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Anyone Use CBN Grinder Wheels?

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  • Anyone Use CBN Grinder Wheels?

    I am thinking of ordering a CBN grinder 80 or 180 for basic grinding for my lathe chisels. In reading one article, it said "CBN is for HSS only, not for mild steel." My question concerns using the CBN for my other wood chisels also. I have a good set of "hand-forged laminated Japanese High-Carbon steel, HRC63 hardness". Can I use the CBN grinding wheel on chisels and specifically the laminated type of high carbon steel?

    The article that I read on the CBN wheels is listed here:
    http://azwoodturners.org/pages/tips/WhatIsCBN.pdf

    Thanks for your response
    Last edited by leehljp; 06-01-2018, 05:24 PM.
    Hank Lee

    Experience is what you get when you don't get what you wanted!

  • #2
    Well, today is a success. I learned something new. Never heard of CBN wheels, but they sound really neat. 15 years ago, I bought a variable speed grinder and two 80 grit AlOx wheels. I'm still on the first one! The cheapo in me says no new wheels until I need one. The second one may still be in the drawer when I pass on.
    Jim Frye
    The Nut in the Cellar.

    Comment


    • #3
      Are the aluminum oxide wheels the white ones? I need to replace my rough gray wheel and really know very little about grinding wheels. I'm assuming the grit number will be on the wheel, but haven't looked yet.

      Comment


      • #4
        Since posting this, I have done some reading and a tad bit of searching for information.

        Most sites with CBN wheels are made primarily for HSS tools in wood turning but in industry, CBN is used for HSS and hardened steel. CBN sharpens without the heat of aluminum oxide or stone ore even diamond wheels. The material that bonds diamonds to wheels breaks down quicker under heat when on high speed steel/hardened steel in addition to heating up the steel. This is where CBNs shine. CBN wheels do not do well with soft steel as it and aluminum will load them up.

        On the other hand, Diamond stones do well on carbide.

        Here is a quick non-exhaustive list that I found over the past week:


        Craft Supplies USA:
        https://www.woodturnerscatalog.com/d...ding_wheel.pdf
        While Craft Supply recommends 1000 - 2000RPM on a grinder, they are one of few that does so. Most companies recommend 2000 - 3600 RPM with CBN and even at the higher RPM, less heat is built up because it grinds fast AND the aluminum wheels dissipate the heat quickly causing less heat build up.

        multiple types:
        https://woodturnerswonders.com/collections/cbn-wheels

        Brief non-(deep)technical description of the difference between diamond and CBN
        http://www.peaceriverwoodturners.org...g%20Wheels.pdf

        Choosing the right grinding wheel:
        https://www.mmsonline.com/articles/c...grinding-wheel

        List at the bottom for CBN wheels more links, a few of of which are below.
        Featured Article: CBN Grinding Wheels by Reed Gray

        2015 AAW (American Association of Wood Turners; Dated somewhat but good reading non-the-less.
        carbon steel tools and Carbide tools on CBN wheels | American Association of Woodturners

        CBN wheels: https://www.baltic-abrasives.com/en/cbn-wheels/
        Diamond Wheels: https://www.baltic-abrasives.com/en/diamond-wheels/

        For those interested in more technical aspects:
        https://www.carbideanddiamondtooling...PCD.CBN.Wheels

        More technical aspects
        Grinding Out Hardened Parts | American Machinist
        Last edited by leehljp; 06-03-2018, 06:25 PM.
        Hank Lee

        Experience is what you get when you don't get what you wanted!

        Comment


        • #5
          Originally posted by Carlos View Post
          Are the aluminum oxide wheels the white ones? I need to replace my rough gray wheel and really know very little about grinding wheels. I'm assuming the grit number will be on the wheel, but haven't looked yet.
          Yes, the aluminum oxide wheels are white and the grit size should be on the hub label. I sometimes wish I had a finer grit than 80, but I grind on the lowest speed of my 6" grinder (1,800 rpm), so it takes a while to heat up a tool edge. I chose a 6" grinder over an 8" for the lower rim speed of the wheel and thus hopefully slower heating of the tool.
          Jim Frye
          The Nut in the Cellar.

