Announcement

Collapse
No announcement yet.

Quick Change Tool Post Indexing

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

  • #46
    Chamfering? I just have a block that I can load with a chamfer tool.

    Comment


    • #47
      Originally posted by npalen View Post

      Would you let me put a spring and ball in the bottom end of the stud and then lock the stud in the t-nut? This along with about three detent positions in the bottom of the t-slot?
      That would be a safer and probably less annoying option. But how would you get at the pin?

      If you used a pair of shorter set screws to lock the T nut in one of the positions you could have the set screws fit down into shallow drill point divots. That would give you the three positions.
      Chilliwack BC, Canada

      Comment


      • #48
        Starting?

        I thought he was leading the pack. And looking back at us with a grin!



        Originally posted by BCRider View Post
        Doozer, you're starting to sound like an old curmudgeon.... just like the rest of us
        Paul A.
        SE Texas

        And if you look REAL close at an analog signal,
        You will find that it has discrete steps.

        Comment


        • #49
          YES!



          Originally posted by BCRider View Post

          This is still a terrible idea. Even worse and more risky that you're thinking to rely on such a setup for positioning. You're setting yourself up to pop off one or both of your compound's T slot lips.

          Take a lesson from why T nuts on milling table clamp sets are not done that way. It's due to how when torquing the nut on the top of the stud can result in more friction in the upper nut than on the T nut. Without the staking the stud can screw through and hit the bottom of the slot and force the T nut upwards and burst the ears of the T slot. This is a very real and fairly commonly found issue in old shool lathes and milling machines. Don't set yourself up to be one of those.

          You always want the ears of the T slot to be pinched between the T nut and the bottom of the tool post by means of a captured stud that is solid in the T nut. There must never be a situation where you are pushing the stud down through the T nut and against the bottom of the slot.

          It's a grand idea to ensure that the T nut on your tool post cannot move. But you do NOT want to use the center tool post hold down stud to do double duty.
          Paul A.
          SE Texas

          And if you look REAL close at an analog signal,
          You will find that it has discrete steps.

          Comment


          • #50
            When I was designing my QC tool post I took the trouble of reading as much as I could about them and making a list of features that I wanted or, at least thought I might want. The first few at the top of the list included repeatability, solidity, and of course, quick tool changes. In looking at the various designs that people sell and have made in their shops, I came to the conclusion that there was no way that I could afford a quality one and any tool post that I was going to make in my shop was not going to have all of those features. I had to make my own and I had to pick and choose the features that I was going to have in the design and those which I was going to omit.

            So I did just that. I choose the features that I thought were the most important to my work and that I had the best chance of making to a degree of accuracy that was going to be acceptable. I knew about the 40 position, Multifix system. Frankly, I never could understand why 40 positions, every 9 degrees. Yes, it included 45 degrees, but, as others have pointed out, omitted the 30 and 60 degree positions. 24 or 48 positions seem to be much better choices because they do include 30, 45, and 60 degree positions. But then, that's me. And there are other, less well known indexing posts.

            Another thing that I saw while looking into this was that many people had extensive collections of holders, each with a different tool. I saw photos of collections of 12, 24, 36, and even some of over 50 holders. To me, and this was just me, it seemed to make more sense to forget an indexing feature that was either very expensive or difficult to make and just make more holders so that tools of various types and angles could be immediately available. And, getting back to that QUICK CHANGE thing, which this type of tool post gets it's name from, it seems a lot faster to grab and slap on a holder with a 30 degree tool than to try to figure out which of those 40 or 24 or 48 positions I need to mount a holder with a tool with a (quick calculation: Want 30 degrees / 9, 18, 27 OK that's three notches but 3 degrees short / need a holder with a 3 degree tool / but which way, +3 or -3? / etc.) OK a tool holder with a +3 degree tool.

            So I decided that a large number of indexable positions was off my list and designed my QC tool post with just ONE position for the holder to index in. Grab it, Slap it on the post. Tighten the adjustable nut I choose to use. That's about a 3 second, no tools needed holder change. I did make the holders themselves with two positions for installing tools at a 90 degree angle to each other. That does provide some flexibility when mounting the tools in the holders.

            And I have holders with turning, facing, chamfering, boring, threading, etc. tools at the ready. In use I have found that I almost never need to change the angle of the tool post.

            But that's me. And others may decide on a different mixture of features that they consider to be the best.



            Originally posted by masheenest View Post
            What's with all these plans to reposition a "QUICK CHANGE TOOL POST" ? Why not "Quickly Change" tools to one with the desired shape?
            Paul A.
            SE Texas

            And if you look REAL close at an analog signal,
            You will find that it has discrete steps.

            Comment


            • #51
              Originally posted by BCRider View Post

              That would be a safer and probably less annoying option. But how would you get at the pin?

              If you used a pair of shorter set screws to lock the T nut in one of the positions you could have the set screws fit down into shallow drill point divots. That would give you the three positions.
              What "pin" are you referring to? The pin in the external quadrant shown by the paper in the original picture? Current plan is to possibly replace that pin with a ball and spring.

              How would we get at the setscrews? Have to remove the tool post each time to change position?

