suspension spring thinning

[Rod]

What is the proper way to "thin" a suspension spring??Do you have to thin it all the way to the top block or can it be thinned from the fork down??

Rod

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NAWCC # 0058915

[Rod]

What is the proper way to "thin" a suspension spring??Do you have to thin it all the way to the top block or can it be thinned from the fork down??

Rod

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NAWCC # 0058915

[fixoclock]

It is generally agreed that the spring should be thinned evenly over its entire length.
Also , the section between the fork and the top block has the greatest effect on the time rating control.
So to thin the spring remove it from the clock, remove the top block and the fork but you can leave the bottom block in place to use as a handle. Stroke the spring from the bottom block up the spring and off the end using a sandwich of 1200 grit emery paper supported on a thin wooden splat eg. lollipop stick.
If you have access to the NAWCC 400 Day Clck Chapter168 journal "Torsion Times " you find plenty of advice on how to thin springs and most everything else about 400 day clocks.
Join the fastest growing chapter in the NAWCC by e-mailing John Hubby on......

pastimes@juno.com

Go for it,
Lindsay Bramall

[Tom McIntyre]

Back in 1967, while living in Canada, I was one of the few people who were willing to repair 400 day clocks. At that time any spring you could conceivably want was available from Horolovar. I had thought the business continued even with the passing of Charlie Terwilliger. Can they no longer supply suspension springs? Or, is there some other reason for wanting to thin a spring?

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Tom McIntyre
President, NAWCC Chapter 174
Pocket Horology Web (http://www.pocketwatch.org)
Tommy the JOAT's Web (http://www.mcintyre.com/McIntyre)

[Rod]

Tom,Yes they do have all the springs that a person might need but what I have is a possible mis-match between the movement and the pendulum,The spring that I installed is very close and instead of cutting another spring to try and slow the clock down I feel that a bit of "thinning" will do the job.It may not be what a pro.would do but the clock is mine and getting it to run and keep good time is what I`m looking for......

Rod

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NAWCC # 0058915

[doug sinclair]

Rod,

You have probably solved this by now, but I would like to comment. I'll probably hear from the proponents of thinning it all the way to the top, but I have had years of excellent results from thinning just the main portion of the spring below the fork with the spring and pendulum right on the clock.

And there are some errors in the Terwilliger book, particularly with one Kundo miniature. The recommended spring is too weak and the next stronger spring is too strong.

Regards,
Doug S.

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