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someone please explain the process ?????

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  • someone please explain the process ?????

    I am always intriged by the ability our members have of scribing lines and numbers on new gauges etc.I can undestand the basics but how do you get them so neatly finished especially the numbers so clearly if I attempted it or anytime I try it the numbers come out uneven and I know that like Maxwell's hammer you only get one wallop before catastophe is unearthed.Alistair
    Please excuse my typing as I have a form of parkinsons disease

  • #2
    the lines are generally done on the lathe. you are basically using the lathe as a shaper, indexing the part in the drill chuck, around so many times per revolution.

    the numbers, i would use a jig with a hole in it and take a lot of time setting it up.


    • #3
      Here's one way - photo etching:


      • #4

        One quick and dirty method I have found for keeping the stamping aligned is to print a 1::1 CAD drawing of the desired dial, glue the drawing on the dial in the proper position, then stamp thru the paper. There are threads here describing elaborate fixtures to hold scribes and stamps in eactly the right posistion, but these do require more than an afternoon to construct.


        • #5
          Alistair, this is how Don Carr does it for curved surfaces. Very simple. I hope it would be of some help. Vic

          Last edited by smagovic; 09-14-2006, 10:10 PM.


          • #6
            Making Graduated Collars

            To make the divisions, one can use a dividing head set up so that it can be attached to be back of the lathe's spindle or one can mark a piece of paper with the proper divisions using a CAD drawing program such that it fits the circumference of the lathe's chuck exactly - then tape it to it. Also, tape a note card on the lathe headstock somewhere for use as a witness mark.

            To stamp the numbers I made the following jig – for perspective the jig is 8 inch long with a آ¾ inch shaft and a 1-آ¼ inch shaft (see attached photos below). The jig has two slots cut into it at 90آ°. If you do not want to make a jig, as I have told others on this board, use a boring bar that is made for square HSS bits. The slots: One is cut the exact width of the stamp and the other is cut larger for stamping a number with two digits. On the second, remember not to cut it double width, as the digits will be too far apart.

            To use it just install it on the compound with a boring bar holder and set it to the same angle as the plane of your collar. For stamping the double digit, hold the stamp body against one side of the jig and for the other digit use the other side. Since the jig or boring bar is on centerline the numeral will automatically be centered and correctly spaced. For single digits just rotate the jig 90آ°.

            Over the past 20 years I’ve made hundreds of graduated collars and this is the only jig I ever needed. Remember the entire collar can be made and stamped in the lathe so think about your setup and order of machining. The last step should be removing the finished collar from the chuck.

            To cut the graduations: I use a boring bar with a very sharp “Vâ€‌ and a small amount of back rake. When setting this up extend the boring bar as far away from the compound holder as possible – this is critical. This allows for some spring that will force the cutting bit into the metal. Always cut lines by PULLING the compound toward the open end – never “pushâ€‌ the line, as this will result in a very deep and unsightly mark. In addition, cut the mark using the compound with the carriage locked. This way you can measure the length of each mark exactly.

            An example:

            Setup: Pull back the cross-slide so that the cutting bit will clear the work. Run the compound to where the graduated mark will begin and set it to zero. Push the cross-slide up so it just touches the collar and then push it in another 20 or 30 thousands depending on your desired cut depth (that’s where the spring of the boring bar comes in) and set the cross-slide’s collar to zero.

            Marking: Pull the compound so the mark will be made - pull back the cross-slide – put compound back to it’s zero mark - push the cross-slide to it’s zero mark - pull compound back to make another cut - rotate work - repeat….repeat….repeat…repeat….

            A couple of reminders:

            When stamping the number just hit it once with a heavy hammer. Multiple hits cause “doubleâ€‌ marking that will ruin the work! As for how hard to hit it – you’ll learn!

            And the BEST advice: Think, Think, Think, Think before hitting that stamp. If you don’t understand what I’m referring to, just wait until that last numeral turns out upside down or backwards. (It’s always the last one by the way!)


            Last edited by Mike Burdick; 09-14-2006, 07:21 PM.


            • #7
              Oh, please protect us all from the dirty words...

              Unbelievable, the censorship police have gotten so bad they are censoring peoples names should they be so unfortunate as to contain those oh so nasty combinations of letters, and even breaking URLs in the process. What a pathetic statement that makes, it’s worse than watching network TV and seeing (or rather hearing) some lame phrase replacing a pretty innocuous and more appropriate phrase, or when they are too lazy to do that, just a gap of silence. <sigh>

              Thanks for the pics and description Mike. I've seen it before, but it's still very nice work.

              For those that can stand the terrible moral assault, you can view the pics by replacing the **** with the obvious characters from Mikes last name... <shaking head>

              Edit: I see he was forced to put them in a different directory not based on his name to get them to show.
              Master Floor Sweeper


              • #8

                Thanks! Guess that problem will always be there so I just made another photobucket account with a different name.




                • #9
                  Alistair, I don't use a hammer anymore. I use a small arbor press and the next job, will add a DTI to give uniform penetration. Works great. After impression, you take a light cut (if still on machine or perfectly centered) or use stone/abrasive paper to bring the impression "crater" down to the surface. Den


                  • #10

                    Nothing home at that PhotoBucket address....

                    One little thing about using stamps - it pays to experiment on some scrap with the blow needed. For example a '1' needs less of a blow than an '8'. The problem normally is that the '1' goes too deep.....
                    Last edited by Peter S; 09-14-2006, 07:48 PM.


                    • #11
                      Pete, thanks. I had it there in a duplicate and deleted a wrong one. It should be OK now. Thanks again. Vic


                      • #12
                        nheng, what is DTI? Thanks. Vic


                        • #13

                          There is a good reason that the word dıck is censored. It's a long story and doesn't bear repeating. It has nothing to do directly with protecting anyone here from mild obscenities.
                          Free software for calculating bolt circles and similar: Click Here


                          • #14
                            DTI is dial test indicator. Any indicator that will measure ram travel can be used. That is a good idea for measuring the depth of the stamp.

                            Another technique when using metal stamps is to stamp from right to left (Provided you are right handed and hold the stamp in your left hand and hammer in your right). That way, your fingers do not obscure the previous character, and you get a better view of the job.
                            Jim H.


                            • #15
                              See "Machinist's Workshop" April/May 2006. It dedicates a whole article to this job.