Motor Compatability

[dmcfeely]

I have an original Shop Smith from the 50s.

I upgraded it in the 80 with the 500 upgrade kit for everything except the motor.

Now the motor is getting tired.

Will the new motor (13964, Motor Mark V 120V (incl 121 122-124)) fit and mount in a 70 year old headstock?

Cheers

[DLB]

In the general sense yes, it will fit and mount. You might have dropped a digit, or where you looked this up has an error, should be 513964. That is motor without sheaves, it is also available with the spacer, key, sheaves, spring, washer, clip; 516152.

Some early Greenies had a different retaining system for the motor sheave parts. The end of the shaft looks like a nut. I'm not familiar with this version. If you have that, it seems likely that there are differences that would not allow you to use all of the old parts on the new motor. Someone else here probably can explain what else you need if you have the older version.

The new motor has 50% more power, 1-1/8HP Vs 3/4HP. That is all good, but the new motor does draw more current. If you have an original switch I'm not sure of compatibility in terms of Amps and HP, so I would check that or change it. Likewise the power cord. I don't know the original version, but I think it needs to be at least 14 gauge (IIRC) and include a ground.

Used, and sometimes rebuilt, motors are frequently available on eBay, but I'm not trying to sway your decision. They often come with more pieces, like all the sheave parts, cord, switch, and frequently a motor pan.

Note - There is some variability over the decades as to whether Neutral is switched or not. That causes variability in wire lengths for the white wire. I have no guess on the current version, so you might have to adjust for this. Not a big deal as either wiring option is okay.

- David

[chapmanruss]

As David said, yes you can change it. I would recommend that you get the motor with the pulley sheaves, spring and retainer with it as some of those parts have changed since your 1950's Mark 5 was made. Also change the switch and power cord since, if original, the cord is 2 conductor so no ground.