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Spinning - Spun R8 Collet in Spindle?

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  • scottdunt
    I just picked up and started inspection - rebuild on a 1988 Enco 103-1530 Mill Drill (RF 30 Clone). I ll get a photo album started and pictures added as I go.
    Message 1 of 15 , Nov 18, 2013
      I just picked up and started inspection - rebuild on a 1988 Enco 103-1530 Mill Drill (RF 30 Clone).

      I'll get a photo album started and pictures added as I go. But this unit has a variable speed belt drive built-in at the factory..

      The Enco parts people tell me it was built by a company called Fing in Tawain, who have gone out of business, and no parts are available.

      What I've found so far, is that the dog headed set screw that is supposed to hold the R8 collet from turning had fallen out.  Apparently the previous owner had been running it that way.  There is considerable wear to the top of the quill shaft and the back side of the drawbar nut that would seem to indicate turning - spinning. But I'm not sure how much of that is attempting to tighten collets for 25 years and how much might be from things spinning.

      I pulled the entire spindle to see why the collet would spin, so I've cleaned, inspected and re-greased the bearings. (Would NSK bearings in the spindle that were made in japan be original or might this have been repaired before?)

      I found the missing set screw during disassembly and now its reinstalled with LocTite on it of course.

      I only got the shaft pressed back in with the bearings, etc and didn't have time last night to get the TDI out and check the run out on the spindle taper.

      Has any one experienced issues like this?

      If they abused the machine and let the collets spin in the quill. Would that kind of 'lap' the taper in the spindle?  Isn't it actually the taper (when all tightened up) that does the actual holding, not the set screw.

      Enco's "no parts available" comment means, if this has excessive runout I'm on my own for a repair. Whats considered normal runout?  I assume .0000 is the ideal, but these must have some run out when new?

      If I have to repair it, my lathe can swallow the entire shaft, so that's not an issue.  I assume its possible to use a tool post grinder to touch up the taper in the quill shaft and the collets will just seat a little deeper?

      Any and ALL comments on similar situations are repairs are welcomed.
    • Corey Renner
      0.0002 runout is typical for a decent spindle. cheers, c Blog: http://coreyrenner.tumblr.com/ YouTube Channel: http://www.youtube.com/user/vandal968
      Message 2 of 15 , Nov 18, 2013
        0.0002 runout is typical for a decent spindle.

        cheers,
        c



        On Mon, Nov 18, 2013 at 7:36 AM, <scott.dunt@...> wrote:
         

        I just picked up and started inspection - rebuild on a 1988 Enco 103-1530 Mill Drill (RF 30 Clone).

        I'll get a photo album started and pictures added as I go. But this unit has a variable speed belt drive built-in at the factory..

        The Enco parts people tell me it was built by a company called Fing in Tawain, who have gone out of business, and no parts are available.

        What I've found so far, is that the dog headed set screw that is supposed to hold the R8 collet from turning had fallen out.  Apparently the previous owner had been running it that way.  There is considerable wear to the top of the quill shaft and the back side of the drawbar nut that would seem to indicate turning - spinning. But I'm not sure how much of that is attempting to tighten collets for 25 years and how much might be from things spinning.

        I pulled the entire spindle to see why the collet would spin, so I've cleaned, inspected and re-greased the bearings. (Would NSK bearings in the spindle that were made in japan be original or might this have been repaired before?)

        I found the missing set screw during disassembly and now its reinstalled with LocTite on it of course.

        I only got the shaft pressed back in with the bearings, etc and didn't have time last night to get the TDI out and check the run out on the spindle taper.

        Has any one experienced issues like this?

        If they abused the machine and let the collets spin in the quill. Would that kind of 'lap' the taper in the spindle?  Isn't it actually the taper (when all tightened up) that does the actual holding, not the set screw.

        Enco's "no parts available" comment means, if this has excessive runout I'm on my own for a repair. Whats considered normal runout?  I assume .0000 is the ideal, but these must have some run out when new?

        If I have to repair it, my lathe can swallow the entire shaft, so that's not an issue.  I assume its possible to use a tool post grinder to touch up the taper in the quill shaft and the collets will just seat a little deeper?

        Any and ALL comments on similar situations are repairs are welcomed.


      • Dave Seiter
        My TWS mill is missing the setscrew to keep the collet from spinning, but I ve never have a collet or other r8 tool spin. I don t put all that much torque on
        Message 3 of 15 , Nov 18, 2013
          My TWS mill is missing the setscrew to keep the collet from spinning, but I've never have a collet or other r8 tool spin. I don't put all that much torque on the drawbar either. I suppose a lot depends on the condition of the r8 tapers and if someone lubed them.

