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Re: [atlas_craftsman] Re: Can I do this on my lathe?

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  • Jon Elson
    ... Not at all. I have often threaded small parts with a die in a die handle. I usually do this under hand power, but sometimes run the motor with the belt
    Message 1 of 29 , Dec 31, 2006
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      joegourlay wrote:

      >3. Thread (die)--of course, this means I need you all to tell me how
      >to hold the die in the tail stock (don't you always want to spin the
      >work against a stationary cutting tool?)
      >
      >
      Not at all. I have often threaded small parts with a die in a die
      handle. I usually
      do this under hand power, but sometimes run the motor with the belt
      loose, and
      once the die is threaded onto the piece straight, I'll blip the belt
      handle for just a
      second, then stop the chuck at the right point with my hand on the
      smooth part
      of the chuck's OD. The problem with this is getting the die started
      straight on the
      work. They always want to start crooked. That's why a die holder in
      the tailstock
      is better. But, the die handle is a LOT faster.

      A die applies even forces to the work, so it won't bend the thin part.

      And, there's really no reason you couldn't spin the die against a
      stationary part, the
      metal can't tell the difference. I don't think it would help in this
      case. But, you might
      at least think about putting the die in the chuck, the work held loosely
      in a jacob's driill
      chuck in the tailstock. Either let the Morse taper stay loose and
      hand-hold the jacob's
      chuck, or leve the jacob's chuck loose so the part can slide axially in
      the jaws. This
      might be the fastest way to thread the piece. Actually, I like the idea
      of leaving the
      morse taper loose. When the part is threaded to full depth, the Jacob's
      chuck slips
      in your hand. Stop and reverse the lathe, and it screws back out of the
      die. Change
      part, and do it again. I think you could do these in under 30 seconds,
      mostly changing
      the piece in the Jacob's chuck.

      Jon
    • joegourlay
      Jon, I just posted a request for sourcing help in a separate message for the hex stock. I assume that s going to get some hits. Two questions, however. 1.
      Message 2 of 29 , Jan 1, 2007
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        Jon,

        I just posted a request for sourcing help in a separate message for
        the hex stock. I assume that's going to get some hits. Two
        questions, however.

        1. This will be used for the points on a marking gauge for wood. The
        points need to stay pointy for a long, long time despite their use in
        hard, abrasive, silica bearing woods. What type of alloy would you
        suggest? I can't decide between "toughness but less wear resistance"
        like 1045 or 1060 and "hard as hell but brittle" like 1095. Where does
        O1 fall? What do you think?

        2. If I can't find suitable hex stock, what else can I do on little
        bitty parts like this so that they can be tightly threaded into a
        tapped brass receiving block and then subsequently removed for
        sharpening? The reason for the hex stock was to allow use of a small
        crescent wrench for installation and extraction. Were these bigger
        parts, I could see using round stock and using my milling attachment
        to mill in flats. But I can't even image how to hold 1/16" round
        stock in that attachment, let alone mill a flat into when it's that
        small. I could file a flat, but I think it would come out not very
        professional looking, and I may want to start selling these. What do
        you suggest?

        --- In atlas_craftsman@yahoogroups.com, Jon Elson <elson@...> wrote:
        >
        > joegourlay wrote:
        >
        > >3. Thread (die)--of course, this means I need you all to tell me how
        > >to hold the die in the tail stock (don't you always want to spin the
        > >work against a stationary cutting tool?)
        > >
        > >
        > Not at all. I have often threaded small parts with a die in a die
        > handle. I usually
        > do this under hand power, but sometimes run the motor with the belt
        > loose, and
        > once the die is threaded onto the piece straight, I'll blip the belt
        > handle for just a
        > second, then stop the chuck at the right point with my hand on the
        > smooth part
        > of the chuck's OD. The problem with this is getting the die started
        > straight on the
        > work. They always want to start crooked. That's why a die holder in
        > the tailstock
        > is better. But, the die handle is a LOT faster.
        >
        > A die applies even forces to the work, so it won't bend the thin part.
        >
        > And, there's really no reason you couldn't spin the die against a
        > stationary part, the
        > metal can't tell the difference. I don't think it would help in this
        > case. But, you might
        > at least think about putting the die in the chuck, the work held
        loosely
        > in a jacob's driill
        > chuck in the tailstock. Either let the Morse taper stay loose and
        > hand-hold the jacob's
        > chuck, or leve the jacob's chuck loose so the part can slide axially in
        > the jaws. This
        > might be the fastest way to thread the piece. Actually, I like the
        idea
        > of leaving the
        > morse taper loose. When the part is threaded to full depth, the
        Jacob's
        > chuck slips
        > in your hand. Stop and reverse the lathe, and it screws back out of
        the
        > die. Change
        > part, and do it again. I think you could do these in under 30 seconds,
        > mostly changing
        > the piece in the Jacob's chuck.
        >
        > Jon
        >
      • Bill Lee
        What overall space do you have to work with? Perhaps using a larger diameter stock and then only machining two flats would work. I.e., 1/4 diameter with two
        Message 3 of 29 , Jan 1, 2007
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          What overall space do you have to work with? Perhaps using a larger
          diameter stock and then only machining two flats would work. I.e., 1/4"
          diameter with two flats and the rest per your previously-stated needs
          (pointy and threaded).

