Cooks sharpener

[bandmiller2]

Banjo Picker, when you use your roller do you get the impression you are putting a lot of pressure on the band wile rolling, or just light pressure. Reason I ask I found a tool, in stock, that has everything your roller has only its  lighter duty. I think the tool is designed for leather belts, the wheels have grooves to impress parallel lines . If I turned new wheels it should work like yours. I get very long service from bands but I always open to improvements. Thank You. Frank C.

[Percy]

I think that blade flatness is important, especially on the wider blades and ones with taller teeth such as the turbo 7 or the 13 degree(ones I mainly use). I don't roll my blades but I do compensat for curvature with set differing on inner and outter teeth. It works well for me and is realativley easy to do with my setter(Suffolk dual tooth).

[TimGA]

     I have been following this with interest. I read an article from Tim Cook a while back, it has inspired me to strive to do better as a sawyer and a person.  Sometimes we get complacent and say it is good enough when we really know it is not.
      If you would like to read the article-  go to Cooks site at left - go to search window type in Following drop down and click on
       Following Rules Of Sawing Success   
                                                                     Tim     

[barbender]

Percy, that's interesting. How much do you find you have to vary the set from side to side?

[Peter Drouin]

I went out and looked at some of the blades that are ready to be heat treated. All 1¼x55x7°
And I did find some light on a couple. Using a razor blade across them.
Maybe 2 thousand. Most were good.
I do run the blade tight, With the needle going around and hit the back side of the pin it rest on.  ;D
So It does happen to some of mine.
Not enough to roll I think.

[Percy]

Percy, that's interesting. How much do you find you have to vary the set from side to side?

About 4 or 5 thou. The procedure with my particular setter makes it easy. My clamp on set guage shows that amount of difference when you zero each side out before measuring set, as my blades get older(more curvature with age). I simply dont zero the gauge when Im measure the outter teeth and set the setter to the same for both sides giving me about 4-5 thou less on the outer teeth. No more diving. I think i run more strain than most(cept Peter maybe ;D). I havent measured it but my air bag is usually at about 85-90 psi.

[barbender]

I have the same setter, but I don't have the clamp on guage. May have to check one out👍

[Banjo picker]

Banjo Picker, when you use your roller do you get the impression you are putting a lot of pressure on the band wile rolling, or just light pressure. Reason I ask I found a tool, in stock, that has everything your roller has only its  lighter duty. I think the tool is designed for leather belts, the wheels have grooves to impress parallel lines . If I turned new wheels it should work like yours. I get very long service from bands but I always open to improvements. Thank You. Frank C.

bandmiller2 you can adjust the pressure you put on the band somewhat with the Cooks roller I have.  If you go back and look at the picture what looks like a handle to move the roller is actually the means of tightening down on the blade. There is a slot on the back that allows the top roller to move up and down.   It has to have enough pressure to make the rollers pull it through, but there is some lea way as to how hard you want to tighten it up.  The handle that you turn is not difficult to turn either.  I guess thats all as clear as mud.  ;) Banjo

[bandmiller2]

Thanks mate, so I guess you really don't have to put a lot of pressure on the band to do the deed. Do you run the band through the rollers several times or just once.?? Possibly Cooks doesn't show much about the roller so cheap blokes like myself won't try to copy it. Thanks again Banjo. Frank C.

[bushhog920]

     Con- no auto shutoff.
I modified mine with a digital counter, micro switch, and a 10 amp 110v relay all costing about $70. micro sw. makes contact with the cam at about the 4 o'clock position. the relay is wired with the power going through the N/C contacts ( so it will run if I do not want to use the counter ) so when the counter closes the N/O contacts at the preset count the relay energizes and opens its N/C contacts killing power to the sharpener. I love this mod I turn it on with adjustment set to not touch the blade, adjust till i'm happy with the grind and push the count reset to zero it then at 165 on the counter ( for a 12' ) auto shutoff. If I want to sharpen twice I just hit the reset to zero power comes back on and off it goes. Just remember to cut the two switches off on the sharpener when done because when you cut off the power to the counter the sharpener will turn on.

