Author Topic: Making Springs, (the way I do it, anyway).  (Read 31847 times)

Offline Dean W

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Making Springs, (the way I do it, anyway).
« on: February 12, 2010, 01:34:35 AM »
Hello folks;

Just thinking someone here my find this of use on occasion, so here it is.



I make my daily bread working on old cameras.  Stuff that was made before anyone ever thought of
taking film out of cameras and replacing it with a computer.  Most of my work involves purely
mechanical cameras, made even before cameras needed batteries, much less chips and memory cards.

I was a full time welder and part time "machinist" for many years, but my body protested after years of
bucking iron, so I made a change of direction some time in the early 90's.  I have no idea how I put
camera repair together with welding and machining.  It seemed sensible at the time.

One of my typical jobs is repairing shutters, which involves taking them to pieces, like the one in the
picture above.







This particular unit is a German made Synchro Compur, and this type was last made about 45 years
ago.  The screwdriver is pointing to the end of the broken mainspring.  I'll bet lots of repair shops, of
any type, rely on a fair percentage of problems caused by someone just not listening to their bit of
machinery, whether it's a camera or a car, or whatever.  Something else was originally wrong with this
shutter that wouldn't let the last operator cock it, so they forced it.   

So, on to what this is really about.  A quick demo on making small springs.
This is the way I do it for small springs, and has worked well for me over some time.
Not the only way to do it, and maybe not even the best way, but effective.





With the spring out of the shutter, it can be measured for a number of need-to-know things.  Mainly,
the wire diameter, the coil diameter, how many coils, and whatever other notes may be useful, like the
direction of any hooks or eyes/loops needed on the ends of the spring.

The original spring is shown in the center of the picture, above.  The wire size on this spring is .014"
diameter.  There are a couple of sources of wire suitable for this type of spring, shown here.  One is
guitar strings, which are really just tarted up music wire.  The other is regular music wire that is sold as
that, or some times called spring wire.  It's all music wire, as far as I know.

Guitar strings are really easy to get in almost any town.  They're very good for small springs of almost
any type, but they only come in a limited size range.  For most modeling needs, you probably would
not need much outside the range that guitar strings offer.  If you want a quick assortment of spring
wire, go buy every different sized solid steel guitar strings you can find, and you'll have a good start.

Wire that is sold as music wire is basically the same stuff, but it doesn't usually come polished like guitar
strings.  (You don't need polished wire, unless that's what you want for appearances.) 

Regular music wire is usually black, and you can get it at hobby stores that sell supplies for RC airplanes
and the like.   








The two wire sizes I had on hand were both slightly different sizes than the original spring.  One was
almost .015", one about .0135".  I'll make a few spring blanks in both sizes.  I always make extras for
a particular job, in case "someone" goofs.







This is the basic setup I use for making SMALL springs.  This way only works well with small wire sizes,
up to about .025".  Larger wire sizes absolutely must be done using a winding jig, for your own safety.

The first consideration here is the size of the arbor that will be used to form the spring coil diameter.  I
do it the simplest way I know how, which is to check the inside of the broken spring using different
sizes of wire.  When I find the wire that fits, I use that size to judge what I think will work.  The spring
wire usually has to be wound smaller than the size spring you actually need, because as soon as it's
done being wound, it springs open a little bit.

For an example of what I mean, the nearest sized wire I had that fit close inside the broken spring was
.062" dia.  If I wind the new spring on that size arbor, the new spring might be too big in dia. 

So, I used the next size smaller wire I had as an arbor, which was .055" dia.  I did make a couple using
an .062" arbor too, because of a peculiar thing that happens to the wire that will be noted a little farther
down in this post.

In the picture above, the winding arbor has been mounted in the chuck on the left, with one of the
chuck jaws pinching on the spring wire.  The chuck on the right is not tight on the wire.  Just closed
down enough to keep the arbor from bending when the spring is wound, but still loose enough that the
arbor can spin freely.

Some safety things that have to be said;

Safety glasses!  Tiny wire will go right into your eyeball, just like a needle.

Gloves are okay as long as you are not using the power on your lathe. 

Start with a piece of wire that will be enough to make your spring, of course, but don't have wire
hanging out and drooping down to the floor, (unless you need that long of a spring).  Keep it short as is
practical.

