Coote grinder service

6

69camaro

Joined
Dec 7, 2006
Messages
35
I purchased a new 2x72x10 grinder from Norm about a month ago. Bolted it down to an 5/8"x18"x20" steel plate, bolted to my bench and extending over the front edge by 6". Cut a notch in the contact wheel side of the base plate for clearance and fabricated a steel brace under the extended portion. Mounted my 1.5 hp motor on a hinge with a 38" v-belt and 3-step pulleys. Man, this thing is ROCK SOLID.

When I first set it up, it had a horrific vibration. I noticed that the 3-step pulley on the drive shaft of the grinder really wobbled. I put a dial indicator on the shaft and it had 10/1000 runout. Called Norm, he suggested a stop on the motor plate to regulate the amount of tension and shipped me a new shaft immediately! I replaced the shaft, that helped a little. I built a stop for the motor plate, that helped even more. Still too much vibration to suit me. I went to the auto parts store and got the cheapest v-belt I could get, took off the high dollar lawn mower belt and that REALLY helped. It seems that the lawn mower belt is too stiff and magnifies even the smallest vibration or run out.

I have too say that Norm Coote has been excellent to me!!! In communication from the day I sent the money and all the way thru my vibration dilemna. It really is a nice machine for the amount of money that it costs!!
 
I use a link belt now and they rule. I second the service on the Coote as well. I wish it came with a platten for the contact wheel instead of one for the platten but what can you do? Also is you have multiple size belts in your car throw a link v belt in and you can use it to replace any size belt on your rig till you get to a garage. Way better than carrying several v belts.
 
69camaro said:
When I first set it up, it had a horrific vibration. I noticed that the 3-step pulley on the drive shaft of the grinder really wobbled.
I have too say that Norm Coote has been excellent to me!!! In communication from the day I sent the money and all the way thru my vibration dilemna. It really is a nice machine for the amount of money that it costs!!
Click to expand...

I had the same problem using the motor as *the* tensioning device. I also had the same problem with a cheapo belt. Mine is bolted to a 2 X 8" wood plank and clamped down to the work table.

I engineered a new motor mount ( a slider based on 2 pieces of electricians channel), baought a new V belt a the auto store, and problem went away. I also experimented with a hinged motor, and got it to work by putting a stop bolt ( a simple carriage bolt and two nuts) on the back of the hinge plate to take off some tension. It seems that allowing the motor to swing totally free sets up a harmonic distortion and will drive you nuts!

One more thing.........I don't know what kind of hinge set up you have, but you really need a Lonnnnng arc to make it work right. (you can't simply put a butt hinge on the motor base, is what I mean).
 
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