Cooks sharpener

[bandmiller2]

Thanks Ox, seems to me the Cook boys should consider a CBN option and a retrofit kit for their grinder. Its a reliable platform and will last just short of forever. Possibly a water based mist to cool the CBN. Frank C.

[gmmills]

   I feel there is a need for clarification on posted misinformation. Not sure of the source of the information but I have never represented myself on this forum as being a Factory Kasco Rep. As Ox previously posted I am nothing more than a very satisfied customer.  A Kasco customer that was part of the development team to R&D their newest blade profile. This team also included 2 other forum members. This new profile was in development for over 24 months before it was released to the market. Through this time frame I was communicating directly with the company's design engineer, head of blade sales, and on occasion in person with the marketing director of the division. Great group of people. All about listening to the customer and wanting to manufacture a quality product. Quite impressive these days.

      The new blade profile was designated as the Maxx 7. We generically call it the 7/40. 7 deg hook angle 40 deg back angle. It was developed in response to customers inquiries regarding  a blade to compete with WM 7/39 turbo blade.  The blade has been in release for a little over a month now. To date it has been a success with the local sawyers in my area.

      For those of you that attended Customsawyers project this year, you were able to see this blade perform first hand.           

[YellowHammer]

I am satisfied with my Cook's, as I already stated, but I will say it is really hard to get a consistent grind (for me) without burning the tips. If I set it light enough that it doesn't burn teeth, it doesn't even touch some. I've tried cranking the blade clamp, varying the tension, doesn't seem to matter. I quit caring about a slight burn. But then I don't get many bf on a sharpening either.

I was getting burned tips on my cooks and I found slowing the feed rate down helped and gave me a nice smooth grind.. although it had a negative impact on how many blades I could do a hour. That said I still have a lot to learn, only sharpened 50 - 60 blades.

I had the best results on speed setting 4 with the Cooks, and three passes average per band.  Seven minutes per pass, three passes and so 21 minutes per band, 3 bands per hour.  I've tried different wheels, different speeds, etc, including max speed, but I got my best grind on these settings.

The CBN usually takes me two passes, with a much higher feed rate, about 4 minutes per pass, 8 minutes per band, so 7 bands per hour.  More than twice the effective rate.

Both machines will grind a band sharper than new.

[ladylake]

 
  Nice review Yellowhammer.  Steve

[Chuck White]

I've noticed that there are several speed control rheostats, pots, etc. for the Cat Claw for instance, on mine I can select anywhere from 0 to 100 (I got it in 2009).  I usually set it at 50 and with good results.

I've found that if I get burn marks, I'm grinding too heavy!  I let it go around and finish the band, then I adjust for a very light grind and it removes the blue marks made on the previous grind!  I get better results with two light grinds! 

[xlogger]

Robert, when you do 2 passes with your cbn wheel do you make any adjustments on height of the blade level or leave it at the same setting? As of now I'm only doing one pass and it seems to me as doing a good job. But there is always room for improvement.

[bandmiller2]

Its very rare for me to do more than one light pass with my Cats Claw. I do not use a band until its dead dull but change it when it has just lost its keen edge. I'am not sure "blue tips" is a bad thing as I believe bands are an air hardening steel. Cams seldom match a new band perfectly, first grind or two I usually just catch the face and back of the tooth, gullet comes later. I realize that when a bands teeth are hardened they use a much higher temp. than the grinder can supply but I have not noticed any problem with a little tooth blue tip. I sharpen several different brands of bands for myself and select customers and the adaptability of the Cat is a distinct advantage. Frank C.

[YellowHammer]

Robert, when you do 2 passes with your cbn wheel do you make any adjustments on height of the blade level or leave it at the same setting? As of now I'm only doing one pass and it seems to me as doing a good job. But there is always room for improvement.

I can occasionally get away with one pass per band with the CBN, but I am very careful to make sure I grind all the way down to the corners, and view the band with a magnifying glass as it comes around for a finishing pass so it also serves as a quality assurance pass.  It's easy to do by just standing there as the teeth autofeed by, looking at the first half a dozen teeth as they feed by.  Here are a couple photos I took a few years ago with the Cooks, which illustrates how even though a band may appear sharp, under closer magnification, it needed another pass.  Same thing with the CBN, its easy to have the chisel leading edge look sharp, but still with just the slightest dulling of the corners.   

