Decided on a Coote grinder....now for the setup.

TonyRV2

TonyRV2

Joined
Feb 21, 2007
Messages
270
I've been lurking around the forum for a few months investigating what I should buy as far as a grinder. Initially I was thinking about the Jet 2X42 with a 9" disc sander...but with your help and the help of others, I saw the error of my ways and decided on the Coote 2X72. I'll drive it with a 1.5 horse single phase TEFC motor and will use pulleys to adjust the speed since I don't yet have 220V in my shop. I"ve decided initially to keep the belt speed on the slow side opting for a 4" step pulley (4, 3.5, 2.5, 2) and a 6" pulley on the Coote. The Coote will be equipped with the 10" wheel so this is going to give me belt speeds from about 1500 to 3000 sfpm. I plan on using the weight of the motor to tension the drive belt as many have done here. My idea is to use 4 bearing blocks and a 1/2" shaft. A pair of bearing blocks will support the outside ends of the shaft, and an inverted pair of bearing blocks will act as a swivel for the motor's mounting plate. This will also allow me to slide the motor on axis in order to line up the step pulley with the drive pulley, if you catch my drift. So my question to the group..."have I done my homework properly and is there anything else I should consider? I should also mention that I plan on ordering the glass platen and the work rest for the wheel. I may order the small contour wheel at a later time...seems I've got enough on my plate for now!
 
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You'll need to keep the pulley drive belt tracking straight. This is usually accomplished using a set of steps pulleys, one on the grinder, one on the motor. This will also give you a wider range of speeds.
 
I have a maker friend who does great work using a Coote and makes a lot of knives. He tried another 2X72 but went back to the Coote.
You should be good.
Frank
 
Oh. i see what you plan on doing to keep the belt lined up. I think the 2 step pulley setup would be easier, and more versatile.
 
Hi Kevin....How do you mean that a 2 step pulley setup would be more versatile than the 4 step that I'd be using. Or are you referring to using two 4 step pulleys, one on the motor and one on the grinder? When I did the math, it seemed that this kind of a setup yielded unusable speeds. For instance, the 4" motor pulley to a 2" grinder pulley is going to give me about 9000 sfpm! The idea using just a 4 step on the motor and single 6" pulley on the grinder gives me 4 speeds ranging from 1500 sfpm to 3000sfpm. A little slow perhaps, but I wanted to at least start out slow...I can always change the grinder pulley to something smaller to speed things up later.
 
You don't need 220V for a variable speed motor. The VFD converts 110 to 220.
 
The VFD converts 110V to 3 phase 220.
It works very well, and isn't too expensive.
 
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