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Upgrading my boring head arbor (might be helpful for you as well)

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  • Upgrading my boring head arbor (might be helpful for you as well)

    Today, i was gonna make a motor plate for my other project,

    everything was going well,,, until i had to bore 26mm diameter hole

    the boring head i had was fine, and the boring bar as well,

    the problem was the excessive overhang caused by the TTS-ER20 chuck and the boring head connection arbor.

    I decided to make a 19mm shank that directly fits the collet(TTS) therefore removing about 9cm.

    this will improve rigidity, precision, and workable Z axis space.

    for those having the same problem as i, I really recommend this upgrade

    before: ........ i know it looks horrible XD....



    After: yup, looks very simple.


    making process video:
    https://youtu.be/MNLz56nVJX8

  • #2
    Nice job. And it looks like I gave you the first "like" too for the video....

    Shortening and tightening up the spacing for the tooling to reduce overhang is often a huge factor in reducing chatter potential and also improving accuracy. And I like how you made the threading so it went right down into the body of the head so you don't even have the slight shoulder that a seating flange would have produced..... but it's possible that this is also your source of the runout you saw. the outer rim around the threading is faced on the boring head. The base of the recess is not given any particular attention because it's not intended to be the register facing. I'll bet that's the cause of your runout. This is purely 20-20 hindsight from watching your video since I would likely have done it the same way as you did for the same reasons. But I wonder if leaving a small center bump on the face of the threaded end would have allowed the threading to do the centering and aligning to a better degree by only touching the base of the recess in the center. Mind you as you said in the video it's a boring head so a touch of runout means absolutely zip all. But it might be interesting for some other time if the head can be unscrewed from the adapter easily enough to glue a small washer sized piece of thin shim stock to the center of the adapter's face and see if it centers up a bit better if you're curious to see if it was a factor or not.

    A couple of things if I may. For the video we don't need to see the bandsawing other than perhaps just as a first passing step done all in fast forward. That'll speed things up. Adding in the thread pitch you determined as a voice over or on screen text might also help someone looking to do the same thing by saving them a bit of time. And it's a nice bit of "hard information" to add to the video. Other than these two things I thought the video was pretty nicely done for someone that's not a profesional YT entertainer such as folks like Old Tony and Abom and others like them. And clearly the camera you used is a good one. I felt like I could reach through the monitor and pick up some of the swarf it was so clear...

    The big take away though is still the reduction in overhang to both stiffen up your tooling and to get back precious Z room. And you certainly got both of those. So yeah, nicely done.

    On the machining side a comment on the HSS tool. It sure looks like you used it just as it came. But those tool bits are just blanks. You need to grind the front, side and top angles into them to form the required relief angles and prepare the cutters before the first use. And with that sort of proper shaping you won't be limited to wisker thin cuts. There's lots of good videos on doing that. In particular the one by Old Tony that even starts with the tool as it comes out of the wrapper..... https://www.youtube.com/watch?v=__A2xtLF0AU
    Last edited by BCRider; 02-15-2019, 02:19 PM.

    Comment


    • #3
      Originally posted by BCRider View Post
      Nice job. And it looks like I gave you the first "like" too for the video....

      Shortening and tightening up the spacing for the tooling to reduce overhang is often a huge factor in reducing chatter potential and also improving accuracy. And I like how you made the threading so it went right down into the body of the head so you don't even have the slight shoulder that a seating flange would have produced..... but it's possible that this is also your source of the runout you saw. the outer rim around the threading is faced on the boring head. The base of the recess is not given any particular attention because it's not intended to be the register facing. I'll bet that's the cause of your runout. This is purely 20-20 hindsight from watching your video since I would likely have done it the same way as you did for the same reasons. But I wonder if leaving a small center bump on the face of the threaded end would have allowed the threading to do the centering and aligning to a better degree by only touching the base of the recess in the center. Mind you as you said in the video it's a boring head so a touch of runout means absolutely zip all. But it might be interesting for some other time if the head can be unscrewed from the adapter easily enough to glue a small washer sized piece of thin shim stock to the center of the adapter's face and see if it centers up a bit better if you're curious to see if it was a factor or not.

