Coin Slot Magazine - #091 - 1982 - September [International Arcade Museum]
RESTORATION & REPAIR
By Marc Harrison
CLOCK
REBUILDING
If any one component could be con
sidered the heart of the slot machine, it
would have to the clock with its spinning
fan and whirring cogs providing the beat
of life to an otherwise mindless and
emotionless apparatus.
Much like the heart of other living
things, the clock remains in continuous
motion throughout the operational life of
the mechanism. When the clock fails
the machine stops; its service life at an
end
But premature clock failure can be prevented by a
regular schedule of cleaning and lubricating, and quite
often a complete rebuilding can resuscitate a dead
clock and restore it to a useful life.
Whether cleaning or rebuilding, the entire clock
must be removed from the machine. Further disassem
bly is accomplished by removing the three screws
holding the upper and lower bearing plates together.
Once unscrewed, the plates can be separated and the
gears and pinions lifted free. The fan and its pinion will
remain with the upper bearing plate. If the fan or the
pinion shaft is bent, you will need to remove the fan by
unsoldering it from its shaft, otherwise the assembly
can be left intact.
Clean each of the parts in solvent, paying particular
attention to globs of hardened grease adhering to gear
main gear is very important. These pawls are often
gummed up with old chassis grease and should be
operated back and forth until smooth movement is
obtained. The small extension springs attached to the
pawls must be tight enough to fully return the pawls to
the engaged position no matter how slightly they are
moved. Stretched out springs should be shortened or
replaced as necessary.
Bushings in the upper and lower bearing plates are
subject to elongation of their bores, and when so worn
can be renewed by first peening the pushing with a ball
peen hammer, and then resizing with the appropriate
diameter number drill. If any bushings tend to fall out of
the bearing plate they can be easily soldered into
place.
The shaft on which the fan spins is usually made of
music wire, making it difficult to straighten when the
runout is untrue. If you exercise patience, you can bow
a slightly sprung shaft until it holds to a satisfactory
runout. If the shaft is badly kinked or bent, then you will
want to replace it with a new shaft cut from a length
of music wire obtainable at your local hobby shop. The
old pinion and collar can be removed from the shaft by
supporting the pinion on top of almost closed vise
jaws, heating lightly with a torch, and then hitting the
shaft down through the pinion, first with a hammer and
finally with a pin punch. After removal, the pinion and
collar can be fitted to the new shaft and soldered in
place. Be certain that you locate the collar so that there
will be slight up and down movement of the shaft after
the bearing plates are screwed together.
After cleaning, inspect the individual parts for wear.
When you are satisfied with the condition of all the
components reassembly can begin. Start with the
upper bearing plate with the main shaft, ratchet wheel,
Excessive wear on the gear teeth will be quite evident,
and operating arm assembly, turning the plate so that
since the teeth will assume a rather sharp saw-toothed
configuration. As no adjustment can compensate for
the ratchet wheel and shaft are facing upwards. Apply
teeth, bushings, and especially, around the three pawls
on the main gear.
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pinion, h
and brass to brass or steel to steel contact must
such wear, both the worn gear and the pinion with
which it mates will have to be replaced. If you are for
tunate enough to be selecting replacement gears from
a large assortment, choose carefully, so that each gear
in the train mates with a pinion made of a different
material. That is, a brass gear should mesh with a steel
be avoided as noisy operation and accelerated wear
will ensue.
"Premature clock failure
can be prevented by
a regular schedule of
cleaning and lubricating..."
Free movement of the three ratchet pawls on the
46 International
— THE COIN
© The
Arcade SLOT
Museum
SEPTEMBER, 1982
http://www.arcade-museum.com/