1947 South Bend Heavy 10 240 1 Phase Motor Replacement/Repair

[f66]

I have a SB 10 in the attached pictures with a 240 single phase motor. Have not used the lathe in over 60 days, before today has worked well. Today went to turn on and motor hums but will not turn, released belt, motor turns freely. Turned switch to on position and turned chuck/headstock. Motor then will run but is slow and rough.
With that as a lead in what are the possible causes for this condition? I would like to fix and not have to replace the motor. If replacement is recommended, Where is the best source for a direct replacement?
Thanks in advance. Frank

 

[jbacc]

Sounds like the start capacitor to me.

 

[PackardV8]

Plan on DIY.

Back in the day, we had three electric motor shops here in town. Two are gone and the third is now industrial only; they don't want to see your little shite.

jack vines

 

[L Vanice]

Nice lathe. A new 3/4 HP motor would not cost much, but the problem with replacing an old motor can be in the frame size. The old motor does not state frame size on the nameplate, so a modern motor might not fit the mounting plate holes, shaft height or shaft/pulley diameter.

As an example, I have several old Hardinge machines with original 3/4 HP motors. They have 3/4" shafts, which you will not find on a new standard frame type motor. The good thing about them is that they are three phase, which means they are simply constructed and have practically nothing to fail, so will outlast me.

As for what can fail in an old single phase motor, I suppose it might have a bad starting capacitor and/or centrifugal switch. Or tired wiring/insulation, but a good motor shop may be required to figure it out.

Larry

 

[f66]

All, Thanks for the quick replies. I will begin with diagnosing the starting capacitor and centrifugal switch, and report back.Frank

 

[Bill D]

On the sb9" lathe the single phase motor is instant reverse. Not a type easy to find today. If you had to switching to vfd and three phase motor will allow instant reverse.
Bill D