Announcement

Collapse
No announcement yet.

Drills - Thinning the Web

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

  • Drills - Thinning the Web

    What's the best, or at least good, way to thin down the web on drills that have been ground down considerably?

    Had never done that, and having several that needed it, tried to get in with the corner of a bench grinder wheel with not a lot of good success.

    These were pretty small, 3/8" and less.

    I have two or three that someone else had done, and they look like someone used one of those little cutoff wheels made for mounting on a die grinder.
    Lynn (Huntsville, AL)

  • #2
    Originally posted by lynnl
    I have two or three that someone else had done, and they look like someone used one of those little cutoff wheels made for mounting on a die grinder.
    Yep.

    Although you might find the 3" air cutoff grinders a little better. 4 1/2" angle grinder can also be used but is more of a pain to clamp in the softjaws of your vise. (Easier to maneuver the drill bit then the grinder
    Play Brutal Nature, Black Moons free to play highly realistic voxel sandbox game.

    Comment


    • #3
      http://i973.photobucket.com/albums/a...ndian/x007.jpg

      Comment


      • #4
        Or... You could dress the 'fine' wheel on your six inch bench grinder to a sharp edge and use that.
        Make sure the 'chisel'end is straight up and down and just touch it to the wheel.The chisel end is your dividing point. Use an angle to approach the wheel like you're sharpening a wood chisel, maybe a little less. Turn it 180 deg and do it again.
        Look at the drill tip end on to see if you have ground enough. If not, do it again.
        Make sure you have plenty of light. Plenty of light on the work.

        Comment


        • #5
          Good topic posting Lynn, something i don't see asked very often.

          Someone makes a narrow smaller grinding wheel for this purpose.

          Maybe someone will post their set up, be easy to set up a small grinder with a narrow stone , if someone is doing a lot of drilling, or just for convenience.

          Comment


          • #6
            Increased thrust is the primary problem caused by a thick web. Splitting the drill point is a variation of web thinning that reduces the thrust required for drilling. And it makes drilling more efficient because the web area cuts rather than extrudes the center material.

            A reasonably sharp corner is needed on the wheel for point splitting but it need not be perfect to do an acceptable job.

            The essence of a simple point splitter is shown here: http://www.gadgetbuilder.com/Brooks%...Point_Splitter Where I used my shop built grinder because it was available.

            Most any grinder with a sharp corner wheel could be used. The concept can be simplified to just a straight edge to set the distance from the wheel and an adjustable stop to terminate motion when the wheel corner is a few thou from the drill's center. Mount the triangular V block holder on a 4" or so square of 1/4" or 1/2" steel where the steel piece is the slide (substitutes for the cutter grinder's table).

            It does take a little puttering to make a point splitter but most everything except the V block could be made from wood to quickly verify that it does what you need.

            John

            Comment


            • #7
              I usually just mount the drill in a vice and fire up my die grinder with a 3 mm stone to make a nicely cutting center portion. Mainly I do this for drills above 20 mm in diameter or for extra long (20D) 10 mm drill bits that have an extremely thick web. Sure makes a world of differeence in cutting pressure needed

              When my flu gets over, I'll post a few pictures of the sharpening.
              Amount of experience is in direct proportion to the value of broken equipment.

              Comment


              • #8
                In attempts at web thinning yesterday I did end up with some crude (very crude) looking split points. I haven't tried them yet to see how they work.

                Probably would've turned out a bit better if I'd taken the time to dress the wheel beforehand. But this was just kind a spur-of-the-moment, puttering around type of undertaking.

                A thought I had tho, - I have a little Ryobi laminate trimmer, router. It could probably be fitted with a small thin grinding wheel mounted on an arbor, and do a halfway decent job of thinning. ...maybe even some point splitting that is only "semi-crude."
                Lynn (Huntsville, AL)

                Comment


                • #9
                  Over here you can buy a cheap saw chain grinder, which would be handy for thinning webs.
                  I have a high quality one and use it for just that job occasionally.
                  Will

                  Comment


                  • #10
                    I'd think....

                    That a dremel tool with a round abrasive point should work well on the job and have several other applications for you as well. The die grinder would be even a better choice if you have one already. That said you can get some of those very cheaply if they are air driven and might be just the ticket for the job.

                    As for split points....my opinion....if you're not just punching holes I'd suggest you not use regrinds. it's very easy to get them off center if you don't have the right tools. It's harder still to get the facets right so it will cut evenly and not make an oversized hole.
                    Allans Rule: Anything worth doing is going to be a pain in the butt.

                    Comment


                    • #11
                      Originally posted by Clevelander
                      As for split points....my opinion....if you're not just punching holes I'd suggest you not use regrinds. it's very easy to get them off center if you don't have the right tools. It's harder still to get the facets right so it will cut evenly and not make an oversized hole.
                      Use them as pilot drills for bigger holes, and clearance holes.

                      Avoid using them for tap holes or holes that need to be straight.
                      Play Brutal Nature, Black Moons free to play highly realistic voxel sandbox game.

                      Comment

                      Working...
                      X