          Bill Lee

          joegourlay wrote:
          > Jon,
          >
          > I just posted a request for sourcing help in a separate message for
          > the hex stock. I assume that's going to get some hits. Two
          > questions, however.
          >
          > 1. This will be used for the points on a marking gauge for wood. The
          > points need to stay pointy for a long, long time despite their use in
          > hard, abrasive, silica bearing woods. What type of alloy would you
          > suggest? I can't decide between "toughness but less wear resistance"
          > like 1045 or 1060 and "hard as hell but brittle" like 1095. Where does
          > O1 fall? What do you think?
          >
          > 2. If I can't find suitable hex stock, what else can I do on little
          > bitty parts like this so that they can be tightly threaded into a
          > tapped brass receiving block and then subsequently removed for
          > sharpening? The reason for the hex stock was to allow use of a small
          > crescent wrench for installation and extraction. Were these bigger
          > parts, I could see using round stock and using my milling attachment
          > to mill in flats. But I can't even image how to hold 1/16" round
          > stock in that attachment, let alone mill a flat into when it's that
          > small. I could file a flat, but I think it would come out not very
          > professional looking, and I may want to start selling these. What do
          > you suggest?
          >
          > --- In atlas_craftsman@yahoogroups.com, Jon Elson <elson@...> wrote:
          >> joegourlay wrote:
          >>
          >>> 3. Thread (die)--of course, this means I need you all to tell me how
          >>> to hold the die in the tail stock (don't you always want to spin the
          >>> work against a stationary cutting tool?)
          >>>
          >>>
          >> Not at all. I have often threaded small parts with a die in a die
          >> handle. I usually
          >> do this under hand power, but sometimes run the motor with the belt
          >> loose, and
          >> once the die is threaded onto the piece straight, I'll blip the belt
          >> handle for just a
          >> second, then stop the chuck at the right point with my hand on the
          >> smooth part
          >> of the chuck's OD. The problem with this is getting the die started
          >> straight on the
          >> work. They always want to start crooked. That's why a die holder in
          >> the tailstock
          >> is better. But, the die handle is a LOT faster.
          >>
          >> A die applies even forces to the work, so it won't bend the thin part.
          >>
          >> And, there's really no reason you couldn't spin the die against a
          >> stationary part, the
          >> metal can't tell the difference. I don't think it would help in this
          >> case. But, you might
          >> at least think about putting the die in the chuck, the work held
          > loosely
          >> in a jacob's driill
          >> chuck in the tailstock. Either let the Morse taper stay loose and
          >> hand-hold the jacob's
          >> chuck, or leve the jacob's chuck loose so the part can slide axially in
          >> the jaws. This
          >> might be the fastest way to thread the piece. Actually, I like the
          > idea
          >> of leaving the
          >> morse taper loose. When the part is threaded to full depth, the
          > Jacob's
          >> chuck slips
          >> in your hand. Stop and reverse the lathe, and it screws back out of
          > the
          >> die. Change
          >> part, and do it again. I think you could do these in under 30 seconds,
          >> mostly changing
          >> the piece in the Jacob's chuck.
          >>
          >> Jon
          >>
          >
          >
          >
          >
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        • jerdal
          ... From: joegourlay To: Sent: Sunday, December 31, 2006 3:48 PM Subject: [atlas_craftsman] Re:
          Message 4 of 29 , Jan 1, 2007
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            ----- Original Message -----
            From: "joegourlay" <jgourlay@...>
            To: <atlas_craftsman@yahoogroups.com>
            Sent: Sunday, December 31, 2006 3:48 PM
            Subject: [atlas_craftsman] Re: Can I do this on my lathe?


            > Jerdal, another follow up question.
            >
            > Instead of threading with a tool, what about using the die, but
            > threading a longer length? This would mean a lot of wasted
            > material, but the material is pretty cheap compared to the time
            > (esp. w/learning curve). Would this work?
            >
            > Also, is material this thin going to want to bend or whip under the
            > pressure of cutting/parting? Should I use a center in the tailstock
            > as support?