          Comment


          • #6
            Originally posted by Jim Frye View Post

            Yes, the aluminum oxide wheels are white and the grit size should be on the hub label. I sometimes wish I had a finer grit than 80, but I grind on the lowest speed of my 6" grinder (1,800 rpm), so it takes a while to heat up a tool edge. I chose a 6" grinder over an 8" for the lower rim speed of the wheel and thus hopefully slower heating of the tool.
            CBNs "load up" with soft steel, but with hardened steel, this is where it shines. I made the mistake of alluding that "still slower speeds" on a CBN wheel would be better to hold heat down and was quickly told that was wrong. In the list of links above, back in 2015 and 2016 turners and wood turning tool companies WERE recommending 2000 RPM (erroneously), but the manufacturing folks corrected the wood turners notions that slow is always better. Grinding HSS & Hardened steel with CBN on aluminum wheels are not affected by the temp spikes at higher speeds, - which allows higher grit to grind faster and cooler on HSS and hardened steel than lower grit on aluminum oxide and similar stones. There are Tormek CBN wheels and they are recommending NOT to use water troughs with them. Heat is not an issue.
            Last edited by leehljp; 06-03-2018, 08:27 PM.
            Hank Lee

            Experience is what you get when you don't get what you wanted!

            Comment


            • #7
              To throw some more your way, CBN has been available for Tormek and its clones, for years (not from Tormek), and I have read about them on several forums, in the turning section. (so there are low speed designed ones). The Tormek forum has had some discussions, which you found I expect.
              That doesn't even mention the new Tormek diamond wheels, that are designed to work in water (with anticorrosion compound) that are due out in July. (and they have flat sides for use)
              She couldn't tell the difference between the escape pod, and the bathroom. We had to go back for her.........................Twice.

              Comment


              • #8
                Originally posted by LinuxRandal View Post
                That doesn't even mention the new Tormek diamond wheels, that are designed to work in water (with anticorrosion compound) that are due out in July. (and they have flat sides for use)
                Tormek DIAMOND wheels - that should be good for carbide and ceramic tools.

                QUESTION: Most new guys (and ladies) on the pen turning forum, after moving from the Harbor Freight cheap HSS tools, most move to the carbide inserts. The carbide inserts certainly don't need sharpening anywhere near as much as HSS, but to me, they just are not as sharp as a good HSS sharpened tool.

                Is this just me or am I missing something?

                I can put my finger on a new carbide insert and it is sharp, but I can't put near the pressure (feeling if it is sharp) on one of my HSS sharpened tools as I can a new carbide insert, or I will get a good razor cut. Still newbies swear by the carbide inserts and I feel like an old fogie (which I am).
                Last edited by leehljp; 06-04-2018, 02:06 PM.
                Hank Lee

                Experience is what you get when you don't get what you wanted!

                Comment


                • #9
                  I spent a summer after high school with a journeyman finish carpenter. He could hand cope a molding by eye with a coping saw and produce an invisible joint. He often said "it's a poor workman who blames his tools". Sometimes new technology is simply an answer in search of a question. If you can produce a razor edge with one method, why do you need another one?
                  Jim Frye
                  The Nut in the Cellar.

                  Comment


                  • #10
                    Originally posted by Jim Frye View Post
                    If you can produce a razor edge with one method, why do you need another one?
                    Because it might be faster, or sharper, or longer-lasting, or one of many possible improvements. Early in my career I learned to never stop improving and trying new things, even if there was an acceptable method already established. "It's a poor workman who stops at just good enough."

                    I work in technology and am always in search of questions, because that's how I make more money, and solve more problems.

