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Complete sets of change gears

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  • Brett Jones
    Does anyone know what gears are included in a complete set? Also, aside from the 96 tooth gear long ago, where there any other optional gears? Circumstances (I
    Message 1 of 19 , Jun 3, 2008
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      Does anyone know what gears are included in a complete set? Also, aside
      from the 96 tooth gear long ago, where there any other optional gears?

      Circumstances (I ran the carriage into the tailstock on my Sheldon
      lathe) have forced me to setup my dividing head to make a replacement
      gear. Dividing heads are a fun tool and I was thinking I'd fill in my
      Atlas gears if I was missing any and make a couple of replacements for
      my long suffering Craftsman project.

      Thanks.

      --
      Brett Jones
      brett@...
    • LouD31M066@aol.com
      Gears sets posted. Louis **************Get trade secrets for amazing burgers. Watch Cooking with Tyler Florence on AOL Food.
      Message 2 of 19 , Jun 4, 2008
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        Gears sets posted.
        Louis



        **************Get trade secrets for amazing burgers. Watch "Cooking with
        Tyler Florence" on AOL Food.
        (http://food.aol.com/tyler-florence?video=4?&NCID=aolfod00030000000002)


        [Non-text portions of this message have been removed]
      • anthrhodes@aol.com
        Brett, I know that the following set is standard for the 6 Atlas and believe it is for the late 12 Atlas: 20, 24, 32(2), 36, 40, 44, 46, 48, 52, 54, 56, &
        Message 3 of 19 , Jun 5, 2008
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          Brett,

          I know that the following set is standard for the 6" Atlas and believe it is
          for the late 12" Atlas:
          20, 24, 32(2), 36, 40, 44, 46, 48, 52, 54, 56, & 64(2).

          For optional gears, extras of any of the above can allow gearing for unusual
          or unlisted pitches. Some will be listed in MoLOaMT.

          Let me suggest, Logan uses 47 and 37 for metric conversion, not perfect but
          more convenient and more accurate than the 44 and 52 used by Atlas. Extra 32s
          are likely to be useful, they produce useful ratios with 16, 24, 36, 40, and
          48 tooth gears. I also suggest 30, 50, and 60.

          If you want to get a bit exotic"
          Drivers 77 and 51, driven 50 and 25 will result in pi within 2 parts in 1
          million.
          Drivers 71 and 40, driven 113 and 32 will result in pi/4 within 85 parts in
          1 billion.
          Pi is useful in cutting DP and module threads.

          Anthony
          Berkeley, Calif.
          ****************************************

          In a message dated Tue Jun 3, 2008 11:47 pm (PDT), Brett Jones writes:

          Does anyone know what gears are included in a complete set? Also, aside
          from the 96 tooth gear long ago, where there any other optional gears?

          Circumstances (I ran the carriage into the tailstock on my Sheldon
          lathe) have forced me to setup my dividing head to make a replacement
          gear. Dividing heads are a fun tool and I was thinking I'd fill in my
          Atlas gears if I was missing any and make a couple of replacements for
          my long suffering Craftsman project.





          **************Get trade secrets for amazing burgers. Watch "Cooking with
          Tyler Florence" on AOL Food.
          (http://food.aol.com/tyler-florence?video=4?&NCID=aolfod00030000000002)


          [Non-text portions of this message have been removed]
        • Michael Fagan
          A 127 tooth gear is considered the standard metric transposition gear, for reference. This was not available from Atlas.
          Message 4 of 19 , Jun 5, 2008
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            A 127 tooth gear is considered the standard metric transposition gear,
            for reference. This was not available from Atlas.

