Spring Making

By Bikerscum

As a few people have pointed out, there's a great site on spring coiling here... http://home.earthlink.net/~bazillion/intro.html  I really admire the guy for the time & effort it must have taken to put that together. I strongly suggest you read what's there first..... a wealth of information, and everything you need to know..... except the best way to coil a spring

So, here we go. To make a precision spring you need exactly three things.... an arbor, a coiling bar, & a "pitch tool". And some wire. And something to make the arbor turn. The arbor is what the spring is coiled around, & controls its final coil diameter. The coiling bar is nothing but a round bar running parallel to the arbor, with it's top surface being about even with the bottom of the arbor. (A pic of the setup is down towards the bottom of this post) The "pitch tool" is the magic item. Winding wire around an arbor is a no-brainer. What's needed is an accurate & repeatable way to control the pitch, or spacing of the coils.... the pitch tool does that. And it's the first thing we need to make.....

The pitch tool is itself a sort of spring, & you make it the same way, except freehand winding. The number of coils, length, pitch, etc. is unimportant,
except that your spring wire must be able to fit in it's "gap". Starting the wire...

This chuck has one jaw tapped with a screw sticking out to catch the wire as its rotated. Handy, but you can also just put a 90 degree bend in the wire & slide
it into the gap in between the chuck jaws. Notice that the wire goes over the coiling bar, & under the arbor. Start rotating the arbor, coiling freehand a few
open coils, & a few dead coils.... again, unimportant how many....

Reverse rotation of the arbor enough to release the coil tension, & remove the pitch tool, it should look something like this....

Trim off the starting end, so it looks like this (again, not critical)...

Finally, grind that end, just like you would grind a spring.... square to the axis, and to a point at the tip.....Pretty simple, huh? So, now for coiling the
spring....

Start your spring wire coiling just like you did with the pitch tool, & coil a few dead coils, and about 1/4 coil with a little pitch, & stop. (Note.... at no time
until you're finished winding, should you let the arbor reverse. You want your spring tight on there). This is shown here....

Notice our pitch tool sitting on the arbor awaiting duty... now's it's time. Rotate the pitch tool into the gap you created in your spring, not forcing it.... just get it started...

Now, continue coiling & the pitch tool will rotate around with the spring until it stops on the coiling bar....

Keep coiling, holding the wire against the pitch tool, until the desired number of coils is reached, accounting for springback. Notice the pitch tool traveling
along the coiling bar with the spring...

Stop winding, & rotate the pitch tool out of the spring...

Coil a couple of dead coils to finish it off, & reverse the arbor until the spring is free of tension. Slide it off of the arbor, but DO NOT cut it free
yet...

Spring end coils are delicate at this point. Cutting the wire close to the spring will send a shock wave through it, causing the end to expand. Wrap one hand around the end of the spring to deaden it, & cut the wire a few inches away. You should have something like this....

One of three things will be true here... either you're a lot more talented than me & your spring will be perfect, or it'll be too long or too short. If it's too short, you need a thicker pitch tool... if it's too long grind the pitch tool thinner.

It is at this point that you want to heat treat the spring. Just put it in the kitchen stove, 500 degrees for music wire, 400 degrees for stainless, for 30 minutes. Let it cool, & THEN trim the extra dead coils off of the ends. You can use wire cutters for small wire, or a cutoff wheel for large wire. Here's the finished spring... ground & ready for duty...

And just to prove that you.... that's right you right there reading this can do it.... here's a pic of making a small spring, like a trigger spring on the legendary Dewalt XRP spring coiling machine...

In this case, the coiling bar is nothing more than my hand, supporting the wire & the pitch tool as it coils...

One last pic.... a lathe coiling setup...

The setup is exactly the same. If coiling heavy wire, you'll need to support the end of the coiling bar, or shorten it & engage the feed so it travels along as you coil. But, it IS NOT controlling the pitch, the pitch tool is. (If you look close, you'll see where I ran the tool holder into the pitch tool & bent it.... DOH!)

A couple of misc. notes.... You'll notice that I use soft copper wire for the pitch tool. Not necessary, but it makes life easier. You want the pitch tool to be about the same size (diameter) as the coiling arbor. Soft wire has almost no springback, so you can coil both on the same arbor. Most springs tend to have pitch a lot wider than their wire size, so the pitch tool needs to be a lot thicker... soft wire is a lot easier to coil in the bigger sizes. Also, you can coil your spring going against the cast in the wire, or with the cast, but try not to let the wire twist so part is with & part is against.... you'll probably get an uneven spring.

That's about it guys. The thought has occurred to me that maybe I think it's simple because I know how to do it. But I swear..... the first time you try it, the light bulb will glow & you'll "see".