Used motors… win some, lose some

[tk1971]

Well, trying to save a buck and I picked up a used 1hp 3ph 208-230v 1725rpm c face motor for my metal bandsaw conversion.

The 1.27hp 10:1 gearbox fit perfectly. The VFD runs everything just fine at 15-30 Hz, then I cranked it up to 60 Hz and the motor started smoking.

Did I pick up a bad motor or did the gearbox add too much load?

The gearbox works just fine with a single phase motor at 1725rpm.

When it cooled down, I pulled the motor apart and found a bad bearing and the windings are toast.

I guess I’m going to try out one of those Amazon motors.

Pics:

 

[Gaffer]

Bummer. I'm in your camp - payz ur money and takes ur chances... I think your motor was toast when you bought it, but I'm no expert.

 

[markba633csi]

Too bad. You take a risk buying used motors. Used anything really. At least you still have the gearbox

 

[matthewsx]

Yep, I've had similar experiences. I'm going to check one out tomorrow, should be cheap enough to take a chance but it didn't pop up on CL until I had pulled the trigger on a new one from eBay. If I'm lucky I'll have one for my 2 x 72 belt grinder and one for my mill.

John

 

[matthewsx]

Going to look at this one tomorrow.




3 phase, 3hp according to seller but can't read the data plate from photo.

This is the one I ordered from eBay, should be here on Tuesday.



Extra part on the end is a brake, figure I should be able to remove it. Price was right at $260 for a new, USA Baldor.

John

 

[Dabbler]

Price was right at $260 for a new, USA Baldor.

WOW!!!! Great deal!!!

 

[cathead]

The wire on older motors has insulation which is not good enough to hold up when using a VFD. It's best to
use a motor rated for inverter duty since there are voltage spikes to consider. That's not to say that one might
get by with it. I have a motor on my mill that has been working fine for years with an added VFD but realize it could
fail at any time if the insulation on the windings breaks down. At that point, I will be shopping for a proper
motor. Of course a defective bearing could have caused the problem as well in your case.