Sander/Grinder

[Slowpoke]

I went to an auction where woodworking machinery was selling pretty cheap. (Add to the bid a 10% buyer's premium and sales tax of 8.75%, or close to 20% over the bid price.)
A old 6" 120V Delta cast iron jointer & stand went for $35. A 3hp Delta cabinet table saw with Besemier? fence, 5' extention table and 8'guide rail went for $395. An 18" band saw for $95. So of course I bid and got a Max brand floor stand 16" disk sander for $100. The only thing I found wrong was the table lift shaft was bent. Not looking it over more closely and in the excitement of the auction, I failed to see the totaly enclosed, 3/4hp, 1800rpm motor is a 3 phase, Frame 203. All this stuff came out of a high school more than 100 miles away. Now what kind of motor can I use that's not going to ruin what I thought was a good deal? Can the motor be rewound for single phase? The shaft is 3/4".

 

[VaTom]

No rewinding, but if it's got 230 v potential all you need is a 3 phase dummy motor and a switch to cobble a phase converter. The last school tool I bought was a huge Powermatic variable speed wood lathe that came with a 208 v motor. I got the lathe for $25 (no auction premiums), then bought a new 1 phase motor for it. That's your other choice, check the online Grainger catalog.

All my large machinery is 3 phase, most of it powered by the phase converter I described. You know you really want to check motor voltages before you bid. If that Unisaw had the wrong motor, it was a $400 correction. Still a good deal.

 

[Dusty MI]

If you want to change the motor, look ID. plate on the motor for the Frame type/number.
Then look for a new motor with the same Frame # and the hp. and voltage you need/want.

Dusty

 

[BDT/NWMN]

Slowpoke, that three phase motor might be a white elephant for you, but someone will have a use for that motor... trade it or sell it outright. Try your luck with Craig's list or your local "motor people"

A single phase motor should be easy to come by..

 

[Jeff NWOH]

You might look into a variable frequency drive for it. It's an electronic box that can make 3 phase and also vary the frequency and therefore the speed of the motor. it will be a dedicated to that sander where a rotary phase converter ( which you can make relatively inexpensively) will work for multiple 3 phase motors.

There are also static converters which are basically a box full of capacitors that will get it started and run it on single phase, but you only get something like 2/3 rated hp.

My understanding is that a vfd is less expensive than a new 1 phase motor. I personally have a couple rotary converters, but I have a few 3 phase machines. If you dont forsee any other 3 phase in your future, I'd probably do the vfd.