are talking about the 400 day clock known as "The German Time Bomb"!!! DO NOT TAKE THIS KIND APART!


You said yours was in a barrel and I told you how to let down the spring inside the barrel - then nothing can unravel! Please clarify for me here!