Coote Tracking issues

flatgrinder

flatgrinder

Joined
Dec 20, 2005
Messages
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I purchased a Coote grinder (2" x 72", 8" wheel) about 2 months ago and recently noticed that it has become easier to put belts on (tension spring becoming worn in?) and also the belt doesn't track as well on the flat platen. It moves about 1/8" left to right, left to right, continuously when the grinder is running -makes it a real pain to get the plunge lines right.

Is there anyway to adjust this? Or is this just the nature of 2 wheel grinders? I also noticed this on my Grizzly.

Is the tracking generally better on flat platens with grinders such as the KMG or Bader (where the upper and lower wheels on either side of the platen) are closer together? How's the tracking on the rotary platen? It must be pretty good if this theory holds ....

Any info or opinions are appreciated.

Thanks! :thumbup:
 
I have gotten into the practice of pushing by hand the handle up after placing the belt on. It works for me; tracks okay then. With all that accumulated dust and what not over the months and years I should really disassemble and clean. The spring is probably not weakened.

rlinger
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Don't know how much it will help on a two wheel, but you could try putting a strip of tape down the middle of the idler wheel. Doming that wheel a little will help with tracking on BII's and the like.
 
Be sure to take the tension off the belt when you are not using it. Otherwise it will "cup" on you and wiggle until it warms up and stretches back out.
 
It moves about 1/8" left to right, left to right, continuously when the grinder is running -makes it a real pain to get the plunge lines right.
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Hmmm...this sounds like a classic case of "wobbly belts" rather than poor tracking. Has it...and does it always wobble side to side? Or is this something that you notice occasionally....but not always.

Belts will wobble..even good ones. Especially when it is hot and humid...and when they've been left on the machine under tension.

My first guess is that the problem is from your belts. It can be a real pain in the neck...and is never a popular answer.

-Rob
 
I've noticed with the longer belts that high humidity plays a role in the belt tracking accuracy also. For whatever that is worth. It can also be the belts at times too though.

STR
 
rfrink said:
Belts will wobble..even good ones. Especially when it is hot and humid...and when they've been left on the machine under tension.

-Rob
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Are there brands that hold up better in heat, humidity and work??
 
Thanks for all the replies!

I take the belts off the grinder when I'm not using it. I'm also using new belts, 50 grit Norton Blaze belts seem to wobble less, but the 3M "gator" belts wobble consistently (even brand new)! Anyone recommend a good 120 and 400 grit belt that doesn't wobble?

I'm not sure what I should do to correct this? :confused:
 
Flatgrinder, I spoke with a Tru Grit rep. today about some Blaze belts I ordered and have not received. I was told that they are having problems with the Blaze belts and that he has shipped approx. 800 belts back. He said that they started making some of them in Mexico and they are having a problem getting the belts straight. He has asked them to not ship him anymore from Mexico, but he does not know what he is going to receive. He said he will refuse them if they ship him the ones from Mexico. He also said that he does not know how this is all going to come out. I opted to get the old Norton hoggers instead of waiting for an unknown length of time. I have a Coote grinder and have not had any of the problems that you have described except with a few belts which were not Nortons.
 
For what its worth when I talked with KMG about this a while back this is his reply. By the way, I've noticed the Gator belts seem to be guilty of this more than all my others. Nortons are great. I'm not having any issues with my Blaze orange belts though.

STR

It is easy to determine if wobble is generated by the machine...or if it is from the belt. Here's a simple test. Put a mark on the belt...like a dot from a magic marker. Then run the machine slowly and observe the dot. If you can't see it make the dot bigger. Does it move the same amount, same direction and at the same spot everytime it goes around for one full revolution?


Or does it randomly move? in varing amounts, at different spots in the rotation?


A wobble that occurs the same time, at the same spot each time the belt makes a revolution around the machine...is caused by a distorted and wobbly belt.


But if the wobble is random, then you can expect it to be the machine. This is because the wheels on the machine rotate several times for each rotation of the belt. As a result, you can expect the belt to wobble several times for each revolution around the machine.
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Thanks for all the tips and recommendations.

I took another look at the grinder today and noticed that the belt wasn't on tight, while grinding the belt could easily be "pushed" sideways. Turns out the spring did settle a little and all it took was a few turns of the screw that holds the spring on and now it's perfect. I'm also using new Blaze belts and the tracking is excellent.

Thanks for all your help!!
 
As odd is this is going to sound....Norton does make wobbly belts that aren't very true when either cut on glued together. I have experienced that problem many times with some out of the box. Some spin perfectly round and others jus seem to move left and right. The coote grinder is an exceptional grinder and if you just find some good trued belts, it will spin perfectly for you. I called Norm coote about it because I was experiencing the same problems with some cheapo belts, but then again some nortons in the batch aren't made that great either. if in fact it is actually the grinder, just call up Norm. I'm sure he'll make it right whether he has to fix it or replace it. But most likely it's a badly made belt.
 
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