Author Topic: How to weaken a spring...??  (Read 5744 times)

Offline Bigmon

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How to weaken a spring...??
« on: May 03, 2017, 04:20:56 PM »
Doing a patchbox repair and need to make a small short flat spring.
I have somehow managed to make what seems to be the perfect size and it even fits.
But it is just too strong.  I have tried heating it red hot and letting it cool, but just too stiff.
It is only about an inch or so long by 3/16" wide and 1/32"+ in thickness.
I could thin it a little but not by much??
Maybe its just too tuff of spring steel?
But I'd love to hear some ideas??
Thanks

Offline rich pierce

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Re: How to weaken a spring...??
« Reply #1 on: May 03, 2017, 05:08:40 PM »
Reducing thickness by 25% reduces strength by about 44%.  Any structural element that is short is hard to bend.
Andover, Vermont

Online P.W.Berkuta

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Re: How to weaken a spring...??
« Reply #2 on: May 03, 2017, 06:52:05 PM »
With the spring that you have it will be the "file a little - try - file a little" method. You can hunt around for that banding stuff that they use to strap down stuff on pallets. That makes a fine little low strength spring also.
"The person who says it cannot be done should not interrupt the person who is doing it." - Chinese proverb

Offline smylee grouch

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Re: How to weaken a spring...??
« Reply #3 on: May 03, 2017, 08:17:05 PM »
I would use a flat diamond stone and stroke it length ways.

westbj2

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Re: How to weaken a spring...??
« Reply #4 on: May 04, 2017, 12:41:32 AM »
If you cant file the spring, it is not heat treated correctly.  You should be able to readily file a good spring.  For longevity, the spring needs to taper in both width and thickness.  File and try.....file and try.....
Jim

Offline James Wilson Everett

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Re: How to weaken a spring...??
« Reply #5 on: May 04, 2017, 02:24:40 PM »
The only way to change the strength of a spring is by changing the shape or thickness of the spring.  Heat treatment will not change the strength of the spring, as you have discovered.  Try the file-n-fit, file-n-fit, file-n-fit process as suggested above.

Jim

Offline Bob Roller

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Re: How to weaken a spring...??
« Reply #6 on: May 04, 2017, 02:43:16 PM »
The only way to change the strength of a spring is by changing the shape or thickness of the spring.  Heat treatment will not change the strength of the spring, as you have discovered.  Try the file-n-fit, file-n-fit, file-n-fit process as suggested above.

Jim

Long and limber, NOT short and stiff is the way. I won't waste time on a spring like you described.

Bob Roller

Offline Bigmon

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Re: How to weaken a spring...??
« Reply #7 on: May 04, 2017, 05:21:20 PM »
thanks  to all.
I have a nice fit of everything now, just need to make it a little easier to function.
And trying to make it look good.

Offline D. Taylor Sapergia

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Re: How to weaken a spring...??
« Reply #8 on: May 06, 2017, 12:53:03 AM »
...and perhaps you are trying to make the spring move too far.  A very short action on a short stiff spring will do the job too.
D. Taylor Sapergia
www.sapergia.blogspot.com

Art is not an object.  It is the excitement inspired by the object.