                    Comment


                    • #11
                      Originally posted by Jim Frye View Post
                      I spent a summer after high school with a journeyman finish carpenter. He could hand cope a molding by eye with a coping saw and produce an invisible joint. He often said "it's a poor workman who blames his tools". Sometimes new technology is simply an answer in search of a question. If you can produce a razor edge with one method, why do you need another one?
                      What Carlos said. But specifically for me: I have my favorite tool for pen turning - a scraper, much like a radiused square carbide insert, only I ground mine so that the tool is presented at about a 15 angle (horizontally) off from perpendicular to the lathe - as I hate straight out from the lathe in the use of tools; it tires my hands. This works 90% of the time but I occasionally need one for the left hand to get into corners from the other direction.

                      I learned in making the first one that shaping takes time and on fast grinders, it heats the chisels considerably. I have 10 laminated metal (Japanese) wood working chisels that have never been sharpened or shaped. I need to shape them. I got the Grizzly Tormek knockoff a couple of years ago, but that thing is S L O W. Cool & great but slow. I spent about 30 minutes on one of the Japanese chisels on the Grizzly wet grinder and still did not get it to shape. My delta grinder 2000 rpm - I was afraid of it getting too hot. and the rest of them have just been waiting for the right grinder. And I have about 12 other HSS lathe tools, only two of which I use on occasion as shaping takes too long on the Grizzly and get too hot on the delta with the original wheels.

                      In short, I need it for shaping as much as sharpening. BTW, razor sharp does not come off the Tormek, Grizzly, CBN, diamond or other. A good tool user will hone the tools afterwards, which is where the razor sharp comes in. Can't do that on a carbide insert easily.

                      Jim, I may have misled you on the razor sharp in my earlier comment. I was comparing razor sharp (HSS) as compared to carbide inserts. My razor sharp comes from honing, but it is made easier by the shaping (angle /hollow grind) with the grinders.

                      I spent a summer after high school with a journeyman finish carpenter. He could hand cope a molding by eye with a coping saw and produce an invisible joint. He often said "it's a poor workman who blames his tools".
                      I don't see it that way. I started off with a Sears radial arm saw as my first saw. I made some beautiful tables with that saw. But I found that table saws were better at some of the procedures and somewhat more precise while not being as dangerous. I never had problems with the radial arm and could finesse it. But that didn't mean that I should stay with it. I still have a DeWalt radial arm and use it on a rare occasion. I use a table saw and even a track saw. That doesn't mean that I blame a small table saw for not ripping 8 ft sheets well as the track saw. Just a different way to cut sheets down. Same for sharpening. I DO have a gripe about the Tormek like Grizzly taking forever to grind to shape. I didn't know what I was getting into. It did well on some smaller chisels but wide chisels and wide skews - be prepared to spend an hour or two. I have better things to do than wait that long for a single tool when I have two dozen that need shaping. In this regard, that quote might be right.

                      As to my main go-to scraper, shaping will be a breeze once a month. Honing the razor sharpness into it will be simple.
                      Last edited by leehljp; 06-04-2018, 09:53 PM.
                      Hank Lee

                      Experience is what you get when you don't get what you wanted!

                      Comment


                      • #12
                        Originally posted by leehljp View Post

                        Tormek DIAMOND wheels - that should be good for carbide and ceramic tools.

                        QUESTION: Most new guys (and ladies) on the pen turning forum, after moving from the Harbor Freight cheap HSS tools, most move to the carbide inserts. The carbide inserts certainly don't need sharpening anywhere near as much as HSS, but to me, they just are not as sharp as a good HSS sharpened tool.

                        Is this just me or am I missing something?

                        I can put my finger on a new carbide insert and it is sharp, but I can't put near the pressure (feeling if it is sharp) on one of my HSS sharpened tools as I can a new carbide insert, or I will get a good razor cut. Still newbies swear by the carbide inserts and I feel like an old fogie (which I am).
                        The most expensive thing that a lot of people have in this world is time. Time and money are two resources that always face a cost benefit analysis. Some people may take much longer to sharpen their tools, because of lack of practice, or tools/budget to make it easier, and there by prefer the carbide. Others, may think like some restaurant friends, who I picked up the commercial Tormek for (the T2). I can get the blades sharper on my T2000/T7, but they can get it "sharp enough", and in under two minutes now, and I get my time back.

