Coin Slot

Coin Slot Magazine - #078 - 1981 - August [International Arcade Museum]
[put another nickel in
Art Reblltz
WIND YOUR OWN COIL SPRINGS
All sorts of coin operated devices rely on springs in
order to function properly. Stiff compression springs
often seem to survive intact over the years, but delicate
extension springs are usually stretched out of shape,
bent, rusted and otherwise malformed to the point
where they no longer do their job. Coin mechanisms,
such as the ratchet assembly in the Mills Violano
accumulator, will not do the job of closing the main
power circuit with large, heavy electrical contact points
when a nickel is deposited, unless each spring has the
correct amount of tension over its required range of
stretch. Hours can be wasted trying to strengthen or
weaken the wrong spring or combination of springs in
attempt to get a mechanism to work, but there is no
need to fool around with rusty old springs, or to spend
hours running from one hardware store to another just
to find that the correct spring isn't available, if you have
a few simple tools: a vise, a micrometer (for measuring
the old and new wire), a variable speed electric drill
(substituting for a lathe), an assortment of small metal
rods (used for mandrels), an assortment of music wire
(available from any piano supply company and some
large industrial supply houses) and a good quality
music wire cutter. (Wire cutters made specially for
music wire are necessary, as cheap side cutters are
softer than the wire and will get nicked each time you
make a cut.)
The first step is to match the original size spring wire,
assuming that part of the original spring is available for
comparison. Then make the winding mandrel of the
correct size. With a hacksaw, cut a piece of rod about
4" long which is just a little smaller in diameter than the
inside of the old spring, and drill a hole through it one
inch from one end. Make the hole large enough for the
largest anticipated size of music wire that will be used
with this mandrel. Chuck the mandrel in the drill with
the little hole about 1A" from the chuck, and secure the
drill in a vise, being careful not to squeeze the drill case
so much that it distorts. Unwind about ten feet of wire
from the appropriate coil of music wire, and insert the
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end of the wire in the hole
mandrel.
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The illustration shows
the a
method
used by your left-
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load the . drill
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handed author,
at the right and the
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mandrel at the :// left.
p
t
more convenient
to do this backwards Set the reversing
ht
switch on the drill accordingly so the top surface of the
mandrel moves away from you — "forward" if the
COIN Arcade
SLOT Museum
© 36-THE
The International
A reversible drill held snugly in a bench vise, with a new
spring wound around the mandrel. The tension has
been backed off, and the spring is ready to be cut loose.
mandrel is pointing to the left, or "reverse" if to the
right. Turn the mandrel and chuck by hand until you are
able to bend the wire 90° where it enters the hole, and
then pull gently on the trigger with one hand, firmly
guiding the wire with the other. It is wise to wear safety
goggles when working with spring wire in case the end
breaks or comes loose from the mandrel and hits you in
the face.) Start slowly, and pull harder on the trigger as
you gain confidence. Guide the wire $o each new coil
will change the characteristics of the spring. After you
have enough windings for the spring plus about 1/>"
extra, stop the drill. Keep holding the tension on the
wire with one hand, change the position of the reversing
switch, and gently pull the trigger, slowly turning the
mandrel until all tension is off the wire so the spring will
stay put and not turn into a pretzel when you let go. Cut
off the spare wire, and cut the spring loose from the
mandrel. You should now have a perfectly formed
spring, a little longer than the finished spring. If the
original spring has loops at the ends, f6rm each loop by
placing the spring on a bench, inserting a thin, rigid
knife between coils, and bending the end coil or two at
a 90° angle to the rest of the spring.
After ruining three or four springs, you will acquire
the knack and will be able to turn out one beautiful
spring after another. Just remember to unwind plenty
of music wire from the coil each time; the Murphy's Law
August 1981
http://www.arcade-museum.com/