Coin Slot Magazine - #077 - 1981 - July [International Arcade Museum]
SERVICING OLD ELECTRIC MOTORS
Continued from page 37
If the motor starts properly, listen for the "click" as
spaghetti (flexible plastic or woven insulating tubing)
the starting switch disengages. If it doesn't click, check
over the old wire. If not, take the motor to a repair shop;
for mechanical problems.
Providing that the windings are good, the motor
don't just wrap plastic electrical tape over the old
rotten insulation or bare wire, as it will come off as soon
as grease or dirt gets into the adhesive.
should now run like new. If so, congratulations! If not,
take it to a repair shop.
Place all washers on their appropriate places on the
In a few rare repulsion start AC induction motors, the
armature, and wipe a thin coat of motor oil on the
armature has a commutator with brushes, as in a DC
motor. Be sure to keep each brush in its own holder. If
mating parts of the bearings and armature. Do not
Lubricate the grease or oil cups with the correct
the brushes are worn too far, replace them. Clean the
commutator by touching it with a commutator stone
lubricant. If the motor has oil tubes, use SAE 20 non-
while running, shut off the motor and blow out the
detergent electric motor oil. If it has grease cups, use
abrasive powder. If new brushes are necessary, have a
lubricate the starting switch!
appropriate grease. I have seen more than one motor
repair shop show you
ruined because someone packed grease into oil cups.
With no means for the grease to travel to the bearings,
commutator the first time you try this; the shop will also
sell you the correct stone for doing this.
Mills Violano motors are specially constructed. While
they follow some of the mechanical principles of
ordinary motors, the electrical characteristics are
deceiving. The theory of operation and maintenance of
a motor will freeze and burn out, or at least ruin the
bearings.
Exceptions are certain motors used in reproducing
pianos which have tubes with wicks, designed for oil,
but facing downward so the oil will run out, or with
channels in the sleeve bearings made in a way that oil
will run into the motor case. The original lubricant was
a "non-fluid" oil which will travel down the string wick to
the bearing but no farther. According to my local motor
shop, this should be mixed with very thin grease or
grease mixed with oil which will very slowly release the
oil to the bearing without running into the motor case
or all over the floor or piano bottom.
Reassemble the end bell opposite the starting switch
to the motor body, insert the armature into the bell
containing the switch, and then insert the armature
into the motor, gently squeezing everything into place.
Exert no great force, as doing so will bend something. If
the motor will not go together under gentle pressure,
how to mate them to the
these special motors will be covered in the new
Violano Service Manual being written by Mike Kitner
and yours truly, to be published later this year by the
Vestal Press and available from the publisher, the
authors, or Coin Slot Books.
Excerpt from Holtzer-Cabot piano motor instruction
book of the mid-1920's:
LUBRICATION
A very common method of lubrication shown in
Figure 1 consists of a wick cup with felt wick to feed the
lubricant to the shaft surface. When the motor is
find out why and correct it.
Tighten the end bell screws or nuts a little at a time,
jumping around from one to the opposite one until they
are all tight, as in tightening lug nuts on an automobile
wheel. If the armature does not spin freely after all of
the nuts or bolts are tight recheck everything to make
sure ypu have not put a bind on the armature. If you can
%not get it to spin, take the motor to a shop or new
bearings. If the armature is bent, there is probably only
a slim chance that it can be repaired.
When you are satisfied that the armature turns
freely, attach the leads coming through the end bell to
their correct binding posts, and attach a power cord.
Plug the motor in, ready to pull the plug if it doesn't
start turning immediately. If it doesn't, recheck the
starting switch to make sure that it is making contact.
com
.
m
:
u
use these may
from -m
determined by the fibre
armature
washers;
d
e
e
have been mixed
during
ad previous disassembly.
load up .a
rc washers
n
w
Adjust or replace
the
fibre
as necessary. Also
Do // end
ww
w
check for shaft
play; ideally, there should be just
:
tp
ht amount
the tiniest
of play. Adjust by adding thin fibre
In many motors, correct contact between switch parts,
and clearance between armature and end bells are
washers. Fibre washers in many sizes are available
from motor repair shops.
COIN
SLOT
© 38-THE
The International
Arcade
Museum
Fi«. I
July 1981
http://www.arcade-museum.com/