CBN grinding wheels?

Discussion in 'Woodturning Discussion Forum' started by bob sesti, Apr 28, 2012.

  1. odie

    odie

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    If you don't think that was giving concession, you ought to see what I could have written! I gave an opinion that I knew beforehand would be strongly opposed by some here. It is something I feel should have been said, mainly because the person it was directed at was a very good example of following advice without considering anything else BUT that advice......even though he could have considered the options.

    I see many things in this woodturning community that revolve around things other than what it should. Some of you have heard me speak of the "herd mentality" a time or two, as well. This is something that serves to stifle personal growth by not promoting self determination......but, is directed by the "group think". That "group think" at it's origin, has a direct link not to the group, but to a select few individuals.......this is along the same lines of the "in crowd" group that we all saw in our school days. There are the "groupies" who follow the "in crowd" hoping for acceptance, right here in this woodturning community........just as there was in our school days. Once some of these things are recognized, can there be a release from these boundaries that once were, and we can evolve according to our own abilities.

    I realize this way of viewing the woodturning community will never be understood, recognized, or accepted by the whole, or any major part of it. The way of doing things, promoting people and products has already been established, and that would be a huge hurdle. However, there is value in reaching a very few who will recognize some of these things, and by this recognition, open the doors to their own blossoming of creativity and character.......

    Most of this will be completely lost on the majority of those who read it, but there will be a few who will have that little bell ring.......and will say to themselves, "I've thought that very same thing".

    ooc
     
    Last edited: Apr 29, 2012
  2. robo hippy

    robo hippy

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    Well, I missed this one yesterday.

    First, the CBN wheels. Cubic boron nitride is made for grinding steel, and is far superior for our use when compared to diamond, which does great on carbide, but clogs up when used on the softer steels. The D Way wheels, and now another one from England, will be the market standard in a very short time. They just out perform any other grinder wheel out there in every single category, with the exception of them costing a bit more, but being a far better investment as you will get more than your money's worth out of them. They do break in, and cut very aggressively when new, but get less so after a bit. Excessive steel removal is more of a 'are you grinding (shaping) or just touching up the edge' thing. There is one advantage to the CBN hones. I turn a lot of wet wood. It splatters on my hone. The CBN one can be taken into the kitchen, splash some water on it and a little dish soap, scrub with a plastic bristle brush, and it is as good as new. You can not do that with the diamond ones.

    As for which cutting edge works best, I don't know. I never hone, and haven't felt or noticed the need. I have tried honing, and maybe I am not doing it right, but there has been no noticeable difference to me in the finished surface. High shear angle, and rubbing the bevel do more for getting a good surface than anything else I have experimented with. The 180 grit wheel leaves a very fine edge. Any of the matrix wheels on the marked have grits of up to 120, though you can find some that are higher. The 80 grit CBN wheel leaves a more polished edge than any 80 or 120 grit matrix wheel.

    I have never gotten to meet or see David Ellsworth. His respect in the turning community has been well earned. He is an innovator that we all have been influenced by. There are so many good turner out there, no one can claim to be the best, and that opinion is just an opinion, and every one is entitled to their own view of things. We do not have to agree, just respect the differences. I think he could be called the Jimmie Hendrix of woodturning, except that he has lived a lot longer.

    robo hippy
     
  3. All right, you CBN guys/gals: If one likes the edge off an 80 grit or 120 grit standard SG or even the regular AO wheels, what CBN grit would you want to get (compare AFTER it's broken in, please)?

    Thanks............Mark
     
  4. hockenbery

    hockenbery AAW Advisor Staff Member

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    Oldie,
    I sense where you are coming from.

    If you happen to catch David doing his natural edge bowl demo you might just allow that he is still up there.

    Best is in the eye of the beholder.

    Oddly a couple of folks I think are near the top with tool usage don't produce any work that sells.

    I would suggest that no turner alive has had more influence on the current state of woodturning than David.
    The people he has encouraged, the tools he has developed, forms people emulate, students he has taught, founding the AAW......

    And he is just a down to earth guy who is fun to be around.

    Al
     
  5. robo hippy

    robo hippy

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    Mark,

    I have both 80 and 180 grit wheels. The newer ones from Optigrind (advertised in AAW magazine and Woodturning Design) have a 220 grit, I think, wheel that I have yet to see. I will talk to them in San Jose. I use the 180 for gouges, and the 80 for my scrapers, and some times gouges as well. I had some CBN matrix type wheels years ago, very similar to the Woodcraft Green River diamond wheels, where about 3/16 inch of grinding matrix is bonded to an aluminum hub. One was 320 grit. I eventually replaced that with a 150 grit. I just got the feeling that the finer grit did not remove enough steel to 'refresh' the edge. I would say that it might have been similar to honing, you can refresh the edge for a while, but eventually you need to go back to the grinder and remove some steel for a better cutting edge.

    robo hippy
     
  6. hockenbery

    hockenbery AAW Advisor Staff Member

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    I use a diamond hone to strike a burr. Makes a cleaner surface.
    Something I learned from Al Stirt

    Polish the grinder burr off then strike a burr with a diamond hone.
    Produces a finer more consistent burr. And the burr can be renewed several times in this manner f before going back to the grinder.
    The scraper is finishing tool and the finer the burr gives a cleaner surface.

