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  • sharpen your own or buy indexable

    Since I'm just getting into a lathe and am learning as much as I can, I was wondering if most folks here sharpen and shape their own HSS lathe tools or if you buy the indexable stuff?

    I ask because I prefer to do as much as I can myself yet at the same time I prefer to enjoy making parts and wonder if I'd be better off just buying preshaped indexable stuff.

    FWIW, this stuff will be used in my Fimms q/c post.

  • #2
    Absolutley learn to sharpen your own HSS blanks. The cost savings is well worth it. The ability to custom make any tool you need is indispensable some times.

    I have some carbide insertable tool holders, but I reserve the carbide inserts for things like blanking out an axle shaft to be shortened. I cut those while still hard. If I had them annealed, I'd use HSS on them. Anything soft enough for HSS sees the HSS.

    I'm working with older equipment in a home shop. I'd guess that you are in the same situation.

    If you were a pro where time=money, you probably wouldn't need to ask. The answer for that situation seems to be carbide for most jobs just to speed thinsg up.

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    • #3
      In my machine shop class, you had to grind your own HSS lathe tool bit. I used the same HSS bit that I made at the beginning of the class all through out the entire class. That's the only one I've ever made. At home, I just buy the Carbide inserts, or tons of the Carbide brazed on bits from ENCO. If I ever need a special bit, I'll grind it (If I still remember how), otherwise it's cheaper to just buy them pre-made.

      -Adrian

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      • #4
        [QUOTE]Originally posted by Nutter:
        [B]Absolutley learn to sharpen your own HSS blanks. The ability to custom make any tool you need is indispensable some times.

        True. A special shape or form for which there is no insert, you'll have the knowledge of how to sharpen your own lathe tools.

        The cost savings is well worth it.

        Inserts cost money. If you have sufficient income for pay for them, it becomes a bit different.

        Get youself a guide on how differnt lahte tools are ground for specific operations. Practice grinding lathe tools from square key stock, less expensive than tool blanks.


        Paying Attention Is Not That Expensive.

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        • #5
          HSS for home shops, no question. The only time I use carbide is when I absolutely need to -- a hard spot in a casting or something.

          ----------
          Try to make a living, not a killing. -- Utah Phillips
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          There are lots of people who mistake their imagination for their memory. - Josh Billings
          Law of Logical Argument - Anything is possible if you don't know what you are talking about.
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          • #6
            Books have been writen about the humble subject of cutting tool selection.Much of the choice is based on your needs and your equipment.
            By all means learn to grind your own lathe bits. Most basic machining books as well as the machineries hand book will explain tool geometry for various metals and cuts.ie left hand right hand roughing finishing shouldering grooving etc. also this will help with learning nomenclature.
            Look for blanks with cobalt added they will last longer.
            HSS advantages easy to grind with regular wheel you can make any shape or angle as needed. Excelent finish at slow speeds.Disadvatage They take TIME to grind.
            Inserts advantages saves time. Repeatability on CNC lathes.Increased productivety. Carbide likes speed(higher rpm) lasts longer on hard material. Disadvantages hihger cost limeted shapes.Bottom line? on a production cnc lathe inserts are the way to go on my 1936 south bend I lean more to HSS.
            Jim
            Ad maiorem dei gloriam - Ad vitam paramus

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            • #7
              I concur! Learn to grind your own. For instance:

              Anyone tell me in 10,000 words or less how to grind a flycutter bit out of HSS for aluminum? The one I made gnaws the surface and leaves a horrendous mess! No doubt, I'm doing something wrong I've not been able to locate an example in any of the referance books I have.

              A close-up picture and I'd be your little-web-buddy for life

              [This message has been edited by Your Old Dog (edited 10-05-2005).]
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              • #8
                I don't use HSS at all, mostly brazed carbide tool bits, and some inserts. HSS is more work that it is worth. The brazed carbide tools are cheap and will by far outlast HSS.

                ------------------
                Paul G.
                Paul G.

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                • #9
                  Its HSS for the home shop. Its easy, cheap, better workmanship because the geometry produces lower cutting forces AND you easily get the geometry you need, and most home shop machines really can't take full advantage of carbide's advantages. yes, you have to learn a tiny bit of stuff to sharpen a cutter, a few angles and what they are called, but you should really know this fundamental knowledge even if you are using carbide. Then again, imo unless you enjoy learning, this is not the right hobby – you should switch to woodworking or something while there’s still time

                  I disagree with the comment hss doesn't last as long. with a hss blank and a carbide insert, I guarantee my hss blank will remove a lot more metal than the insert.

