# shortening or weakening a spring



## kd0afk (Jan 13, 2013)

I need a spring for a push button. I can find the right length but not the right strength or I can find the strength i need but not short enough. I'm not set up to do controlled heat treating so I would like to make a longer spring shorter but i don't want to loose that nice transition on the end.


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## OrangeAlpine (Jan 13, 2013)

If I was a smart ass, I'd say cut the excess out of the middle.  But I won't say that.

Seriously, making a spring is a lot like making threads, only you wrap piano wire around a mandrel while the wire is kept in tension.  Clamping it between two pieces of board works well.  The finished spring does not require heat treating.


Bill


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## ShedBoy (Jan 13, 2013)

You can cold cut a small spring like this and just tighten up the bend as it gets to the end so it sits flat. Technicall springs are a lever and reducing the amount of coils has the same effect as shortening a lever. It will get firmer. When I was younger and wanted to lower my car I thought I would just cut the spring, car got lower alright but as the spring only had 4 or so coils it firmed the ride up too much. The older chap who lived in my street explained the concept to me "Imagine it is a straight piece of spring not in a coil and you just lobbed off 25%". Probably won't matter with a spring this size. There is formulas available for calculating the strength of a spring, I have it in a suspension training book somewhere.

Brock


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## 8ace (Jan 14, 2013)

Here is a good site i've used in the past to make compression springs

http://home.earthlink.net/~bazillion/intro.html

8ace


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## deverett (Jan 14, 2013)

If the spring is just for a push button, why can you not cut off the excess spring with a pair of wire cutters and lightly grind the end on your off hand grinder?

I would imagine that a push button spring would be pretty light gauge, so would not be too hard to cut.  Slip the wanted part of the spring over a suitable bar with just haf a coil or so protruding and *Gently* touch that end onto your grinding wheel.  Touch lightly, dip in water, touch lightly dip and so on until you have the end flat.  You may lose temper in the very end of the spring where it gets thin, but that should not affect its purpose and you will have that nice transition you are looking for.

Dave
The Emerald Isle


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