DC Motor on the mill????

[joe_m]

I swung by Al's Machinery while on a quick trip to Tucson this morning so I could ask about finding a replacement motor - his assistant was the only one there and he told me that when they had a mill with a bad motor they didn't try to find a replacement, they just gerry-rigged something like mine. He did help me pull the pulley and look to confirm all I would need is a face-mount motor with a long enough shaft. Unfortunately nobody is selling such a monster at a reasonable price.

I did find a price on that replacement one online with the correct mount - $750 + shipping which is just a bit more than I have ($27, and two lint-covered lifesavers).

But surfing some more I found this article by someone who put a DC motor on their mill and is happy with the results:

http://www.truetex.com/dcdrv.htm

Anyone ever done this or seen it done?

Joe

 

[Ray C]

Just out of curiosity, what kind of motor are you looking to replace and from what piece of equipment? $750 seems pretty steep... I've replaced a couple motors (120 and 220 in the 1-2 HP range) here and there and I usually find a suitable replacement for half that.

... But no, I've never seen or heard about that modification. Kinda blew me away because DC motors tend to produce all their torque at low RPM and lose it rapidly as speeds increase. But I guess it works for this guy so, who's to knock it?

 

[Kennyd]

Joe, it would help if you stop starting new threads on this.

 

[strantor]

DC motors w/DC drives are just as versatile as AC motors w/ VFDs. Torque and speed can be controlled independently. Without a DC drive though, it's like Ray C said, torque will drop off as speed increases, and depending on the type of DC motor, the speed and torque may be totally dependent on the load and almost completely unpredictable. DC motors and drives cost more than AC motors and drives, so if I were you I would try to find an AC replacement from a different brand with the same spec and mounting scheme. If you can't find one, then look for DC but keep in mind you'll most likely need to factor in the price of a DC drive to go with it.