not knowing exactly what motor is in your 3N1, i can only speculate.
i saw the spec's for the unit and it said 3/4hp motor.
you may be able to use a 56frame 3/4 or 1 hp motor, (sold as the farm duty motors at HF if you are going on price alone about $150)
using a different motor may require making or modifying the drive pulley(s),
but don't fear mods can be easy!
This shows the motor part as "YCYS7144". If this is a motor nameplate, I do not recognize the coding scheme. The part diagram shows the motor to be flange/face mounted, which makes sense.
I would measure the existing motor mounting bolt circle diameter, thread pitch, shaft diameter and key dimensions. This will tell you if the motor is metric or imperial. I am guessing metric. The motor nameplate should state voltage and RPM.
As Ulmadoctor mentioned, some modifications may be required to fit the motor you find.
EBay may be a cheap source if you can find the right motor. DealersElectric is a good place to find what may be readily available.
Thanks all! I was hoping to find someone that had replaced one before and would know the specifics. The motor went out several years ago and I had replaced it with one of the HF farm motors. Since I had the 3n1 bolted down to a bench, I just figured out the distances and so forth, took the mount off the back of the cabinet and bolted it to my bench. Now I am wanting to sell it and trying to figure out how to mount a motor back similar to original specs. Dave, you are right. The original motor (as I recall) did have a face mount. And Bogus, I tried to have the original rebuilt but no one would touch the Chinese motor. I guess I'll have to make a bracket of some kind to mount the farm motor unless I can find a buyer with a solid bench to put it on.
here is a link to an IEC (metric) motor chart from marathon motors inc.
if you know the original shaft size, you can reverse look up the IEC frame # and find an appropriate motor to replace the replacement
you may have a B5 mount- 63 or possibly a 71 frame, but that is pure speculation on my part.
here is a chart to see for yourself http://www.marathonelectric.com/docs/BackCover.pdf
FYI, if you do not find your motor measurements in the chart, you are not alone.
I have a Grizzly lathe, made in Taiwan which has IEC 90L motor.
I also have a Grizzly milling machine, also made in Taiwan, which has a motor of unknown specification. The motor is typical rigid base/foot mount. The mounting holes are close to a NEMA 145, but the shaft is 3/4in. A NEMA 145 motor would be 7/8in shaft. An odd combination.
Dave, I have bought parts from grizzly that fit the HF 44142, in particular the crossfeed nut. I think they used their own specs to make the motors just so if you wanted to easily replace it, you'd have to buy theirs. The car makers do the same thing. On most of the new cars, some critical parts are only available from the dealers. I'll just make a mount similar to the original and mount the farm motor. Thanks all!
I have a Harbor Freight 44142 that I just completed swapping in a 48C motor for the lathe. There was some minor modification involved. If anyone is interested, I can post the details of what was involved.