Making Springs on the Small Lathe
This article deals with making small springs using a metal
lathe. There may be other,
better ways of doing it. This is how I've done things in my own
home shop for years,
and these methods have worked well for me.
You will find two parts to this write up. This one, and a second
part linked to
at the bottom of this page. This first part deals with small
Safety glasses are a must in any machine shop, at all times. This
is never more true
than when working with spring wire. Wear safety glasses!
Now, on to the fun stuff.
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
less chips and memory cards.
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
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 just that,
or some times called spring wire. It's all music wire, as far as
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. If you want a
quick assortment of small 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
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 that in Part 2.
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
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 process 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
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 bottomed
channel filed in them so they won't rock around on the spring once it
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
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
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.
Part 2 of this write up shows how I use the lathe for making springs
with larger diameter
wire, and shows making compression springs, as well as extension
Click on the link:
More Taig Lathe & Mill Projects
Copyright Dean Williams