            On Thu, Jun 5, 2008 at 10:18 PM, <anthrhodes@...> wrote:
            > Brett,
            >
            > I know that the following set is standard for the 6" Atlas and believe it is
            > for the late 12" Atlas:
            > 20, 24, 32(2), 36, 40, 44, 46, 48, 52, 54, 56, & 64(2).
            >
            > For optional gears, extras of any of the above can allow gearing for unusual
            > or unlisted pitches. Some will be listed in MoLOaMT.
            >
            > Let me suggest, Logan uses 47 and 37 for metric conversion, not perfect but
            > more convenient and more accurate than the 44 and 52 used by Atlas. Extra
            > 32s
            > are likely to be useful, they produce useful ratios with 16, 24, 36, 40, and
            > 48 tooth gears. I also suggest 30, 50, and 60.
            >
            > If you want to get a bit exotic"
            > Drivers 77 and 51, driven 50 and 25 will result in pi within 2 parts in 1
            > million.
            > Drivers 71 and 40, driven 113 and 32 will result in pi/4 within 85 parts in
            > 1 billion.
            > Pi is useful in cutting DP and module threads.
            >
            > Anthony
            > Berkeley, Calif.
            > ****************************************
            >
            > In a message dated Tue Jun 3, 2008 11:47 pm (PDT), Brett Jones writes:
            >
            > Does anyone know what gears are included in a complete set? Also, aside
            > from the 96 tooth gear long ago, where there any other optional gears?
            >
            > Circumstances (I ran the carriage into the tailstock on my Sheldon
            > lathe) have forced me to setup my dividing head to make a replacement
            > gear. Dividing heads are a fun tool and I was thinking I'd fill in my
            > Atlas gears if I was missing any and make a couple of replacements for
            > my long suffering Craftsman project.
            >
            > **************Get trade secrets for amazing burgers. Watch "Cooking with
            > Tyler Florence" on AOL Food.
            > (http://food.aol.com/tyler-florence?video=4?&NCID=aolfod00030000000002)
            >
            > [Non-text portions of this message have been removed]
            >
            >
          • anthrhodes@aol.com
            Michael, You re correct. One of several metric conversion setups is to use a 127 driven and 100 driver gear. 127 / 100 = 1.27 Not only is the 127 not
            Message 5 of 19 , Jun 6, 2008
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              Michael,

              You're correct. One of several metric conversion setups is to use a 127
              driven and 100 driver gear. 127 / 100 = 1.27

              Not only is the 127 not available from Atlas (though it is available from
              other sources), but it's difficult to fit on the lathe. The 47 / 37 gears I
              mentioned, as used by Logan, calculate 47 / 37 = 1.27027. When divided by the
              desired value of 1.27 the result is 1.00021 or 2 parts error in 10,000, not
              perfect but not bad and about 1/3 the error of the Atlas standard using 44 / 52
              which they settled for simply because they were included in the standard gear
              set.

              There are other workarounds. Standard gear pitch for larger Atlas lathes is
              16 DP. Largest standard Atlas gear was 96 (no longer used) which would have
              an OD of 6.125". Largest current Atlas gear is 64, OD 4.125". A 16 DP 127 gear
              would have an OD of 8.0625". You can see the difficulty.

              As an alternative, the 127 and 100 gears could be made as 32 DP gears and
              setup so that the 100 would always drive the 127, no other gears ever meshing
              with the teeth of these two gears. A 32 DP 127 = 4.03125" OD, a 32 DP 100 =
              3.1875" OD. Obviously both of these fall within the size range of standard
              Atlas gears. Use Atlas standard bore and keyways on the gears.

              If you're interested in gear setups for the lathe, the best book I know of
              on the subject for hobbyist machinists is "Screwcutting in the Lathe" by
              Martin Cleeve. VERY HIGHLY RECOMMENDED reading.

              Anthony
              Berkeley, Calif.
              ***********************************

              In a message dated 6/6/2008 1:25:12 P.M. Pacific Daylight Time, Michael
              Fagan writes:

              A 127 tooth gear is considered the standard metric transposition gear,
              for reference. This was not available from Atlas.




              **************Get trade secrets for amazing burgers. Watch "Cooking with
              Tyler Florence" on AOL Food.
              (http://food.aol.com/tyler-florence?video=4?&NCID=aolfod00030000000002)


              [Non-text portions of this message have been removed]
            • Bill Libecap
              Can you please explain more about this 127 tooth gear adn how it is used? ... believe it is ... for unusual ... perfect but ... Atlas. Extra ... 36, 40, and
              Message 6 of 19 , Jun 6, 2008
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                Can you please explain more about this 127 tooth gear adn how it is used?

