Announcement

Collapse
No announcement yet.

milling a 3-sided taper?

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

  • milling a 3-sided taper?

    While my mind was running around in a circle, looking for fun little projects that would help me embrace my inner 12 year old I came across the idea of a 3-sided stabbing weapon. Not that I have any need of one of course (barring any zombie apocalypse.)

    I just couldn't figure out how to mill that form. Sure, I can turn a taper (however roughly.)

    Milling the flats on a 3 sided taper just stumped me. I started thinking about it and got as far as a sine plate for the angle with a v-block. But getting the angles right (equilateral) has me flummoxed.

    - Bored and perplexed
    Last edited by madwilliamflint; 09-04-2012, 10:45 AM.
    ----
    Proud machining permanoob since September 2010

  • #2
    How about between centers on your dividing head with the tailstock shimmed up to the required taper? Although, I'm guessing that a "3-sided stabbing weapon" might be forged and ground in real life and not milled.

    Tom

    Comment


    • #3
      I just take a triangle file and grind the teeth off tada done and it will take an edge that you can shave with.

      Comment


      • #4
        The first thought is always to clamp something in the vise. In this case, it can be done but not easily.

        The easiest way to do it is to leave some material on both ends. These stubs will act as a reference point and a way to grip it. Then it's trivial to prop one end on a block of some sort that is higher than the other end. Mill that surface, turn 60 degrees, repeat.

        If you need a cheap 60 degree reference, attach a hex bolt to one of the stubs. Every other flat gives you the angle you wanted.


        Dan
        At the end of the project, there is a profound difference between spare parts and extra parts.

        Comment


        • #5
          Originally posted by danlb View Post
          The first thought is always to clamp something in the vise. In this case, it can be done but not easily.

          The easiest way to do it is to leave some material on both ends. These stubs will act as a reference point and a way to grip it. Then it's trivial to prop one end on a block of some sort that is higher than the other end. Mill that surface, turn 60 degrees, repeat.

          If you need a cheap 60 degree reference, attach a hex bolt to one of the stubs. Every other flat gives you the angle you wanted.


          Dan
          Wouldn't that be turn 120 degrees.......??
          RPease

          Comment


          • #6
            6” Yuasa Tilting Indexer

            That would be a good excuse to get one of these.



            They say that even a blind Hog finds an Acorn sometimes. I bought this at an auction years ago and didn’t even know what it was. I don’t remember the price but it was late and small things were going cheap. In conjunction with an adjustable tailstock it is very handy.
            Byron Boucher
            Burnet, TX

            Comment


            • #7
              The hex nut idea is genius. And yeah, I think leaving stock on the point end is the key to making it work. Otherwise, after the first cut you're milling a face on an unsupported length of bar stock far enough out that I'd imagine it would cause problems. Then I imagine it'd be trivial to part off the 'tailstock end' of the piece and grind down the final faces on the point.

              Of course it occurred to me afterwards that one could, nowadays, just start from hex bar stock. But if I hadn't read the thing about the hex nut I would never have gotten there.

              Thanks guys. Another mystery solved.

              o/
              ----
              Proud machining permanoob since September 2010

              Comment


              • #8
                You could put it in a collet in a spindex. Set the spindex in the mill vise at the appropriate angle. Then use an end mill and run it so one side of the end mill is always cutting towards the pointed end of the workpiece, pulling away from the spindex. Cut one side, index 120 degrees, repeat. Then you could cut the end to a sharp point.

                Comment


                • #9
                  Originally posted by duckman View Post
                  I just take a triangle file and grind the teeth off tada done and it will take an edge that you can shave with.
                  Also known as a deburring knife.

                  Comment

                  Working...
                  X