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Getting or making a medium sized spring

Unless someone knows where I can get one, it looks like I may have to make a compression spring for my power saw. Its 3 inch OD, 2 inches long and 1/4inch diameter steel - 4 turns. I haven't spotted any car or bike springs that diameter and spring rate - but maybe there is kit out there that uses one and I can buy one as a spare part. I am open to suggestions.

If I have to make it, what grade steel should I use ? I read that turning on a 2inch bar should get me the right finished diameter. Presumably I then have to find someone to heat treat it, which would mean mild steel is not much cop, as it doesn't harden up. It sounds a lot easier to find something close and make it fit !

Has anyone had a go at this sort of thing ?

Ta, Steve

Reply to
Steve
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Why not use spring steel rod that is readyly available (hardened). You wind it around a bar (caution!) and then you temper it at 200°C for some hours to remove the stress you got from winding it.

Hardening it by yourself is nearly impossible without an oven.

Nick

Reply to
Nick Müller

Nick, you must be a stronger man than I.

This might work for 1mm steel wire, but I think it is too tight a curve for 6.5mm even if I had the strength !

Thanks, Steve

Reply to
Steve

That might be true. ;-)

I have to admit, that I didn't do the math (inch - mm) and 6.5mm is quite thick. But I still would try it. You need a jig for that or you will get at least bloody fingers! You might consider doing the bending in a lathe. Set the feed for the desired pitch, clamp one loose end in the bar (that is in the lathe's chuck) and the other end in a fixture that goes onto your tool holder. That fixture is made out of hard wood and has a groove for the wire.

Be cautious, winding springs is _very_ dangerous!

Nick

Reply to
Nick Müller

probably to expensive at £48 for a custom spring, Small Order Springs in Uxbridge tel 01895 420 149... might be a very substantial discount for beer tokens.

any of the usual suspects like Lee Spring or Terry springs will wind custom springs, it's just time verses cost.

Reply to
Jonathan Barnes

Steve, I have some fairly strong die springs you can have if they would be any good to you. Theres a picture below with a 6" ruler for scale.

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Peter

Reply to
Peter Neill

Thanks Peter,

I really need closer to 2.5inch ID, those look more 1.5inch, also I suspect those will also be a lot stiffer than the same spring with

1/4inch round. Good idea though, and thanks for the offer. I'll bet there is a spring out there somewhere.

Steve

Reply to
Steve

Jonathan,

Thanks for the info. Have you contact details for Terry Springs ? I have managed to track down the other two - just exploring in case any have a stock spring close enough.

Steve

Reply to
Steve Richardson

Search " spring " ( my database, 15 years collecting ! :-) ) threw up lee spring tel 0118 978 1800 terry springs tel 01386 443 366 baron springs tel 0141 550 3477 small order springs tel 01895 420 149 irvine spring co tel 01294 279 396 universal spring & pressing tel 01527 857 446

Might be worth asking a vintage motorcycle group where they get suspension springs.

Hope this helps

Reply to
Jonathan Barnes

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