When I first read D. L. Bullock's account of electric motor rebuilding,
I remained silent, even though I thought his rebuilder's prices were
out of sight.  Now that Sam Harris has used that service and reported
it here on MMD, I feel it is time to speak up.  Nearly seven hundred
dollars without rewinding is absurd!

I have been servicing these motors for over 25 years and usually do no
more than clean them up, inside and out.  These are simple motors with
simple components.  They are built very well and survive nicely.  There
are a few conditions that do warrant additional repairs.

First, some early Ampico motors do not have the more common wadding
packed lubricant area surrounding the bearings.  Instead, these motors
are lubricated with a grease or tallow wick in a spring loaded tube.
These motors typically have bad bearings that must be replaced.  These
are not good motors and have to be watched carefully in use as the
lubrication system is unreliable.  These motors have the early mounting
system that resembles a ring around the motor.  They are may be found
in some pianos from around 1922, but there is no clear crossover date.

Second, all reproducing piano motors are subject to emitting a foul
odor when hot.  This appears to be caused by rancid tallow lubricants
that are common in these motors.  The only cure for this is to rewind
the motor as the lubricant has impregnated the field windings.  If this
odor is mild or piano use is very light, rewinding can be omitted.

All motors should be cleaned and lubricated.  The old lubricant should
be removed, by replacing the packing around the bearings.  If the motor
operates normally once it is properly lubricated, nothing else is
required.

Typically the motor in a grand piano will have thrust bearings that are
made of fiber or wood.  These can be replaced, if necessary for a few
dollars.  Grands with vertical shafts are not troubled by excessive end
play, as the weight of the shaft and induction armature are always
against the thrust bearing.  On upright installations, end play can be
adjusted by placing appropriate motor washers on the shaft.  Again, the
cost less than $5.00.

If the motor runs with a cyclical or very slow throbbing hum on the
bench, the bearings are bad.  Most motor shops can replace them for
less than fifty dollars.  Rewinding is about $125 to $200.  Connection
wire $5.00.

The internal start switch should be cleaned, points filed, and checked
for proper operation.  None of these motors is thermally protected.
That means the operator should always be aware of the motor status and
double check that the piano is indeed off before moving on to other
activities.  Motors will be quite hot after extended use.  After one
hour of play, placing a hand on the motor housing will be very
uncomfortable.  This is normal.

A properly restored reproducing piano never has audible motor noise.
The noise of the belt and pump are much louder, but they too, will be
almost silent.

Motor shafts should not be built up as it makes no economic sense.
It is easier to bore the new bearings to match the shaft.  A $50 job.
If it is going to cost more than $400.00 to fix the motor, buy another
motor that shows no sign of bearing wear, clean it up, and install it
instead. Then put the bad motor on eBay auction.

Bob Taylor