                --- In atlas_craftsman@yahoogroups.com, "Michael Fagan"
                <woodworker88@...> wrote:
                >
                > A 127 tooth gear is considered the standard metric transposition gear,
                > for reference. This was not available from Atlas.
                >
                > On Thu, Jun 5, 2008 at 10:18 PM, <anthrhodes@...> wrote:
                > > Brett,
                > >
                > > I know that the following set is standard for the 6" Atlas and
                believe it is
                > > for the late 12" Atlas:
                > > 20, 24, 32(2), 36, 40, 44, 46, 48, 52, 54, 56, & 64(2).
                > >
                > > For optional gears, extras of any of the above can allow gearing
                for unusual
                > > or unlisted pitches. Some will be listed in MoLOaMT.
                > >
                > > Let me suggest, Logan uses 47 and 37 for metric conversion, not
                perfect but
                > > more convenient and more accurate than the 44 and 52 used by
                Atlas. Extra
                > > 32s
                > > are likely to be useful, they produce useful ratios with 16, 24,
                36, 40, and
                > > 48 tooth gears. I also suggest 30, 50, and 60.
                > >
                > > If you want to get a bit exotic"
                > > Drivers 77 and 51, driven 50 and 25 will result in pi within 2
                parts in 1
                > > million.
                > > Drivers 71 and 40, driven 113 and 32 will result in pi/4 within 85
                parts in
                > > 1 billion.
                > > Pi is useful in cutting DP and module threads.
                > >
                > > Anthony
                > > Berkeley, Calif.
                > > ****************************************
                > >
                > > In a message dated Tue Jun 3, 2008 11:47 pm (PDT), Brett Jones writes:
                > >
                > > Does anyone know what gears are included in a complete set? Also,
                aside
                > > from the 96 tooth gear long ago, where there any other optional gears?
                > >
                > > Circumstances (I ran the carriage into the tailstock on my Sheldon
                > > lathe) have forced me to setup my dividing head to make a replacement
                > > gear. Dividing heads are a fun tool and I was thinking I'd fill in my
                > > Atlas gears if I was missing any and make a couple of replacements for
                > > my long suffering Craftsman project.
                > >
                > > **************Get trade secrets for amazing burgers. Watch
                "Cooking with
                > > Tyler Florence" on AOL Food.
                > >
                (http://food.aol.com/tyler-florence?video=4?&NCID=aolfod00030000000002)
                > >
                > > [Non-text portions of this message have been removed]
                > >
                > >
                >
              • Brett Jones
                I had read the Atlas gears were 14.5 PA and 14 DP. Which is correct 16 or 14? ... -- Brett Jones brett@5foot2.com
                Message 7 of 19 , Jun 7, 2008
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                  I had read the Atlas gears were 14.5 PA and 14 DP. Which is correct 16
                  or 14?

                  anthrhodes@... wrote:
                  >
                  >
                  > Michael,
                  >
                  > You're correct. One of several metric conversion setups is to use a 127
                  > driven and 100 driver gear. 127 / 100 = 1.27
                  >
                  > Not only is the 127 not available from Atlas (though it is available from
                  > other sources), but it's difficult to fit on the lathe. The 47 / 37 gears I
                  > mentioned, as used by Logan, calculate 47 / 37 = 1.27027. When divided
                  > by the
                  > desired value of 1.27 the result is 1.00021 or 2 parts error in 10,000, not
                  > perfect but not bad and about 1/3 the error of the Atlas standard using
                  > 44 / 52
                  > which they settled for simply because they were included in the standard
                  > gear
                  > set.
                  >
                  > There are other workarounds. Standard gear pitch for larger Atlas lathes is
                  > 16 DP. Largest standard Atlas gear was 96 (no longer used) which would have
                  > an OD of 6.125". Largest current Atlas gear is 64, OD 4.125". A 16 DP
                  > 127 gear
                  > would have an OD of 8.0625". You can see the difficulty.
                  >
                  > As an alternative, the 127 and 100 gears could be made as 32 DP gears and
                  > setup so that the 100 would always drive the 127, no other gears ever
                  > meshing
                  > with the teeth of these two gears. A 32 DP 127 = 4.03125" OD, a 32 DP 100 =
                  > 3.1875" OD. Obviously both of these fall within the size range of standard
                  > Atlas gears. Use Atlas standard bore and keyways on the gears.
                  >
                  > If you're interested in gear setups for the lathe, the best book I know of
                  > on the subject for hobbyist machinists is "Screwcutting in the Lathe" by
                  > Martin Cleeve. VERY HIGHLY RECOMMENDED reading.
                  >
                  > Anthony
                  > Berkeley, Calif.
                  > ***********************************


                  --
                  Brett Jones
                  brett@...
                • anthrhodes@aol.com
                  Brett, 16 DP, 14.5 PA. Just out of curiosity, do you recall where you read 14 DP? Anthony Berkeley, Calif. ************************************** In a message
                  Message 8 of 19 , Jun 7, 2008
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                    Brett,

                    16 DP, 14.5 PA.

                    Just out of curiosity, do you recall where you read 14 DP?

