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Re: Leadscrew

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  • drpshops
    ... of ... up. ... work ... I was wondering, are bicycle chains are the answer ,most bicycle chains and sprockets aren t designed for high speed or high torque
    Message 1 of 27 , Oct 31, 2006
      --- In multimachine@yahoogroups.com, "David G. LeVine" <dlevine@...>
      wrote:
      >
      > A couple of simplistic questions. Locally 1/2-20 threaded rod is
      > easy to obtain, would similar metric rod be easy to obtain in "out
      of
      > the way" places?
      >
      > Given 20 TPI, 2:1 gives 40 and 10 TPI, 13:20 gives 13 TPI and 30.7
      > (not useful) TPI, 16:20 gives 16 and 25 TPI, etc. All of these can
      > be gotten with bicycle chain and sprockets.
      >
      > Using 1 mm pitch, 1.25 is 5:4, or 20:16 Hmmm... a lot seem to line
      up.
      >
      > Has anyone looked inside an automatic transmission at the reverse
      > setup? If memory serves, it is a planetary gear set which might
      work
      > on an MM. Something common like a GM 2 speed Powerglide with bad
      > bands should be really cheap.
      >
      > Thoughts on Halloween. BOO!
      >
      > David G. LeVine
      > Nashua, NH 03060
      > Hello David
      I was wondering, are bicycle chains are the answer ,most bicycle
      chains and sprockets aren't designed for high speed or high torque
      service. Most of the larger sprockets are aluminum,and use a 3/32
      wide chain.Under severe service they would wear out quick.
      Maybe a larger chain would work better,a#35 chain would be a better
      size.
      Just my thoughts
      Keith
    • Jeff
      allthread sizes Ratio Master 2:1 1:2 1:4 5/8-11 5.6 22 44 9/16-12 6 24 48 1/2-13 6.5 26 52 7/16-14 7 28 56 3/8-16 8 32 64 5/16-18 9 36 72 1/4-20 10 40 80 Seven
      Message 2 of 27 , Oct 31, 2006
        allthread sizes
        Ratio
        Master 2:1 1:2 1:4
        5/8-11 5.6 22 44
        9/16-12 6 24 48
        1/2-13 6.5 26 52
        7/16-14 7 28 56
        3/8-16 8 32 64
        5/16-18 9 36 72
        1/4-20 10 40 80

        Seven pieces of allthread and three ratios covers all of the US sizes
        and a few not so usefull.
        David found a different way to get between these sizes. I was just
        happy to see that all of the thread pitches could be derived from a
        few easy to find pieces. Using the 1:2 ratio to cut a second set of
        masters could remove the need for the 1:4 ratio.
        I found a thread chart here.
        http://icrank.com/cgi-bin/pageman/pageout.cgi?
        path=/tapsizechart.htm&t=2
        Jeff

        --- In multimachine@yahoogroups.com, "David G. LeVine" <dlevine@...>
        wrote:
        >
        > A couple of simplistic questions. Locally 1/2-20 threaded rod is
        > easy to obtain, would similar metric rod be easy to obtain in "out
        of
        > the way" places?
        >
        > Given 20 TPI, 2:1 gives 40 and 10 TPI, 13:20 gives 13 TPI and 30.7
        > (not useful) TPI, 16:20 gives 16 and 25 TPI, etc. All of these can
        > be gotten with bicycle chain and sprockets.
        >
        > Using 1 mm pitch, 1.25 is 5:4, or 20:16 Hmmm... a lot seem to line
        up.
        >
        > Has anyone looked inside an automatic transmission at the reverse
        > setup? If memory serves, it is a planetary gear set which might
        work
        > on an MM. Something common like a GM 2 speed Powerglide with bad
        > bands should be really cheap.
        >
        > Thoughts on Halloween. BOO!
        >
        > David G. LeVine
        > Nashua, NH 03060
        >
      • Pat Delany
        Thanks Jeff! This is almost unreal! I do need help with something else. Advancing the cutting tool on an external cut or threading operation is easy if a screw
        Message 3 of 27 , Nov 1 5:44 AM
          Thanks Jeff!
          This is almost unreal!

          I do need help with something else. Advancing the
          cutting tool on an external cut or threading operation
          is easy if a screw is put in the carriage so that it
          can push the cutter out. However I can't think of a
          simple or easily built way to adjust the boring bar
          cutting or threading bit. The boring bar itself needs
          to be adjusted with some sort of an adjustment screw
          on the second (boring)carriage. Any ideas?