Don't let go of the wire when winding until you have let it relax.  The small wire size being used here
won't break anything if you should turn it loose, but it's not good practice, and if you were to do it with
larger wire, it will scare you at the best, scar you at the worst.







The piece of wire is now gripped tightly with pliers, and the headstock pulley on the lathe is turned by
hand to form the coils.  Unplug the lathe, turn it by hand, when using this method.

As soon as a coil or two are formed, the wire is moved to the left, as shown in the picture above.  This
keeps the coils tight against each other.  At the same time this is being done, pressure is kept on the
wire, pulling it back toward the operator.  You have to pull pretty hard, and keep an eye on the coils to
make sure they are staying tight against each other.

When the coils are long enough to make the length of spring you need, give it a few more turns, then,
slowly turn the arbor backward until all the tension on the new spring is released.  It will relax a little and
open up slightly.  You must not just let go of the wire when the spring is as long as you need it.  If you
do, the wire will be pulled back toward the chuck, and make a rats nest, not to mention flailing around a
bit when it does so.

I want to mention again here, you can only make springs that use small diameter wire with this
method.  And again, .025" wire is about the max.  Anything larger than that needs a winding fixture. 

Serious!
 
I have a small setup for winding springs that use larger wire.  I'll show it another time. 







When the spring is long enough for your needs, let it relax slowly, and cut off the tail.  Then you can
take it out of the lathe and off the arbor. 






I made five blanks for this job.  Ideally, I'll only need one, but since the next step takes a while, and I
don't want to repeat it if I should mess up when bending the eyes, I make extras.  I've been making
springs like this for ten years or so, and have learned it's easier just to make a few more than you need
than to start the whole thing over.

You can see a couple there that have a loose coil.  That's the reason those two are longer than the
rest.  I just made them a little longer when I saw the bad coil, and I can cut the bad part off later and
still have a usable spring. 







This next bit, including the following few pictures show the method I use to heat the springs.  They have
to be stress relieved after the winding process, or they won't hold their shape well.  If you don't do this
step, the springs won't be as springy as they should be, and can easily be stretched out of shape.

I make a nest for them using steel wool and foil.  Put the springs on one half of the steel wool.







Fold the steel wool over to make a sandwich.







Fold the foil lightly around the wool to make a loose packet. 







Pop it in the oven.  This little toaster oven does a good job on music wire.  I put it on its highest setting,
which is 450f, and leave them for an hour, then turn off the oven and let it cool naturally.

It takes about an hour and a half, and that's why I make extra springs.  The five springs took me about
10 minutes to make, but 1 1/2 hours to cook and cool.  If I only made one spring, and messed it up
after cooking, I'd have to start all over again.

There is another way to do the heating thing.  You can use a small can, like a tuna can, fill it half full of
brass shavings, put the springs in, and fill it the rest of the way with shavings.  It does the same thing.  I
find the steel wool way more convenient.







This is what you want to see when you open the packet.  The steel wool should be somewhat blue
from the heat treatment.  The springs that were shiny to begin with will be slightly off color.  The springs
that were black will still be black.

Here's where the peculiar thing I mentioned earlier comes into play when sizing the arbor for winding
the spring.  When you heat this stuff to stress relieve it, it gets a little smaller.  The diameter changes
just a touch.  So, if you need a spring that has to be an exact diameter across the coils, you'll have to
experiment a little with the arbors you use to wind them.  If someone had asked me before I had ever
done this, I would have thought they would get larger.  But, they shrink.
 

Something you married folks should probably know before you do this step in the house.  Steel wool
has a tiny trace of oil on it, to keep it from turning to a ball of rust between the time you buy it and the
time you get around to using it.  That little bit of oil does make a slight odor when you cook it.  My dog
doesn't care about that odor, or, if she does, she doesn't mention it.  A spouse may not feel the same
way.







Here's one of the heat treated springs, ready for the final sizing and pulling out the eyes.
The two brass pieces are for holding the spring.  They each have a small round bottom channel filed in
them so they won't rock around on the spring once it is positioned between them.  I've made a lot of
this size spring over the years.  You can see some grooves that look similar to threads have started to
wear into the slots where spring coils bear against them.

