I have an ancient GE 1/2hp 66 frame single phase motor on my 1949 South Bend,
and lately it has started making a noise I don't like. Actually, I like dead
silence out of motors, any noise I don't like, but this is an annoying buzz. It
doesn't vibrate, it just buzzes. It sounds like single phase motors often do
while starting, but once they spin up the noise stops.

When it's slowing to a stop, I can very clearly hear the centrifugal switch
clicking back closed.

If this were a 56 frame motor, I'd just replace it and toss this battleax. I
have the feeling that trying to replace a 66 frame motor would be spendy.
(Buying *any* motor when you need one is spendy, the only way to get them cheap
is to buy them when you don't need them.) I probably have about 4 56 frame
motors sitting around anyway.

I suppose this problem is either that the centrifugal switch is failing to open
at speed, or the start cap is drying out, probably the former. I don't think
it's a cracked rotor bar or end ring, as those usually vibrate. I also don't
think the stator windings came loose, this normally causes vibration too.

It happens regardless of spin direction. The noise doesn't change any at all if
I put oil in the oil cups. It's nothing to do with my lathe, I've tested it
without the belts. The mounting bolts are tight, and the motor ran very quietly
for many years and I didn't change anything about the setup.

It isn't a bearing noise. Anyway, the bearings are nice and smooth and silky
when I turn the shaft by hand.

Anyone?

Grant Erwin
Kirkland, Washington

Hi Grant,

I think it could be the start cap. A couple of weeks ago I did some
experiments using a three phase motor and variable run capacitance. Too
much made it noisy, as did too little, but just right and the motor was
almost silent. However, in my case I would describe the noise as being
more of a hum or whine than a buzz.

Chris

Christopher Tidy wrote:

Hi Grant,

I think it could be the start cap. A couple of weeks ago I did some
experiments using a three phase motor and variable run capacitance. Too
much made it noisy, as did too little, but just right and the motor was
almost silent. However, in my case I would describe the noise as being
more of a hum or whine than a buzz.

Chris


Oh, yes, I am very familiar with start caps making a buzz in phase converters.
However, in a single phase motor the start cap is *supposed* to be cut out of
the circuit by the centrifugal switch. The motor appears to have full power.

Puzzle.

GWE

Could be loose laminations; most likely in the stator. If the start cap is
cut out via a potential rely instead of the usu. centrifugal switch, the
relay could be the culprit.

Bob Swinney
"Grant Erwin" wrote in message
...
Christopher Tidy wrote:

Hi Grant,

I think it could be the start cap. A couple of weeks ago I did some
experiments using a three phase motor and variable run capacitance. Too
much made it noisy, as did too little, but just right and the motor was
almost silent. However, in my case I would describe the noise as being
more of a hum or whine than a buzz.

Chris


Oh, yes, I am very familiar with start caps making a buzz in phase
converters. However, in a single phase motor the start cap is *supposed*
to be cut out of the circuit by the centrifugal switch. The motor appears
to have full power.

Puzzle.

GWE

I have an ancient GE 1/2hp 66 frame single phase motor on my 1949 South Bend,
and lately it has started making a noise I don't like. Actually, I like dead
silence out of motors, any noise I don't like, but this is an annoying buzz. It
doesn't vibrate, it just buzzes. It sounds like single phase motors often do
while starting, but once they spin up the noise stops.

When it's slowing to a stop, I can very clearly hear the centrifugal switch
clicking back closed.

If this were a 56 frame motor, I'd just replace it and toss this battleax. I
have the feeling that trying to replace a 66 frame motor would be spendy.
(Buying *any* motor when you need one is spendy, the only way to get them cheap
is to buy them when you don't need them.) I probably have about 4 56 frame
motors sitting around anyway.

I suppose this problem is either that the centrifugal switch is failing to open
at speed, or the start cap is drying out, probably the former. I don't think
it's a cracked rotor bar or end ring, as those usually vibrate. I also don't
think the stator windings came loose, this normally causes vibration too.