                  Of course in the privacy of your garage you can use anything from marshmallows to diamond, but hopefully the number of experienced peeps advocating hss at least compels you to check it out
                  .

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                  • #10
                    In the home shop, grind them, but have some carbide sintered or a couple of different indexables handy for harder stuff.

                    In the school shop, I have this strange philosophy. The students use carbides at first. They also use pre-ground tools for forming and threading - tools I grind up and test.

                    Then, they make their own. The theory is this. My students have learned proper chip formation from different tools, and know the feels and sounds of the tool when it is right. I also teach the angles and such during this part. They know surface finish, and effects of nose radius on wear. Basically, they know the way things SHOULD BE. Then, as they grind tools, they instantly know if the tool they ground is junk or good. I do not have to teach the proper chip formation and such. They know good or not. They take to grinding the tool better, and take less time figuring out the problems - solutions, and the best tool. They also get into some very complex form grinding as well - much faster, and do it with the highest of quality.

                    I base this on 18 years of teaching, the first 10 spent doing the "grind first", and having moderate success getting this down. Now I can teach tool grinding in one week, and get the students making very fine turning left and right hand, profile tools, thread tools of a great variety, chamfer tools, and radiusing and even little specialty tools. And they work great!!!!!! before, I was lucky to get a turning and thread tool that would pass muster and make the projects without looking like bevers attacked them.

                    This goes against all that past apprenticeships teach - including mine, but it has been proven to my industrial supporters, and they love this method now.

                    It also helps that I consider tool grinding of all types the highest art of machining, so perhaps my love of this, and my desire to take it to the next level is passed on.


                    CCBW, MAH

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                    • #11
                      Learn to sharpen HSS. Once you have mastered it switch to brazed carbide. You will be able to sharpen them and they are cheap. $3.50 for a 3/8 shank. I agree with Mcgyver that one piece of HSS will move a larger volume of chips in its life than one insert. However; the insert will move 4 or 5 times as much in a given amount of time. Carbide is more porductive than HSS without question. If it were not they would not sell as many as they do. Ever see a HSS both at IMTS?

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                      • #12
                        Just read spope's post sounds like a good way to learn. Might work well for the homeshop guys. Makes perfect sense to me.

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                        • #13
                          I'm planning on buying a few preshaped and doing my own mostly but want the preshaped around as a reference to compare to mine so I know when they are spot on.

                          I can definitely see the value in doing it yourself.

                          [This message has been edited by Junk (edited 10-06-2005).]

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                          • #14
                            <font face="Verdana, Arial" size="2">Originally posted by C. Tate:
                            However; the insert will move 4 or 5 times as much in a given amount of time. Carbide is more porductive than HSS without question. If it were not they would not sell as many as they do. Ever see a HSS both at IMTS?</font>
                            what you say is true but needs qualifying - firstly, IF the machine is capable. work is cubic units of removal per time - a lot (most?) home shop machines hit the wall either rigidity or horsepower before they can take advantage on these higher removal rates. wont' see a used Harrison, used Colchester or shaper booth there either, but they might the best thing for the home shop

                            Don't forget, they are not purely interchangable - the angles hss is capable of are much better for cutting resulting in lower cutting forces which is farourable to our lighter/older home shop machines. Carbide has its place, but not as frequently as it does in industry, imo.

                            Old dog, here's a sketch of how I grind a fly cutter. this ones ready to drop in run counter clockwise. Its the same as any other cutter, needs rakes and clearances. These ones are almost the same as a facing tool - the radius is put in with the edge of the wheel and is exaggerated in the sketch




                            [This message has been edited by Mcgyver (edited 10-05-2005).]
                            .

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                            • #15
                              YODThis is the way I do it, not nessceraly right. I grind it close to the way that I would if I was going to use it for the lathe. I do grind a fairly large radis on the nose say maybe 1/8 inch.

                              It would be mounted in the flycutter at apporx a 30* angle.

                              Take light cutts and use plantey of cutting fluid. For the cutting fluid I use cutting oil or some stuff that comes in a green can(dont remember the name at present). It is made for cutting aluminum. Just keep the chip from welding back to the parent metal.

                              Hope this give you some help.
                              Don\'t ask me to do a dam thing, I\'m retired.
                              http://home.earthlink.net/~kcprecision/

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