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Sharpening HSS End Mills By Hand

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  • Sharpening HSS End Mills By Hand

    Is this practical, with a microscope ? If anyone does this routinely, I'd SURE appreciate your description of the process.


  • #2
    Scroll down to sharpen end mills.

    [This message has been edited by JCHannum (edited 09-19-2003).]
    Jim H.


    • #3

      Muchas gracias, there are no sharpening facilities near me so I think that I can make use of the technique described in the website.

      Cheers !


      • #4
        in the last few issues of Model Engineer Workshop there has been a series on "Beginers Milling Projects". The first project was a small boring head, then a grinder rest, then the endmill sharpening fixture for the grinder rest. All made with bar stock.

        It is not a Quorn (then it would be a big PITA project), but it can do a good job if you are diligent. Not bad for a one day project.

        [This message has been edited by Thrud (edited 09-20-2003).]


        • #5
          Since the "end mill" so often must take a cut on the side, I have always wondered why there are so many articles about sharpening the END only.

          I cannot recall ever using merely the end of the "end mill". Surely the side edges are as important or more so.

          Can someone explain this?


          • #6
            A clever guy with an eye for geometry could build a gadget from wood and nails that guides the cutter flutes past the grinding wheel. It's a desparation move but it works in a limited sense.

            It's very difficult to grind the flutes of a milling cutter without minimum equipment. There's been some fixtures designed over the years that supposedly allows you to grind milling cutter flutes from a bench grinder. A guy gave me one years ago. I monkeyed with it and mangled up a few cutters but it's poorly suited for end mills smaller than 5/8" or so. No sensitivity.

            A basic import end mill sharpener can be had for $1200 or so. I've seen them on specials.

            Here's a link. The National (the same basic type as my mickey mouse gadget) closes in 17 hours. The Darex unit is actually a fair piece of equipmentbut it's a bit pricey.


            Most people are better advised to farm out their milling cutters to a mom and pop sharpening shop. You really have to ruin a few before you get the hang of it.


            • #7
              Thanks all, there is no local facility for sharpening my cutters but maybe I can arrange a mail/UPS transaction to an urban area.

              In the meantime, I have a couple of dead soldiers that I will use to evaluate the hand sharpening technique. Happily, two of the cutters have dulled ends only - side flutes are OK.


              • #8

                Home Shop Machinist had a project by Robert Hedin in the 1985 Jul-Aug issue. It was titled "End Mill Sharpening Fixture". It was very simple to make and it used a bench grinder.

                I don't have a copy of this article but as I remember, it seemed like something that would work. Maybe someone that has this article could send you a copy or give a review of it.


                [This message has been edited by Mike Burdick (edited 09-20-2003).]


                • #9
                  Thanks Mike, Thrud also mentioned a simple device for sharpening cutters, I'm interested in examining both articles if anyone cares to scan and e-mail them.

                  I did try the technique described in the link provided by a previous poster. I can see how this could be successful with large cutters but for me (old eyes) it's not workable for the smaller diameters.

                  Clearly the website owner had no difficulty with his procedure BUT I did note that he later modified a piece of equipment to sharpen his end mills...

                  Saw a universal sharpener (import) for $599 recently, think it was HF. Seems like a reasonable price but still out of my range, particularly if quality is unknown.


                  • #10
                    Randy if you have a 5C spin index and a compound miter saw you can make a temporary setup to sharpen your end mills. With a new center depressed grinding wheel in place of the saw blade and the spin index clamped on the left side you can do a very good job with a little bit of trial and error.

                    My first setup was like I described above, this is what I use now. I had to mount the index on the right on this one due to the type of grinder that I used. Visability is better if you can mount it on the left. By adding an old clapper compound I now have a precise means of feeding the end mill to the stone.






                    [This message has been edited by G.A. Ewen (edited 09-21-2003).]
                    To invent, you need a good imagination - and a pile of junk. Thomas A. Edison


                    • #11
                      G.A. Ewen:

                      Veeeerrrrrry interesting. I do have a miter saw that I rarely use. Looked at your photos (nice and sharp) to see how you did it and I understand.

                      Don't have a spare compound but I can rig up something to take the place of one. Also don't have a spin indexer BUT one was already included in next month's budget, happily.



                      • #12

                        VERY slick set up. thanks for sharing it with us poor folks. i, too, have a miter saw that is about to be replaced. i have had it 30 years and am 'attached' to it. looks like it isn't gonna have to go to the scrap pile after all.

                        question[s]: is that a chain saw grinder motor? how did you attach it to miter saw frame?

                        i recently built a diamond grinder with some wheels i got from a guy in Ohio. am not computer literate enough to post pictures, nor do i have a place to store them. i can email a picture if anyone is interested. wheels are 4-1/4" x 2-1/2". they have the look of 'high dollar' tooling. government [or someone must have paid big bucks for them originally. carbide, hss, doesn't matter. grinder puts a razor edge on stuff. i use a little water out of a squirt bottle to lube it. i have wanted a 'carbide grinder' for a long time. by the time i bought grinder and wheels i would have a $1,000 bill + invested. this one cost about $75 but most of it was junk i had laying around. nice cast iron sewing machine legs on it that i have had for 20 years looking for a place they fit.

                        goes to show you that you should save your junk. now, if i just had a project [s] for the other 5 or 6 tons of junk.......... [i mean materials]

                        have a good day.
                        ........i dremel. therefore i am..........................


                        • #13

                          Rather than sharpening end mills that are dull on the OD, you can easily turn them into roughers. Take a thin wheel and hand grind a series of notches around the outer cutting edge. The notches serve to break up the normally long chips making even a dull cutter perform better than a new sharp one.

                          Save your new cutters for finishing work.


                          • #14
                            Many times pople will tell you to sharpen an endmill on the end only due ot the need to hold size. They do not want an undersize endmill. If you are only using say .200 deph of cut why pull the entire od. Just cut it off and resharpen the end.

                            I have my own tool grinding shop and this is what i see all the time. i always resharpen tools back to center cut, even the ones that were not originally center cut. once past the undercut.

                            If you read the technical data section in most end mill cataloges they will tell you that once an end mill is ground beyond 12% of it original size you loose cutting effiency of the tool.

                            I reshaarpen all tools on machine. No hand grinding here. Use Cincinnati Monoset to do ends. You can purchase the universal grinding attachments, but have not seen one that will produce a true center cutting end mill.

                            I have been doing this kind of work for about 25 years. many changes have come to the trade, mainly cnc wouldn't give a plug nickle for one. too boring to run. great for production but lack of control can damage expensive wheels very fast.

                            I work as a craftsman and practice my trade. Many so called machinist today couldn't machine their butt out of a paper sack. Machine operators are the appropriate name for the people today.

                            Most people are too cheap to have spare cutting tools available or to pay to have professinal sharpening done. Purchase foreign made junk instead. I have had them come into my shop and be off size and out of round on shank so bad they will not fit my holders. I won't damage a $200 holder for a cheap import endmill.


                            • #15
                              The Widget I reffered to in Model Engineer Workshop (UK magazine) does allow you to grind the flutes of endmills and drills.