              With the proposed spring and ball installed in the lower end of the stud, the only thing requiring loosening and tightening would be the nut at the top.
              Loosen the nut, slide the toolpost over to another detent and retighten the stud.

              I promise that a setscrew will be installed in the t-nut to keep the stud from bottoming in the t-slot. I will even loctite it permanent if that helps and even peen the bottom thread.

              Edit: I removed the toolpost again to examine the stud and find that the threads on the bottom end are too short to protrude thru the t-nut, so we are safe.

              This type of press-in ball plunger would be easy to install but the threaded type would give some adjustment:


              Last edited by npalen; 03-19-2023, 09:27 AM.

              Comment


              • #52
                Originally posted by Paul Alciatore View Post
                ....................................

                So I decided that a large number of indexable positions was off my list and designed my QC tool post with just ONE position for the holder to index in. Grab it, Slap it on the post. Tighten the adjustable nut I choose to use. That's about a 3 second, no tools needed holder change. I did make the holders themselves with two positions for installing tools at a 90 degree angle to each other. That does provide some flexibility when mounting the tools in the holders.

                And I have holders with turning, facing, chamfering, boring, threading, etc. tools at the ready. In use I have found that I almost never need to change the angle of the tool post.

                But that's me. And others may decide on a different mixture of features that they consider to be the best.
                So............ that seems to be trading an easy post movement for needing a lot of holders. Each tool at all the angles ? That's a lot of holders, even though not all tools need moved..

                Sure, if you needed to go get a wrench every time, yeah, but moving a lever, turning the post, and moving the lever back? Not an issue, and any angle you need is available.... you don;t HAVE TO use the detent positions if a different angle is better.

                CNC machines only go through the motions.

                Ideas expressed may be mine, or from anyone else in the universe.
                Not responsible for clerical errors. Or those made by lay people either.
                Number formats and units may be chosen at random depending on what day it is.
                I reserve the right to use a number system with any integer base without prior notice.
                Generalizations are understood to be "often" true, but not true in every case.

                Comment


                • #53
                  Originally posted by Paul Alciatore View Post
                  Starting?

                  I thought he was leading the pack. And looking back at us with a grin!


                  Originally posted by BCRider View Post

                  Doozer, you're starting to sound like an old curmudgeon.... just like the rest of us



                  I appreciate you noticing me as a leader.
                  I set my own fashion trends as well.

                  --Doozer
                  DZER

                  Comment


                  • #54
                    Originally posted by Doozer View Post
                    I set my own fashion trends as well.

                    --Doozer
                    No, please, not more of the hair shirt!
                    in Toronto Ontario - where are you?

                    Comment


                    • #55
                      Originally posted by npalen View Post
                      I'm looking at a way to allow indexing (clocking?) of my QCTP at various angles so that a turning tool, for example, can be easily rotated to a chamfering angle such as 30 or 45 degrees...
                      A dedicated tool holder with the correct chamfering tool works for me.

                      A pin sliding in a hole must have clearance. So you lose repeatability. I haven't done this, but it seems that a simple shop-made angle-setting jig (for each angle) would be much simpler and absolutely repeatable.

                      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


                      • #56
                        Originally posted by ezduzit View Post

                        A dedicated tool holder with the correct chamfering tool works for me.

                        A pin sliding in a hole must have clearance. So you lose repeatability.................
                        You assume chamfering is tha only usage that is an issue

                        Pins do not lose ANY centering..................if they are tapered. Think outside the box.
                        CNC machines only go through the motions.

                        Ideas expressed may be mine, or from anyone else in the universe.
                        Not responsible for clerical errors. Or those made by lay people either.
                        Number formats and units may be chosen at random depending on what day it is.
                        I reserve the right to use a number system with any integer base without prior notice.
                        Generalizations are understood to be "often" true, but not true in every case.

                        Comment


                        • #57
                          Originally posted by J Tiers View Post
                          ...Pins do not lose ANY centering..................if they are tapered...
                          If they slide in a hole they must have clearance, which equals a loss of repeatability. The taper can only take out the play on one of the mating parts.

                          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


                          • #58
                            Originally posted by ezduzit View Post

                            If they slide in a hole they must have clearance, which equals a loss of repeatability. The taper can only take out the play on one of the mating parts.
                            You taper ream the hole in both. It cannot "snap-in" then, but that is the trade-off for near-perfect. Outside the box!

                            Last edited by J Tiers; 03-19-2023, 05:10 PM.
                            CNC machines only go through the motions.

                            Ideas expressed may be mine, or from anyone else in the universe.
                            Not responsible for clerical errors. Or those made by lay people either.
                            Number formats and units may be chosen at random depending on what day it is.
                            I reserve the right to use a number system with any integer base without prior notice.
                            Generalizations are understood to be "often" true, but not true in every case.

                            Comment


                            • #59
                              Originally posted by J Tiers View Post

                              You taper ream the hole in both. It cannot "snap-in" then, but that is the trade-off for near-perfect. Outside the box!
                              Good luck getting them apart.
                              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


                              • #60
                                I dn't get it. Any time you change the compound, the absolute the angle of this "Thingy" is GONE, so what does a "relative" change mean anyway?? :-(
                                ...lew...

                                Comment

                                Working...
                                X