    John Jordan produces a similar burr using a slip stone.

    Al
     
    Last edited: Apr 29, 2012
  7. john lucas

    john lucas

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    I rarely hone my tools, except the skew. Proper feed rate and tool orientation will give you a very good finish. I do hone them on occasion to see if I can improve the finish. Usually when turning very punky woods.
    I've looked at the CBN wheels but they are very very expensive. My white wheels are 5 years old now and have many years left in them so I just can't justify the CBN wheels.
    If money wasn't a problem I would probably go with them becuase I'm kind of sharpening nut and always looking for a better way. It just has to be in the budget.
     
  8. odie

    odie

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    Thanks for this information, Al......

    I am going to make it a point to give this a try.

    edit: Are you using the diamond hone in the same direction the grinding wheel turns to produce this burr?
    What grit diamond hone are you using?

    The burr I am getting from my SG Norton wheel does do a very decent job of making a good usable burr.......but, I'm always interested in finding better ways of doing things. There are times when I'd prefer to clean up the tool finish a little more prior to sanding, and if this works, I'll use it. I'll probably have to wait until a good test piece and situation comes up, but that won't take too long. This won't cost me anything to try, and there is no biased need for a particular outcome.

    I have one of the carbide scraper burnishers made by "Veritas", I think it is. With this device, I've not had much success at producing a viable burr. When lathe tools were more commonly made from carbon steel, I believe something like this would work much better. This may be a hold-over concept from a previous era. Even if it did work, it's useless for my most used 1/2" thick scrapers, because the carbide cone is not tall enough to do the job.

    ooc
     
    Last edited: Apr 29, 2012
  9. robo hippy

    robo hippy

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    Scraper burrs:

    The burr from a CBN wheel is far superior to the burr from an standard grinding wheel. This is my primary burr for roughing and shear cuts with a scraper.

    A honed burr is good only for very light shear cuts, or on a negative rake scraper. Gone in seconds. I NEVER use a scraper flat on the tool rest for finish cuts, no matter what edge is on it.

    A burnished burr is nice, but in most cases not worth the extra effort of honing off the grinder burr and then burnishing. Some one did an article in the AAW mag a few years back about the different cuts from different edges on the scraper, with highly magnified pics of the wood after the cuts. The burnished burr provided the cleanest cuts, but not by much. I am too cheap to buy the Veritas Burnisher. I just use a triangle burnishing tool for card scrapers. A few light strokes will produce a good sturdy burr. The main problem with burnished burrs, is if you put too much pressure on the burnisher as you turn the burr. You can actually roll the burr over like a breaking wave. With a 70 degree bevel, you want your burnisher at 80 to 90 degrees, or slightly off parallel with the bevel. I remember one demonstrator stating flat out that it was impossible to raise a burr with a hand burnisher. Why did the hippy cross the road? Cause some one told him not to. While I am some one who has plenty of brute strength when necessary, technique is far more important. A few light strokes is all it takes. The triangle burnisher works far better than a round one. The burr can be burnished down and back up again when dull a couple of times, just like a card scraper.

    Myth: a scraper will not cut without a burr. It will cut nicely, and you can also do a bevel rubbing cut with one. I do like the cutting action of a burr better.

    I did like Richard Raffen's article on using scrapers in the latest magazine. His box scrapers looked more like my bowl scrapers.

    robo hippy
     
  10. Steve Worcester

    Steve Worcester Admin Emeritus

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    The idea behind a CBN wheel is pretty simple, they outlast standard bonded grinding wheels and don't need balancing or loose their circumference.

    Yes, they cost more, but so does a higher end lathe or a Baldor. Will they do the same thing? Yep. Do they perform better? I think so, but that is subjective.

    I don't hone anything but some spindle gouges, and only because it is faster to freshen up the edge and I am lazy. But that isn't honing in the context of this thread.

    And the idea that an 80 grit wheel gives an 80 grit finish is crap, a myth. In the hands of the right maker, you would never guess the wheel the tool was sharpened on.

    But I will say that CBN wheels do heat the tool, just less than a "normal" wheel does.
     
  11. Paul M. Kaplowitz

    Paul M. Kaplowitz

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    Reply To Odie

    I have followed your contributions to this forum over the years and have found your opinions and advice to be very helpful. I was therefore stunned to read your comments about David Ellsworth. I hope the day comes that I can produce hollow forms like his, or any other work of the quality, imagination and skill level he manifests. He is a superb teacher and was instumental in making woodturning what it is today. Your crack about hearing from the David Ellsworth lovers was perceptive. I'm one of them. Paul M. Kaplowitz
     
  12. odie

    odie

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    Hello Paul.......

    Well......so be it.