          -Dave
          --------------------------------------------
          On Mon, 11/18/13, scott.dunt@... <scott.dunt@...> wrote:

          Subject: [mill_drill] Spinning - Spun R8 Collet in Spindle?
          To: mill_drill@yahoogroups.com
          Date: Monday, November 18, 2013, 2:36 PM






























          I just picked up and started inspection - rebuild on a 1988
          Enco 103-1530 Mill Drill (RF 30 Clone).

          I'll get a photo album started and pictures added as I
          go. But this unit has a variable speed belt drive built-in
          at the factory..

          The Enco parts people tell me it
          was built by a company called Fing in Tawain, who have gone
          out of business, and no parts are available.

          What I've found so far, is that the dog headed set screw
          that is supposed to hold the R8 collet from turning had
          fallen out.  Apparently the previous owner had been
          running it that way.  There is considerable wear to the
          top of the quill shaft and the back side of the drawbar nut
          that would seem to indicate turning - spinning. But I'm
          not sure how much of that is attempting to tighten collets
          for 25 years and how much might be from things spinning.

          I pulled the entire spindle to see why the collet would
          spin, so I've cleaned, inspected and re-greased the
          bearings. (Would NSK bearings in the spindle that were made
          in japan be original or might this have been repaired
          before?)

          I found the missing set screw during disassembly and now its
          reinstalled with LocTite on it of course.

          I only got the shaft pressed back in with the bearings, etc
          and didn't have time last night to get the TDI out and
          check the run out on the spindle taper.

          Has any one experienced issues like this?

          If they abused the machine and let the collets spin in the
          quill. Would that kind of 'lap' the taper in the
          spindle?  Isn't it actually the taper (when all
          tightened up) that does the actual holding, not the set
          screw.

          Enco's "no parts available" comment means, if
          this has excessive runout I'm on my own for a repair.
          Whats considered normal runout?  I assume .0000 is the
          ideal, but these must have some run out when new?

          If I have to repair it, my lathe can swallow the entire
          shaft, so that's not an issue.  I assume its
          possible to use a tool post grinder to touch up the taper in
          the quill shaft and the collets will just seat a little
          deeper?

          Any and ALL comments on similar situations are repairs are
          welcomed.
        • Dave Seiter
          Sorry about the untrimmed reply- my emailer puts the previous text off-screen, so sometimes I forget it s there! -Dave
          Message 4 of 15 , Nov 18, 2013
            Sorry about the untrimmed reply- my emailer puts the previous text off-screen, so sometimes I forget it's there!

            -Dave
          • Scott Dunt
            That s good to know.. My TWS mill is missing the setscrew to keep the collet from spinning, but I ve never have a collet or other r8 tool spin. I don t put all
            Message 5 of 15 , Nov 18, 2013
              That's good to know..

              My TWS mill is missing the setscrew to keep the collet from spinning, but I've never have a collet or other r8 tool spin. I don't put all that much torque on the drawbar either. I suppose a lot depends on the condition of the r8 tapers and if someone lubed them.

              -Dave

              Right now all I have is the 7/16 collet that was in the spindle when I got it. Which I have my doubts about.

              Sounds like i need to order up some collets or arbors and use them as gauges to see what the situation is.
              -- 
              Scott Dunt
              
            • markknx
              Scott, Just to add a couple of things. The draw bar could be bad also. If it has bad threads or is to long one might think it was tight when it was not. Also
              Message 6 of 15 , Nov 18, 2013

                Scott,

                Just to add a couple of things. The draw bar could be bad also. If it has bad threads or is to long one might think it was tight when it was not. Also if the previous owner let swarf get in the taper that could cause the collet to spin

                The damage to the bottom of the draw bar could be from not loosening it enough before tapping it out. (So some people then beat instead of tap) most likelly the spinning did it though

                Mark 



                ---In mill_drill@yahoogroups.com, <scott.dunt@...> wrote:

                I just picked up and started inspection - rebuild on a 1988 Enco 103-1530 Mill Drill (RF 30 Clone).

                I'll get a photo album started and pictures added as I go. But this unit has a variable speed belt drive built-in at the factory..

                The Enco parts people tell me it was built by a company called Fing in Tawain, who have gone out of business, and no parts are available.

                What I've found so far, is that the dog headed set screw that is supposed to hold the R8 collet from turning had fallen out.  Apparently the previous owner had been running it that way.  There is considerable wear to the top of the quill shaft and the back side of the drawbar nut that would seem to indicate turning - spinning. But I'm not sure how much of that is attempting to tighten collets for 25 years and how much might be from things spinning.

                I pulled the entire spindle to see why the collet would spin, so I've cleaned, inspected and re-greased the bearings. (Would NSK bearings in the spindle that were made in japan be original or might this have been repaired before?)