The little tail on one end of the spring is clipped off with flat nosed wire cutters, and it's then positioned
between the blocks.






The first eye is pulled up.  The spring has to be put between the blocks just so, in order for the end of
the coil to end up in the correct place.  You'll have to figure that out for what ever spring type you're
making.

Then, using a small rod filed to the shape of a screwdriver end, it's wedged between the end coils, and
levered up to bring up the eye.  The clamp has to be pretty tight on the spring to do this, in order to
keep the second coil in line from pulling up with the first one.  Once it is pried up a little, I put a rod down
the center of the spring, and pry against it a little to get the eye pointing straight out.







Here's the new spring, and the old one.  In this shot, I'm just getting a sense of the position for the
second eye needed on the other end.  The the eye pulling process is repeated.

The new spring looks somewhat fatter in this picture.  It's a trick of the camera, though.  The new one
is within .001" dia. of the old one.







Well, that's it.  The new spring is done, and by now, it's in the old shutter, ticking away.

Thanks for having a look.

Dean
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Offline spuddevans

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Re: Making Springs, (the way I do it, anyway).
« Reply #1 on: February 12, 2010, 01:47:13 AM »
That was a very good writeup, thank you Dean :thumbup: Nicely shown and told.

Tim
Measure with a micrometer, mark with chalk, cut with an axe  -  MI0TME

Offline sbwhart

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Re: Making Springs, (the way I do it, anyway).
« Reply #2 on: February 12, 2010, 03:22:14 AM »
Very interesting Dean I learnt a lot from that thread  :thumbup: :thumbup: :thumbup:

Thanks for taking the time and sharing with us

Stew
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Offline raynerd

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Re: Making Springs, (the way I do it, anyway).
« Reply #3 on: February 12, 2010, 05:00:30 AM »
 Dean, super write up! Thanks a lot. Nice little taig? lathe as well.

Whenever I look on ebay and do a blank search on "Metal working" and sort to nearest first, I always get 100`s of springs from a local seller. When I was looking for some springs for my first engine a while back I purchased off the seller and asked to collect. I actually found it was a small shop which made just springs....but springs for all sorts. Massive ones, little ones, all sorts. And the machinary they had was immense. They coiled the wires just as you did using an old lathe with different shafts but they had something that automatically held the free wire at the correct tension. I asked the bloke if small ones, like the ones I was buying, could be made at home and he said not - you`ve just proved him totally wrong.

Thanks again
Chris

Offline Stilldrillin

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Re: Making Springs, (the way I do it, anyway).
« Reply #4 on: February 12, 2010, 05:49:54 AM »
Dean,

Thank you for showing so clearly!  :thumbup:

David D
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Still modifying bits of metal... Occasionally, making an improvement!

Offline NickG

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Re: Making Springs, (the way I do it, anyway).
« Reply #5 on: February 12, 2010, 06:24:07 AM »
Thanks Dean, very interesting.

Nick
Location: County Durham (North East England)

Offline PTsideshow

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« Last Edit: February 12, 2010, 06:38:45 AM by PTsideshow »
"The internet just a figment, of my imagination!' 
 
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and I'm working on the first two!
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Offline Bernd

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Re: Making Springs, (the way I do it, anyway).
« Reply #7 on: February 12, 2010, 09:18:05 AM »
Dean,

First, thankyou for that educational write up. That was a very nice detailed how to.  :bow:  :bow:  :bow: :thumbup:

Being a model railroader that will come in very handy. Now if we can get you to write up on doing a compression spring and a few other types of springs that would be greatly appreciated.  :poke: No pressure mind you you.  :lol:

Again thanks for that nice detailed write up.

Bernd
Route of the Black Diamonds

Offline Darren

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Re: Making Springs, (the way I do it, anyway).
« Reply #8 on: February 12, 2010, 09:49:21 AM »
Thanks Dean, I knew how to make them and have done so a few times. But I had no idea they needed heat treating.

I do now  :beer:
You will find it a distinct help… if you know and look as if you know what you are doing. (IRS training manual)

Offline jatt

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Re: Making Springs, (the way I do it, anyway).
« Reply #9 on: February 12, 2010, 03:42:43 PM »
 :clap:

Top writeup
From an early age my father taught me to wear welding gloves . "Its not to protect your hands son, its to put out the fire when u set yourself alight".


