Motor hums, doesn't know 'Quietly"

T Bredehoft

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My Atlas/Clausing MK2 lathe came to me with a Westinghouse motor SER DH76, S#317P 025 Type FHT, 115 V 6.1 A, FR SSB562. 1/3 HP
(I don't know if any or all of that is meaningful. ) When I got the lathe, either 3 or 4 years ago, the lathe itself showed no wear on the ways, I have to assume the motor may have been original. Anyway, it's taken to growling, enough that it transmits a nasty chatter to the tool as it cuts. With the belt unhooked, it still growls badly.
Is it time to replace the motor? is there anything I can do to reduce the growl? Is there a equal sized DC motor I can substitute? if so where do I look for it.?
 
I think I would try and determine the source of the problem and then decide if the motor needs replacing. It could be several things contributing to the noise and chatter. I would first check to see if the motor mounting bolts are loose. If not, then back them off and remove the drive belt and check it’s condition. Check for loose set screws on the pulleys. Turn the shaft over by hand and see if there is any resistance to rotation, possibly bad bearings.
I guess where I’m heading is to see if is possible to determine whether it is a mechanical problem or if not, electrical. If you can get headed in the right direction, it shouldn’t be a hard problem to solve. Just a matter of eliminating one source of the problem at a time, then move on to the next.
Others here will chime in and help you get up and running, good luck.
Bill
 
So is it a hum like 60 cycle or is it more like a nasty garbage disposal type of noise? If the latter then probably a bad bearing
Mark
 
Growl is there with the pulley removed. Mounting screws are tight, there's a rubber damper (1/16) under the mounts. It may be a 60 cycle hum, but its kinda raspy. I'll put a stethoscope on each end....

The bearing away frm the pulley has a real rasp to it.
 
I'd guess the 'rest' the motor had between mfgr (ca 1970 or so and 2015 let the bearing go dry. Is there a currently produced motor that would take it's place, or are bearings easily replaceable?
 
Lots of internet videos and articles on replacing bearings in motors. You should be able to replace the bearings. Need to get them out to find the code/size.

An example video. The ends are pulled apart around the 7min mark. In this video the bearing came off with the shaft. Sometimes they stay with the end.

Motor rebuild video

This may be closer design to your motor.

Craftsman motor rebuild
 
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Could it be a sleeve bearing motor? I could see that going dry
 
I would suspect bearings. Does you motor have a sticker that says something like this :)


WestinghouseMTRLabel.PNG

If the bearings are crunchy you should replace them, sealed bearings are probably a better choice than the originals which are most likely shielded on one side and open on the other.
 
x2 on bearing replacement. Generally pretty easy job. Mike
 
. Does you motor have a sticker that says something like this

No but it does mention intermittent service, so many drops over 5 years..... I'll look into bearings, but I need it soon, may have to run it with wobbly bearings.
 
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