                I found the missing set screw during disassembly and now its reinstalled with LocTite on it of course.

                I only got the shaft pressed back in with the bearings, etc and didn't have time last night to get the TDI out and check the run out on the spindle taper.

                Has any one experienced issues like this?

                If they abused the machine and let the collets spin in the quill. Would that kind of 'lap' the taper in the spindle?  Isn't it actually the taper (when all tightened up) that does the actual holding, not the set screw.

                Enco's "no parts available" comment means, if this has excessive runout I'm on my own for a repair. Whats considered normal runout?  I assume .0000 is the ideal, but these must have some run out when new?

                If I have to repair it, my lathe can swallow the entire shaft, so that's not an issue.  I assume its possible to use a tool post grinder to touch up the taper in the quill shaft and the collets will just seat a little deeper?

                Any and ALL comments on similar situations are repairs are welcomed.
              • leasingham_connelly
                I would say that what has been said many times here before once again holds true, Get a ER collet chuck and mount that in the spindle. R8 collets need to be an
                Message 7 of 15 , Nov 19, 2013

                   

                  I would say that what has been said many times here before once again holds true, Get a ER collet chuck and mount that in the spindle. R8 collets need to be an exact match for the tool, The double angle of the ER collets grips parallel over a range and so a set of 18 ER32 covers 2mm up to 20mm with no gaps. If the spindle taper is damaged then R8 collets may not work very well. The ER collet chuck will not care if the taper is not perfect as long as it mounts concentrically.
                   
                  Martin

                  ---In mill_drill@yahoogroups.com, <mayo3013@...> wrote:

                  Scott,

                  Just to add a couple of things. The draw bar could be bad also. If it has bad threads or is to long one might think it was tight when it was not. Also if the previous owner let swarf get in the taper that could cause the collet to spin

                  The damage to the bottom of the draw bar could be from not loosening it enough before tapping it out. (So some people then beat instead of tap) most likelly the spinning did it though

                  Mark 



                  ---In mill_drill@yahoogroups.com, <scott.dunt@...> wrote:

                  I just picked up and started inspection - rebuild on a 1988 Enco 103-1530 Mill Drill (RF 30 Clone).

                  I'll get a photo album started and pictures added as I go. But this unit has a variable speed belt drive built-in at the factory..

                  The Enco parts people tell me it was built by a company called Fing in Tawain, who have gone out of business, and no parts are available.

                  What I've found so far, is that the dog headed set screw that is supposed to hold the R8 collet from turning had fallen out.  Apparently the previous owner had been running it that way.  There is considerable wear to the top of the quill shaft and the back side of the drawbar nut that would seem to indicate turning - spinning. But I'm not sure how much of that is attempting to tighten collets for 25 years and how much might be from things spinning.

                  I pulled the entire spindle to see why the collet would spin, so I've cleaned, inspected and re-greased the bearings. (Would NSK bearings in the spindle that were made in japan be original or might this have been repaired before?)

                  I found the missing set screw during disassembly and now its reinstalled with LocTite on it of course.

                  I only got the shaft pressed back in with the bearings, etc and didn't have time last night to get the TDI out and check the run out on the spindle taper.

                  Has any one experienced issues like this?

                  If they abused the machine and let the collets spin in the quill. Would that kind of 'lap' the taper in the spindle?  Isn't it actually the taper (when all tightened up) that does the actual holding, not the set screw.

                  Enco's "no parts available" comment means, if this has excessive runout I'm on my own for a repair. Whats considered normal runout?  I assume .0000 is the ideal, but these must have some run out when new?

                  If I have to repair it, my lathe can swallow the entire shaft, so that's not an issue.  I assume its possible to use a tool post grinder to touch up the taper in the quill shaft and the collets will just seat a little deeper?

                  Any and ALL comments on similar situations are repairs are welcomed.
                • Scott Dunt
                  The drawbar is rather worn - messed up on the top end. Last night I cleaned up the flats on the head of it, and turned a square shoulder up to the head,
                  Message 8 of 15 , Nov 19, 2013
                    The drawbar is rather worn - messed up on the top end. Last night I
                    cleaned up the flats on the head of it, and turned a square shoulder up
                    to the head, removed about a 1/4 inch of worn section. Then I made a
                    brass spacer out of some scrap that I will use as a washer to compensate
                    for the worn section.

                    I ran a thread die over the drawbar threads and other than 125 year old
                    dried grease, I did not find much.

                    A bench test of the spindle shaft re-installed in the bearings
                    (re-greased) and pressed back into the quill housing (rack sleeve) shows
                    ZERO run out on the inside of the taper.. I used my (imported) finger
                    type TDI and there might a .0001 run out, but while turning the spindle
                    by hand the TDI did not move.

