Announcement

Collapse
No announcement yet.

Tricks for dial engraving?

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

  • Tricks for dial engraving?

    I know I've seen some of you guys- here and in the magazine- with some setups for engraving new machine dials, but I'm having a hard time finding some of the good write-ups.

    Here before too long I'll need to engrave both new dials for my big Springfield lathe- one with 100 lines, the other with 250. I have a good dividing head, and just ordered some number stamps, so what I'm looking for is a good way to engrave the hash marks.

    I have a diamond drag engraver tip for my CNC router, but I don't know how deep a line it will cut. And I want a nice, clear, smooth readable line.

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

  • #2
    There's a cutter style out there where you turn the end to a tapered point, then grind half of the bit away. It works, but can be extremely fragile. I tried them for PC Board routing, but found a .8mm end mill worked better. As you increase the angle, you decrease the fragility of the tip.

    If you want to play, a pack of those half 1/8" V-cutters runs about $10 from Amazon... Plus shipping time. I'd probably go with a 30 and 20 degree set to start with. They're carbide. You'll get a fine line, but will break a couple of them getting speed and feed right.

    Depending on how big your dials actually are, a small end mill might work best. You'll probably need to go quite slow depending on your material.

    Comment


    • #3
      https://youtu.be/jyNed1SyGR4

      https://youtu.be/Tw1HQIId7xE

      https://youtu.be/ZlKHrhAz8M8

      I'm sure there's more- those came to mind

      Comment


      • #4
        I suggested in your other thread, do not rotate the cutter....that way you can get a deep narrow V. If you rotated the cutter you be using a pin point shaped cutter that would easily break. Cutter is similar to what you call a threading tool in the lathe, is round and held in the locked spindle. table is moved to create shaping action

        number stamp with a guide and support under the work. Final step, carefully run a very fine file over the surface to knock off the bruises. ( last photo was before this was done)





        Last edited by Mcgyver; 01-21-2017, 10:27 AM.
        .

        Comment


        • #5
          I use McGyvers method, and have excellent results (like his pic shows) I took a broken 1/4" end mill and ground the tip for the shape he shows. I note he also has a 'brace/prop?' under his dial, that helps with 'bounce' when stamping the letters.

          When I first started to make a dial I had to make 2-3 "prototypes" before I got the knack down. Those first ones were for the notoriously awful, small, unreadable South Bend dials - drastic improvement!
          If everything seems to be going well, you have obviously overlooked something........

          Comment


          • #6
            I suggest making dials much larger diameter than typical. A good example would be the dials on Hardinge chuckers, they must have been close to 5" diameter with the area with the markings being white plastic for visibility.

            Comment


            • #7
              I ground a point similar to a threading tool and locked the spindle of the mill and it came out looking like Mcgyver"s. When done I put it back in the lathe and knocked off the burrs, filed and scotchbrited it. To stamp the numbers I made a jig to hold the dial, bushing in the center, big washer and bolt to clamp it in position, and then a guide for the stamp, came out good. The one I did was a larger dial for my Lodge and Shipley 12" lathe. It was a .200 per rev. and only about 1 1/2" or 2" dia. Now it is about 3 1/4" , what a difference.

              Comment


              • #8
                http://neme-s.org/images/PDF_Files/M...d_Collars1.pdf

                Excellent article on marking dials
                Errol Groff

                New England Model Engineering Society
                http://neme-s.org/

                YouTube channel: http://www.youtube.com/user/GroffErrol?feature=mhee

                Comment


                • #9
                  Originally posted by DR View Post
                  I suggest making dials much larger diameter than typical.
                  -I was considering that, but the dials are already quite a bit larger than those on my Sheldon, which has diameter-reading 250-graduation dials. I have no problem with those, and so the new one for the Springfield should be a bit more readable still.

                  The saddle extension has a face/flange that the dial buts against and carries the index mark. If I made the new dial more than just a bit larger, I'd have to make an extension, or cut the flange off and fab a new bolt-on face, or something, to match.

                  Not undoable, of course, but I'd rather not at the moment.


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

                  Comment


                  • #10
                    I believe you have a shaper? Use that along with your dividing head. Set the stroke for length of line, power off and manually operate the ram. Something like Mcgyver's UPT or similar punch holder helps. That's how i do mine.

                    Comment


                    • #11
                      For engraving the lines on the dials for my Sheldon, I made a printout, using CAD, with 125 equally spaced lines on the length of the circumference of my 6 inch chuck. I used double stick tape to fix the strip to the chuck. I used a fixed pointer to align each line on the strip to transfer the line onto the dial blank. I used a threading tool, turned sideways, to scribe the lines, utilizing the compound set parallel to the ways to get the lines a precise length. The bore of the dials were machined for a firm fit to the original dials and lock tight used to secure them. It took some tweaking to get the lines to fit, but with CAD you can set the line interval to 4 decimal places, plenty accurate for this work.

                      ...David

                      Comment


                      • #12
                        Fly cutter. A boring bar in your mill, with a sharp V tool bit, will give you any width/depth/shape groove you want.

                        Comment


                        • #13
                          You can install larger dials without drastic modifications to your machine. To get the larger diameter ring with the fiducial mark, make a top-hat section piece that fits over the existing flange on the ID and brings it out to the new diameter. The "face", or the very top of the hat crown in section doesn't need to be very thick, just .020 or .030". This would ordinarily leave a gap for the new dial, so put a shallow recess in the back of it. This isn't fussy since the depth can be deeper and the diameter larger than the flange projection. All the parts will cuddle up together and look original. Oh, the top-hat piece will need a small setscrew to fix it to the old flange.

                          May I also recommend that you not make all the 1-4 an 6-9 marks the same length. Try 2 & 3 longer along with 7 & 8. It makes the exact number a lot easier to pick out. My unproved theory is that the brain can use pattern matching more easily than counting over to the matching digit. Sorry this is such a washed out photo, but compare the first and second dials in this photo.

                          [IMG][/IMG]
                          .
                          "People will occasionally stumble over the truth, but most of the time they will pick themselves up and carry on" : Winston Churchill

                          Comment


                          • #14
                            TGT.
                            Great idea. Very nice work!

                            Comment


                            • #15
                              TGT,
                              I find the second from the left very confusing and I'm certain that I for one would be making mistakes.
                              However the third from the left with gradual increases I find very pleasing and have some M&W rules laid out this way, in fact i think it was a test by them or them in conjunction with a university that came up with this idea but it's probably been around for ages, just took M&W to re-find it.
                              .

                              Sir John , Earl of Bligeport & Sudspumpwater. MBE [ Motor Bike Engineer ] Nottingham England.



                              Comment

                              Working...
                              X