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Ball bearing Jacobs chuck

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  • Ball bearing Jacobs chuck

    I have a need to turn 3/8 bolt shafts. At this time, I am center drilling the head for the live center, turning the desired shape and then cutting the head off.

    I have a thought that I can save time and production steps if I had a Jacobs (or other drill) chuck in the tail stock that was mounted on bearings, so it rotates as does a live center. I could then cut the heads off with the saw, mount and true the bolt in the head stock, grab the free end in the rotating chuck to act as a live center and proceed with my turning to shape.

    Any comments, suggestions or otherwise are desired.

    Pops

  • #2
    Sorry, but I'm having a real hard time imagining what it is that you are doing. Have you a better description of the process and/or sketch of the part?

    I have a lot of experience in running machines with pick-off spindles and back-working tools, if that's what you are describing. Is that what you are looking to do?

    How many parts to do over what length of time, and how much do you get for them? This all helps define how you should do them.
    Last edited by PixMan; 12-17-2011, 05:08 PM.

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    • #3
      If your going to that much work, why not use a 2 1/2 or 3" scroll chuck instead of mounting a drill chuck? A lot more versitility and the cost of the chuck would be about the same as a middle of the road drill chuck.
      (about $55.00 for a 3" 3 jaw chuck from Grizzly)
      They are available ready made too, but they're spendy (500.00!)
      Here's a link to a ready made and it shows a cutaway drawing too:
      http://www.use-enco.com/CGI/INPDFF?PMPAGE=484&PMCTLG=00
      Last edited by Scottike; 12-17-2011, 05:10 PM.
      I cut it twice, and it's still too short!
      Scott

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      • #4
        If I understand your posting correctly, why not make an adapter that is socketed on one side to accept the bolt shaft and the other side slips over the end of a live center?

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        • #5
          Interesting concept- I've thought of that but never done it. One thing I would like though is to be able to spin a drill bit from the tailstock chuck, so I can rotate both the bit and the workpiece at the same time. I think that would lead to more accurate center-drilled holes.

          My thoughts on achieving this leads me to think that a custom way-mounted housing containing a motorized spindle and lever operated advance mechanism would be better than creating something to mount in the existing tailstock. If it wasn't for the sloppiness of many of the small drill press spindles, I'd go about adapting one to my lathe for this very purpose.

          What I've settled on for design is to procure a 'good' drill press spindle, then fabricate two mounts that are fitted to the bedways, then bore each mount using tooling held in the lathe chuck. These mounts are then spaced a suitable distance apart and made into one structure, then the quill is inserted through the bores and a way made to advance it using the teeth milled on the quill for that purpose. Looking at it another way, you would mate the 'head' of a drill press to your lathe. Fabricating and boring your own quill mounts however would let you control the tightness of the fit and the accuracy of the axis- both paramount conditions for making this a useful accessory for the lathe.

          As described, this is basically a second tailstock, but made for the specific purpose of spinning a drill chuck on axis with the lathe spindle, and being able to advance and retract it under lever control instead of by leadscrew.
          I seldom do anything within the scope of logical reason and calculated cost/benefit, etc- I'm following my passion-

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          • #6
            If I understand correctly, you want to be able to "grab" that loose end (so as not to put a hole in it for the point of the center?) to help with the stability...?
            Could you not accomplish the same thing by using a cup in a center that has interchangeable heads?
            There is still pressure required to hold that end on center and my understanding is a cup would do that...I guess, maybe, for that matter if the 3/8" is the only and consistent size, you could get an arbor with a machinable end (with whatever Morse taper your tailstock needs) and make a "socket" that would be slightly oversize, lube it before putting the bolt end in...

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            • #7
              I've used three bits that would accomplish your objective. First one is what Russ said -- the inverted cone in an interchangeable tip live center set. Mine's a Royal, but an import would probably do. You'd have to properly cut off the bolt head; and perhaps chamfer it as well.

              Second is a 2.5" lathe chuck adapted to the threads (1/2-20 in my case) of another interchangeable live center. No reason a regular 3 jaw chuck wouldn't work as well.

              Third is a Jacobs chuck setup meant for turning motor armatures. There's a headstock chuck that grips to around 3/4". The tailstock chuck has flat brass jaws so it acts as a steady rest. It's set as close as you can go while the part (e.g. your bolt) still rotates freely.

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              • #8
                You need an armature chuck.

                THANX RICH

                People say I'm getting crankier as I get older. That's not it. I just find I enjoy annoying people a lot more now. Especially younger people!!!
                People say I'm getting crankier as I get older. That's not it. I just find I enjoy annoying people a lot more now. Especially younger people!!!

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                • #9
                  Petem has you answer. The "live tailstock chuck" was very common in every auto electric shop. They're still out there somewhere.

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                  • #10
                    You can buy them new.

                    http://www.micromark.com/Rotating-Ta...8371.html.html

                    or here http://www.littlemachineshop.com/pro...ProductID=2504



                    If you want a real tailstock chuck, pricey.. but Bison (and others) make them. MSC, travers etc all supply them them.

                    http://compare.ebay.com/like/2608800...Types&var=sbar
                    Last edited by lakeside53; 12-18-2011, 01:19 AM.

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                    • #11
                      Originally posted by v860rich
                      You need an armature chuck.
                      I've not yet found one to buy, but I did find this, which might interest some of you.

                      http://www.youtube.com/watch?v=LZqOr-wi9Ik

                      Pops

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                      • #12
                        you might have missed post #10

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                        • #13
                          That rotating tail stock chuck is exactly what I had in mind to fab. And, both of the ones you linked fit my 2MT tailstock.

                          Thank you. I would have spent much more in time than the cost of either of those, had I tried to fab something.

                          Pops

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                          • #14
                            Originally posted by lakeside53
                            you might have missed post #10
                            Yup, I was typing as he posted. That's why I always go back and scan the thread after posting, because you guys are FAST.

                            Pops

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                            • #15
                              I just ordered the one from Little Machine Shop.

                              Again, thank you all. You helped me find what I needed and taught me some other things as well.

                              Pops

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