                    Of course that says nothing about real actual accuracy mounted in the
                    machine and running.

                    I'm wondering, does an R 8 Collect 'locate' itself based on the taper
                    only? Locate, probably. But I think I just figured why Bridgeport
                    designed R 8 collets that way. When you are milling and putting SIDE
                    PRESSURE on a cutter, the drawbar and the rear shank of the collet are
                    what transfers those side forces to the spindle. So IF the rear shank
                    is loose in the spindle, its possible under load for the collect to tip
                    sideways in the spindle. FUN....

                    The collect that was in the machine, and what tooling is 7/16 inch and
                    you might run at top speed?, the used collet in the machines has a shank
                    that measures .9475 - .948 with digital calipers, I know get the Mic's
                    out and check it for sure. The diagram I have says R 8 shank should be
                    .949 - .9495

                    Any ideas on the spec for the inside dimensions of the spindle? And BOY
                    is that going to be fun to measure.

                    Fortunately the solution to a worn spindle is possible. Modern
                    chemicals are just amazing. I could use Devcon steel putty or Titanium
                    putty to build up the recess in the spindle, then turn that back to the
                    correct size. I think because that area is for locating the collet and
                    transferring loads to the spindle, putty would be an acceptable repair.
                    The compression strength of this stuff is spec'd at 8,000 psi. So it
                    exceeds the strength of the 6,000 psi (6013) welding rod.

                    I need to temporarily mount one of my single phase motors to the
                    mill-drill so I can spin it up.

                    I'm watching this TECO VFD discussion with interest. Considering that
                    for a few bucks more than a new 1 1/2 hp single phase motor would cost
                    me I can add 3 phase capability and electronic variable speed to my
                    shop?? How cool is that.. When I can locate a cheap 3 phase motor for
                    the big lathe, I can swap the TECO box back and forth to the lathe and
                    not have to mess with the belts or back gears? Now that's COOL...

                    Thanks gang..

                    P.s. I love to 'rescue' old equipment.. I paid all of $124 for this
                    machine. Drove from Central Illinois to Omaha, NE to pick it up, 7 hours
                    each way. Ok I stopped at my brothers on the way back. But for what I've
                    got into this machine.. I am tickled silly.

                    --
                    Scott Dunt
                  • Scott Dunt
                    Thanks Martin. I ve actually been kind of thinking that way as well. With the potential to have to build up the inside of the spindle shaft on this guy. Using
                    Message 9 of 15 , Nov 19, 2013
                      Thanks Martin. I've actually been kind of thinking that way as well.

                      With the potential to have to build up the inside of the spindle shaft
                      on this guy. Using an ER adapter might be a really good idea. If I fine
                      tune the rebuild work I do to fit the ER 32 adapter perfectly, even if a
                      drill chuck adapter won't fit quite so perfectly, I could get some
                      really, really great setups that way..

                      The possibility of ER 32 in my shop also has some merits. I have a 7x
                      mini lathe and a 14 inch monarch model A lathe. Both of which only have
                      3 - 4 jaw chucks. Adding collects to the 14 inch has been on my list.
                      I was thinking along the lines of going 5C on that guy. But ER 32's
                      could be used on all three machines, both lathes and the mill.

                      That could be a really nice setup.

                      Scott Dunt

                      On 11/19/2013 07:54 AM, martin@... wrote:
                      > I would say that what has been said many times here before once again
                      > holds true, Get a ER collet chuck and mount that in the spindle. R8
                      > collets need to be an exact match for the tool, The double angle of
                      > the ER collets grips parallel over a range and so a set of 18 ER32
                      > covers 2mm up to 20mm with no gaps. If the spindle taper is damaged
                      > then R8 collets may not work very well. The ER collet chuck will not
                      > care if the taper is not perfect as long as it mounts concentrically.
                      > Martin
                    • internal_fire
                      Scott, Stop, take a deep breath, and consider what you have. This sort of machine is never going to provide tenth-type precision or accuracy. The rigidity,
                      Message 10 of 15 , Nov 19, 2013

                        Scott,


                        Stop, take a deep breath, and consider what you have. This sort of machine is never going to provide tenth-type precision or accuracy. The rigidity, tramming, vibration, etc. will far overshadow any slight runout in the spindle.


                        As others have pointed out, the little protrusion inside the spindle taper is very close to useless. Unless there is evidence of scoring it is unlikely that the collets have spun. If serious cutting forces have been used it is more likely that the tool spun inside the collet.


                        Perhaps you just like to tinker with old machines. However, if you simply want to use it the best advice is to fire it up and try it, as is.