            The problem is how close you can or need to get to the shoulder. I don't
            think you said what thread you were doing. A longer part is no problem to
            thread, but it doesn't put threads up to the shoulder any better.

            If I have your part pictured right in my mind, whip/deflection won't be a
            big problem.

            You would work as close to the chuck/collet as possible. With minimal
            stickout, turn the thread area, and thread, then loosen holder and move out
            the stock to cut off and point.

            Instead of a formed cutoff tool, you could set the compound to the angle of
            the point, and "turn" it off as a partoff means also, working back towards
            the chuck.... less force on teh part sticking out.. That has less force
            against the work, and re-reading, you have a rather long point... more so
            that I thought at first read..

            or you could reverse it, parting the point off with the point on the end of
            the stock, but then you have to cut the threads. If you have a lot to do,
            that could be an issue, a die is much faster if you can do it. Of course if
            your die won't get close enough to the shoulder it makes no difference.

            What is the thread?

            JT





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          • jerdal
            I got annoyed, and decided to try it. The link shows what I made similar to your part. I had a lot of trouble getting the camera to focus on it, I finally gave
            Message 5 of 29 , Jan 1, 2007
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              I got annoyed, and decided to try it.

              The link shows what I made similar to your part. I had a lot of trouble
              getting the camera to focus on it, I finally gave up and that is what you
              get.....

              http://img.photobucket.com/albums/0803/jstanley/point2.jpg

              The problem is the threading vs cutoff.

              This stock breaks off (annealed hex key) before the point is sufficiently
              formed. I suppose it might be OK, depending on your needs, but I doubt ANY
              cutoff OR pointing operation will get a truly sharp point if you want it
              sharp like a knife is sharp.

              Also,it needs a "box tool" probably, to hold it steady against cutting
              force. I doubt that turning it around would help a lot, but it might allow
              you to point it after a separate cutoff operation.

              However, turning around also makes threading a separate operation with a
              threading tool, not a die.

              A different steel would probably work better. But sharpening the point
              might be needed separately even so, for a pin-point tip.

              JT



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            • joegourlay
              Excellent! That s exactly what I m thinking about! I think the point you have is fine. I plan on making a jig of some kind that allows precision
              Message 6 of 29 , Jan 1, 2007
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                Excellent! That's exactly what I'm thinking about! I think the point
                you have is fine. I plan on making a "jig" of some kind that allows
                precision sharpening of the tip on a grinder. So the rounded tip you
                have is fine because I can finish it on the grinder.

                Thread: At work tomorrow I need to look up what thread size would be
                appropriate. The biggest thread possible on the stock.

                In the final piece, I'll have a brass block with two holes threaded in
                it, and these two holes need to be as close to exactly 3mm c-to-c
                apart as I can get it. The two points then go in the block so those
                two points will be 3mm apart.

                So the stock size is dictated by the spacing, the thread size
                determined by the stock.

                --- In atlas_craftsman@yahoogroups.com, "jerdal" <jerdal@...> wrote:
                >
                > I got annoyed, and decided to try it.
                >
                > The link shows what I made similar to your part. I had a lot of trouble
                > getting the camera to focus on it, I finally gave up and that is
                what you
                > get.....
                >
                > http://img.photobucket.com/albums/0803/jstanley/point2.jpg
                >
                > The problem is the threading vs cutoff.
                >
                > This stock breaks off (annealed hex key) before the point is
                sufficiently
                > formed. I suppose it might be OK, depending on your needs, but I
                doubt ANY
                > cutoff OR pointing operation will get a truly sharp point if you
                want it
                > sharp like a knife is sharp.
                >
                > Also,it needs a "box tool" probably, to hold it steady against cutting
                > force. I doubt that turning it around would help a lot, but it
                might allow
                > you to point it after a separate cutoff operation.
                >
                > However, turning around also makes threading a separate operation with a
                > threading tool, not a die.
                >
                > A different steel would probably work better. But sharpening the point
                > might be needed separately even so, for a pin-point tip.
                >
                > JT
                >
                >
                >
                > --
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                > Checked by AVG Free Edition.
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                12/31/2006
                >
              • jerdal
                The thread in the picture is 3-48. Done with a die. JT ... From: joegourlay To: Sent: Monday,
                Message 7 of 29 , Jan 1, 2007
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                  The thread in the picture is 3-48. Done with a die.

                  JT


                  ----- Original Message -----
                  From: "joegourlay" <jgourlay@...>
                  To: <atlas_craftsman@yahoogroups.com>
                  Sent: Monday, January 01, 2007 1:31 PM
                  Subject: [atlas_craftsman] Re: Can I do this on my lathe?


