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  • #16
    Originally posted by nickel-city-fab View Post
    What if I have a brazed carbide tool that i want to re-shape? Then I need two different grinders? I thought you couldn't do steel on diamond?
    Up to now I've used a green wheel. It didn't do well with the regular steel. So I'd grind away the steel up to the brazed line on a regular wheel first. Then just touch up the carbide on the green.

    Like some of you are saying though I didn't really find that the green wheel gave a truly nice finish. I've used a folding diamond lap to touch them up.

    But I'm keen on getting a medium and fine cup diamond pair of wheels and would be looking to mount them more or less in a fairly permanent manner onto a low cost grinder just for carbide grinding.



    Chilliwack BC, Canada

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    • #17
      Originally posted by BCRider View Post

      Up to now I've used a green wheel. It didn't do well with the regular steel. So I'd grind away the steel up to the brazed line on a regular wheel first. Then just touch up the carbide on the green.

      Like some of you are saying though I didn't really find that the green wheel gave a truly nice finish. I've used a folding diamond lap to touch them up.

      But I'm keen on getting a medium and fine cup diamond pair of wheels and would be looking to mount them more or less in a fairly permanent manner onto a low cost grinder just for carbide grinding.


      I havent found too many youtube videos showing setups using these diamond cup wheels.

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      • #18
        For carbide, my diamond wheels I use are 320 for roughing and 1200 for finishing.
        For shaping I use silicon carbide. But using it for a cutting edge is pretty crude.
        I guess it just depends on what your expectations are.

        -Doozer
        DZER

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        • #19
          Originally posted by Doozer View Post
          For carbide, my diamond wheels I use are 320 for roughing and 1200 for finishing.
          For shaping I use silicon carbide. But using it for a cutting edge is pretty crude.
          I guess it just depends on what your expectations are.

          -Doozer
          This is what Im trying to find out. A good grit for sharpening carbide not shaping. I can use my siilicone carbide wheel for this but for finish work ,what grade.Would a piece of cast iron charged with diamond lapping paste be better suited for finish polishing of a cutting edge.

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          • #20
            Originally posted by BCRider View Post
            ...
            But I'm keen on getting a medium and fine cup diamond pair of wheels and would be looking to mount them more or less in a fairly permanent manner onto a low cost grinder just for carbide grinding.
            I mounted my diamond cup on a treadmill motor. I had to make an adapter for the 1/2" shaft, but no big deal. I didn't make any kind of rest - free hand is good enough for me. And I just used a full wave rectifier (no variable speed). A double ended motor gives you a coarse & fine wheel at the same time. No cost for the dump-found motor.

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            • #21
              Originally posted by nickel-city-fab View Post
              What if I have a brazed carbide tool that i want to re-shape? Then I need two different grinders? I thought you couldn't do steel on diamond?
              You shouldn't grind steel on a diamond wheel unless it's very low speed or very little and very rarely. At low speed it's not an issue. At high speed it's an issue if you do it frequently or heavily. Better to grind the steel back with a regular bench grinder on a brazed tool, then finish only the carbide on the diamond wheel. Your diamond wheel will last much longer this way.

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              • #22
                Originally posted by plunger View Post

                I havent found too many youtube videos showing setups using these diamond cup wheels.
                Not on general use grinders. They do show up if you search for T&C grinder videos though.

                Granted I've only used a couple of the green wheels in my day but I found that they treat the edges much like Doozer suggested a couple of posts above.

                Truthfully I don't use a huge amount of carbide tooling... so far.... so it hasn't really been a big problem to rough them on the green wheel and then finish with the diamond hand hones. The bigger issue for me is that the couple of green wheels I've used tended to wear fast. And that leads to more frequent dressing which wears them out even faster. And what is left of my current green wheel is getting close to trash time..... VERY close to trash time. So that's why I'm interested in doing a more coarse and a fine cup wheel.

                The other option I've also considered is a single more coarse grit cup wheel for grinding out any chipping and then use a slow speed lapping setup like Stefan G made up a couple of years ago for the final honing. The lapidary discs he used for his setup are very reasonably priced. And with the same magnetic chucking to hold the discs they are easily swapped. In fact I wonder if just using coarse grit lapidary discs would replace the green wheel even for grinding back chipped corners.

                Another advantage of the slower speed is that the carbide dust would not fly around. Especially if the discs are run wet.

                For myself a slow speed setup such as Stefan's would also serve for diamond honing a lot of my wood working tools. So double duty from the one machine.

                https://www.youtube.com/watch?v=GOBtH4m2TYo&t=1s
                Chilliwack BC, Canada

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                • #23
                  Originally posted by nickel-city-fab View Post
                  What if I have a brazed carbide tool that i want to re-shape? Then I need two different grinders? I thought you couldn't do steel on diamond?
                  I put it in the mill and cut the soft steel under the carbide, then grind with diamond. Been doing that for years, so I didnt have to use the messy Green wheel. That little bit of steel wont hurt the wheel using kerosene.
                  Last edited by Fasturn; 08-23-2021, 01:43 PM.

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                  • #24
                    Originally posted by nickel-city-fab View Post
                    What if I have a brazed carbide tool that i want to re-shape? Then I need two different grinders? I thought you couldn't do steel on diamond?
                    Depends on the bond of your diamond wheel.