                        Gene



                        ---In mill_drill@yahoogroups.com, <scott.dunt@...> wrote:

                        The drawbar is rather worn - messed up on the top end. Last night I
                        cleaned up the flats on the head of it, and turned a square shoulder up
                        to the head, removed about a 1/4 inch of worn section. Then I made a
                        brass spacer out of some scrap that I will use as a washer to compensate
                        for the worn section.

                        I ran a thread die over the drawbar threads and other than 125 year old
                        dried grease, I did not find much.

                        A bench test of the spindle shaft re-installed in the bearings
                        (re-greased) and pressed back into the quill housing (rack sleeve) shows
                        ZERO run out on the inside of the taper.. I used my (imported) finger
                        type TDI and there might a .0001 run out, but while turning the spindle
                        by hand the TDI did not move.

                        Of course that says nothing about real actual accuracy mounted in the
                        machine and running.

                        I'm wondering, does an R 8 Collect 'locate' itself based on the taper
                        only? Locate, probably. But I think I just figured why Bridgeport
                        designed R 8 collets that way. When you are milling and putting SIDE
                        PRESSURE on a cutter, the drawbar and the rear shank of the collet are
                        what transfers those side forces to the spindle. So IF the rear shank
                        is loose in the spindle, its possible under load for the collect to tip
                        sideways in the spindle. FUN....

                        The collect that was in the machine, and what tooling is 7/16 inch and
                        you might run at top speed?, the used collet in the machines has a shank
                        that measures .9475 - .948 with digital calipers, I know get the Mic's
                        out and check it for sure. The diagram I have says R 8 shank should be
                        .949 - .9495

                        Any ideas on the spec for the inside dimensions of the spindle? And BOY
                        is that going to be fun to measure.

                        Fortunately the solution to a worn spindle is possible. Modern
                        chemicals are just amazing. I could use Devcon steel putty or Titanium
                        putty to build up the recess in the spindle, then turn that back to the
                        correct size. I think because that area is for locating the collet and
                        transferring loads to the spindle, putty would be an acceptable repair.
                        The compression strength of this stuff is spec'd at 8,000 psi. So it
                        exceeds the strength of the 6,000 psi (6013) welding rod.

                        I need to temporarily mount one of my single phase motors to the
                        mill-drill so I can spin it up.

                        I'm watching this TECO VFD discussion with interest. Considering that
                        for a few bucks more than a new 1 1/2 hp single phase motor would cost
                        me I can add 3 phase capability and electronic variable speed to my
                        shop?? How cool is that.. When I can locate a cheap 3 phase motor for
                        the big lathe, I can swap the TECO box back and forth to the lathe and
                        not have to mess with the belts or back gears? Now that's COOL...

                        Thanks gang..

                        P.s. I love to 'rescue' old equipment.. I paid all of $124 for this
                        machine. Drove from Central Illinois to Omaha, NE to pick it up, 7 hours
                        each way. Ok I stopped at my brothers on the way back. But for what I've
                        got into this machine.. I am tickled silly.

                        --
                        Scott Dunt
                      • Scott Dunt
                        you are right. I have a bit of perfectionist in me. All of my machines have their limitations and run out. And I know it and work around it.. Now that I have
                        Message 11 of 15 , Nov 19, 2013
                          you are right. I have a bit of perfectionist in me. All of my machines
                          have their limitations and run out. And I know it and work around it..

                          Now that I have the spindle cleaned up and reinstalled and belts
                          tightened, etc. I need to get it spun up for sure. Patching the spindle
                          is a 'later' project.

                          For what its worth, I have a copy of the book "machine tool
                          reconditioning" by Edward Connelly (Hey, when a copy showed up for $30 I
                          bought it.)

                          There is a section on Vertical mills, Bridgeport style of course. And
                          the spec's given by them for spindle run out, if someone wants to
                          measure these things and I know how Rick Sparber likes to measure
                          things.:-). The run out at 1 1/4 inch from the spindle should be max of
                          .0005 and at 12 inches from the spindle, using ground standards rod in a
                          collet, should be .001 inches. Of course that's for Bridgeport.

                          Next step is actually lifting the unit back onto the base and bolting it
                          down then swapping in a test electric motor.

                          Scott Dunt

                          On 11/19/2013 08:47 AM, gefuller5@... wrote:
                          > Stop, take a deep breath, and consider what you have. This sort of
                          > machine is never going to provide tenth-type precision or accuracy.
                          > The rigidity, tramming, vibration, etc. will far overshadow any slight
                          > runout in the spindle.
                        • markknx
                          Scott, Can you tell me where you found reference to compression strength of 6013. Or are you refering to 60,000 psi tensil strength? ... The drawbar is rather
                          Message 12 of 15 , Nov 19, 2013

                            Scott,

                            Can you tell me  where you found reference to compression strength of 6013. Or are you refering to 60,000 psi tensil strength? 