                    Anthony
                    Berkeley, Calif.
                    **************************************

                    In a message dated Sat Jun 7, 2008 2:16 am (PDT), Brett Jones writes:

                    I had read the Atlas gears were 14.5 PA and 14 DP. Which is correct 16
                    or 14?




                    **************Get trade secrets for amazing burgers. Watch "Cooking with
                    Tyler Florence" on AOL Food.
                    (http://food.aol.com/tyler-florence?video=4?&NCID=aolfod00030000000002)


                    [Non-text portions of this message have been removed]
                  • Jon Elson
                    ... OK, you obtain a 100 and a 127 tooth gear in any resonable pitch diameter, could even be metric. You bore the ID and cut the keyways to match the Atlas
                    Message 9 of 19 , Jun 7, 2008
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                      Bill Libecap wrote:
                      > Can you please explain more about this 127 tooth gear adn how it is used?
                      OK, you obtain a 100 and a 127 tooth gear in any resonable pitch
                      diameter, could even be metric. You bore the ID and cut the
                      keyways to match the Atlas gear hubs. Combine these gears with
                      some Atlas gears that you have two the same size of, say a
                      32-tooth. Now, when you insert these gears in the train, the
                      spindle drives some idler which drives the 32-tooth Atlas gear,
                      the 100 tooth is on the same hub. That meshes with the 127
                      tooth, which drives an atlas 32-tooth on the same hub. this
                      then feeds some other reduction ratio to drive the Atlas
                      leadscrew. Now, the Atlas 10 and 12" lathes have 8 TPI
                      leadscrews. Let's say you want to make a 1 mm pitch thred.
                      You need the leadscrew to advance .03937" per spindle rev.
                      Since the leadscrew advances by .125" per rev, it needs to
                      turn 0.315 of a turn per spindle rotation, or the spindle turns
                      3.175 times per leadscrew rotation. Now, 3.175 * 127/100 =
                      2.5000, so you need an additional 2.5 : 1 reduction ratio.
                      If the gear on the same hub as the 127-tooth gear is made a
                      16-tooth, then you put a 40 tooth gear on the leadscrew, and you
                      can cut a 1 mm pitch with accuracy as good as the lathe is.

                      Just to prove it, 1 spinde rev * 100/127 * 16/40 * 0.125 =
                      0.0393700787401575, and 1 over that number is 25.4 exactly.

                      Jon
                    • anthrhodes@aol.com
                      Bill, The following is true, in principle, for all lathes but I will use the Atlas with 8 TPI leadscrew and 16 DP gears for the specific example. Install a
                      Message 10 of 19 , Jun 7, 2008
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                        Bill,

                        The following is true, in principle, for all lathes but I will use the Atlas
                        with 8 TPI leadscrew and 16 DP gears for the specific example.

                        Install a spacer and a 32 gear on the leadscrew.
                        Install any large gear on the change gear bracket (banjo) as an idler so
                        that it meshes with the leadscrew gear.
                        Swing the banjo up so that the idler gear meshes with the stud gear (center
                        gear on the reverse tumbler).

                        The idler has no effect on the gear ratio, all it does is reverse the
                        direction of rotation of the gears after it and span the distance between the stud
                        gear and the screw gear (on the leadscrew). So you have a simple 32 to 32
                        gear train or 1 to 1 ratio, therefore every time the spindle turns one
                        revolution the leadscrew also turns one revolution. In one revolution the leadscrew
                        will drive the carriage 1/8". In 8 revolutions of the spindle, and of the
                        leadscrew, the leadscrew will drive the carriage 1". 8 Revolutions of the spindle
                        while the carriage traverses 1" will produce 8 TPI. (I know this is well
                        known and obvious to many users, but for some this may be where the light bulb
                        suddenly comes on.)

                        If you gear down so that he leadscrew makes less than 1 turn for every
                        revolution of the spindle, the carriage will traverse a shorter distance,
                        therefore requiring more revolutions of the spindle to drive the carriage 1",
                        therefore more TPI (shorter pitch but more TPI). As an example, 32 stud gear, 64
                        screw gear, 1/2 revolution of the leadscrew for every revolution of the spindle,
                        requires 16 revolutions of the spindle to traverse the carriage 1",
                        therefore 16 TPI.

