wild_musk
Plastic
- Joined
- Apr 4, 2011
- Location
- albuquerque
I have a 12" Logan lathe that came with a 3ph, 1hp, 66 frame motor. It burned up, and I am attempting to replace it. Baldor makes a pre-1952 NEMA 66 frame motor, $600-700. Before I commit, I have a couple questions.
The old motor was wired through a phase converter, which I never liked. I am thinking of using a 3ph with VFD instead. Any reason not to? If I replaced it with a single phase motor, I could continue to use the Logan system to change rpm...I think. Realize most probably aren't familiar - it's a mechanical system of changing rpm infinitely from low to high (think it goes from around 600 to 2500rpm) by tensioning a system of belts with the crank on the front...VFD would be electronic. Lathe has back gears for slower speeds. Does the motor produce 1hp at any VFD-selected rpm? Will it bog down at lower rpm settings on VFD, and should I consider higher HP?
I assume all VFDs are not equal, and am leery of buying a bad one. Suggestions on where to go or brand, assuming it's even a good idea?
The 66 frame is the only motor with a .75" shaft...don't laugh, but does shaft size matter? Old motor was foot mounted to a height-adjustable plate which I can easily adjust for a different motor mount. If I used a 56c with 5/8" shaft, any consideration as far as turning metal on a medium size machine? I would have to make a sleeve for it to fit the original pulley...or a new pulley, etc.
End of day, just want to know if any particular setup is better or to be avoided. Machine is great, want to do it justice. Thanks very much,
Coty
The old motor was wired through a phase converter, which I never liked. I am thinking of using a 3ph with VFD instead. Any reason not to? If I replaced it with a single phase motor, I could continue to use the Logan system to change rpm...I think. Realize most probably aren't familiar - it's a mechanical system of changing rpm infinitely from low to high (think it goes from around 600 to 2500rpm) by tensioning a system of belts with the crank on the front...VFD would be electronic. Lathe has back gears for slower speeds. Does the motor produce 1hp at any VFD-selected rpm? Will it bog down at lower rpm settings on VFD, and should I consider higher HP?
I assume all VFDs are not equal, and am leery of buying a bad one. Suggestions on where to go or brand, assuming it's even a good idea?
The 66 frame is the only motor with a .75" shaft...don't laugh, but does shaft size matter? Old motor was foot mounted to a height-adjustable plate which I can easily adjust for a different motor mount. If I used a 56c with 5/8" shaft, any consideration as far as turning metal on a medium size machine? I would have to make a sleeve for it to fit the original pulley...or a new pulley, etc.
End of day, just want to know if any particular setup is better or to be avoided. Machine is great, want to do it justice. Thanks very much,
Coty