Spring winding using screws

[cfellows]

The past few springs I've had to wind were done using machine screws as the winding form.  The screws in this picture, from left to right, were done using 6-32, 5-40, and 4-40 screws. 



The wire is .010" music wire.  In most cases, with this wire size, the finished spring will be from .010" to .020" larger in diameter than the screw used.

To wind the spring, I just chuck the screw into my mini lathe, clamping one end of the wire between the screw and one of the chuck jaws.  Then I run the lathe slowly in reverse and hand feed the wire onto the screw, holding it taught so it wraps tightly into the thread grooves.

Chuck

[b.lindsey]

Very useful tip Chuck assuming the diameters come out close enough. It sure makes the evenness of the windings near perfect!!

Bill

[RonGinger]

When I wind springs I feed the wire through two blocks of wood, the size of a lathe tool bit split in two. By tightening the screws that hold the tool bit in the holder I adjust the tension on the wire. This has worked well for me, up to some rather large spring wire.

Years ago I was in a junk yard where I often bought steel. They had a 4ft square crate full of tool steel parts. It was all to be sold by the pound. I found about a dozen boxes of brand new spring wire, still in the original packages. I picked through until I had one of every size. I forget the cost, but it was cheap. I also found gear cutters, and collected about 25 of them, for a total of $5. It was one of my better days in the junk yard 

[crueby]

I did some tiny check valve springs just like that a few weeks ago (2-56 or 3-48 screws I think it was). Worked great. Would doing that on larger diameter springs/wire work too? On the small ones I just hand fed them, turnong the chuck by hand.

[b.lindsey]

With only a little more trouble it could be generalized to most any size of wire and pitch and diameter.  Marv has a program, I think based on Kozo's equations, called Mandrel that determines the mandrel size needed based on wire size and final ID needed. Combining that for the diameter  and threading a piece of steel to the approximate TPI to give the spring turns per inch needed should work for a wide variety of diameters and wire sizes and spring ID's.

Bill

[Maryak]

Neat Tip

Thanks Chuck 

Best Regards
Bob

[fumopuc]

Thanks Chuck, good idea. I will try it.

[PJW]

Once again, thanks for the tip Chuck

[Hugh Currin]

Chuck:

I've thought about building a mandrel with "threads" on it, but hadn't thought about using an existing screw. Thanks.

With only a little more trouble it could be generalized to most any size of wire and pitch and diameter.  Marv has a program, I think based on Kozo's equations, called Mandrel that determines the mandrel size needed based on wire size and final ID needed. Combining that for the diameter  and threading a piece of steel to the approximate TPI to give the spring turns per inch needed should work for a wide variety of diameters and wire sizes and spring ID's.

That was the last straw. I've thought several times about getting Marv's programs to work, but seemingly not trivial on my linux system. But I wanted to see this spring mandel program. So I again looked into it. To my surprise "dosbox", a DOS emulator, has a linux version. I started  to download and install it but part way though the process found it readily available in my KUbuntu repository. Easy to install and ran Marv's program right off. So, thank you Marv for the library of programs.

I've thought of relieving the mandrel, to the spring ID, before and after the coils (threading). This should allow winding a closed spring, coils touching at start and end. I've yet to wind a spring, but it's in my future.

Thanks Chuck and Marv.

Hugh

[mklotz]

So, thank you Marv for the library of programs.

You're very welcome.  I'm always pleased to hear that someone is actually making use of the programs.

I knew that DosBox had a Linux version but it's not mentioned on my page.  I suppose I should remedy that.  Of course, most of the emails I get are from people who are too lazy to read the Introduction so it may not be worth the effort.