It happens regardless of spin direction. The noise doesn't change any at all if
I put oil in the oil cups. It's nothing to do with my lathe, I've tested it
without the belts. The mounting bolts are tight, and the motor ran very quietly
for many years and I didn't change anything about the setup.

It isn't a bearing noise. Anyway, the bearings are nice and smooth and silky
when I turn the shaft by hand.

Anyone?

Grant Erwin
Kirkland, Washington
Maybe a little bit of play in the field windings/laminations and the
case. You didn't say if it comes up to normal speed. A small wooden
wedge between the laminations and the case would be a good starting
point to see if it makes a difference. Also, sometimes the "parts" of
the centrifugal switch (the rotating actuator, rubbing arms, etc)
change with wear. Sometimes the bakelite rotating disk will get a
crack in it and make a buzzing sound as it (the crack) passes over the
rubbing pads on the contact arm(s).
HTH
Ken.

"Grant Erwin" wrote in message
...
I have an ancient GE 1/2hp 66 frame single phase motor on my 1949 South
Bend, and lately it has started making a noise I don't like. Actually, I
like dead silence out of motors, any noise I don't like, but this is an
annoying buzz. It doesn't vibrate, it just buzzes. It sounds like single
phase motors often do while starting, but once they spin up the noise
stops.

I have an old motor on my SB10L as well- Radio something, I forget the name.
I think it has lost torque over the years. I need to bite the bullet and
replace it with a new one, preferably a one horsepower.

I have an ancient GE 1/2hp 66 frame single phase motor on my 1949 South Bend,
and lately it has started making a noise I don't like. Actually, I like dead
silence out of motors, any noise I don't like, but this is an annoying buzz. It
doesn't vibrate, it just buzzes. It sounds like single phase motors often do
while starting, but once they spin up the noise stops.

When it's slowing to a stop, I can very clearly hear the centrifugal switch
clicking back closed.

If this were a 56 frame motor, I'd just replace it and toss this battleax. I
have the feeling that trying to replace a 66 frame motor would be spendy.
(Buying *any* motor when you need one is spendy, the only way to get them cheap
is to buy them when you don't need them.) I probably have about 4 56 frame
motors sitting around anyway.

I suppose this problem is either that the centrifugal switch is failing to open
at speed, or the start cap is drying out, probably the former. I don't think
it's a cracked rotor bar or end ring, as those usually vibrate. I also don't
think the stator windings came loose, this normally causes vibration too.

It happens regardless of spin direction. The noise doesn't change any at all if
I put oil in the oil cups. It's nothing to do with my lathe, I've tested it
without the belts. The mounting bolts are tight, and the motor ran very quietly
for many years and I didn't change anything about the setup.

It isn't a bearing noise. Anyway, the bearings are nice and smooth and silky
when I turn the shaft by hand.

Anyone?

Grant Erwin
Kirkland, Washington
Well....... do we have a final outcome, Grant???????? Let us know.
Ken.

Ken Sterling wrote:
I have an ancient GE 1/2hp 66 frame single phase motor on my 1949 South Bend,
and lately it has started making a noise I don't like. Actually, I like dead
silence out of motors, any noise I don't like, but this is an annoying buzz. It
doesn't vibrate, it just buzzes. It sounds like single phase motors often do
while starting, but once they spin up the noise stops.

When it's slowing to a stop, I can very clearly hear the centrifugal switch
clicking back closed.

If this were a 56 frame motor, I'd just replace it and toss this battleax. I
have the feeling that trying to replace a 66 frame motor would be spendy.
(Buying *any* motor when you need one is spendy, the only way to get them cheap
is to buy them when you don't need them.) I probably have about 4 56 frame
motors sitting around anyway.

I suppose this problem is either that the centrifugal switch is failing to open
at speed, or the start cap is drying out, probably the former. I don't think
it's a cracked rotor bar or end ring, as those usually vibrate. I also don't
think the stator windings came loose, this normally causes vibration too.

It happens regardless of spin direction. The noise doesn't change any at all if
I put oil in the oil cups. It's nothing to do with my lathe, I've tested it
without the belts. The mounting bolts are tight, and the motor ran very quietly
for many years and I didn't change anything about the setup.