I make a slight adjustment to the sharpener to keep the CBN properly and fully contacting the profile for the second pass, depending on what I see with the magnifier.

This is a tooth that looked sharp to my unaided eye, but under magnification, was still dull in the tooth corners.  This was also a little blue from the dry grind, and you can also see the burrs.



This is a fully sharpened tooth that is ready to go, same band, next pass, noticeably different from the first picture, almost a hollow grind on the chisel face, and very sharp corners.  Still a little burr, but ready for setting.  This is with a the Cooks sharpener, and this tooth is about as sharp as a tooth can get, i.e. razor sharp.


Here is why getting the tooth corners sharp is important since I switched over from setting then sharpening.  I didn't like the geometry of the setting anvils on my dual tooth, and didn't like the fact that they contacted the tooth in a spot other than where the dial indicators measured, but lower down in the tooth which causes the deflection to be amplified at the tip, and gave me slightly inconsistent results.  I also didn't like the way the anvil would leave little indentations of a couple thousandths into the tooth metal, which also would give me some inconsistency.  So I reground the setting anvils to a full flat face angle that strikes the tooth at the inside tip and pushes outward.  That way I am minimizing deflection error on my the setter and only moving the part of the tooth that is getting actually measured with the dial indicator.  Push on one side of the tooth corner, measure the other.  However, in order make this work, just like in any close tolerance measuring, every tooth must be the same geometry, so the anvils must push on a fully developed and consistent tooth corner.  So if I was to set on a dull band with corners that have wear, I am indexing off a certain amount of randomness.  Certainly the setter could make these adjustments, but it seemed I could avoid this with a few tweaks.  Here's another picture of a partially sharpened tooth.  Notice it has some taper toward the tip, and if I was to index the setter off it, I would get a lessened, incorrect deflection because the geometry isn't fully developed and consistent.  It may not be much of an error, but is directly equal to the amount of the missing tooth tip corner, maybe a few thousandths, so it needs another pass. 


Once I started making extra sure I had a fully ground tooth, then everything fell into place, the setter worked very well, the setting error went down significantly, I didn't have to make as many band to band adjustments to the setter and the boards come out with a noticeably flat surface with minimal teeth marks.  I'm not doing all this because I'm a sharpening expert, to the contrary, I dislike sharpening and the time spent doing so.  Time is money, but quality rules.  The only way I can justify it is if I can get a very good result than with a minimum of time.  All in all, this technique works best for me.



   

[Ox]

Very good writeup, YellowHammer.

What magnification tool do you use and would you buy it again if you had to?

[YellowHammer]

Available online or any drugstore for about twenty bucks, also has a built in light. 

[ladylake]

A while back I tries some really hard stones that blued the tooth quite a bit and those bands didn't stay sharp very long, switched back to a softer wheel with no bluing or just a bit on the top of the tooth , none on the face and they now last like new blades.  I'm also a 1 pass sharpener like Frank and also miss the bottom of the gullet on the first sharpening.  Steve

[Alyeska Pete]

Re: Reply #36..
gmmills:
I have to disagree with your statement about Cook's dual tooth setter not clamping the blade prior to setting. One of the main features of this setter is the fact that it does first clamp the blade, then sets the tooth. The clamping force is adjustable to make the setter compatible with virtually any thickness band.
Arguably, the Cook's dual tooth setter does have a myriad of adjustments to make it function properly. But it is the fact that it has all these adjustments, that make it the most accurate, fastest, and versatile dual tooth setter on the market today. 
I think you sent back a setter that just had not been adjusted properly for your particular band.

[Kbeitz]

Sharping a blade for wood is sure different than sharping a tool for cutting metal.
After I sharpen a metal cutting bit I need to dull it by honing it with a diamond hone .
If you don't do this the sharp tip will just break off first cut. I wonder if this happens
with hard wood ?

[Cutting Edge]

Kbeitz,

You bring up a good point... two actually.

1.  What you describe in doing for metal cutting is actually done for pallet dismantler blades.  This is sometimes done during manufacturing, sometimes done/repeated by the customer.  Now, these blades do not fit well in the application of lumber production, but the principle applies non the less.

2.  "Does this happen in hardwood ?"