                            ---In mill_drill@yahoogroups.com, <scott.dunt@...> wrote:

                            The drawbar is rather worn - messed up on the top end. Last night I
                            cleaned up the flats on the head of it, and turned a square shoulder up
                            to the head, removed about a 1/4 inch of worn section. Then I made a
                            brass spacer out of some scrap that I will use as a washer to compensate
                            for the worn section.

                            I ran a thread die over the drawbar threads and other than 125 year old
                            dried grease, I did not find much.

                            A bench test of the spindle shaft re-installed in the bearings
                            (re-greased) and pressed back into the quill housing (rack sleeve) shows
                            ZERO run out on the inside of the taper.. I used my (imported) finger
                            type TDI and there might a .0001 run out, but while turning the spindle
                            by hand the TDI did not move.

                            Of course that says nothing about real actual accuracy mounted in the
                            machine and running.

                            I'm wondering, does an R 8 Collect 'locate' itself based on the taper
                            only? Locate, probably. But I think I just figured why Bridgeport
                            designed R 8 collets that way. When you are milling and putting SIDE
                            PRESSURE on a cutter, the drawbar and the rear shank of the collet are
                            what transfers those side forces to the spindle. So IF the rear shank
                            is loose in the spindle, its possible under load for the collect to tip
                            sideways in the spindle. FUN....

                            The collect that was in the machine, and what tooling is 7/16 inch and
                            you might run at top speed?, the used collet in the machines has a shank
                            that measures .9475 - .948 with digital calipers, I know get the Mic's
                            out and check it for sure. The diagram I have says R 8 shank should be
                            .949 - .9495

                            Any ideas on the spec for the inside dimensions of the spindle? And BOY
                            is that going to be fun to measure.

                            Fortunately the solution to a worn spindle is possible. Modern
                            chemicals are just amazing. I could use Devcon steel putty or Titanium
                            putty to build up the recess in the spindle, then turn that back to the
                            correct size. I think because that area is for locating the collet and
                            transferring loads to the spindle, putty would be an acceptable repair.
                            The compression strength of this stuff is spec'd at 8,000 psi. So it
                            exceeds the strength of the 6,000 psi (6013) welding rod.

                            I need to temporarily mount one of my single phase motors to the
                            mill-drill so I can spin it up.

                            I'm watching this TECO VFD discussion with interest. Considering that
                            for a few bucks more than a new 1 1/2 hp single phase motor would cost
                            me I can add 3 phase capability and electronic variable speed to my
                            shop?? How cool is that.. When I can locate a cheap 3 phase motor for
                            the big lathe, I can swap the TECO box back and forth to the lathe and
                            not have to mess with the belts or back gears? Now that's COOL...

                            Thanks gang..

                            P.s. I love to 'rescue' old equipment.. I paid all of $124 for this
                            machine. Drove from Central Illinois to Omaha, NE to pick it up, 7 hours
                            each way. Ok I stopped at my brothers on the way back. But for what I've
                            got into this machine.. I am tickled silly.

                            --
                            Scott Dunt
                          • Scott Dunt
                            Whoops actually was thinking of tensile strength and also dropped a digit. So not quite so tough as 6013. But in this case might be strong enough. For
                            Message 13 of 15 , Nov 19, 2013
                              Whoops actually was thinking of tensile strength and also dropped a digit.  So not quite so tough as 6013. But in this case might be strong enough.  For example Devcon putty melts at 250 degrees. But if the shaft in the mill gets above the boiling point of water, we've got other problems.

                              But you are correct, thanks for the reply..

                              Scott Dunt
                              
                              On 11/19/2013 10:03 AM, mayo3013@... wrote:
                               

                              Scott,

                              Can you tell me  where you found reference to compression strength of 6013. Or are you refering to 60,000 psi tensil strength? 



                              ---In mill_drill@yahoogroups.com, <scott.dunt@...> wrote:

                              The drawbar is rather worn - messed up on the top end. Last night I
                              cleaned up the flats on the head of it, and turned a square shoulder up
                              to the head, removed about a 1/4 inch of worn section. Then I made a
                              brass spacer out of some scrap that I will use as a washer to compensate
                              for the worn section.

                              I ran a thread die over the drawbar threads and other than 125 year old
                              dried grease, I did not find much.

                              A bench test of the spindle shaft re-installed in the bearings
                              (re-greased) and pressed back into the quill housing (rack sleeve) shows
                              ZERO run out on the inside of the taper.. I used my (imported) finger
                              type TDI and there might a .0001 run out, but while turning the spindle
                              by hand the TDI did not move.