      A couple of things if I may. For the video we don't need to see the bandsawing other than perhaps just as a first passing step done all in fast forward. That'll speed things up. Adding in the thread pitch you determined as a voice over or on screen text might also help someone looking to do the same thing by saving them a bit of time. And it's a nice bit of "hard information" to add to the video. Other than these two things I thought the video was pretty nicely done for someone that's not a profesional YT entertainer such as folks like Old Tony and Abom and others like them. And clearly the camera you used is a good one. I felt like I could reach through the monitor and pick up some of the swarf it was so clear...

      The big take away though is still the reduction in overhang to both stiffen up your tooling and to get back precious Z room. And you certainly got both of those. So yeah, nicely done.

      On the machining side a comment on the HSS tool. It sure looks like you used it just as it came. But those tool bits are just blanks. You need to grind the front, side and top angles into them to form the required relief angles and prepare the cutters before the first use. And with that sort of proper shaping you won't be limited to wisker thin cuts. There's lots of good videos on doing that. In particular the one by Old Tony that even starts with the tool as it comes out of the wrapper..... https://www.youtube.com/watch?v=__A2xtLF0AU
      oh, thank you dear, for detailed response!
      what's happening inside the body of the boring head is, the arbor face is not even touching the recess (of the boring head internal face).
      there's some precision @ internal face, so i thought putting a precision washer to fill the gap might help register better(face-wise).

      i think a small center bump wont help, because the center part of the internal face is not machined accurately.
      however, the outer part of the inner face looks to be machined accurately. and that's where i am going to register.

      one thing good about the arbor i made, the arbor registers the spindle nose.
      you can't see it very well in the vid, but there is accurate register.
      so we know inaccuracy was not coming from there.

      the thread was machined in such way, that the thread alone will tighten the parts (without face registering).
      this means, i think, at least axially, it is as accurate as it gets (axially), the error must be coming from... the non-face registering problem.
      i will fix that tomorrow and post a detailed review on this forum.

      i will indeed try to speed up a bit. i am quite a novice when it comes to video editing. i really appreciate your positive feedback.
      i am happy to hear the camera is ok,
      i was afraid it lacked quality.
      i am soon planning to get a better camera for even more clear footage and close ups.

      As for the HSS tool, thank you for letting me know, i thought blanks were capable of machining out of the box
      they seem to have some grinding in them,
      but i will have to educate myself about them.

      thank you again for your sharp observation, i hope i could steadily improve my skills.
      Last edited by dovidu; 02-15-2019, 03:19 PM.

      Comment


      • #4
        You're welcome. I look forward to seeing more of your videos.

        You're the one that has the stuff on hand to see what is what. And it sounds like you got it figured out. My thinking about the base of the recess was based on seeing the same recess on my own boring head when I installed a commercial R8 arbor a few years back.

        Old Tony isn't the only one out there with videos on grinding lathe tools either. There's quite a few actually. And some of the shapes will be somewhat different. But in the end they all have front, end, back and side rake angles to allow cutting into the material more effectively and with less drag.

        Comment


        • #5
          Why go to the trouble of making an adapter when you can buy an arbour for the boring head that
          is a direct fit in your spindle. A 1-1/2"-18 thread is about as common as dirt on boring heads and
          can be had with any spindle mount you might need. The arbours are made with a shoulder on the
          outside so the back face of the boring head registers against that. It would make an even more
          rigid and compact setup...
          Keith
          __________________________
          Just one project too many--that's what finally got him...

          Comment


          • #6
            Well thats a read, and you all know me. Not the most proficient reader.

            I only had a question, is the TTS a proprietary taper, like a jarno. JR
            My old yahoo group. Bridgeport Mill Group

            https://groups.yahoo.com/neo/groups/...port_mill/info

            Comment


            • #7
              Well, it's a hobby, right? So doing it himself is part of the fun and learning.