          Pat

          --- Jeff <jhan5en@...> wrote:

          > allthread sizes
          > Ratio
          > Master 2:1 1:2 1:4
          > 5/8-11 5.6 22 44
          > 9/16-12 6 24 48
          > 1/2-13 6.5 26 52
          > 7/16-14 7 28 56
          > 3/8-16 8 32 64
          > 5/16-18 9 36 72
          > 1/4-20 10 40 80
          >
          > Seven pieces of allthread and three ratios covers
          > all of the US sizes
          > and a few not so usefull.
          > David found a different way to get between these
          > sizes. I was just
          > happy to see that all of the thread pitches could be
          > derived from a
          > few easy to find pieces. Using the 1:2 ratio to cut
          > a second set of
          > masters could remove the need for the 1:4 ratio.
          > I found a thread chart here.
          > http://icrank.com/cgi-bin/pageman/pageout.cgi?
          > path=/tapsizechart.htm&t=2
          > Jeff
          >
          > --- In multimachine@yahoogroups.com, "David G.
          > LeVine" <dlevine@...>
          > wrote:
          > >
          > > A couple of simplistic questions. Locally 1/2-20
          > threaded rod is
          > > easy to obtain, would similar metric rod be easy
          > to obtain in "out
          > of
          > > the way" places?
          > >
          > > Given 20 TPI, 2:1 gives 40 and 10 TPI, 13:20 gives
          > 13 TPI and 30.7
          > > (not useful) TPI, 16:20 gives 16 and 25 TPI, etc.
          > All of these can
          > > be gotten with bicycle chain and sprockets.
          > >
          > > Using 1 mm pitch, 1.25 is 5:4, or 20:16 Hmmm... a
          > lot seem to line
          > up.
          > >
          > > Has anyone looked inside an automatic transmission
          > at the reverse
          > > setup? If memory serves, it is a planetary gear
          > set which might
          > work
          > > on an MM. Something common like a GM 2 speed
          > Powerglide with bad
          > > bands should be really cheap.
          > >
          > > Thoughts on Halloween. BOO!
          > >
          > > David G. LeVine
          > > Nashua, NH 03060
          > >
          >
          >
          >
          >




          ____________________________________________________________________________________
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          (http://smallbusiness.yahoo.com)
        • Pat Delany
          It could be just a part of a bolt instead of allthread. Also I think the problem of a long piece of allthread whipping around was addressed in an earlier post
          Message 4 of 27 , Nov 1 5:56 AM
            It could be just a part of a bolt instead of allthread. Also I think
            the problem of a long piece of allthread whipping around was addressed
            in an earlier post with the suggestion that a small tailstock could
            be added to support the end of long pieces of allthread.

            Pat
            --- In multimachine@yahoogroups.com, "David G. LeVine" <dlevine@...>
            wrote:
            >
            > A couple of simplistic questions. Locally 1/2-20 threaded rod is
            > easy to obtain, would similar metric rod be easy to obtain in "out of
            > the way" places?
            >
            > Given 20 TPI, 2:1 gives 40 and 10 TPI, 13:20 gives 13 TPI and 30.7
            > (not useful) TPI, 16:20 gives 16 and 25 TPI, etc. All of these can
            > be gotten with bicycle chain and sprockets.
            >
            > Using 1 mm pitch, 1.25 is 5:4, or 20:16 Hmmm... a lot seem to line up.
            >
            > Has anyone looked inside an automatic transmission at the reverse
            > setup? If memory serves, it is a planetary gear set which might work
            > on an MM. Something common like a GM 2 speed Powerglide with bad
            > bands should be really cheap.
            >
            > Thoughts on Halloween. BOO!
            >
            > David G. LeVine
            > Nashua, NH 03060
            >
          • Pat Delany
            ... I had always assumed that the chain would be easy to remove between threading operations. Pat
            Message 5 of 27 , Nov 1 6:12 AM
              --- In multimachine@yahoogroups.com, "drpshops" <drpshops@...> wrote:
              >
              > --- In multimachine@yahoogroups.com, "David G. LeVine" <dlevine@>
              > wrote:
              > >
              > > A couple of simplistic questions. Locally 1/2-20 threaded rod is
              > > easy to obtain, would similar metric rod be easy to obtain in "out
              > of
              > > the way" places?
              > >
              > > Given 20 TPI, 2:1 gives 40 and 10 TPI, 13:20 gives 13 TPI and 30.7
              > > (not useful) TPI, 16:20 gives 16 and 25 TPI, etc. All of these can
              > > be gotten with bicycle chain and sprockets.
              > >
              > > Using 1 mm pitch, 1.25 is 5:4, or 20:16 Hmmm... a lot seem to line
              > up.
              > >
              > > Has anyone looked inside an automatic transmission at the reverse
              > > setup? If memory serves, it is a planetary gear set which might
              > work
              > > on an MM. Something common like a GM 2 speed Powerglide with bad
              > > bands should be really cheap.
              > >
              > > Thoughts on Halloween. BOO!
              > >
              > > David G. LeVine
              > > Nashua, NH 03060
              > > Hello David
              > I was wondering, are bicycle chains are the answer ,most bicycle
              > chains and sprockets aren't designed for high speed or high torque
              > service. Most of the larger sprockets are aluminum,and use a 3/32
              > wide chain.Under severe service they would wear out quick.
              > Maybe a larger chain would work better,a#35 chain would be a better
              > size.
              > Just my thoughts
              > Keith
              >

              I had always assumed that the chain would be easy to remove between
              threading operations.