                              Of course that says nothing about real actual accuracy mounted in the
                              machine and running.

                              I'm wondering, does an R 8 Collect 'locate' itself based on the taper
                              onl y? Locate, probably. But I think I just figured why Bridgeport
                              designed R 8 collets that way. When you are milling and putting SIDE
                              PRESSURE on a cutter, the drawbar and the rear shank of the collet are
                              what transfers those side forces to the spindle. So IF the rear shank
                              is loose in the spindle, its possible under load for the collect to tip
                              sideways in the spindle. FUN....

                              The collect that was in the machine, and what tooling is 7/16 inch and
                              you might run at top speed?, the used collet in the machines has a shank
                              that measures .9475 - .948 with digital calipers, I know get the Mic's
                              out and check it for sure. The diagram I have says R 8 shank should be
                              .949 - .9495

                              Any ideas on the spec for the inside dimensions of the spindle? And BOY
                              is that going to be fun to measure.

                              Fortunately the solution to a worn spindle is possible. Modern
                              chemicals are just amazing. I could use Devcon steel putty or Titanium
                              putty to build up the recess in the spindle, then turn that back to the
                              correct size. I think because that area is for locating the collet and
                              transferring loads to the spindle, putty would be an acceptable repair.
                              The compression strength of this stuff is spec'd at 8,000 psi. So it
                              exceeds the strength of the 6,000 psi (6013) welding rod.

                              I need to temporarily mount one of my single phase motors to the
                              mill-drill so I can spin it up.

                              I'm watching this TECO VFD discussion with interest. Considering that
                              for a few bucks more than a new 1 1/2 hp single phase motor would cost
                              me I can add 3 phase capability and electronic variable speed to my
                              shop?? How cool is that.. When I can locate a cheap 3 phase motor for
                              the big lathe, I can swap the TECO box back and forth to the lathe and
                              not have to mess with the belts or back gears? Now that's COOL...

                              Thanks gang..

                              P.s. I love to 'rescue' old equipment.. I pai d all of $124 for this
                              machine. Drove from Central Illinois to Omaha, NE to pick it up, 7 hours
                              each way. Ok I stopped at my brothers on the way back. But for what I've
                              got into this machine.. I am tickled silly.

                              --
                              Scott Dunt

                            • davidhallsten
                              I might be a little late here but scott, if I were checking for slop in the spindle I would actually side- mill something with the largest diameter mill I had,
                              Message 14 of 15 , Nov 20, 2013

                                I might be a little late here but scott, if I were checking for slop in the spindle I would actually side- mill something with the largest diameter mill I had, one pass, then try to go back the way you came, very slowly,  are you getting swarf from that way too?  humm, of course, but would it be from slop in the spindle, or the end mill pushing itself away from the work on the first cut. . . either way, these small mills can only do so much without being overtaxed. 

                                just sayin. . . . . . 

                                yours is probably as good as anyone else's. 

                                when I got my rong fu 30, the R8 on the drill chuck couldn't start a hole without a major wobble.  I found that the drawbar was too friggin long by at least 3/8" and after shortening it by at least that amount it now is good as gold.  im using my hobby tools for mostly repairing things and making gadgets but its still not near what my Bridgeport was.   I just compensate accordingly.    



                                ---In mill_drill@yahoogroups.com, <scott.dunt@...> wrote:

                                Whoops actually was thinking of tensile strength and also dropped a digit.  So not quite so tough as 6013. But in this case might be strong enough.  For example Devcon putty melts at 250 degrees. But if the shaft in the mill gets above the boiling point of water, we've got other problems.

                                But you are correct, thanks for the reply..

                                Scott Dunt
                                
                                On 11/19/2013 10:03 AM, mayo3013@... wrote:
                                 

                                Scott,

                                Can you tell me  where you found reference to compression strength of 6013. Or are you refering to 60,000 psi tensil strength? 



                                ---In mill_drill@yahoogroups.com, <scott.dunt@...> wrote:

                                The drawbar is rather worn - messed up on the top end. Last night I
                                cleaned up the flats on the head of it, and turned a square shoulder up
                                to the head, removed about a 1/4 inch of worn section. Then I made a
                                brass spacer out of some scrap that I will use as a washer to compensate
                                for the worn section.

                                I ran a thread die over the drawbar threads and other than 125 year old
                                dried grease, I did not find much.

                                A bench test of the spindle shaft re-installed in the bearings
                                (re-greased) and pressed back into the quill housing (rack sleeve) shows
                                ZERO run out on the inside of the taper.. I used my (imported) finger
                                type TDI and there might a .0001 run out, but while turning the spindle
                                by hand the TDI did not move.