                        You can also get the reduction by compounding, using 2 gears on a single
                        axis on the banjo to span the distance between the stud and screw gears. In such
                        an example, the stud drives one gear on the banjo through their teeth. The
                        second gear on the banjo is drive from the first one through the keyed bushing
                        on which the are both mounted, no tooth engagement between these gears. The
                        second banjo gear drives the screw gear through their teeth. Stud gear and
                        second banjo gear are drivers, first banjo gear and screw gear are driven. To
                        get the resulting pitch, multiply all drivers together, divide sequentially by
                        all driven gears, and multiply by the pitch of the leadscrew, in our case
                        .125" (not the 8 TPI which is the reciprocal of the pitch.

                        As a compound example, 32 stud (driver), 64 first banjo gear (driven), 32
                        second banjo gear (driver), 32 screw gear (driven), calculating 32 x 32 = 1024
                        divide by 64 = 16 divide by 32 = 0.5 x .125" = .0625" pitch or 16 TPI. Before
                        somebody complains, you can't set this train because the 64 prevents the 32
                        second banjo gear from reaching the 32 screw gear. To make it work insert a
                        40 or larger gear as an idler between the 32 second banjo gear and the 32
                        screw gear, doesn't alter the gear ratio but does allow the gears to mesh with
                        each other.

                        The above example is unnecessarily complex but does illustrate compounding
                        which is necessary for the English-metric conversion. Setting up an example,
                        32 stud, 127 first banjo, 100 second banjo, 32 screw gear, calculating 32 x
                        100 = 3200 divide by 127 =
                        25.19685 divide by 32 = 0.7874 x .0125" = .098425" x 25.4 (metric
                        conversion) = 2.5 mm. With this gear train your 8 TPI will traverse 2. 5 mm per spindle
                        revolution. Changing the stud or screw gears or changing the 100 to a
                        different gear, or adding additional compounding gears on the banjo will produce
                        different metric pitches. For example, changing the 100 to an 80 would produce
                        2 mm pitch. (Don't think this will set, probably needs an idler between the
                        80 and the screw gear.)

                        Is any of this helpful?

                        Anthony
                        Berkeley, Calif.
                        *******************************************

                        In a message dated Fri Jun 6, 2008 11:08 pm (PDT), Bill Libecap writes:

                        Can you please explain more about this 127 tooth gear adn how it is used?




                        **************Get trade secrets for amazing burgers. Watch "Cooking with
                        Tyler Florence" on AOL Food.
                        (http://food.aol.com/tyler-florence?video=4?&NCID=aolfod00030000000002)


                        [Non-text portions of this message have been removed]
                      • Jerome
                        OK Anthony, I ll bite. What is MoLOaMT ... believe it is ... for unusual ... perfect but ... Extra 32s ... 36, 40, and ... parts in 1 ... parts in ... aside
                        Message 11 of 19 , Jun 7, 2008
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                          OK Anthony, I'll bite. What is MoLOaMT




                          --- In atlas_craftsman@yahoogroups.com, anthrhodes@... wrote:
                          >
                          > Brett,
                          >
                          > I know that the following set is standard for the 6" Atlas and
                          believe it is
                          > for the late 12" Atlas:
                          > 20, 24, 32(2), 36, 40, 44, 46, 48, 52, 54, 56, & 64(2).
                          >
                          > For optional gears, extras of any of the above can allow gearing
                          for unusual
                          > or unlisted pitches. Some will be listed in MoLOaMT.
                          >
                          > Let me suggest, Logan uses 47 and 37 for metric conversion, not
                          perfect but
                          > more convenient and more accurate than the 44 and 52 used by Atlas.
                          Extra 32s
                          > are likely to be useful, they produce useful ratios with 16, 24,
                          36, 40, and
                          > 48 tooth gears. I also suggest 30, 50, and 60.
                          >
                          > If you want to get a bit exotic"
                          > Drivers 77 and 51, driven 50 and 25 will result in pi within 2
                          parts in 1
                          > million.
                          > Drivers 71 and 40, driven 113 and 32 will result in pi/4 within 85
                          parts in
                          > 1 billion.
                          > Pi is useful in cutting DP and module threads.
                          >
                          > Anthony
                          > Berkeley, Calif.
                          > ****************************************
                          >
                          > In a message dated Tue Jun 3, 2008 11:47 pm (PDT), Brett Jones writes:
                          >
                          > Does anyone know what gears are included in a complete set? Also,
                          aside
                          > from the 96 tooth gear long ago, where there any other optional gears?
                          >
                          > Circumstances (I ran the carriage into the tailstock on my Sheldon
                          > lathe) have forced me to setup my dividing head to make a replacement
                          > gear. Dividing heads are a fun tool and I was thinking I'd fill in my
                          > Atlas gears if I was missing any and make a couple of replacements for
                          > my long suffering Craftsman project.
                          >
                          >
                          >
                          >
                          >
                          > **************Get trade secrets for amazing burgers. Watch "Cooking
                          with
                          > Tyler Florence" on AOL Food.
                          > (http://food.aol.com/tyler-florence?video=4?&NCID=aolfod00030000000002)
                          >
                          >
                          > [Non-text portions of this message have been removed]
                          >
                        • Russ Kepler
                          ... I m guessing Manual of Lathe Operations and Machinists Tables from Atlas.
                          Message 12 of 19 , Jun 7, 2008
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                            On Saturday 07 June 2008 14:14:35 Jerome wrote:
                            > OK Anthony, I'll bite. What is MoLOaMT

