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  • Tell me about spindle noses

    Hi all,
    I have some other post about the threaded 1 1/2-8 spindle nose. I am thinking I got this threaded nose figured out as far as a dedicated chuck to a particular machine or, swapping to other machine,
    Please tell me about the 'others' noses,
    L-00
    D1-3
    A2-3
    Say for example, you have multiple machines all with one of the aforementioned nose, can you take chucks and swap them with various machines and they are still running true?
    When I say 'running true', please quantify in your comments:
    true <.003"
    true <.002"
    true <.001"
    true <.0006"
    true <.0003"
    true <.0002"


  • #2
    I have about 8 chucks mounted to D1-6. Many have soft-jaws installed and are can be swapped on and off the machine all day. Registration axially and radially is dead nuts on; like a couple of 10ths at the work if the work is still clamped by the chuck. I am meticulous about cleaning both the nose and chuck every time. I also use the same index position (i.e. a mark on the spindle and chuck, and tighten the stud locks odd/even to "about" the same torque (eyeball hand measure).

    Not all spindles are created equal, and same with chucks. Mine are all top quality.
    Last edited by lakeside53; 01-26-2020, 09:52 PM.

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    • #3
      Originally posted by Ringo View Post
      Hi all,
      .........................................
      L-00
      D1-3
      A2-3
      ........................, can you take chucks and swap them with various machines and they are still running true?
      When I say 'running true', please quantify in your comments:
      Yes for all
      "true" is a function of Machine manufacturer's Quality and the Quality of the Chuck
      Quality is what you pay for, so the better the machine, the better chance you have of utmost accuracy.

      I read your other post and didn't answer as i didn't understand some of your comments.
      Threaded Spindles have been around for ages and there are some serious misconceptions that persist because some famous machinists have made assertions that are not correct.
      Please be aware that -There is no "Registration"
      Accurate and repeatable chuck centering on a Threaded Spindle is based on Accurate threads ground on the spindle and a "Face " for the chuck plate to stop against
      It is imperative that when the threads are cut in a chuck plate, that the rear "Face" of the chuck plate be machined at the same time !!!! --- without removing the work piece. !
      This is what determines the repeatability of the chuck.
      If your spindle nose is buggered, it will prevent accurate repeatability
      Rich

      PS , My Buck Chuck and Pratt Bernard repeat and are within .0002" and know this ...the 6 jaw Buck Chuck has a C'Bore that is .025" larger than the so called register ...and came that way
      Last edited by Rich Carlstedt; 01-26-2020, 09:58 PM.
      Green Bay, WI

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      • #4
        Ringo
        What you need to do is Blue the threads and spin a back plate or face plate on and off and see what you have
        A high spot will show up. you want to see even marks and keep the top of the spindle orientation marked with a felt tip beforehand.
        Rich
        Green Bay, WI

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        • #5
          I started this thread in regards to tapered spindle, not threaded.
          Can you take a chuck (tapered mount) and swap it to another machine, and it run true?
          Last edited by Ringo; 01-27-2020, 07:50 AM.

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          • #6
            Originally posted by Ringo View Post
            I started this thread in regards to tapered spindle, not threaded.
            Can you take a chuck (threaded mount) and swap it to another machine, and it run true?
            It should... but its not as likely as with the other chuck mounting interfaces.

            Threaded parts leave lots of options where and how they actually contact. Cylindrical or tapered mount leaves less uncertainty and is a LOT easier to check with dykem/engineers blue.
            Location: Helsinki, Finland, Europe

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            • #7
              Sorry, I had to correct my post #5.
              #5 is edited, should read in reference to tapered

              "I started this thread in regards to tapered spindle, not threaded.
              Can you take a chuck (tapered mount) and swap it to another machine, and it run true?"

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              • #8
                Originally posted by Ringo View Post

                Can you take a chuck (tapered mount) and swap it to another machine, and it run true?"
                Most likely.
                Still possibility that one lathe has bent spindle and backing plate is machined in-situ but that should be a obvious if you run dial gauge against the taper surface.
                With threaded spindle its at least 10 times harder to check for run-out.