              JR, TTS is the Tormach system of arbors where a special R8 collet with a short flat nose is used with a straight shank arbor. The shoulder of the arbor is pushed up tight to the nose of the spindle and then the collet drawn up. As it tightens on the parallel shank it pulls the shoulder up tight to the spindle. So the idea is that it has the wider footprint for less flexing. It's a pretty smart system actually. It would be especially nice for a large diameter extended spindle for things like slitting saws or for where we need to reach down past a feature where the main spindle or parts of the work would be in the way.

              Google for "tormach tts diagram" and then study the images. Pretty nice setup.

              Comment


              • #8
                Actual TTS is by Tormach and IIRC is just a 3/4" straight shank and a shoulder to register it against a surface on the collet holder. I don't know if the OP actually has that or something "similar".

                https://littlemachineshop.com/images...ing_System.pdf
                1601

                Keep eye on ball.
                Hashim Khan

                Comment


                • #9
                  i've done the mod, now the runout 0.01~0.02mm
                  i can confirm that registering the face will increase accuracy, coupled with accurate tight thread.
                  the shaving on the finger is result of tight fit slicing some of the ring off.



                  Comment


                  • #10
                    Originally posted by J Tiers View Post
                    Actual TTS is by Tormach and IIRC is just a 3/4" straight shank and a shoulder to register it against a surface on the collet holder. I don't know if the OP actually has that or something "similar".

                    https://littlemachineshop.com/images...ing_System.pdf
                    yes indeed,
                    the arbor is registering the spindle nose, but not the boring head body.

                    Comment


                    • #11
                      Originally posted by J Tiers View Post
                      Actual TTS is by Tormach and IIRC is just a 3/4" straight shank and a shoulder to register it against a surface on the collet holder. I don't know if the OP actually has that or something "similar".

                      https://littlemachineshop.com/images...ing_System.pdf
                      i have 6 er20 tts holders, they are good except its design is unnecessarily long, about 10mm extra. other then that it's fine

                      Comment


                      • #12
                        For some reason none of your pictures show up for me. Just tiny square outlines.

                        Firefox latest version. Only your pictures seem to be like that, all others appear normally.
                        1601

                        Keep eye on ball.
                        Hashim Khan

                        Comment


                        • #13
                          I am missing something, please advise.
                          How did you get a straight shank arbor into the spindle. At least it looks like that to me.
                          Does your mill spindle have a morse taper or R8 taper, and you put a straight shank in there?
                          You did remove a ER20 chuck, correct?

                          Comment


                          • #14
                            Originally posted by BCRider View Post
                            Well, it's a hobby, right? So doing it himself is part of the fun and learning.

                            JR, TTS is the Tormach system of arbors where a special R8 collet with a short flat nose is used with a straight shank arbor. The shoulder of the arbor is pushed up tight to the nose of the spindle and then the collet drawn up. As it tightens on the parallel shank it pulls the shoulder up tight to the spindle. So the idea is that it has the wider footprint for less flexing. It's a pretty smart system actually. It would be especially nice for a large diameter extended spindle for things like slitting saws or for where we need to reach down past a feature where the main spindle or parts of the work would be in the way.

                            Google for "tormach tts diagram" and then study the images. Pretty nice setup.
                            it's pretty clever, tool change is easier, although there is less wear to the spindle and less chance of microscopic chips entering the spindle,
                            it does wear a small bit.

                            one down side is as opposed to using just R8 collet alone, you sacrifice additional 0.01mm accuracy,
                            so TTS + Er20 for example will have 0.01~0.02mm run out.

                            another downside is you sacrifice some rigidity. R8 collet is shorter overall, thus more rigidity.

                            using just R8 collet will be a bit more accurate, although tool change and spindle wear is greater.

                            but these two sacrificed for convenience and time

                            i think it's worth it.

                            Comment


                            • #15
                              Originally posted by JRouche View Post
                              Well thats a read, and you all know me. Not the most proficient reader.

                              I only had a question, is the TTS a proprietary taper, like a jarno. JR
                              you can use TTS if you have R8 collet.

                              you could also convert your mill into auto tool changer by using TTs + pneumatic system.

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