It won't have the torque. I recently hooked up a bench grinder to mine, even that didn't have the power to start the grind.........I'm not giving up though!
What? Grinders are 3,450 rpm's you in a hurry grinding grain?
Well 3/4 HP on up can be had with 1,750 rpm's also.
Grinders do not have the starting torque like a compressor motor
or one connected to a well or hydraulic pump.
Factor in the diameter of your knurled rollers also.
Like them "low riders, be slow and be cool" for minimum
flour with less grain tearing and damage.
I can work around a 12 minute grain crush in the morning
while doing other things while heating water.
Remember the speed of the grain going thru the mill is quite different
in inches per / second or feet per / second depending on the rollers diameters.
Same speed reduction on a 1 1/2" roller mill vs a 2" roller mill the surface speed
increase is 1.333 times the smaller roller mill or .75 times going the other way in
mill roller diameters. Your 200 rpm 1 1/2" diameter roller mill will have a roller surface
speed of 942 inches a minute vs a 2" roller mill at 1,256.6 inches a minute surface speed.
Your 200 rpm's on the smaller 1 1/2" roller mill is like 266 rpm's on the 1 1/2" mill with a 2"
roller mills surface speed.
Manufactures sell their mills pushing the limits to get the highest numbers or pounds a
minute their unit can crush vs other manufactures, the winner there is the loser, you
unless you like making extra flour. I don't.