First Grinder Build Q's

boy&hisdogs said:
I would like a vfd if it wasn't going to cost too much more. The pulleys, bearings, extra shaft, belt, and all that will likely get close to $100 all said and done. For me the limiting factor was the price of the motor itself. I just don't know where people are finding these cheap 3ph motors.
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I got a new baldor 1.5hp 3ph for 85 bucks on ebay. And it is not even close ... vfd over pulleys
 
Correct me if I'm wrong but don't you loose about a third of the horsepower if you run a 3 phase motor through a vfd on a single phase feed?

May be something to consider when ordering a motor.
 
scott kozub said:
Correct me if I'm wrong but don't you loose about a third of the horsepower if you run a 3 phase motor through a vfd on a single phase feed?

May be something to consider when ordering a motor.
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You may be thinking of running through a static phase converter.
That, or you would also de-rate a VFD that's rated for a three phase INPUT voltage, if only using a single phase.

For a 1 phase in, 3 phase out, the VFD nameplate rating should be relatively accurate. I might also add here: You can run a lesser HP motor on a higher HP rated VFD, but NOT the other way around.
 
I don't believe any power is lost. Either that, or the 1.5hp Dayton I have is way underrated! Because it's got power to spare! I can't bog it down.

Even a 1hp is going to be plenty for 99% of knifemakers. Before this, I have been using a single speed .75hp. And although I could bog it down, it still worked just fine for my knifemaking.
 
knife to a gunfight said:
You may be thinking of running through a static phase converter.
That, or you would also de-rate a VFD that's rated for a three phase INPUT voltage, if only using a single phase.

For a 1 phase in, 3 phase out, the VFD nameplate rating should be relatively accurate. I might also add here: You can run a lesser HP motor on a higher HP rated VFD, but NOT the other way around.
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Yep I think your right. I was forgetting about phase converters.

I just replaced my air compressor with a 7.5 hp leeson. Man would that make a good grinder.
 
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