              Pat
            • Jeff
              Keith The chart looked good when I published it, was almost readable when Yahoo posted it, has become useless after a few reposts but you get the idea. I
              Message 6 of 27 , Nov 1 8:22 AM
                Keith

                The chart looked good when I published it, was almost readable when
                Yahoo posted it, has become useless after a few reposts but you get
                the idea.
                I wasn't to woried about the chain mainly because most people will be
                using less than a 2 horse motor on the MM. If you were to drive it
                with a gas motor and try to make a real cut you would probably need to
                replace the drill chuck with a more positive drive system then the
                chain chain would probably come into play next. I think that you could
                easily put 1/2 hp through a bicycle chain without worying about it. My
                son gets the best quality bicycle chain from used garage door openers.
                A garage door opener is usualy at least 1/2 hp, geared way down and
                the chain isn't the weak link.
                The allthread is pinched between two pieces of hardwood to drive the
                carraige. Unless you have a realy long threading job I dont think that
                it should whip. Adding a bushing and pillow block to the end is an
                easy fix. Make it a thrust surface as well and you can help to control
                any end play issues that you may have.
                Jeff

                --- In multimachine@yahoogroups.com, "Pat Delany" <rigmatch@...> wrote:
                >
                > --- In multimachine@yahoogroups.com, "drpshops" <drpshops@> wrote:
                > >
                > > --- In multimachine@yahoogroups.com, "David G. LeVine" <dlevine@>
                > > wrote:
                > > >
                > > > A couple of simplistic questions. Locally 1/2-20 threaded rod is
                > > > easy to obtain, would similar metric rod be easy to obtain in "out
                > > of
                > > > the way" places?
                > > >
                > > > Given 20 TPI, 2:1 gives 40 and 10 TPI, 13:20 gives 13 TPI and 30.7
                > > > (not useful) TPI, 16:20 gives 16 and 25 TPI, etc. All of these can
                > > > be gotten with bicycle chain and sprockets.
                > > >
                > > > Using 1 mm pitch, 1.25 is 5:4, or 20:16 Hmmm... a lot seem to line
                > > up.
                > > >
                > > > Has anyone looked inside an automatic transmission at the reverse
                > > > setup? If memory serves, it is a planetary gear set which might
                > > work
                > > > on an MM. Something common like a GM 2 speed Powerglide with bad
                > > > bands should be really cheap.
                > > >
                > > > Thoughts on Halloween. BOO!
                > > >
                > > > David G. LeVine
                > > > Nashua, NH 03060
                > > > Hello David
                > > I was wondering, are bicycle chains are the answer ,most bicycle
                > > chains and sprockets aren't designed for high speed or high torque
                > > service. Most of the larger sprockets are aluminum,and use a 3/32
                > > wide chain.Under severe service they would wear out quick.
                > > Maybe a larger chain would work better,a#35 chain would be a better
                > > size.
                > > Just my thoughts
                > > Keith
                > >
                >
                > I had always assumed that the chain would be easy to remove between
                > threading operations.
                >
                > Pat
                >
              • David G. LeVine
                ... Running a leadscrew for threading is neither high speed nor high torque, or I would not have suggested ANY chain. When a chain lets go at high speed, it
                Message 7 of 27 , Nov 2 9:51 AM
                  >I was wondering, are bicycle chains are the answer ,most bicycle
                  >chains and sprockets aren't designed for high speed or high torque
                  >service. Most of the larger sprockets are aluminum,and use a 3/32
                  >wide chain.Under severe service they would wear out quick.
                  > Maybe a larger chain would work better,a#35 chain would be a better
                  >size.

                  Running a leadscrew for threading is neither high speed nor high
                  torque, or I would not have suggested ANY chain. When a chain lets
                  go at high speed, it can be VERY damaging.

                  As an alternative, has anyone looked at an automotive timing chain
                  and sprockets? All are 2:1 and are designed to survive 6,000 RPM
                  (with splash lubrication). Timing belts ( for OHC vehicles) are
                  designed to handle 6,000 RPM with no lubrication for over 1,000 hours
                  of operation. Okay, not as clean as a QC gearbox, but...


                  David G. LeVine
                  Nashua, NH 03060


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                • David G. LeVine
                  As a thought, centerdrill the allthread (yes, an MM will do that pretty well with a cheap center drill.) Centerdrill a hunk of angle iron on the flat. Put a
                  Message 8 of 27 , Nov 2 9:57 AM
                    As a thought, centerdrill the allthread (yes, an MM will do that
                    pretty well with a cheap center drill.)

                    Centerdrill a hunk of angle iron on the flat.

                    Put a ball from a ball bearing between the two.

                    Viola! You now have both a good, low friction thrust bearing and a
                    good, low friction radial bearing. A drop of oil or grease to
                    prevent galling and thread away.

                    ============O>|
                    Allthread Bearing Angle with centerdrill hole

                    David G. LeVine
                    Nashua, NH 03060


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                    Checked by AVG Free Edition.
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