                  > Excellent! That's exactly what I'm thinking about! I think the point
                  > you have is fine. I plan on making a "jig" of some kind that allows
                  > precision sharpening of the tip on a grinder. So the rounded tip you
                  > have is fine because I can finish it on the grinder.
                  >
                  > Thread: At work tomorrow I need to look up what thread size would be
                  > appropriate. The biggest thread possible on the stock.




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                • Jon Elson
                  ... Probably any tool steel will work well, as long as they aren t dropped on concrete. You probably want more wear resistance, and the brittleness is not the
                  Message 8 of 29 , Jan 1, 2007
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                    joegourlay wrote:

                    >Jon,
                    >
                    >I just posted a request for sourcing help in a separate message for
                    >the hex stock. I assume that's going to get some hits. Two
                    >questions, however.
                    >
                    >1. This will be used for the points on a marking gauge for wood. The
                    >points need to stay pointy for a long, long time despite their use in
                    >hard, abrasive, silica bearing woods. What type of alloy would you
                    >suggest? I can't decide between "toughness but less wear resistance"
                    >like 1045 or 1060 and "hard as hell but brittle" like 1095. Where does
                    >O1 fall? What do you think?
                    >
                    >
                    >
                    Probably any tool steel will work well, as long as they aren't dropped
                    on concrete.
                    You probably want more wear resistance, and the brittleness is not the main
                    factor. You'd need to watch out for the brittle condition to use the
                    same sort
                    of thing to mark steel, for instance.

                    >2. If I can't find suitable hex stock, what else can I do on little
                    >bitty parts like this so that they can be tightly threaded into a
                    >tapped brass receiving block and then subsequently removed for
                    >sharpening? The reason for the hex stock was to allow use of a small
                    >crescent wrench for installation and extraction. Were these bigger
                    >parts, I could see using round stock and using my milling attachment
                    >to mill in flats. But I can't even image how to hold 1/16" round
                    >stock in that attachment, let alone mill a flat into when it's that
                    >small. I could file a flat, but I think it would come out not very
                    >professional looking, and I may want to start selling these. What do
                    >you suggest?
                    >
                    >
                    You could flat them in the lathe, with a cutter mounted on the milling
                    attachment.
                    You use the indexing holes in the bull gear to make the two (or 6)
                    flats. Not something
                    I'd want to be doing in production, though.

                    Annealing hex keys from the hardware store (or MSC) might be the way to
                    start out.
                    Once you have a bunch of orders that prove the market, call some
                    specialty metal
                    suppliers and get a quote on having some stock rolled for you.

                    And, of course, if there is a big market for this, a screw machine shop
                    could probably
                    make them for a couple cents each, including the stock. But, they
                    wouldn't want to
                    even think about making less than several thousand at a time.

                    Jon
                  • jerdal
                    A better picture of the rough approximation.... finally got better focus n teh subject... http://img.photobucket.com/albums/0803/jstanley/point3.jpg The thing
                    Message 9 of 29 , Jan 1, 2007
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                      A better picture of the rough approximation.... finally got better focus n
                      teh subject...

                      http://img.photobucket.com/albums/0803/jstanley/point3.jpg

                      The thing did not take long to do, once I found the cutters etc.

                      Threading is the longest operation, you'd be wise to get a tailstock die
                      holder for that.

                      if you will sharpen the point later it should be quite easy, the "breakoff"
                      happens after sufficient pointing to make subsequent sharpening reasonable.
                      Particularly if a two-angle point is OK.... with a slightly more blunt
                      angle of the final point.

                      JT




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                    • jmartin957@aol.com
                      In a message dated 1/1/07 12:00:31 AM Eastern Standard Time, ... Pitfalls? Quite a few, I m guessing. As I said, I think it s quite an ambitious first
                      Message 10 of 29 , Jan 1, 2007
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                        In a message dated 1/1/07 12:00:31 AM Eastern Standard Time,
                        jgourlay@... writes:

                        >
                        > Jon, I definitely have the same concerns. But I've got to get through
                        > it. These parts are the "big problem/high risk" portion of a larger
                        > project (not involving metal). So...the whole project grinds to a
                        > screeching without these parts.
                        >
                        > After these come the brass parts which should be a lot easier, and
                        > which I'll ask you about when the time arrives :-)
                        >
                        > Which specific pitfalls do you think I"m going to run into?
                        >
                        > After reading the other posts, my plan for now is:
                        > 1. Grind a HSS tool with the final cone angle for parting.
                        > 2. turn the threaded section plus enough for clearance from the shoulder.
                        > 3. Thread (die)--of course, this means I need you all to tell me how
                        > to hold the die in the tail stock (don't you always want to spin the
                        > work against a stationary cutting tool?)
                        > 4. Move the cone tool in to part off.
                        > 5. Screw the work into a handle for the purpose and use that to polish
                        > the point on the felt wheel.
                        > 6. Into the oven at 500 and roll around in the Brownell's non-scale.
                        > 7. Dip the tippy tip in clay slurry (slow the quench down a bit).
                        > 8. MAPP gas heat and oil quench the points to harden the bejeesus out
                        > them.
                        > 9. Boil to remove the non-scale.
                        >

