another motor question

[beochie]

this motor thing is driving me nuts. I'm trying to buy a motor from my grinder

I bought this: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=170367737290&ssPageName=STRK:MEWNX:IT

looking at buying this:
http://www.baldordirect.com/product.sc%3Bjsessionid=44F691D4C8C93BF567C47DEB247A6313.qscstrfrnt02?productId=303

and I cant help but think I'm totaly lost: WTF is a SCR Control I can get this motor for less than $75 shipped. cant help but wondering why its so cheap

 

[DAMNENG]

The motor in the link is a 12VDC motor. With a full load on the motor, a one HP motor will draw about 37 amps current at 12VDC. Wire and switches will be fairly large.
DC motors loose their torque as the speed is reduced. Cut the voltage in half and the power goes to .25%, cut teh voltage to one quarter and the power goes to 1/16. Easy to stall. I suggest an AC motor with a Variable Frequency Drive.

Jim Arbuckle