Announcement

Collapse
No announcement yet.

Workholding in a different light

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Workholding in a different light

    So...

    A week or so ago my boss comes to me and informs me that I need to find a way to do something we don't usually do. At least we don't do it this way.

    I was brought some Scales for one of our knives. they have a plain bolster, but it seems the customer wanted lined bolsters. A bolster is the end cap on a knife handle near the blade. You can see exactly what I'm talking about by looking at the first few pictures in the thread linked Here

    I was handed this scale to work with. The thread linked previously describes the process we use to form and line bolsters. These ones have a radius of approximately .75 ", and there are only about 75 of these to be done. The lines need to be uniform, about 20-25 thou deep and must match on both the mark and pile side of the knife. (Don't ask me why there called mark and pile side, I have no idea what so ever. The mark side is (for us right handed folks) the side of the knife that is where your thumb is when holding the knife in a working position.the scale pictured below is the markside).


    Anyhoo...

    I'm at a loss to figure out an easy way to get this done, in a reasonable amount of time, with minimal expense. After wandering around aimlessly for a while, thinking unclearly, it dawned on me that all I really needed to do was get back to basics. I headed for the stock rack and snagged some 2 inch 1144 and lopped off a chunk. It turned into this nifty little fixture.


    This fixture (as ugly as it is) allowed me to set up and machine the line in the lathe. I'll explain the rubber band as we go! I made two sliders that have pins in them that allow me to fix the position of the scale relative to the slightly angled end of the bolster so that the lines would be parallel. I also left room enough in the design to fixture both sides.



    I used the rubber bands mostly because it saved me a ton of time figuring out a way to secure the scales on the fixture. It was also reasonably fast to load and unload. and with the scale being in a fixed position due to the pins I figured it would be more than enough to do the job, and it was.




    to be continued in a reply.

  • #2






    Comment


    • #3
      I ended up investing about an hour and 15 minutes in getting all the scales turned with excellent results. I used my standard 60 degree thread cutting bit and had no issue what so ever getting the line to come up very nicely. This isn't stuff that required any super precision or anything as it's only decorative, but I thought it was a neat way out of an odd position.

      The bottom slider was made as a clamping eccentric , the purpose was to allow minor adjustment to the scale position to make the lines parallel to the bolster where it meets the handle. The top slider allowd me to position the slightly off center bolster so that the line depth was the same on both edges. All of our bolster and caps are made originally by hand, so that radius was pretty damn close, but it doesn't mean it's perfect.



      I hope y'all enjoyed this tidbit. I ended up having fun doing the project.
      Last edited by Walter; 09-17-2010, 03:36 AM.

      Comment


      • #4
        This looks like a good candidate for a "How I did it" sticky thread. Good work!
        Weston Bye - Author, The Mechatronist column, Digital Machinist magazine
        ~Practitioner of the Electromechanical Arts~

        Comment


        • #5
          I know a clamp eccentric is a simple arrangement but I am forever amazed at how many problems they will solve. Thanks for all the pics Walter.
          - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
          Thank you to our families of soldiers, many of whom have given so much more then the rest of us for the Freedom we enjoy.

          It is true, there is nothing free about freedom, don't be so quick to give it away.

          Comment


          • #6
            Great idea. I never would have thought of using rubber bands for work holding. I have to store that in inviolable memory for later use. Light cuts only I am sure, but a clever idea.
            Paul A.
            SE Texas

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

            Comment


            • #7
              Great thinking! Gary P. Hansen
              In memory of Marine Engineer Paul Miller who gave his life for his country 7-19-2010 Helmand Province, Afghanistan. Freedom is not free, it is paid for with blood.

              Comment


              • #8
                Originally posted by Walter
                ... A week or so ago my boss comes to me and informs me that I need to find a way to do something we don't usually do....

                Walter,

                Just curious... Does your employer know you posted this solution? The reason I ask is that you're "technically" giving company information away that your employer paid you to develop. Now one may say it is trivial, but your competitor most likely doesn't have someone as clever as you working for them. I would imagine knife making is a "cut" throat business and any "edge" one can get on the competition could make a big difference.

                Comment


                • #9
                  Mike,

                  Knife making is cutthroat, however there are no real secrets. Were this rocket science I'd not be divulging anything. There are a few, and only a few, big knife makers in the business any longer. Everyone knows everyone, and most have done work for one another. Honestly there is nothing I'm giving away. This little solution is not and never will be a viable long term solution for anyone, it's simply a quick fix. Rest assured that I'm far from the super secret clever guy hidden away in the basement shop that no one ever see's, Everyone knows who I am, what I do, and where to find me. Oh, and I am hidden away in a basement shop in an old mostly unused portion of the building, but I like to think it's because I'm such a grumpy old fart!

                  Seriously though, you raise a good point, and you are right, but frankly no one would care. No one really cares what I do as long as I solve problems in a reasonable amount of time without spending a ton.

                  Weston, Thanks

                  YOD, I love love love cams for so many things. Absolutely one of the most handy things I have is a couple of boxes full of cam positioners for tooling plates. So many different types for a multitude of jobs. One of these days I have it in mind to build a mid size tooling plate with cam locks that have built in adjustment screws for minute movements.

                  Paul, I was pretty unsure at first on the bands, but they are new, heavy bands, inspected before use. I was only running about 660 rpm's and the scales were pretty well locked in on the pins anyways. All the cutting forced were directed to the pins anyways, and my infeed was only .0015 on auto feed with a diamond honed razor sharp HSS bit. She never so much as made a funny sound.

                  Gary, Thank you !
                  Last edited by Walter; 09-17-2010, 02:06 PM.

                  Comment


                  • #10
                    A good reply Walter you are so correct.Alistair
                    Please excuse my typing as I have a form of parkinsons disease

                    Comment


                    • #11
                      Originally posted by Weston Bye View Post
                      This looks like a good candidate for a "How I did it" sticky thread. Good work!
                      -Ew. Why would you want something this cool to be buried in that mess?

                      Doc.
                      Doc's Machine. (Probably not what you expect.)

                      Comment


                      • #12
                        Kinda scary after seeing how many rubber bands iv seen snap unexpectedly. I guess its ok if you carefully stretch them first to check for weak ones.. but I think I would have tried to use two rubber bands on each side for redundancy.
                        Play Brutal Nature, Black Moons free to play highly realistic voxel sandbox game.

                        Comment


                        • #13
                          Looks like someone woke this morning and started to revive long dead threads. This one is 4 years old.

                          Comment


                          • #14
                            Originally posted by Black_Moons View Post
                            Kinda scary after seeing how many rubber bands iv seen snap unexpectedly. I guess its ok if you carefully stretch them first to check for weak ones.. but I think I would have tried to use two rubber bands on each side for redundancy.
                            The bands were new and well tested but again all the forces were directed against the pins in the jig so no real worries :-)

                            Do not go gentle into that goodnight.

                            Comment


                            • #15
                              Alistair and Doc, thanks!

                              Do not go gentle into that goodnight.

                              Comment

                              Working...
                              X