    It's unfortunate that you, and others have misunderstood the meaning of my posts here. There was never an attempt to ridicule David Ellsworth other than to suggest his influence is (IMHO) less than the sainthood status some people bestow on him. The main thrust of my posts were aimed at those who put him on this pedestal and worship his legend in a manner his true contributions do not live up to.

    Is he a man of great influence in this woodturning community? Sure, he was, and he is. As far as his developing a technique of closed hollowforms, he is an innovator, and one of the best at what he does. If the subject were strictly hollow forms, I'd have to say he's one of the best of the best at this aspect of turning.....but, the subject was more general than that specific subject.

    His name will forever be known for the "Ellsworth grind", but is he the inventor of this sharpening technique? I have my doubts, because it is my understanding that others were experimenting with this grind and other creative sharpening techniques at the same time, but it is he who brought it to light......there is no question about that.

    There is nothing to retract in anything I said, and as I said before, these things needed to be said, simply because there is a "herd mentality" that is predominant among many turners that ultimately gets in the way of creative thought among them, and by association, all of us......whether there is an awareness of this, or not.

    Others have said David Ellsworth is an innovator, a really nice guy, great teacher, and someone they admire. Would it surprise you to know I think all these things are probably true? (I have never met him personally, but I have my ears to the ground......and, I am not doubting these things at all.)

    ooc
     
  13. Brian McInturff

    Brian McInturff

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    Well Oodie, unfortunately it now just comes across as just some amateur who is jealous and envious. You really should think about what you type and the various ways people will interpret it.
     
  14. odie

    odie

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    No, it is you who should not make assumptions, or attempt to steer the commentary in directions it wasn't intended. My comments were directed at the attitude you expressed.....not David Ellsworth.

    .....As far as your declaration of "jealous and envious"......you can believe as you will. I'm confident in my pursuit of my own personal aspirations.....and, I keep it in perspective.

    You are right about one thing, though. If I had known you and a few others would have taken my comments to places they weren't intended, I would have made a special effort to make my thoughts a bit more clear. Still, these things need to be brought to light, because you are only one of many who display the sort of thing I was attempting to illuminate.

    ooc
     
  15. Bill Boehme

    Bill Boehme Administrator Staff Member

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    IOC, I think that you poked a stick in the hornet's nest just for the fun of it.

    So, you think that using a grinding wheel is "wasting metal" while using a 600 grit diamond "stone" is "sharpening". So then, where precisely is the line of demarcation? Huh? I contend that metal can be wasted with a 600 grit diamond stone -- it just takes longer.

    Why you singled out a living individual by name who has absolutely nothing to do with the subject at hand completely baffles me. Is it because you think that he never reads these threads? Or, is it because you you view him as a public figure icon that is fair game for pot shots? Regardless of whether any of your personal opinions of the man have any validity, Mr Ellsworth has earned the respect of turners because of his generosity in sharing his knowledge.

    Think about it -- would you blindside any of the regulars on this forum by hijacking an unrelated thread to make the attack?
     
  16. odie

    odie

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    Bill,

    I believe if you'll check what I said about sharpening in post number 6, I said "metal removal", not "wasting metal". There is a difference, and that difference suggests purpose. Removing metal is a necessary element to the final shape and in preparation to the final sharpened edge.

    The rest is instigation, and suggests you have not, or choose not to understand the meaning of my posts. Since it appears you are "fishing", I decline to comment.

    ooc
     
  17. hockenbery

    hockenbery AAW Advisor Staff Member

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    David Ellsworth has had more influence on the state of woodturning in America than any other individual.
    Renowned teacher, founder of AAW, artistry recognized in dozens of books, innovation in tools,innovations in forms,

    In my opinion David does the best natural edge bowl demo I have ever seen. Saw one just last year.

    Ridiculing his admirers is your prerogative

    Al
     
    Last edited: Apr 30, 2012
  18. hockenbery

    hockenbery AAW Advisor Staff Member

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    Odie a question?

    WHO DO YOU THINK HAS CONTRIBUTED THE MOST THE STATE OF WOODTURNING IN AMERICA
     
  19. KellyDunn

    KellyDunn

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    Thanks for this thread. Another like it on wow suggests the wheels are an investment for the future. So when I need another wheel I will spend the money. For most turning I find honing a waste of time. But when I need that really sharp edge I 500 grit diamond hone then go to a pulley belt with tripoli on it. Thats shaving sharp. But last for just a few cuts. Which is what i want.
    I would submit that Dale Nish is the most influential person on the field. David Ellsworth is a big boy and I would venture to guess could give a rats backside what Odie thinks of him(status) not even knowing him. As I have spent time with David I think everything about him is well deserved. Dale Nish says David is the most copied turner in the world. I for one am thankfull for all the personal time he has spent with me over about the last 25 years. He is a very good teacher.
     
  20. Steve Worcester

    Steve Worcester Admin Emeritus

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    You might want to read what he says about this, I did..

    http://www.ellsworthstudios.com/interviews/interviewDavidEllsworth.pdf
     

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