Announcement

Collapse
No announcement yet.

Straight line knurling?

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

  • Straight line knurling?

    I have a roller 125mm long I would like to put a linear knurl on. It is 35mm in diameter made out of steel. Is that possible with a linear knurling roller? I would think the diameter would have to be exactly matched to the pitch of the knurling roller. With the cross hatch type knurling I have done it seems it is not absolutely critical. What am I missing?

    My knurl roller has a pitch of 1.5mm. my calculations work out to a diameter of 34.395 giving me a pretty close correct diameter for the roller to track correctly. ??????
    Last edited by Black Forest; 01-22-2020, 04:59 AM.
    Location: The Black Forest in Germany

    How to become a millionaire: Start out with 10 million and take up machining as a hobby!

  • #2
    Do it with an index head and a shaper . :-)
    ...lew...

    Comment


    • #3
      I've done straight knurling with a single wheel from the diamond knurl. Mount it on something where it can spin as designed, but rotate the holder so the diagonal grooves on the knurl wheel are parallel with the centerline. Mind, the ones I've done have been just short knobs or buttons so getting the grooves absolutely parallel on a long part might take some tweaking. But basically, the process just works.

      I also don't fuss with calculating circumference and knurl pitch, Cram the knurl into the work hard enough and it will find and register a single pattern. I know this is a subject of some controversy and others will not agree. I can only attest to my experience with lots of knurls.
      .
      "People will occasionally stumble over the truth, but most of the time they will pick themselves up and carry on" : Winston Churchill

      Comment


      • #4
        Cram the knurl into the work hard enough and it will find and register a single pattern.
        This has always worked for me.
        "A machinist's (WHAP!) best friend (WHAP! WHAP!) is his hammer. (WHAP!)" - Fred Tanner, foreman, Lunenburg Foundry and Engineering machine shop, circa 1979

        Comment


        • #5
          Originally posted by mickeyf View Post

          This has always worked for me.
          Me too. In fact, jamming the knurling tool into the work WITHOUT the knurl diameter and work diameter calculation always worked better and gave nicer knurls.

          Comment


          • #6
            I've got a "coining" knurl that I use fairly often. I do find that with the coining or even diamond knurling that I tend to get a better start of the pattern if I start it on an edge so the wheels are only about half engaged. And some may not agree with this but for the straight "coining" knurl I feel I get better results if I set it with a slight lead angle. Just enough ahead so it doesn't quite look square. So maybe just a couple of degrees.

            If for some reason I don't get a clean starting pattern I'll turn down the start and run off .005 or so from the rest and try again. Maybe 1:5 times I need to do that.
            Chilliwack BC, Canada

            Comment


            • #7
              Originally posted by Black Forest View Post
              I have a roller 125mm long I would like to put a linear knurl on. It is 35mm in diameter made out of steel. Is that possible with a linear knurling roller? I would think the diameter would have to be exactly matched to the pitch of the knurling roller. With the cross hatch type knurling I have done it seems it is not absolutely critical. What am I missing?

              My knurl roller has a pitch of 1.5mm. my calculations work out to a diameter of 34.395 giving me a pretty close correct diameter for the roller to track correctly. ??????
              I get a value for the new diameter just slightly different from your value of 34.395 mm.

              D = 35 mm
              P = 1.5 mm

              pi * D / P = 73.303...

              truncate this to 73 for an integer number of pitches on the new circumerence, then the new circumference and diameter are...

              C = 73 * 1.5

              d = C / pi = 73 *1.5 / pi = 34.855

              Regards, Marv

              Home Shop Freeware - Tools for People Who Build Things
              http://www.myvirtualnetwork.com/mklotz

              Location: LA, CA, USA

              Comment


              • #8
                Cramming works because there is usually a depth that actually works out, and knurling is not too dependent on the exact depth, although the pattern definition can vary. The folks who say they just cram it in are actually stopping when they find the right setting, they may just not realize it.

                That said, you are in fact correct, and knurls for screw machine work were sold according to (IIRC) diametric pitch or a similar measurement. There were methods to set up perfect knurling using them and the turned diameter. Screw machine folks want it to "just work" and work every time with no adjustment, just one setting and go.

                1601

                Keep eye on ball.
                Hashim Khan

                Comment


                • #9
                  John Stevenson once posted a photo of a tapered workpiece that he'd successfully knurled; I thought this was pretty good proof that the diameter doesn't need to be calculated when knurling. I tend to use machine oil on the work & rollers, and like others say, mash the knurls into the work.

                  Ian
                  All of the gear, no idea...

                  Comment


                  • #10
                    Originally posted by TGTool View Post
                    I also don't fuss with calculating circumference and knurl pitch, .
                    we haven't that one recirculate to the top in awhile

                    I'm with you, I've never found it matters, surprisingly even for cut knurls. Either that, or I'm the luckiest bloody knurler on the planet.

                    in Toronto Ontario - where are you?

                    Comment


                    • #11
                      This afternoon I made a holder for one of the straight knurl wheels. I mounted the 35mm stock in the chuck and had at it. I crammed the wheel into the work at 200 rpm and gave it a .97 mm per rev feed. The knurl turned out perfect for the 25mm that I tested it. This roller will be for a bottom roller for my leather splitter that I will motorize.
                      Location: The Black Forest in Germany

                      How to become a millionaire: Start out with 10 million and take up machining as a hobby!

                      Comment


                      • #12
                        Originally posted by J Tiers View Post
                        The folks who say they just cram it in are actually stopping when they find the right setting, they may just not realize it.
                        That is not an accurate statement.

                        You're implying that to use this method, we keep pushing the knurl in until it tracks right; that is not what happens.

                        When I do this, and I think most others too, I tighten my scissor knurling tool on the edge of the knurl area to what I think the work and tooling can handle prior to any revolutions of the part. Once it's tight, then I turn on the lathe and the knurl just tracks right. There is no "stopping when I find the right setting".

                        Comment


                        • #13
                          Originally posted by Ian B View Post
                          John Stevenson once posted a photo of a tapered workpiece that he'd successfully knurled; I thought this was pretty good proof that the diameter doesn't need to be calculated when knurling. I tend to use machine oil on the work & rollers, and like others say, mash the knurls into the work.

                          Ian
                          This isn't the tapered workpiece example, but another thread that John started on straight knurling

                          Comment


                          • #14
                            I don't think we actually stop feeding in at the right point. At least I don't. I feed in until I get a complete shape with nicely defined top edge that is fully swaged closed.

                            Mind you more than once I've gotten a double start and upon feeding in a bit more it switched to a single. But often times the forms look "blurred" for those cases. Like the knurls are not quite matching the patter but are being smeared or pulled to fit. And then the knurling does not come out all that well. So now I tend to start the feed, stop an check with a light "registering only" pattern. If I'm getting a double strike I'll push in slightly more and check again. If it doesn't switch by the time I'm in around .01 or so I stop and machine off the pattern and shave the stock down with a .003 to .004 cut and try again. That usually does the trick. But a few times the results have been a little rough when the knurl and part pitches didn't quite jive but were sort of "close enough".
                            Chilliwack BC, Canada

                            Comment


                            • #15
                              You basically described the process of "stopping when it's right".....

                              But, there are just two choices...

                              1) The knurl works out perfectly around the FINAL average diameter.

                              2) The knurl does not, but the wheel slides a bit on each "tooth" so it ends up being "basically the same result" as being even around the average FINAL diameter.

                              If it did not END UP being even like "1", or "2", there would be half "teeth".
                              1601

                              Keep eye on ball.
                              Hashim Khan

                              Comment

                              Working...
                              X