                I'd expect less than 0.01mm or 0.0004" runout on good quality lathe spindle taper. Mix and match chucks between two machines and you might have 0.02mm 0.0008" run-out in worst-case.
                Last edited by MattiJ; 01-27-2020, 08:13 AM.
                Location: Helsinki, Finland, Europe

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                • #9
                  The D1-X series will swap just fine. I can barely see any needle movement on the spindle taper of my Victor 1660 with a tenths indicator (<0.0001"), so the runout will be a function of the chuck. If your spindle has that low of a runout, then the installed position shouldn't matter, otherwise you may need to try a few different positions for the camlocks to get the lowest runout. Once you find that position, mark it.

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                  • #10
                    I fully understand interest in how well chucks reseat truly after removal and replacement.
                    However, I am a bit puzzled as to WHY chucks would be exchanged between machines. In a lifetime working as a machinist/ mechanic I do not believe I ever saw it done.
                    As a hobbyist I have occasionally purchased odd used chucks, and some new ones, again I do not remember ever arranging or expecting that a chuck could be exchanged between machines, nor doing it even when I have had two or more machines with the same nominal spindle noses,
                    When I am choosing which lathe to use for the job in hand it is the capacity and capability of the machine which most influences my decision, not the type or size of the chuck which happens to be on the mandrel while I am figuring out the machining sequence.
                    I am a relative youngster, just coming 70. thanks to arthritis I find chuck changing a task I would rather avoid if possible.
                    Regards to all, Have fun, work safe, David Powell.

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                    • #11
                      When you mean "runout" you're asking about runout of the body of the chuck. Not a piece held in the chuck. At least I hope so since self centering scroll chucks are notorious for not consistently and accurately centering the work held in them. Anything within a couple of thou is generally considered to be very nice.

                      When I made my 5C collet chuck to fit my threaded nose I followed the procedure mentioned by Rich and the thread, the counterbore and the register face were all done with one hold on the part. Then the chuck was turned around and put onto the threaded nose of the lathe and the running surfaces for the 5C collets was all done with one seating. After it was done I unmounted and remounted the chuck body about 8 or 10 times and checked the runout of the tapered mouth that would receive the collets. The runout at each mounting was at worst within a tenth or two with a lot of the tests being less than I could reliably see. Just the usual needle jitter as it runs on any part when turning it.

                      So threaded spindles can re-center very accurately if given a chance and the mountings on the chucks are done correctly for each case.

                      All the other options with tapers or camloc also have very specific tight design specifications. An issue with threaded spindles is that there never was any standards. So with those one would need to do some checking beforehand to be sure that one mountable item did not foul or lock against some feature other than the flat registration face on the spindle.
                      Chilliwack BC, Canada

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                      • #12
                        I would not expect exact interchangability, say between camlock chucks on different machines. I would expect one combination to be slightly superior, but inside the acceptable limits.
                        I would not expect it to be common for swapping of chucks and faceplates between machines, so very few people would ever be in a position to find out.
                        I use a Smart & Brown model A which has a 1 3/4 X 8W threaded spindle and was lucky to get a very good 9" faceplate for it on ebay. It got screwed on and a tool set up to give it a skim, when something prompted me to check the runout with a dti. It had a runout of 0.0005" tir, and I saved myself the bother of skimming the face.

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                        • #13
                          Originally posted by David Powell View Post
                          I fully understand interest in how well chucks reseat truly after removal and replacement.
                          However, I am a bit puzzled as to WHY chucks would be exchanged between machines. In a lifetime working as a machinist/ mechanic I do not believe I ever saw it done.
                          I have two lathes and a couple of rotary tables. Big lathe is threaded spindle and small one uses chucks with a plain back. Between them I have 6 chucks. There are times that I'd like to throw the er32 chuck (Morse taper mount) from the small lathe on the bigger one. That works out fine since both have the same spindle taper. Occasionally I wish I could mount the 5 inch chuck from the bigger lathe on my smaller one. I have a DRO on the smaller one as well as variable speed so it's sometimes a better choice.

                          As I type this I realized that I can make a threaded spindle for the smaller lathe out of an MT3 stub arbor. Once that's in place I can screw the chucks from the bigger lathe onto it. Might consider doing that.
                          At the end of the project, there is a profound difference between spare parts and left over parts.

                          Location: SF East Bay.

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                          • #14
                            The big advantage of having backplates between the spindle and the chuck, is that the backplates can stay with the different lathes and have their face machined to share one particular chuck. That way, it is easy to use a favourite chuck on more than one machine.

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