                            I'm guessing "Manual of Lathe Operations and Machinists Tables" from Atlas.
                          • carvel webb
                            Jon , This looks like a good candidate for the Wiki FAQ ? I noticed one typo and that is 3.175 * 127/100= 2.500 should read 3.175*100/127=2.500 ? Also just
                            Message 13 of 19 , Jun 8, 2008
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                              Jon ,

                              This looks like a good candidate for the Wiki FAQ ?

                              I noticed one typo and that is "3.175 * 127/100= 2.500" should read
                              "3.175*100/127=2.500" ?

                              Also just to note for anybody interested that not all applications require
                              the degree of accuracy offered by the 127 T gear approach . Myford use a 63T
                              in their conversion , and the "standard" Atlas combination of 52/44 for
                              Metric conversion would yield a result of 25.415 as opposed to 25.4 in your
                              validation .

                              Nice summary ,

                              Carvel


                              -----Original Message-----
                              From: atlas_craftsman@yahoogroups.com
                              [mailto:atlas_craftsman@yahoogroups.com] On Behalf Of Jon Elson
                              Sent: 07 June 2008 07:58 PM
                              To: atlas_craftsman@yahoogroups.com
                              Subject: Re: [atlas_craftsman] Re: Complete sets of change gears

                              Bill Libecap wrote:
                              > Can you please explain more about this 127 tooth gear adn how it is used?
                              OK, you obtain a 100 and a 127 tooth gear in any resonable pitch
                              diameter, could even be metric. You bore the ID and cut the
                              keyways to match the Atlas gear hubs. Combine these gears with
                              some Atlas gears that you have two the same size of, say a
                              32-tooth. Now, when you insert these gears in the train, the
                              spindle drives some idler which drives the 32-tooth Atlas gear,
                              the 100 tooth is on the same hub. That meshes with the 127
                              tooth, which drives an atlas 32-tooth on the same hub. this
                              then feeds some other reduction ratio to drive the Atlas
                              leadscrew. Now, the Atlas 10 and 12" lathes have 8 TPI
                              leadscrews. Let's say you want to make a 1 mm pitch thred.
                              You need the leadscrew to advance .03937" per spindle rev.
                              Since the leadscrew advances by .125" per rev, it needs to
                              turn 0.315 of a turn per spindle rotation, or the spindle turns
                              3.175 times per leadscrew rotation. Now, 3.175 * 127/100 =
                              2.5000, so you need an additional 2.5 : 1 reduction ratio.
                              If the gear on the same hub as the 127-tooth gear is made a
                              16-tooth, then you put a 40 tooth gear on the leadscrew, and you
                              can cut a 1 mm pitch with accuracy as good as the lathe is.

                              Just to prove it, 1 spinde rev * 100/127 * 16/40 * 0.125 =
                              0.0393700787401575, and 1 over that number is 25.4 exactly.

                              Jon

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                            • Jon Elson
                              ... Thanks! I will have to check that 100/127 or vice-versa, I reversed it just before posting it. Jon
                              Message 14 of 19 , Jun 8, 2008
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                                carvel webb wrote:
                                > Jon ,
                                >
                                > This looks like a good candidate for the Wiki FAQ ?
                                >
                                > I noticed one typo and that is "3.175 * 127/100= 2.500" should read
                                > "3.175*100/127=2.500" ?
                                >
                                > Also just to note for anybody interested that not all applications require
                                > the degree of accuracy offered by the 127 T gear approach . Myford use a 63T
                                > in their conversion , and the "standard" Atlas combination of 52/44 for
                                > Metric conversion would yield a result of 25.415 as opposed to 25.4 in your
                                > validation .
                                >
                                > Nice summary ,
                                Thanks! I will have to check that 100/127 or vice-versa, I
                                reversed it just before posting it.