                        Pitfalls? Quite a few, I'm guessing. As I said, I think it's quite an
                        ambitious first project on your lathe.

                        First of all is the size of the stock. You are talking about using 1/16" -
                        or, even smaller, 3/64" - hex steel. I haven't seen it below 1/8", but maybe
                        you can find a source. If not, you will be limited to Allen keys, which you
                        can find in 1/16" (.0625") or in the even smaller sizes .050", .035" and .028".
                        Plus metric sizes.

                        Allen keys are pretty tough. Hardened, you would need carbide or grinding
                        processes to machine them. You'll have a tough time with carbide on parts this
                        small, so you are looking at annealing first and then using HSS cutters, which
                        is not a problem.

                        How to hold it. Unless you have a brand new 3 jaw scroll chuck, you'll
                        probably find that holding pieces this small with accuracy and rigidity is quite
                        difficult. A collet would be better. I haven't seen hex collets smaller than
                        1/8", but you may find one. You could probably get away with a round collet,
                        though, maybe.

                        Thread size. JT turned up a piece with a #3-48 thread. The maximum you will
                        get with a 1/16" hex is a #0, which is .060" major diameter. If you want a
                        shoulder to locate against your brass pieces, you're now talking about #00 or
                        #000 threads - which are really, really tiny. OK, there are also #0000 threads
                        and a series of even smaller UNM threads. Better be sitting down before you
                        check the prices for taps and dies for these. Even the #0 is pretty fussy to
                        work with. And, it's not real strong - you may just find those points
                        snapping off in use, at the thread roots.

                        Threading something this small, by the way, isn't something you would do
                        under power. Even a slack belt would have more than enough grip to shear the
                        screw. Instead, I'd turn the tailstock die holder by hand.

                        Cone tool. You are trying to turn the taper on the piece being cut off.
                        Anything less than a very blunt angle will not be possible - the piece will break
                        off well before you get that width of cut. Tailstock support or a follower
                        rest would help, but I don't think these are practical in your case. Grinding
                        the point after parting off is the only viable option.

                        Hardening. Again, these are pretty small pieces. Differential hardening is
                        done every day, but I don't think packing some clay around the tip of a piece
                        this small is going to affect things very much. The threads are so fine that
                        any scale at all is going to wipe them out - the anti-scale compound may or
                        may not be effective enough. By the way, you are planning on tempering
                        afterward, aren't you? The pieces will snap if you don't.

                        Here's what I would do instead.

                        If you really have to have the hex design, go with much larger stock. Larger
                        thread size. Don't try to cut the point on the lathe, but grind it. Forget
                        hardening - the annealed key stock will be plenty hard enough as is. This is
                        a marking gauge, I believe, for scribing wood. All of the marking gauges I've
                        seen had points that were soft enough to file. Even soft, they last for
                        years. And, the better ones (those that have been made or modified by real
                        craftsmen) typically do not have conical points, but small elliptical stubs filed
                        sharp on leading and trailing edges. If you are doing enough of these, and
                        really insist on having them hardened, send them out to a heat treater. They will
                        harden them in an inert atmosphere, obviating the need for any anti-scale
                        compound.

                        I realize that the hex design with threads seems more elegant, but I'd
                        instead consider a plain round shaft. Press fit into the brass pieces, or held with
                        Loctite, or a setscrew. Or, use a long setscrew as the point itself,
                        threaded in from the back. If you go with plain round, you could make them from
                        drill rod, drill blanks or reamer blanks. Pretty tough stuff, even without
                        hardening. Dowel pins would be harder as bought. Maybe you could find a supply of
                        old 78 rpm phonograph needles. Or drawing divider points, or something
                        similar.

                        Just my thoughts, though. Take 'em or leave 'em.

                        John Martin
                        Cumberland, Maine





                        [Non-text portions of this message have been removed]
                      • joegourlay
                        John, thanks for your thoughts. The set screw idea is a good one, and solves lots of problems. Using larger stock is my preference. The only problem there is
                        Message 11 of 29 , Jan 2, 2007
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                          John, thanks for your thoughts. The set screw idea is a good one, and
                          solves lots of problems. Using larger stock is my preference. The
                          only problem there is that for the smallest arm in the set, the points
                          need to be no farther apart than .125"

                          Of course, if I'm using set screws it makes it easier to use somewhat
                          larger stock than .063".

