by Zac Oliver
The Williams' Flipper Unit
Though the flipper units of most
manufacturers perform essentially
the same function, each is distinctly
designed . Some use Direct Current
(DCl. most Alternating Current
(AC). Plastic or metal flippers come
in a variety of sizes and shapes.
Coil -windings differ as do bushings,
coil stops, coil brackets, springs,
plungers, flipper buttons and rubber
rings . Differences in any of these
elements will effect flipper response
in different ways. Some good, some
not so good . Perhaps the ideal flipper
would be the synthesis of all
manufacturer's models.
Let's look at the flipper unit
produced by William's Electronics.
You probably know and recognize
every part but since the Williams
terminology may differ from yours,
you should refer to the diagram
below.
Unit performance begins with a
press of the flipper button ; and since
it is an extension of the player's
hand , the entire mechanism should
respond to its maximum design
capabilities. Briefly, here's what
happens when the player presses the
flipper button . The coil magnetic
field (large gauge winding,FL20-
300) pulls the plunger. It's connec-
tion, the fiber link, swings the flipper
pawl which is pivoted by the shoe
and shaft. On the playfield board, the
plastic flipper and rubber ring hits the
ball. The pawl's swinging motion
opens the end-of-stroke switch
(E.O.S.) which shorts-out the small
gauge winding (28-400) . This wind-
ing , now in series with the large
gauge winding , increases the coil
resistance, thus, preventing it from
burning regardless of how long a
player may hold the flipper buttons.
Performance depends on several
factors . Assuming normal voltage,
the following problems will result in
weak or sluggish flipper action :
• Dirty or improperly adjusted
contact points
• A worn out coil sleeve
• Loose or broken bushing
• Wrong coil or connections
(Note the two large gauge
windings used by William 's)
• Worn
out
fiber
links
• Weak or broken return spring
• Loose coil between retaining
bracket and coil -stop
There are othe'r performance
factors to be considered. Depending
on the game, a large or narrow·
flipper rubber ring wi ll be used . A
narrow rubber ring will rebound less
providing better control; a larger one
rebounds more, cutting down con-
trol. Proper alignment of the plastic
flipper is the key to skill shots. A bent
shoe will scratch the playfield, and a
missing plastic sleeve will "eat up"
the E.O.S. switch long-blade which
will eventually burn out the coil.
When the machine warms up, a
flipper may "stick" if a pawl is
swinging too close to the bushing or
if it is fouled with ~rease and dust.
(Please, never lubricate the plunger,
spring or bushing . Lubrication , at
best, is a temporary remedy for
sticking that will cause more
problems later. Besides, you will find
most of the time that the causes of
sticking are hardly ever lube
problems) .
. Flipper performance can be af-
fected by other potential problem
areas. Just remember that because
of its heavy usage, maintenance of
the flipper and coil assembly is
required more often than any other
part of the machine. It can be awfUlly
annoying to playa game with bad
flippers . Our friend Roger Sharpe
can tell you! So tighten screws
periodically, check mechanical con-
nections; replace a coil stop when
needed , also, sleeves, links (es-
pecially), springs, rotate rubber
rings, file the plunger end that
strikes the coil stop; file and adjust
switch contacts, including the
switches; and give special attention
to
the
E. O.S .
switches.
The William's flipper unit is very
reliable. With proper care it will work
trouble-free for many, many games.
Before setting up on location,
however, even if your machines is
factory fresh, check the flippers .
Make sure they are corresponding to
the game's demands (flipper ad-
justments will make the game liberal
or conservative, also). Keep your
players satisfied. Good flipper re-
sponse will attract more of those
silvery discs. That's what our
business is all about.
Rubb e r Ring
Bu s hi CJ
Pl a s Li c S] e v e
Sere'"
( 2)
---~ Co.E: Pin
Co il Stop
Jt.~~ ,
Ro ll p '
FL20-300-28-400
( 2 4 VOLT)
P lungc::r
Stop Or e ket
Plung e r
1/8"
~n xl/2 "
FL 2 1- 3 75:"2 8 - 400
Hctaini ng
Bracke t ( Adj )
.L 24 VOL T)
47