- Yes.  Most manufacturers offer some sort of blades intended for Resaws.  These blades are designed to be run continuously, possibly multiple shifts depending on species.  Many times these blades are discarded once removed and new installed for manpower/downtime reasons. 

These blades will still "feel sharp" and still could continue to cut.  Take that same blade and magnify the tip of the tooth (min. 120x + or on an Optical Comparitor) and the edge will actually be jagged w/ what I can best described as "potholes".  YellowHammer's pic of missing corners are almost a given.  Essentially the edge has broken/fractured away from the tip.  This is becomes more apparent in the harder species, logs that are dirty and most especially in the winter time when you now have frozen hardwoods.

Many times a cost conscious sawmill owner will purchase blades such as these based on soley price.  But these cheaper blades are not really meant for such an application.  Varying width cuts, dirt/mud, etc. are part of sawmilling.  When in actuality, those blades are best suited for narrow, clean cants. 

Using these cheaper "resaw" blades can actually become more expensive in the long run due to shorter run times and the fact that as the blade is resharpened, it's ability to maintain that fresh edge diminishes due to how the teeth are tempered.  There are also owners whom prefer to run once or twice and then discard.  Every situation is different.

[irvi00]

Yellowhammer, that was a great post. I learned a ton from that.

[Ga Mtn Man]

Yes, that was a very informative post Yellowhammer.  I am sometimes guilty of leaving rounded corners and always regret it.  Yeah they will cut poplar but put em up against some knotty-pine and.... :'( 

On a related topic previously discussed in this thread-  Does anyone know if the CBN wheels or cams are available yet for the new Kasco Maxx 7 blades?  I'm assuming the profile differs enough from the standard Kasco 7° to require a different wheel. 

[4x4American]

Paul, I took some side x side comparisons of the kasco 7/35 and the new kasco 7/40.  My cook's will sharpen the 7/35's perfectly but I cant seem to get it to work perfectly on the 7/40's.  I hope someone will make a cam for these new deep gullet blades soon.  The turbo 7's also a struggle.  I can get it halfway decent but no where near as good as I can get it to sharpen wm 7/34's, k7/35's and the likes.
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[4x4American]

Re: Reply #36..
gmmills:
I have to disagree with your statement about Cook's dual tooth setter not clamping the blade prior to setting. One of the main features of this setter is the fact that it does first clamp the blade, then sets the tooth. The clamping force is adjustable to make the setter compatible with virtually any thickness band.
Arguably, the Cook's dual tooth setter does have a myriad of adjustments to make it function properly. But it is the fact that it has all these adjustments, that make it the most accurate, fastest, and versatile dual tooth setter on the market today. 
I think you sent back a setter that just had not been adjusted properly for your particular band.

Hey Pete howzit goin?  Taint heard from ya in a spell.  I made a vidjayo response to show what gmmills is talking aboot eh




http://www.youtube.com/watch?v=NZbYsRPiwSQ

[ladylake]

 
I would try adjusting the clamping for your blade thickness then report back.   Maybe gmmills can explain how to do that. Steve

[4x4American]

It's adjusted for .055" 7/8" spacing blades but the one I grabbed in the vidjayo was a .050" 1" spacing cause thats what I grabbed first out of the barrel of broken blades..it don't matter how well its adjusted the anvils press before it clamps the blade it's how its designed.  The single tooth clamps then bends

[ladylake]

 
I'd think so long as it clamps the blade tight done by the right adjustment it will set the tooth the same no matter if the anvil hit a bit before the blade clamps solid. If you have it adjusted so the blade clamps solid it wont be flexing when its bending the teeth over.  This machine as any other machine needs to be adjusted right .  Steve

[4x4American]

I have played with that adjustment quite a bit, I adjusted it the way Cook's says, which is not too tight but not too loose.  They say it shouldn't take much effort to do it.  So there's a happy medium and I've tried both sides of the equation.. if you make it clamp it real good then setting a blade or twenty can wear on your arm, if you have it too loose then it's too loose.  Even there on that .050" blade it was a bit stiff the handle was you can see the thing jump in the first part of the vidjayo

[ladylake]

 Like I said so long as it clamps the blade tight it will set the teeth even.  Steve

[4x4American]

That dont change the fact that it pushes the teeth (which twists the blade body) before it clamps the blade body

[ladylake]

 
That doesn't matter so long as it clamps the blade good, the final bend will come after it clamps the blade.  Steve