                          In marking gauges, a larger proportion of the use is cross grain:
                          that's why you see the elliptical profile. In with the grain use, the
                          preference is for a true point. These are mortising gauge arms, so
                          the point prevails- except for the arm in the set meant for cross
                          grain use, that will have the elliptical which is easy.

                          Most marking gauge points do last for years when used in spruce,
                          cherry, walnut. But cocobolo, ebony, teak, and the like chew them up
                          pretty quickly. Then you're pulling them out to regrind and the holes
                          get loose. Or filing and then the points are uneven.

                          I'm trying to make something that retains what is best about the
                          marking gauges found in the late 1800's early 1900's before power
                          tools (which is quite a lot), while making some modern changes to
                          bring the tool a "step up".

                          I hadn't thought about scale erasing the threads. Hmmm...that's a
                          problem to ponder. Set screws and grinding solves that problem too,
                          however. Lots to like about that solution.

                          --- In atlas_craftsman@yahoogroups.com, jmartin957@... wrote:
                          >
                          > In a message dated 1/1/07 12:00:31 AM Eastern Standard Time,
                          > jgourlay@... writes:
                          >
                          > >
                          > > Jon, I definitely have the same concerns. But I've got to get through
                          > > it. These parts are the "big problem/high risk" portion of a larger
                          > > project (not involving metal). So...the whole project grinds to a
                          > > screeching without these parts.
                          > >
                          > > After these come the brass parts which should be a lot easier, and
                          > > which I'll ask you about when the time arrives :-)
                          > >
                          > > Which specific pitfalls do you think I"m going to run into?
                          > >
                          > > After reading the other posts, my plan for now is:
                          > > 1. Grind a HSS tool with the final cone angle for parting.
                          > > 2. turn the threaded section plus enough for clearance from the
                          shoulder.
                          > > 3. Thread (die)--of course, this means I need you all to tell me how
                          > > to hold the die in the tail stock (don't you always want to spin the
                          > > work against a stationary cutting tool?)
                          > > 4. Move the cone tool in to part off.
                          > > 5. Screw the work into a handle for the purpose and use that to polish
                          > > the point on the felt wheel.
                          > > 6. Into the oven at 500 and roll around in the Brownell's non-scale.
                          > > 7. Dip the tippy tip in clay slurry (slow the quench down a bit).
                          > > 8. MAPP gas heat and oil quench the points to harden the bejeesus out
                          > > them.
                          > > 9. Boil to remove the non-scale.
                          > >
                          >
                          > Pitfalls? Quite a few, I'm guessing. As I said, I think it's quite an
                          > ambitious first project on your lathe.
                          >
                          > First of all is the size of the stock. You are talking about using
                          1/16" -
                          > or, even smaller, 3/64" - hex steel. I haven't seen it below 1/8",
                          but maybe
                          > you can find a source. If not, you will be limited to Allen keys,
                          which you
                          > can find in 1/16" (.0625") or in the even smaller sizes .050", .035"
                          and .028".
                          > Plus metric sizes.
                          >
                          > Allen keys are pretty tough. Hardened, you would need carbide or
                          grinding
                          > processes to machine them. You'll have a tough time with carbide on
                          parts this
                          > small, so you are looking at annealing first and then using HSS
                          cutters, which
                          > is not a problem.
                          >
                          > How to hold it. Unless you have a brand new 3 jaw scroll chuck, you'll
                          > probably find that holding pieces this small with accuracy and
                          rigidity is quite
                          > difficult. A collet would be better. I haven't seen hex collets
                          smaller than
                          > 1/8", but you may find one. You could probably get away with a
                          round collet,
                          > though, maybe.
                          >
                          > Thread size. JT turned up a piece with a #3-48 thread. The maximum
                          you will
                          > get with a 1/16" hex is a #0, which is .060" major diameter. If you
                          want a
                          > shoulder to locate against your brass pieces, you're now talking
                          about #00 or
                          > #000 threads - which are really, really tiny. OK, there are also
                          #0000 threads
                          > and a series of even smaller UNM threads. Better be sitting down
                          before you
                          > check the prices for taps and dies for these. Even the #0 is pretty
                          fussy to
                          > work with. And, it's not real strong - you may just find those points
                          > snapping off in use, at the thread roots.
                          >
                          > Threading something this small, by the way, isn't something you
                          would do
                          > under power. Even a slack belt would have more than enough grip to
                          shear the
                          > screw. Instead, I'd turn the tailstock die holder by hand.
                          >
                          > Cone tool. You are trying to turn the taper on the piece being cut
                          off.
                          > Anything less than a very blunt angle will not be possible - the
                          piece will break
                          > off well before you get that width of cut. Tailstock support or a
                          follower
                          > rest would help, but I don't think these are practical in your case.
                          Grinding
                          > the point after parting off is the only viable option.
                          >
                          > Hardening. Again, these are pretty small pieces. Differential
                          hardening is
                          > done every day, but I don't think packing some clay around the tip
                          of a piece
                          > this small is going to affect things very much. The threads are so
                          fine that
                          > any scale at all is going to wipe them out - the anti-scale compound
                          may or
                          > may not be effective enough. By the way, you are planning on tempering
                          > afterward, aren't you? The pieces will snap if you don't.
                          >
                          > Here's what I would do instead.
                          >
                          > If you really have to have the hex design, go with much larger
                          stock. Larger
                          > thread size. Don't try to cut the point on the lathe, but grind it.
                          Forget
                          > hardening - the annealed key stock will be plenty hard enough as is.
                          This is
                          > a marking gauge, I believe, for scribing wood. All of the marking
                          gauges I've
                          > seen had points that were soft enough to file. Even soft, they last
                          for
                          > years. And, the better ones (those that have been made or modified
                          by real
                          > craftsmen) typically do not have conical points, but small
                          elliptical stubs filed
                          > sharp on leading and trailing edges. If you are doing enough of
                          these, and
                          > really insist on having them hardened, send them out to a heat
                          treater. They will
                          > harden them in an inert atmosphere, obviating the need for any
                          anti-scale
                          > compound.
                          >
                          > I realize that the hex design with threads seems more elegant, but I'd
                          > instead consider a plain round shaft. Press fit into the brass
                          pieces, or held with
                          > Loctite, or a setscrew. Or, use a long setscrew as the point itself,
                          > threaded in from the back. If you go with plain round, you could
                          make them from
                          > drill rod, drill blanks or reamer blanks. Pretty tough stuff, even
                          without
                          > hardening. Dowel pins would be harder as bought. Maybe you could
                          find a supply of
                          > old 78 rpm phonograph needles. Or drawing divider points, or something
                          > similar.
                          >
                          > Just my thoughts, though. Take 'em or leave 'em.
                          >
                          > John Martin
                          > Cumberland, Maine
                          >
                          >
                          >
                          >
                          >
                          > [Non-text portions of this message have been removed]
                          >
                        • anthrhodes@aol.com
                          If these two components need to be precisely 3 mm apart and radialy symetrical, each one needs to be smaller than an 0-80 screw. According to my calculations:
                          Message 12 of 29 , Jan 2, 2007
                          • 0 Attachment
                            If these two components need to be precisely 3 mm apart and radialy
                            symetrical, each one needs to be smaller than an 0-80 screw.

