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petelang
Joined: 21 May 2009 Posts: 446 Location: Nottingham
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Posted: Tue Jun 16, 2020 11:58 pm Post subject: Where to find a spiral spring? |
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Having got round to another of those niggling little jobs, my Daimler 15 drivers door latch had a nasty habit of sticking so I took it apart to find some historic abuse to the latch return spring where it looks as if it's broken and someone before me has splashed weld all over it.
I thought I had maybe seen a spring like this somewhere in the garage on an old door handle or yale lock, only to recall, on the last tidy up, I threw them all out....curses to my over enthusiastic cleaning!
Anyhow, I have been scouring t'internet for two days since trying to find something similar without having to ship a batch from China. Looked at "flat springs" "spiral springs" "constant tension springs, clock springs, (yawn...the list is long...) I'm having not much luck so maybe someone has a tin in the shed somewhere with something you might never use???
Or, does anyone know where I could get such a thing? It's a hard thing to define exactly what to call it.
Picture below:
https://flic.kr/p/2jcBrvN |
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Peter_L
Joined: 10 Apr 2008 Posts: 2680 Location: New Brunswick. Canada.
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peter scott
Joined: 18 Dec 2007 Posts: 7121 Location: Edinburgh
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Posted: Wed Jun 17, 2020 8:48 am Post subject: |
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It's a bit like the assistor springs used in window winder mechanisms. You might be able to canibalise one from a scrap yard.
Peter _________________ http://www.nostalgiatech.co.uk
1939 SS Jaguar 2 1/2 litre saloon |
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Ray White
Joined: 02 Dec 2014 Posts: 6330 Location: Derby
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Posted: Fri Jun 19, 2020 11:21 am Post subject: |
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I have recently repaired an "extending" dog's lead which has a flat coil spring about 1/2" wide. Is that what it looks like? Could be a cheap option.? |
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misterbridger
Joined: 09 Oct 2015 Posts: 46
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Posted: Fri Jun 19, 2020 4:57 pm Post subject: |
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Looks very much like the return spring on my drill press. I think that's what I searched for on ebay to find a replacement for my broken one. |
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Penman
Joined: 23 Nov 2007 Posts: 4765 Location: Swindon, Wilts.
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Posted: Fri Jun 19, 2020 6:12 pm Post subject: |
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Hi
You could try making one with a strip of steel from your local hardware store.
It looks like fairly simple spiral with locating tab for the pivot, though we can't see the end behind the horizontal.
Then;-
Quote: | First you need a steel that is suitable for being heat treated by heating to the point where it looses its ferromagnetic property and then being quenched in some liquid.
Usually this will mean steel that contains 0.5% to 1.0% carbon. Most steels used for making springs contain other elements like Manganese in small quantities.
The heat treating process, itself can take many forms, especially in dedicated heat treating shops.
At its simplest, you shape the metal (in its normal or annealed state) into the desired spring shape.
Next you heat it red hot until it loses its attraction for a magnet. Then you quickly quench it in a suitable liquid that is often water, brine, 50/50 antifreeze, or oil.
At this point the metal has become very hard, possibly like a file; but too brittle to be used as a spring. A second heat treatment is required, which will typically involve heating it to about 560 F or 293 C.
If a few places on the hardened piece are polished to a bright white surface, the surfaces can be used as tempering indicators. When the item is gently and carefully and uniformly reheated they will turn yellow, then brown, then blue (as in clock-spring blue) when their surface reaches the correct temperature.
It is best to uses a temperature controlled oven for tempering; but many cruder methods that require more operator skill and judgment have long been used, successfully." |
The lower temeratures for the second stage are only just under Gas Mark 10 or the top end of a domestic electric cooker 500F / 260C _________________ Bristols should always come in pairs.
Any 2 from:-
Straight 6
V8 V10 |
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Miken
Joined: 24 Dec 2012 Posts: 544
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Posted: Wed Jun 24, 2020 11:17 pm Post subject: |
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To make a spring you need actual " spring steel" . Ordinary Mild steel will be useless.
Spring steel is readily available in flat stock form from model engineer suppliers in various widths and thicknesses. Try " live steam models" , Blackgates engineering, or Reeves 2000.
It comes in soft form so you can form it to shape, but you will then have to heat treat it. |
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Clactonguy
Joined: 20 Mar 2018 Posts: 104 Location: clacton on sea
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Posted: Sat Sep 26, 2020 5:06 pm Post subject: spring steel. |
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Miken is correct. Tthere are many different steels out there and 'spring steel' is needed as other steels are simply not suitable. Some engineering places may be able to source or even build a spring for you (££ouch) you would need old one as 'sample' or exact dimensions.thickness etc and even then spring rates can be very different. Ideally a replacement exact item is best. |
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petelang
Joined: 21 May 2009 Posts: 446 Location: Nottingham
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Posted: Sun Sep 27, 2020 11:39 pm Post subject: |
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Thank you all for knowledge contributions. I've actually had a bit of good fortune with this as I mentioned it to lots of people and it jogged the memory of a friend who re-discovered an original box of Wilmcote Breedon door lock spares, probably unused for 30 plus years, and lo and behold, there was the perfect replacement.
I did also discover that these springs are more abundantly available in the States if ever I need another.
Peter |
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