                                Jon
                              • Brett Jones
                                Sorry for the late reply, I had wildfire training all weekend. I had to dig around to find this: All Atlas 9-inch, 10-inch and 12-inch lathe used changewheels
                                Message 15 of 19 , Jun 8, 2008
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                                  Sorry for the late reply, I had wildfire training all weekend.

                                  I had to dig around to find this: "All Atlas 9-inch, 10-inch and 12-inch
                                  lathe used changewheels of 14DP with a 14.5-degree pressure angle."

                                  This line of text is at Tony's site, http://www.lathes.co.uk/atlas/.

                                  anthrhodes@... wrote:
                                  >
                                  >
                                  > Brett,
                                  >
                                  > 16 DP, 14.5 PA.
                                  >
                                  > Just out of curiosity, do you recall where you read 14 DP?
                                  >
                                  > Anthony
                                  > Berkeley, Calif.
                                  > **************************************
                                  >
                                  > In a message dated Sat Jun 7, 2008 2:16 am (PDT), Brett Jones writes:
                                  >
                                  > I had read the Atlas gears were 14.5 PA and 14 DP. Which is correct 16
                                  > or 14?
                                  >
                                  > **************Get trade secrets for amazing burgers. Watch "Cooking with
                                  > Tyler Florence" on AOL Food.
                                  > (http://food.aol.com/tyler-florence?video=4?&NCID=aolfod00030000000002
                                  > <http://food.aol.com/tyler-florence?video=4?&NCID=aolfod00030000000002>)
                                  >
                                  > [Non-text portions of this message have been removed]
                                  >
                                  >

                                  --
                                  Brett Jones
                                  brett@...
                                • Michael Fagan
                                  For cutting metric threads on a lathe equipped with National (American/English) leadscrew, you need to convert between the pitch in inches and the pitch in mm.
                                  Message 16 of 19 , Jun 8, 2008
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                                    For cutting metric threads on a lathe equipped with National
                                    (American/English) leadscrew, you need to convert between the pitch in
                                    inches and the pitch in mm. The necessary ratio very nearly 1.27:1,
                                    which can be created using a 127 tooth gear and a 100 tooth gear, or,
                                    more conveniently, a 47 tooth gear and a 37 tooth gear, as well as
                                    several other combinations. I just brought it up because on many
                                    lathes other than the Atlas, it is not uncommon to see a 127 tooth
                                    gear as part of the "complete" change gear set, specifically for this
                                    purpose. It is often seen packaged with lathes that already have a
                                    quick change gearbox, where it is usually known as a "transposing
                                    gear", because it transposes between SAE and metric thread cutting.

                                    On Fri, Jun 6, 2008 at 11:08 PM, Bill Libecap <Mr_Bill@...> wrote:
                                    > Can you please explain more about this 127 tooth gear adn how it is used?
                                    >
                                    > --- In atlas_craftsman@yahoogroups.com, "Michael Fagan"
                                    >
                                    > <woodworker88@...> wrote:
                                    >>
                                    >> A 127 tooth gear is considered the standard metric transposition gear,
                                    >> for reference. This was not available from Atlas.
                                    >>
                                    >> On Thu, Jun 5, 2008 at 10:18 PM, <anthrhodes@...> wrote:
                                    >> > Brett,
                                    >> >
                                    >> > I know that the following set is standard for the 6" Atlas and
                                    > believe it is
                                    >> > for the late 12" Atlas:
                                    >> > 20, 24, 32(2), 36, 40, 44, 46, 48, 52, 54, 56, & 64(2).
                                    >> >
                                    >> > For optional gears, extras of any of the above can allow gearing
                                    > for unusual
                                    >> > or unlisted pitches. Some will be listed in MoLOaMT.
                                    >> >
                                    >> > Let me suggest, Logan uses 47 and 37 for metric conversion, not
                                    > perfect but
                                    >> > more convenient and more accurate than the 44 and 52 used by
                                    > Atlas. Extra
                                    >> > 32s
                                    >> > are likely to be useful, they produce useful ratios with 16, 24,
                                    > 36, 40, and
                                    >> > 48 tooth gears. I also suggest 30, 50, and 60.
                                    >> >
                                    >> > If you want to get a bit exotic"
                                    >> > Drivers 77 and 51, driven 50 and 25 will result in pi within 2
                                    > parts in 1
                                    >> > million.
                                    >> > Drivers 71 and 40, driven 113 and 32 will result in pi/4 within 85
                                    > parts in
                                    >> > 1 billion.
                                    >> > Pi is useful in cutting DP and module threads.
                                    >> >
                                    >> > Anthony
                                    >> > Berkeley, Calif.
                                    >> > ****************************************
                                    >> >
                                    >> > In a message dated Tue Jun 3, 2008 11:47 pm (PDT), Brett Jones writes:
                                    >> >
                                    >> > Does anyone know what gears are included in a complete set? Also,
                                    > aside
                                    >> > from the 96 tooth gear long ago, where there any other optional gears?
                                    >> >
                                    >> > Circumstances (I ran the carriage into the tailstock on my Sheldon
                                    >> > lathe) have forced me to setup my dividing head to make a replacement
                                    >> > gear. Dividing heads are a fun tool and I was thinking I'd fill in my
                                    >> > Atlas gears if I was missing any and make a couple of replacements for
                                    >> > my long suffering Craftsman project.
                                    >> >
                                    >> > **************Get trade secrets for amazing burgers. Watch
                                    > "Cooking with
                                    >> > Tyler Florence" on AOL Food.
                                    >> >
                                    > (http://food.aol.com/tyler-florence?video=4?&NCID=aolfod00030000000002)
                                    >> >
                                    >> > [Non-text portions of this message have been removed]
                                    >> >
                                    >> >
                                    >>
                                    >
                                    >
                                  • anthrhodes@aol.com
                                    Brett, Measure your own gears to verify this for yourself. Take any of your change gears, even tooth count preferred for simplicity. Measure th OD across the
                                    Message 17 of 19 , Jun 9, 2008
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                                      Brett,