                            According to my calculations:
                            3 mm = 0.11811"
                            3 mm / 2 = 0.05906"
                            Over crest diameter of a #0 screw = 0.06000"
                            Over crest diameter of a #00 screw = 0.04700"

                            It's dificult to work with materials in such small sizes so it may be
                            necessary to alter the form of the points. If the sharp tip can be off-center from
                            the mounting thread it would be easier to handle the components but each of the
                            components would have to be rotated to a position which would place the point
                            at the correct distance from the other one, then locked in that position. Any
                            rotation of the component would alter the center-to-center setting of the
                            points.

                            It might be superior to produce the points as a single component with the
                            center distance fixed or to make two points that attach to a mounting block which
                            would seperately be mounted to the parent component.

                            Just some considerations.

                            Anthony
                            Berkeley, Calif.

                            In a message dated Mon Jan 1, 2007 11:46 am AM Pacific Standard Time,
                            joegourlay writes:
                            In the final piece, I'll have a brass block with two holes threaded in
                            it, and these two holes need to be as close to exactly 3mm c-to-c
                            apart as I can get it. The two points then go in the block so those
                            two points will be 3mm apart.


                            [Non-text portions of this message have been removed]
                          • LouD31M066@aol.com
                            The fine work required may be easier to accomplish on a watchmaker s lathe or a Unimat (sp). Seem to recall a testimonial of a small lathe purchaser being
                            Message 13 of 29 , Jan 2, 2007
                            • 0 Attachment
                              The fine work required may be easier to accomplish on a watchmaker's lathe
                              or a Unimat (sp).
                              Seem to recall a testimonial of a small lathe purchaser being able to make
                              screws to repair
                              pocket watches in his collection. Don't know about other issues.
                              Louis


                              [Non-text portions of this message have been removed]
                            • Buckshot
                              I would use a collet modified to hold the hex stock. I would cut the cylindrical part and thread it, then pull out enough length from the collet to just cut
                              Message 14 of 29 , Jan 2, 2007
                              • 0 Attachment
                                I would use a collet modified to hold the hex stock.