It isn't a bearing noise. Anyway, the bearings are nice and smooth and silky
when I turn the shaft by hand.

Anyone?

Grant Erwin
Kirkland, Washington

Well....... do we have a final outcome, Grant???????? Let us know.
Ken.


No, no real resolution. I'm just going to start looking for a 66 frame motor, or
maybe I'll just bite the bullet and make a 3/4 to 5/8" keyed shaft bushing and
drill/tap the horizontal power unit for a 56 frame motor, then it will be
trivial to swap motors. 56 frame motors are a dime a dozen.

GWE

"Grant Erwin" wrote in message
...
Ken Sterling wrote:
I have an ancient GE 1/2hp 66 frame single phase motor on my 1949 South
Bend, and lately it has started making a noise I don't like. Actually, I
like dead silence out of motors, any noise I don't like, but this is an
annoying buzz. It doesn't vibrate, it just buzzes. It sounds like single
phase motors often do while starting, but once they spin up the noise
stops.

When it's slowing to a stop, I can very clearly hear the centrifugal
switch clicking back closed.

If this were a 56 frame motor, I'd just replace it and toss this
battleax. I have the feeling that trying to replace a 66 frame motor
would be spendy. (Buying *any* motor when you need one is spendy, the
only way to get them cheap is to buy them when you don't need them.) I
probably have about 4 56 frame motors sitting around anyway.

I suppose this problem is either that the centrifugal switch is failing
to open at speed, or the start cap is drying out, probably the former. I
don't think it's a cracked rotor bar or end ring, as those usually
vibrate. I also don't think the stator windings came loose, this normally
causes vibration too.

It happens regardless of spin direction. The noise doesn't change any at
all if I put oil in the oil cups. It's nothing to do with my lathe, I've
tested it without the belts. The mounting bolts are tight, and the motor
ran very quietly for many years and I didn't change anything about the
setup.

It isn't a bearing noise. Anyway, the bearings are nice and smooth and
silky when I turn the shaft by hand.

Anyone?

Grant Erwin
Kirkland, Washington

Well....... do we have a final outcome, Grant???????? Let us know.
Ken.


No, no real resolution. I'm just going to start looking for a 66 frame
motor, or maybe I'll just bite the bullet and make a 3/4 to 5/8" keyed
shaft bushing and drill/tap the horizontal power unit for a 56 frame
motor, then it will be trivial to swap motors. 56 frame motors are a dime
a dozen.

GWE

Grant, do you know if all of the 1940's era SB10L lathes used 56 frame
motors?

Grant, do you know if all of the 1940's era SB10L lathes used 56 frame
motors?



I don't know if even one did. Mine sure didn't.

GWE

"Grant Erwin" wrote in message
...


Grant, do you know if all of the 1940's era SB10L lathes used 56 frame
motors?

I don't know if even one did. Mine sure didn't.

GWE

Oops. That should have read 66 frame motors.

"ATP*" wrote in message
...

"Grant Erwin" wrote in message
...


Grant, do you know if all of the 1940's era SB10L lathes used 56 frame
motors?

I don't know if even one did. Mine sure didn't.

GWE

Oops. That should have read 66 frame motors.

Mine is a lot bigger, with a 5" "D" dimension. But it's an oddball, built in
1945 for Navy shipboard use. It also included a DC motor, which has been
removed, so I don't know anything about it.

The base also is somewhat larger than the commercial 10Ls of the time.

--
Ed Huntress

Well....... do we have a final outcome, Grant???????? Let us know.
Ken.


No, no real resolution. I'm just going to start looking for a 66 frame
motor, or maybe I'll just bite the bullet and make a 3/4 to 5/8" keyed
shaft bushing and drill/tap the horizontal power unit for a 56 frame
motor, then it will be trivial to swap motors. 56 frame motors are a
dime a dozen.

GWE

You could replace with a 66 frame 3 phase motor and a vfd. I have an
old and dirty 3 phase 66 frame that you can have pick up for free or
for shipping cost (from Portland OR).

-- Greg