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Offline dsquire

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Re: Making Springs, (the way I do it, anyway).
« Reply #10 on: February 12, 2010, 09:21:06 PM »
Dean

Thanks for that great How-To on making springs. I certainly learned a bit today and am looking forward to your next one on compression springs when you have the time. That was also quite a career change from welder/machineing to camera repair. Looks like you found something you like doing that doesn't wear the body out.  :ddb: :ddb:

Cheers  :beer:

Don
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Offline Dean W

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Re: Making Springs, (the way I do it, anyway).
« Reply #11 on: February 13, 2010, 09:05:53 PM »
Thanks for all the kind comments from everyone.  Appreciate that!

I'll have part two coming up directly.

I asked the bloke if small ones, like the ones I was buying, could be made at home and he said not - you`ve just proved him totally wrong.

Thanks again
Chris

Hi Chris;
 I've worked in a shop that had a spring job come in now and then.  That wasn't my job, as I usually got put on simple turning jobs when I wasn't welding something.  The boss knew what he was doing! : )

Anyway, I watched when ol' Jack did spring jobs on his big Monarch.  He could have done the same thing on a miniature scale, and much better than I've shown here.  I suppose there is a lower limit on a lathe, because eventually, the arbor will have to be so small that it won't hold up.  Then you would have to make a rolling jig, but I think it could still be done in the home shop.

Bernd and Don, the next part has a bit about compression springs, along with coiling larger wire sizes.

Thanks again, all.

Dean

 
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Offline Jonny

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Re: Making Springs, (the way I do it, anyway).
« Reply #12 on: February 28, 2010, 09:44:55 PM »
Certainly a good write up but its soft and unhardened why?

Offline Dean W

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Re: Making Springs, (the way I do it, anyway).
« Reply #13 on: February 28, 2010, 11:18:41 PM »
Certainly a good write up but its soft and unhardened why?


If by "it" you are referring to the wire, it's definitely not soft.  It's music wire, otherwise known as piano wire or spring steel.  It's quite hard. 
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Offline Jonny

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Re: Making Springs, (the way I do it, anyway).
« Reply #14 on: March 07, 2010, 12:37:23 PM »
Dont get me wrong i am genuinely interested and have a right pain of a spring to make at work, tried everything spent days for whats worth about a £5.
Either breaks, collapses or both, its a wavy type compression spring 3/4" free length that needs to compress 1/4".
Know what i am doing with V springs using bearing oil and whale oil for tempering. Steel is minimum 35 years old better than the new stuff.

When you put the spring in the oven, you annealed it and therefore its soft. In the wire wool you probably back tempered it looking at the colour so still hardish.

Offline ronginger

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Re: Making Springs, (the way I do it, anyway).
« Reply #15 on: March 07, 2010, 08:24:53 PM »
A nice write up on springs.

I have one suggestion. Instead of holding the wire with a pliers I make 2 wood blocks that fit into my tool post just like a tool bit. I run the wire between the 2 blocks and tighten the tool holder screw to create enough drag on the wire to give me uniform spring. This keep the wire tension very constant and makes the spring very uniform.

If I want an open coil (compression ) spring I use the lathe threading gears to control the pitch of the spring.

There is a table in MACHINERY HANDBOOK that give the mandrel size for various combinations of wire size and desired spring ID

Offline Dean W

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Re: Making Springs, (the way I do it, anyway).
« Reply #16 on: March 08, 2010, 02:08:31 AM »

When you put the spring in the oven, you annealed it and therefore its soft. In the wire wool you probably back tempered it looking at the colour so still hardish.


I don't know what to tell you, Jonny.  You insist the springs are soft, but they are not.   At 450 F the springs will not be annealed to a soft state.  You can call it annealing if you like.  For hard drawn carbon wire, that is a stress relieving temperature.  All I can tell you is springs of the size I make do not break, and they do not loose their tension.

Please look up a book called Materials for Springs by Toshio Kuwabara of the Japanese Society of Spring Engineers.  This book has a recent copyright or I would be glad to quote what Mr. Kuwabara has to say about springs, post forming heat, (stress relief) and it's beneficial effect of improving the characteristics of piano wire and hard drawn carbon wire.  You can see some sample pages from it on Google Books.

