Winding small springs

Lately I've been tinkering with electromechanical instruments, some of
which are a few decades old and in rather used/abused shape. Often
there are smallish extension and compression springs which are rusted
out, broken, stretched beyond restoration, covered with oil that has
aged into a very durable varnish, or (very often) some combination.
Many are music wire but some seem to be stainless and/or brass.
Usually the diameter of the spring is 1/8", 3/16", or 1/4", which are
standard sizes, but some are even smaller. The wire the springs are
made out of seems to be between 0.016" and 0.05". And sometimes, of
course, the spring is just plain gone so I don't really know what was
supposed to be there. I've been buying some off-the-shelf springs from
MSC with great success, but there remain a few that don't seem to be on
anyone's shelf.
How hard is it to wind something like this from scratch? I'm guessing
that to make a 3/16" extension spring, I might start with a rod a
little bit smaller than 3/16", wind it with music wire to greater than
the desired unextended length, cut the ends, and then use some pliers
to force the ends into a hook. Probably won't look as nice as one from
a factory but it'll be a start.
How do the factory ones look so perfect, with the hooks on the end in
such perfect alignment, anyway? Some magical tools that I can never
afford, or some simple tools that I could buy cheaply or maybe fashion
myself? Any tricks to working with that skinny music wire without it
poking any more holes in my fingers than I already have?
Tim.
Reply to
Tim Shoppa
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Try this site.... Very useful info on design and how to make including home made jigs.
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Reply to
Randy Zimmerman
You might try here for some info on making springs:
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Mike
Reply to
Mike Henry
I do this all the time when I don't have a spring in my box of springs that can be modified. Sometimes I even unwind a junk spring and rewind it using that wire. Long springs can be wound on a lathe.
They use an automated spring winder. Sort of like an automated screw machine for making springs.
You just need a pair (that's two separate tools) of miniature pliers. For really small work, 2 hemostats work great.
Jon
Reply to
Jon Elson
Oh wow, that has exactly what I needed. Thanks (and thanks to the other guys who pointed out the same site!)
Tim.
Reply to
Tim Shoppa
One of the best articles on helical spring making ever published is found in the May-June and July-August, 1987 issues of HSM. Instead of clumsy equations, the design data are presented in the form of nomographs that make design easy and quick to try. I say "try", as you will usually need at least 2 or 3 trials to get the exact spring you need if the any particular characteristic or dimension is critical. There are just too many uncontrolled variables in spring making by hand to hit the desired spring first time unless you get lucky.
Also, the use of a screw-cutting metal lathe is essential to make mandrels and to wind the correct pitch once the mandrel is made. Once you get the hang of it, you can make springs that are indistinguishable from factory made.
Randy
Reply to
R. O'Brian
I make quicky spring mandrels all the time for special sizes or gauges. Slot one end of the mandrel [1/8" brazing rod, 1/4" etc.] and bend a crank handle in the other end. Drill two blocks of wood for bearings & clamp them at the extreme ends of the vise jaws. Insert the mandrel, insert the spring end in the slot and wind away. Look out for the backlash when you stop. Clip the wire and slip the finished spring off. For compression springs you can make a winding space gauge or just stretch a tension spring to the length you want. Bugs
Reply to
Bugs
Great Reading, Thanks!
Thinking about springs drifted me towards rubber bands, which I guess could be considered springs. Then I remembered something nifty I bet a lot of folks here don't know.
We've all seen how when we bend a piece of something like coat hanger wire back and forth rapidly a few times and then feel the bent area it's noticably warm, but did you ever feel something which gets cool when tension on it is released?
Try this (It's not a joke, trust me.):
take a common rubber band, preferably a "fat" one, say 3/16" to 5/16" wide.
Stretch it out between your hands as far as you feel it's safe to do and hold it that way for 5 or 10 seconds so it pretty much comes down to room temperature.
Touch the center of the stretched band against your upper lip and move your hands closer together quickly.
Feel it get cold?
The entropy explanation for this can be viewed at:
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Reply to
Jeff Wisnia

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