                                I would cut the cylindrical part and thread it, then pull out enough length
                                from the collet to just cut the point on the part and the part off at the
                                same time, finishing the point on the parts later if I had to with a file.

                                Buckshot

                                ----- Original Message -----
                                From: "joegourlay" <jgourlay@...>
                                To: <atlas_craftsman@yahoogroups.com>
                                Sent: Sunday, December 31, 2006 11:51 PM
                                Subject: [atlas_craftsman] Re: Can I do this on my lathe?


                                > Jon, I definitely have the same concerns. But I've got to get through
                                > it. These parts are the "big problem/high risk" portion of a larger
                                > project (not involving metal). So...the whole project grinds to a
                                > screeching without these parts.
                                >
                                > After these come the brass parts which should be a lot easier, and
                                > which I'll ask you about when the time arrives :-)
                                >
                                > Which specific pitfalls do you think I"m going to run into?
                                >
                                > After reading the other posts, my plan for now is:
                                > 1. Grind a HSS tool with the final cone angle for parting.
                                > 2. turn the threaded section plus enough for clearance from the shoulder.
                                > 3. Thread (die)--of course, this means I need you all to tell me how
                                > to hold the die in the tail stock (don't you always want to spin the
                                > work against a stationary cutting tool?)
                                > 4. Move the cone tool in to part off.
                                > 5. Screw the work into a handle for the purpose and use that to polish
                                > the point on the felt wheel.
                                > 6. Into the oven at 500 and roll around in the Brownell's non-scale.
                                > 7. Dip the tippy tip in clay slurry (slow the quench down a bit).
                                > 8. MAPP gas heat and oil quench the points to harden the bejeesus out
                                > them.
                                > 9. Boil to remove the non-scale.
                                >
                                > -- In atlas_craftsman@yahoogroups.com, jmartin957@... wrote:
                                >>
                                >> In a message dated 12/31/06 5:02:41 PM Eastern Standard Time,
                                >> jgourlay@... writes:
                                >>
                                >> > Also, is material this thin going to want to bend or whip under the
                                >> > pressure of cutting/parting? Should I use a center in the tailstock
                                >> > as support?
                                >> >
                                >>
                                >> Yes, the material is going to want to bend and whip.
                                >>
                                >> I'd like to know, though, how you plan to use a center after you
                                > have ground
                                >> the end of the stock to a point. Maybe a female center? Won't
                                > leave you much
                                >> room to work.
                                >>
                                >> Somehow, trying to thread, point and part off something as small and
                                > tough as
                                >> 1/16" (or smaller) hex key stock on a 12" lathe strikes me as a bit
                                > difficult
                                >> for your first project. I'd work up to it, slowly.
                                >>
                                >> John Martin
                                >>
                                >>
                                >> [Non-text portions of this message have been removed]
                                >>
                                >
                                >
                                >
                                >
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                              • jerdal
                                ... From: Buckshot To: Sent: Tuesday, January 02, 2007 7:43 PM Subject: Re: [atlas_craftsman] Re:
                                Message 15 of 29 , Jan 2, 2007
                                • 0 Attachment
                                  ----- Original Message -----
                                  From: "Buckshot" <buckshot@...>
                                  To: <atlas_craftsman@yahoogroups.com>
                                  Sent: Tuesday, January 02, 2007 7:43 PM
                                  Subject: Re: [atlas_craftsman] Re: Can I do this on my lathe?


                                  > I would use a collet modified to hold the hex stock.
                                  >
                                  > I would cut the cylindrical part and thread it, then pull out enough
                                  length
                                  > from the collet to just cut the point on the part and the part off at the
                                  > same time, finishing the point on the parts later if I had to with a file.

                                  That is exactly how I made the example part....

                                  However, the parts envisioned are about 1/4 the already small size that I
                                  made. I think that is just too small to fool with, and one is far better off
                                  with two holes and setscrews or the like to hold solid round shank parts, as
                                  mentioned by someone else.

                                  That will be something like 5 times stronger, plus, if the user breaks one,
                                  they won't swear at you while they try to unscrew the remainder. You KNOW
                                  it will break at the second thread down from the surface.........

                                  The solid one could be loosened and shaken out.... or if the maker was smart
                                  and drilled thru, pushed out with a bit of wire.

                                  JT



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