Good luck with your springs.


A nice write up on springs.

I have one suggestion. Instead of holding the wire with a pliers I make 2 wood blocks that fit into my tool post just like a tool bit. I run the wire between the 2 blocks and tighten the tool holder screw to create enough drag on the wire to give me uniform spring. This keep the wire tension very constant and makes the spring very uniform.

If I want an open coil (compression ) spring I use the lathe threading gears to control the pitch of the spring.


Hi Ron;  I addressed the use of winding jigs and using lathe gearing for compression springs a few weeks ago in the second part of this spring making article.  It's in the same section of the forum as this part, called Making Springs PT 2.

Thanks for your interest and nice remarks!

Dean

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Offline Jonny

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Re: Making Springs, (the way I do it, anyway).
« Reply #17 on: March 11, 2010, 07:40:57 PM »
You have just triggered what problems i have had in the past with small cross section diameter coil springs and such like from carbon wire. Its supplied hard but can be easilly bent within reason and stays there. Dare say compression would require some form of heat treatment as you say.

Normally i work with at least 35 year old probably a lot older flat bar, machine and file up before hammer forging and annealing. Its then filed up again and appropriate sets put in before hardening in hydraulic or bearing oil, dried off then blazed off in whale oil. Its then stress relieved by filing exactly where theres no give.
Taken about 8 years ago its all can show you, dont want to give the game away plus wrong section.




« Last Edit: March 12, 2010, 05:45:06 AM by Darren »

Offline Jonny

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Re: Making Springs, (the way I do it, anyway).
« Reply #18 on: March 11, 2010, 07:54:28 PM »
Another weird one considering what the various springs go on is that we had some sand casted sent to us by a customer, turned out no where near as strong and looked crap even after filing up and polishing etc.

Numerous ways to make various types of spring and numerous ways to harden and temper. New stuff supposedly to exact specs as old stuff collapses and to get round it has to be hardened in cold water for instance.

How do you get on with larger diameter coil wire say 1/8"+, is it same process?
Larger guage compression and torsion springs i know the pros use a mandrel and make them cold, send away for hardening etc unless a one off.

Offline Dean W

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Re: Making Springs, (the way I do it, anyway).
« Reply #19 on: March 11, 2010, 10:33:45 PM »
Jonny, I'm not sure if we're even talking about the same thing.  If you read the write up, then you know that what I've been talking about all this time is coil springs.  Extension springs in this part, and compression springs in Part 2.

Hard drawn or cold drawn carbon wire for springs, and music wire, has been available since long before anyone on this board was born, and manufacturing plants have been pumping out springs since.   I'm talking about spring wire, not flat bar.  Somehow, it must not seem as simple as it really is.  Sorry if that's the case.

Here's a link to a company that makes spring wire, (and springs), and they provide heat treating temperatures for springs that have been formed from hard drawn spring wire.  No heating.  No quenching.  Form it, and temper it.  You will see that the temps I gave for what I did to temper the wire is right in line with what they recommend.  Hopefully they know what they are talking about, since they make the stuff.

http://www.acewirespring.com/heat-treatment.html



How do you get on with larger diameter coil wire say 1/8"+, is it same process?
Larger guage compression and torsion springs i know the pros use a mandrel and make them cold, send away for hardening etc unless a one off.

I don't have a large enough lathe to make springs much larger than 3/32" wire diameter.  I worked in a shop where large springs were made on occasion.  It was done the same way, using spring wire, but it fed off a spool onto a mandrel on the lathe.  The only kinds of springs I saw made there were compression springs, and the largest of about 1/4" wire diameter.  After they were coiled, they were put into a tempering oven, but it took longer than for the small springs I make.  They were not quenched.  Just tempered and left to cool.

Dean
« Last Edit: March 12, 2010, 05:46:53 AM by Darren »
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Offline gldwight

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Re: Making Springs, (the way I do it, anyway).
« Reply #20 on: April 01, 2010, 03:02:45 AM »
That Ace Springs site is impressive!
More springs that I knew existed and I'm an old man with many yrs exp
messing with things that use springs. Have made a few myself even.

Thank you for a great link.

Is there a sticky here somewhere for all these :  helpful links  ??

George