                                      Measure your own gears to verify this for yourself. Take any of your change
                                      gears, even tooth count preferred for simplicity. Measure th OD across the
                                      tips of two teeth. Count the teeth (n) and add two (n + 2). Divide OD by (n +
                                      2), the result should be very close to 16 (15.95, 16.03, whatever). Do this on
                                      several gears so that you're comfortable with the result. If the quoted info
                                      is still on Tony's site he simply has it wrong.

                                      The PA would be more dificult to determine on your own, just accept that it
                                      is 14.5.

                                      Anthony
                                      Berkeley, Calif.
                                      *************************************************

                                      In a message dated Sun Jun 8, 2008 8:17 pm (PDT), Brett Jones writes:

                                      Sorry for the late reply, I had wildfire training all weekend.

                                      I had to dig around to find this: "All Atlas 9-inch, 10-inch and 12-inch
                                      lathe used changewheels of 14DP with a 14.5-degree pressure angle."

                                      This line of text is at Tony's site, _http://www.lathes.http://www.lh_
                                      (http://www.lathes.co.uk/atlas/)





                                      **************Get trade secrets for amazing burgers. Watch "Cooking with
                                      Tyler Florence" on AOL Food.
                                      (http://food.aol.com/tyler-florence?video=4?&NCID=aolfod00030000000002)


                                      [Non-text portions of this message have been removed]
                                    • LouD31M066@aol.com
                                      Has anyone asked Clausing Atlas or gauged gears? Louis **************Get trade secrets for amazing burgers. Watch Cooking with Tyler Florence on AOL Food.
                                      Message 18 of 19 , Jun 9, 2008
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                                        Has anyone asked Clausing Atlas or gauged gears?
                                        Louis



                                        **************Get trade secrets for amazing burgers. Watch "Cooking with
                                        Tyler Florence" on AOL Food.
                                        (http://food.aol.com/tyler-florence?video=4?&NCID=aolfod00030000000002)


                                        [Non-text portions of this message have been removed]
                                      • Michael Fagan
                                        Someone with an optical comparator confirmed the Pressure Angle a couple years ago. ... [Non-text portions of this message have been removed]
                                        Message 19 of 19 , Jun 10, 2008
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                                          Someone with an optical comparator confirmed the Pressure Angle a couple
                                          years ago.

                                          On 6/9/08, LouD31M066@... <LouD31M066@...> wrote:
                                          >
                                          > Has anyone asked Clausing Atlas or gauged gears?
                                          > Louis
                                          >
                                          > **************Get trade secrets for amazing burgers. Watch "Cooking with
                                          > Tyler Florence" on AOL Food.
                                          > (http://food.aol.com/tyler-florence?video=4?&NCID=aolfod00030000000002)
                                          >
                                          > [Non-text portions of this message have been removed]
                                          >
                                          >
                                          >


                                          [Non-text portions of this message have been removed]
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