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  • Hand stoning cutters

    How do you hand stone cutters?

    When ever I try to hand stone a cutter, it cuts like crap! What am I doing wrong?

    Thanks for the help.

    Bob

  • #2
    Your hand stoning them with something that sucks. I bought a stone for doing just this, turns out that its just a block of A/O, argh. Try a diamond or a Jap wet stone.

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    • #3
      Bob,

      I think the tendency when honing a tool bit by hand is to “roundâ€‌ back the cutting edge ever so slightly. The bit will be sharp to the feel but the cutting edge will be just back a little so there is no cutting edge clearance.

      For me the solution was practice, practice, and more practice! Another thing that helps me, is to use a magnifying glass or a loupe (10X or better) and look at my progress when honing. When I hone something, I start from the cutting edge and push forward (don’t go back and forth) – for me at least, this keeps the edge from being rounded.

      ________________________



      [This message has been edited by Mike Burdick (edited 02-22-2005).]

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      • #4
        A lot of my lathe stuff was done with carbide, but now I'm using more HSS in my home shop.

        I try to grind the cutting edges flat on the sides so that the hand stone will be somewhat self-guided.

        Does that sound like a reasonable way to do it?

        I notice that HSS bits that end up with a subtle roundness to the sides makes for a bit that's hard to hand stone with any real degree of success.
        C9

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        • #5
          C9,

          That is my problem I think? The rounding. What stones are you using? can someone give a link so I know what to look for? I see in previous posts they say an India slip?

          Of course a pic is worth 1000 words!

          Thanks Bob

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          • #6
            A lot of my HSS lathe tools I stone and have no problem with rounding the cutting edges. But my tool bits while they may be roughed out at the pedestal grinder are always finished on the surface grinder using one of 4 different special jigs. One universal and 3 different threading tool jigs (2 60D and one 29D acme). The only corners that get rounded are the ones below the cutting edge. Overkill. Probably but it works for me and that's all that counts in my book. Besides I usually only use HSS in the lathe for profiles, chamfers,threading and finishing work. End mills I sometimes will hone the bottom edge but I find that trying to hone the flutes is usually more trouble than it is worth. All honing done with hard and soft Arkansas Stones
            Forty plus years and I still have ten toes, ten fingers and both eyes. I must be doing something right.

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            • #7
              Spin Doctor,

              I have been making little jigs like crazy after seeing the treading one! I too am now using the surface grinder and getting excelent results! When using the surface grinder, do you still hand stone? I was going to try and see if I had beter luck then before.

              I also need to get the proper hand stones.

              Bob

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              • #8
                Make sure you're holding the tool firmly in toolpost or vise when you stone it. Holding it in your hand is begging for rounded edges. I use a fairly fine AO stone for HSS, diamond slip for anything harder.

                BillB

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                • #9
                  When I hand stone, I put the stone on a flat surface and try to hold the tool loosely enough so that it guides itself. I hold it near the tip with the rest of it free. My forefinger is about 1/4" above the edge I am sharpening and that edge is trailing as I move the tool. The finger pressure is a bit above and a bit behind the flat area below the edge being sharpened and tends to hold it flat against the stone.

                  I stop and observe the progress on the flat and adjust as needed.

                  I bought a small belt sander (1 x 30 I think) a while back and find that it is a far better way to touch up a tool. A fine belt and light pressure will allow you to make a mirror finish. Adding a bit of cutting oil will help.

                  All the above is for HSS of course. For carbide I use a diamond pad. It's amazing how fast it cuts. Only takes a few dozen strokes to cut back past a small chip on the edge.

                  Paul A.
                  Paul A.

                  Make it fit.
                  You can't win and there is a penalty for trying!

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                  • #10
                    Bob, while I do use some 3/8ths HSS bits most of the ones I use on a regular basis are 1/2. This allows for much larger surfaces that can bear on the stone. The primary stone I use is a Norton Soft Fine Arkansas Stone with smaller stones used to stone chip breakers and such. With care and practice a great deal of contol can be achieved. The big problem when grinding tools on surface grinders or touch up on belt sanders is heat control. While too much hat can of course effect the hardness by tempering too much heat can also promote the formation of untempered Matinsite in the tool. This can lead to stress cracks and premature tool failure. This I got from a metalurgy class they ran at work taught by a metalurgist who had worked for both Ampco Corp and Timken. He really knew his stuff
                    Forty plus years and I still have ten toes, ten fingers and both eyes. I must be doing something right.

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                    • #11
                      <font face="Verdana, Arial" size="2">Originally posted by Spin Doctor:
                      BThe big problem when grinding tools on belt sanders is heat control. </font>
                      Every belt grinder gives a rounding to the edge, because the belt isn't rigid. Even if backed up by a surface, it always has some give, and the top and bottom of the surface are ground more than the middle.

                      They are great for roughing out the bit though.
                      1601

                      Keep eye on ball.
                      Hashim Khan

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                      • #12
                        First I have to say that I don't find any difference in heat on a belt sander vs. a regular grinding wheel. But now that you have mentioned it, I will look more carefully. I always keep a container of water near the grinder or sander and frequently use it to cool any tool that I am grinding. Or sanding.

                        As for any rounding, I would agree that it will occur. But I have examined the tools I have sharpened this way and I have to state that it must be very minimal. At least on my sander which has a solid, flat steel backplate behind the belt, no padding. It seems to work very well for me. Judge for yourself, of course.

                        Paul A.
                        Paul A.

                        Make it fit.
                        You can't win and there is a penalty for trying!

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                        • #13
                          have you tried using the wheel on the end of a belt sander to get a concave finish that looks about the same as a grinder

                          Matt in AK
                          Matt in AK

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                          • #14
                            When starting out, it will help if you "blue" the edge with layout die. This will help you see what's happening as you develop your technique.

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                            • #15
                              Ted Coffey beat me to the punch...Layout dye or magic marker works well to help you see what you are doing.

                              And, practice, practice, practice....I use Norton India stones exclusively on HSS tools. For most work a medium grit is fine.

                              Andy Pullen
                              Clausing 10x24, Sheldon 12" shaper, Clausing 8520 mill, Diacro 24" shear, Reed Prentice 14" x 34"

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