                        A tech story my uncle told. He owned and operated a survey company for years. He did things such as state borders/pipelines/government bases and did them with satellite based systems. After that, he taught about those systems for a while and was asked why/when buy new equipment and such.
                        His reply was we buy new equipment to older and slower. (age/stress as there is a learning curve to get up to speed as compared to what we know) If there is some new feature that you know can benefit you, good. But a lot of it is due to Uncle Sam and the tax code saying either spend the money on this stuff, or give it to us. The trick is the balance and not to waste money on things that give no benefit back.
                        She couldn't tell the difference between the escape pod, and the bathroom. We had to go back for her.........................Twice.

                        Comment


                        • #13
                          Jim,
                          Concerning the idea of - if one tool can do it, why do you need another? Here is a quote from a fellow on the pen forum: "When I first started turning I thought my T 7 Tormek was the answer to all of my sharpening needs. Well it was for years for my knifes and wood chisels. So I thought I was going to save some money. That did not happen After about 10 minutes on the tormek with a turning chisel. I went and bought a Rikon set up with a 180 and 350 (CBN) and never looked back."

                          Tormeks in general are the standard by which sharpeners are often compared. But the TIME required is totally antiquated by CBN wheel standards. This is not about 5 minutes versus 7, but 3 minutes versus 30 - 40 minutes with the same high quality grind. This is not about not knowing how to use the tool but new technology - similar to using a cordless impact driver to drive a 3 inch screw versus using a cordless drill to drive the same screw. World of difference. Different technology.
                          Last edited by leehljp; 06-05-2018, 08:38 AM.
                          Hank Lee

                          Experience is what you get when you don't get what you wanted!

                          Comment


                          • #14
                            When I use my limited spare time in the shop, I want to use it on things that I enjoy, not "work." Some may find sharpening enjoyable, most don't. My wife actually seems to enjoy sharpening her lathe tools. Great for her. If I could pay someone to come by and make my stuff sharp when I'm not using the shop, I would.

                            Sanding--I hated it. But hey, all sanders are the same, they just shake around, why would anyone look for a better sander? So I got a really nice PC sander, and the Abranet discs. Now I not only don't hate sanding, but I spend 1/3 the time to do it.

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                            • #15
                              OK, Hank, I see your need for something better. My turning efforts are far more mundane (mostly some sort of spindle work), but I can see why you would want to explore the CBN stuff. I recall back in the mid '90s, I was at a woodworking show sponsored in part by American Woodworker Magazne and sat in on a presentation by a famous turner who also wrote for them. He was showing how to work with a fingernail gouge and was demonstrating sharpening one on a grinder with an aluminum oxide wheel with no guide. He went through the process and asked the audience for questions. I stupidly raised my hand and asked how he honed the tool after grinding. He laughed and said he didn't hone turning tools, just "whipped" up an fresh edge on the grinder. Most of the audience sort of did a collective inhale at that. Thereupon, he banged the freshly ground edge on the lathe bed and called me up on the stand to show how easy it was. I didn't even own a lathe yet! He stood behind me and guided me through the process to put a fresh edge on the dinged gouge. Then he proceeded to produce these long ribbons of wood from the work piece. When he was done, all that was needed was a bit of sanding. Someone also asked him about the new Tormek units that had recently come on the market. His response was that if you needed one and had the money for it, fine. He just didn't see the need. Once I learned how to use a lathe (after I built one) I continued to "just whip up a fresh edge" on whatever tool I was using. I'm lucky in that I can mount my grinder right next to my lathe headstock when I'm making round things. Since I don't turn all day long, I guess I don't need fancy stuff. HSS tools are what are in my quiver.
                              Jim Frye
                              The Nut in the Cellar.

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