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  • #16
    Originally posted by ezduzit View Post
    By "it" I was referring to the workpiece. ie there's no reason to check runout in the chuck as that doesn't move. Yes, of course you center the needle on the workpiece. But then you simply run the carriage back and forth to check taper.
    That won't work either. If the piece being used as the "standard" and the indicator fingers are not both on center then the final angle setting will be off. To cut a taper that matches EVERYTHING from the standard used to set the taper, the indicator used to check for runout and the cutting edge all have to be dead nutz on center height. Any one of these being out will result in the wrong taper on the final work.
    Chilliwack BC, Canada

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    • #17
      Originally posted by BCRider View Post
      That won't work either. If the piece being used as the "standard" and the indicator fingers are not both on center then the final angle setting will be off...
      Yes, it will work. As I said, "...you center the needle on the workpiece." That is all the setup you need to do to find taper.
      12" x 35" Logan 2557V lathe
      Index "Super 55" mill
      18" Vectrax vertical bandsaw
      7" x 10" Vectrax mitering bandsaw
      24" State disc sander

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      • #18
        Why would you not take the time to accurately center the reference standard? I'll grant you that you can set the angle without a centered reference if the gauge finger is centered on the reference. But if the chuck turns at all? Now you're not centered up anymore. Just seems like a risky shortcut which could bite you in the backside when it only takes a couple of minutes more to center up the reference correctly.
        Chilliwack BC, Canada

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        • #19
          I don't understand "center the needle". Do you mean center the contact point of the indicator on a properly centered workpiece?
          Jim

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          • #20
            you can shank out a test indicator, or use use of those bent wire tips on a plunger indicator to dial in the compound to a male master taper. No need for it to be on center vertically in that case.

            Originally posted by BCRider View Post
            I think the worst would be a taper for an ER chuck. The collets are too springy to use as a master for setting the angle unless they are "sprung" over something like a piece of proper size drill rod. And then I wouldn't be sure that the collet was not spread more than what is nominal for it or that it was seated correctly along the full length.
            When I made my er25 collet holder I made small male masters first (made a er16, 25, and 32). Checking them against new or like new collet holders. From there it was easy to double check the female socket of the holder I was making and adjust to get perfect contact. I should add this was done with a CNC lathe but the principal is the same. Set the angle (program), cut a part, check contact, and adjust to suit.

            If you slid an er collet onto a shaft that was a bit bigger than the nominal collet size, I bet it would hold it snug enough to be able to dial in your compound to the correct angle. Friction should hold it tight enough.
            Last edited by Dan Dubeau; 11-12-2017, 07:45 PM.

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            • #21
              Originally posted by BCRider View Post
              ...But if the chuck turns at all?...
              The pressure of the indicator needle in the tapered bore is certainly not enough to turn the chuck.
              12" x 35" Logan 2557V lathe
              Index "Super 55" mill
              18" Vectrax vertical bandsaw
              7" x 10" Vectrax mitering bandsaw
              24" State disc sander

              Comment


              • #22
                Use an indicator to check the change in diameter over a known distance. To do this the easiest way is to center the indicator in the bottom of the taper. Run the cross slide in and out and the smallest reading on the indicator is the lowest point aka "on center". A Starrett 670 hole attachment would be handy here. Then run the carriage in/out with 2nd indicator on the bed. You now have the change in radius over a known distance.
                Mike
                Central Ohio, USA

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                • #23
                  Originally posted by loose nut View Post
                  .................................................. .......................... So is the only way to do it, turn a a male taper and shove it into the female taper and then measure across the interface between the too???
                  Is there a simpler way???............................................ ....................................

                  Part 2.

                  Adjusting the top slide to the right taper. I can measure the taper angle accurately with a DRO function but then to set the angle you loosen and tap the slide, then remeasure and repeat the tapping and so on and so on etc. always missing the mark. Is there a way to adjust the top slide and get it correct without the trial and error method.........................................
                  Yes Loose Nut----There are other ways.
                  1.
                  You need to make a taper measurement tool...and it's rather simple...let me throw out some imaginary numbers
                  say the tapered bore goes from 9/16 to 13 /16 . You want two disks mounted on a threaded rod.
                  get a 1/4 inch threaded rod, say 4 inches long and CAREFULLY center-drill both ends. now make two round disks that are bored/drilled to slide on the threaded rod, but no slop .. but first mount them on a threaded rod stub in the lathe and turn them to diameter ( 5/8 and 3/4 ie) leaving SHARP EDGES ( BUT NO BURR ) they can be 1/4'"thick, or 1/8" or whatever, just have a clean sharp edge.
                  Take 4 nuts and put two in the middle of the rod, then place the small disk on one end and capture it with a nut on the end and one of the middle nuts,
                  Place the tool into the bore to be measured, and the small disk will bottom on the taper,. now place the larger disk in the bore and follow it with a nutand snug it up against the large disk. Remove the tool and run the middle nut up to the big disk.. You now have a accurate measurement by measuring the front edge distance between the disks. You ,may want to play with it a bit, but you get the drift. Having the rod center-drilled allows you to use it between centers
                  This tool is neat, because you get to measure a bore you wish to match or the one you are working on and it can be used to set your tool-slide as well or between centers.

                  2.
                  For setting tapers easily, you need to rework your tool-slide ( On some lathes !) I have on mine.
                  Take the tool-slide off. You can mill it, but grinding is better. Set the positive side of the dovetail surface on a dowel pin and grind the outside parrallel and perpendicular to the positive side, then flip and grind the other side, Now you have a tool-slide with perfectly parrallel surfaces to the way surface.
                  To do a taper, I clamp a ground piece of flat stock ( say 1/4 x 6 x 6 ) to the side of the slide with a C clamp and swivel it against the form which is chucked in the lathe . My tool-slide EXACTLY matches the taper as I clamp the slide. Remove the plate and cut your work......so fast and no hunting at all.

                  Hint #3 if you do not want to do # 2 above, clamp a temporary bar of about 18" in length to the tool slide. use the end for leverage to get very small movement of the slide. keeps the slide from jumping too !

                  Rich

                  I like my disks to be about 3/8" to 1/2" thick. Part off drill rod and clean the OD as size means nothing !

                  Be careful using aluminum (no-no) as it can wedge and give a false reading
                  Last edited by Rich Carlstedt; 11-12-2017, 09:21 PM.
                  Green Bay, WI

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                  • #24
                    I've been earning my living doing it this way for 60 years this is the fastest and easiest method that I have found[IMG]


                    Sent from my iPhone using Tapatalk
                    Last edited by Edwin Dirnbeck; 11-13-2017, 11:11 AM.

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                    • #25
                      I have been earning my living doing it this way for 60 years this is the fastest and easiest method that I have found[IMG]]


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                      • #26
                        I have been earning my living doing it this way for 60 years it is the fastest and easiest method that I have found


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                        • #27
                          For angles closer to 90°


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                          • #28
                            You can also use Edwin's method on the side of the tailstock ram.

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                            • #29
                              More options

                              Originally posted by Erich View Post
                              You can also use Edwin's method on the side of the tailstock ram.
                              Yes indeed. any machined surface that is parallel with or perpendicular to the ways can be used. Also you can get a little
                              better accuracy if you use 2 or 3 inch compound travel.Just double or triple your indicater movement value. JUST REMEMBER WHEN USEING THE COMPOUND TRAVEL METHOD ,USE THE SIN YES THE SIN OFTHE ANGLE. Good luck Edwin Dirnbeck

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                              • #30
                                rich, i didnt get no. 2.

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