[Rachiano]

I came across this video on a band roller..
https://youtu.be/Hdc5xipiZpY

[Pabene]

About blades flatness,
I think that the blades "out of flatness" does not depends on what kind of wheel belt you have but the wheel diameter is important. It is a fact that a band, as is bent with a radius, will also be concave (cross the band direction), on the outside of the radius. You can convince your self by a simple test. Bend e new flat blade, with a radius of about 4-5", without any wheel involved, just a free bend. Keep it in this position and check the flatness across the outside.
When the blade is running in the saw it will "remember" more and more of this effect and it will be permanent out of flatness. This behavior for a bent band has a name as I can't remember but it is well known in the "stress theory". My English is not good enough to explain things like this better.

[Kbeitz]

I would think it would have to do with how much crown you'r wheels have.
The band when bent over the crown will take it's shape after a while.

[ladylake]

 

The band bends away from the crown on the wheel, concave on the outside of the band.  Steve

[barbender]

Steve, I was surprised to find that on the blades I checked. They were bent away from the wheel.

[Deese]

Ladylake and barbender are correct. It is a term called anticlastic curvature.

[bandmiller2]

In light of this anticlastic curvature and having one wheel of the roller flat and the other rounded which way do you feed the band through the rollers. Do you run the rounded roller in the valley or on the hill top.?? Frank C.

[Kbeitz]

Google says it's stronger that way... In other words don't fix it...
So that makes one less thing that I have to build..

[JB Griffin]

It might be stronger,  but that don't mean it'll saw better that way. Just saying.

[4x4American]

Google was wrong!   :D :D


Fact of the matter is that it depends on your guides.  Think of it like a chair.  If your blade is touching roller guides the way a rocking chain touches the floor, that blades gonna walk all over the place.  If your blade touches the guide like a regular chair touches the ground, it will be stable.  If you have sandwich guides or like Bakers bullet guides I reckon it don't much matter.


Frank I run the rounded roller on the crown/hilltop side.  Never tried it the other way and I think I will for experimental purposes. 

[Percy]

Google was wrong!   :D :D


  Think of it like a chair.  If your blade is touching roller guides the way a rocking chain touches the floor, that blades gonna walk all over the place.  If your blade touches the guide like a regular chair touches the ground, it will be stable.   

Very good analagy. This anticlastic thing gave me much grief years ago. I never could find a cooks roller so I compensated with less set on the outer teeth or more set on inner teeth. Experimented till the dive went away. Sometimes if I am pushing hard, I get a small wave which your analagy explains. Thanks.

[kelLOGg]

Google says it's stronger that way... In other words don't fix it...
So that makes one less thing that I have to build..

What's stronger?? and what does that way refer to???

Subsequent posters must know but I'm lost.
Bob

[Kbeitz]

Google says it's stronger that way... In other words don't fix it...
So that makes one less thing that I have to build..

What's stronger?? and what does that way refer to???

Subsequent posters must know but I'm lost.
Bob

The shape formed in the steel.
It's like tubing. Weight for weight tubing is much stronger than flat steel.
anticlastic curvature makes for a strong structural shape.
I know it has nothing to do with a saw blade but I had to put in my $0.02.
I'm not having problems with my sawing so I'm not going to roll my bands.

[kelLOGg]

Thx. get it now.

[YellowHammer]

Here's a very special grind profile I developed using the CBN but I'm sure the Cooks would make it also. It took about 2 hours to make it. I think it will work great sawing popsicle sticks from balsa wood. 

Actually, this is what you get when the auto shut off mechanism doesn't function, the dog distracts me, I leave for awhile, get busy doing something else, and my wife later comes in saying "the sharpener is running but nothing is happening" :D :D