                    If you have a metal bonded wheel, grinding of steel isn't recommended. But most of the import cup wheels are vitreous bonded. They are often used to grind hardened steels because the bond breaks down and exposes more diamonds. I used them to resharpen HSS endmills for 15 years. They cut cleaner, faster, and cooler the Alox wheels. Plus, they lasted for 6 months or more on a Darax endmill sharpener as compared to a couple of weeks per white AlOx cup wheels.

                    For just removing the steel from under the brazed carbide, just walk to the nearest alox wheeled grind and undercut the steel back to how much you plan on removing from the carbide.
                    If you think you understand what is going on, you haven't been paying attention.

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                    • #25
                      Originally posted by dalee100 View Post

                      Depends on the bond of your diamond wheel.

                      If you have a metal bonded wheel, grinding of steel isn't recommended. But most of the import cup wheels are vitreous bonded. They are often used to grind hardened steels because the bond breaks down and exposes more diamonds. I used them to resharpen HSS endmills for 15 years. They cut cleaner, faster, and cooler the Alox wheels. Plus, they lasted for 6 months or more on a Darax endmill sharpener as compared to a couple of weeks per white AlOx cup wheels.

                      For just removing the steel from under the brazed carbide, just walk to the nearest alox wheeled grind and undercut the steel back to how much you plan on removing from the carbide.
                      Most of the import diamond wheels I've seen are resin bond. I haven't seen any vitreous bond diamond wheels on eBay. And although diamond wheels may work somewhat ok on light steel grinding under certain circumstances, CBN works much better, and is available for about the same price. Are you sure you weren't using CBN wheels?

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                      • #26
                        I mistyped, they were resin bonded and not vitreous bond. Thanks for catching my errant typing.

                        They still worked very well for grinding HSS endmills. CBN does work better, but when the costs were considered we just used the diamond cups.
                        If you think you understand what is going on, you haven't been paying attention.

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                        • #27
                          Plunger, about this time last year I posted my version of a diamond wheel carbide sharpening setup. https://bbs.homeshopmachinist.net/fo...-sharping-tool
                          some liked it some made fun of it, but it worked out great for me.
                          _____________________________________________

                          I would rather have tools that I never use, than not have a tool I need.
                          Oregon Coast

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                          • #28
                            Originally posted by lugnut View Post
                            Plunger, about this time last year I posted my version of a diamond wheel carbide sharpening setup. https://bbs.homeshopmachinist.net/fo...-sharping-tool
                            some liked it some made fun of it, but it worked out great for me.
                            Lugnut .Thanks for posting. I like it.

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                            • #29
                              With brazed carbide, all you can do is minimise the steel contact with the wheel. If you are only using it for occasional sharpenings, then don't worry, steel needs to be used against diamond a huge ammount to degrade it badly. I often sharpen scissors and scribers on the plated diamond wheel and it still works, even though the surface seems smooth to touch. If you are still worried, then use a file to cut back the steel which is level with the carbide edge.

                              The wheels I use are neither resin or vitreous bonded, they are electroplated with nickel and the diamonds are trapped in the nickel as the plated thickness builds up. This is taking advantage of the way nickel plating works. The filtration in a nickel plating bath has to be very good and continuous if any tiny particals floating in the solution are not going to stick to the surface spoiling it. Diamond dust of the required grit size is purposely added to the bath solution without filtration and it sticks all over the surface which is not masked off by an electrical insulator. The thickness of the nickel is allowed to build up to about half the grit diameter and the diamonds are trapped.
                              Last edited by old mart; 08-24-2021, 12:35 PM.

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                              • #30
                                Originally posted by BCRider View Post

                                Not on general use grinders. They do show up if you search for T&C grinder videos though.

                                Granted I've only used a couple of the green wheels in my day but I found that they treat the edges much like Doozer suggested a couple of posts above.

                                Truthfully I don't use a huge amount of carbide tooling... so far.... so it hasn't really been a big problem to rough them on the green wheel and then finish with the diamond hand hones. The bigger issue for me is that the couple of green wheels I've used tended to wear fast. And that leads to more frequent dressing which wears them out even faster. And what is left of my current green wheel is getting close to trash time..... VERY close to trash time. So that's why I'm interested in doing a more coarse and a fine cup wheel.

                                The other option I've also considered is a single more coarse grit cup wheel for grinding out any chipping and then use a slow speed lapping setup like Stefan G made up a couple of years ago for the final honing. The lapidary discs he used for his setup are very reasonably priced. And with the same magnetic chucking to hold the discs they are easily swapped. In fact I wonder if just using coarse grit lapidary discs would replace the green wheel even for grinding back chipped corners.

                                Another advantage of the slower speed is that the carbide dust would not fly around. Especially if the discs are run wet.

                                For myself a slow speed setup such as Stefan's would also serve for diamond honing a lot of my wood working tools. So double duty from the one machine.

                                https://www.youtube.com/watch?v=GOBtH4m2TYo&t=1s
                                Having used the AccuFinish (i think?) slow speed grinder during a King-Way class, I can say that with the low speed and proper grit (120 for coarse) you can hog out big cuts on carbide very quickly. I had some scraper blades that I needed to change the radius on and it went surprisingly quick with 120 rough / 600 finish using WD40 as a lubricant.

                                I have the fixings to make my own using lapidary discs but need to find a suitable motor.
                                -paul

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