                                Of course that says nothing about real actual accuracy mounted in the
                                machine and running.

                                I'm wondering, does an R 8 Collect 'locate' itself based on the taper
                                onl y? Locate, probably. But I think I just figured why Bridgeport
                                designed R 8 collets that way. When you are milling and putting SIDE
                                PRESSURE on a cutter, the drawbar and the rear shank of the collet are
                                what transfers those side forces to the spindle. So IF the rear shank
                                is loose in the spindle, its possible under load for the collect to tip
                                sideways in the spindle. FUN....

                                The collect that was in the machine, and what tooling is 7/16 inch and
                                you might run at top speed?, the used collet in the machines has a shank
                                that measures .9475 - .948 with digital calipers, I know get the Mic's
                                out and check it for sure. The diagram I have says R 8 shank should be
                                .949 - .9495

                                Any ideas on the spec for the inside dimensions of the spindle? And BOY
                                is that going to be fun to measure.

                                Fortunately the solution to a worn spindle is possible. Modern
                                chemicals are just amazing. I could use Devcon steel putty or Titanium
                                putty to build up the recess in the spindle, then turn that back to the
                                correct size. I think because that area is for locating the collet and
                                transferring loads to the spindle, putty would be an acceptable repair.
                                The compression strength of this stuff is spec'd at 8,000 psi. So it
                                exceeds the strength of the 6,000 psi (6013) welding rod.

                                I need to temporarily mount one of my single phase motors to the
                                mill-drill so I can spin it up.

                                I'm watching this TECO VFD discussion with interest. Considering that
                                for a few bucks more than a new 1 1/2 hp single phase motor would cost
                                me I can add 3 phase capability and electronic variable speed to my
                                shop?? How cool is that.. When I can locate a cheap 3 phase motor for
                                the big lathe, I can swap the TECO box back and forth to the lathe and
                                not have to mess with the belts or back gears? Now that's COOL...

                                Thanks gang..

                                P.s. I love to 'rescue' old equipment.. I pai d all of $124 for this
                                machine. Drove from Central Illinois to Omaha, NE to pick it up, 7 hours
                                each way. Ok I stopped at my brothers on the way back. But for what I've
                                got into this machine.. I am tickled silly.

                                --
                                Scott Dunt

                              • Scott Dunt
                                WELL... It seems that this machine is trying to make a liar out of me.. I finally tested the spindle run out with .0001 (finger type) TDi and the run-out is
                                Message 15 of 15 , Nov 24, 2013
                                  WELL... It seems that this machine is trying to make a liar out of me..
                                  I finally tested the spindle run out with .0001 (finger type) TDi and
                                  the run-out is less than .0001. I tested with the spindle locked and
                                  running at slow speed and the indicator's needle stays in between 2
                                  lines on the dial.

                                  Saga is: I got the engine hoist (cherry picker) from my buddy and got
                                  the mill up on the stand. Stand is bolted to the concrete floor, the
                                  mill is bolted to the stand. Photos in my Album..

                                  The tooling I ordered to test with, R8 to JT6 arbor and 1/2 - 3 jaw
                                  chuck and a 3/8 capacity R8 collet (shars brand if that makes any
                                  different in the telling of this tale) arrived. Which is what I planned
                                  to use to test Run out on the spindle. At first I stuck the drill chuck
                                  arbor in the spindle, without the chuck, thinking that the taper that
                                  stuck down would be a good place to run an indicator.

                                  Then after thinking about it for a while, I decided that the indicator
                                  might move up or down on that taper and give a false reading.. So I
                                  switched to a straight shank, the new 3/8 collet and a new 3/8 end mill
                                  I have seemed like the right ticket.

                                  Now the fun starts, I pulled the drill arbor back out of the spindle,
                                  and attempted to install the 3/8 collet and end mill. I got the 3/8
                                  collet into the spindle to the point where the rear boss would start to
                                  engage and it would go no further. Light tapping on it would not help.
                                  Great. the arbor fits in the spindle, the old 7/16 collet that same with
                                  the machine goes in .. But my new 'precision shars' collet will not go in.

                                  Mic'd up the new 3/8 collet with a real mic and it reads .9495 which the
                                  notes I have says it is in spec, on the high end, but in spec. I turned
                                  the head to the side of the mill so I could look up into the spindle,
                                  and did not see any obstructions. I felt around the inside of the
                                  spindle with my fingers, looking for a bur, etc, nothing. I backed the
                                  dog headed set screw out thinking I might be holding the collet off
                                  center or something. No joy. The only indications were that my fingers
                                  came out kind of dirty.

                                  OK, so shop rag and paint thinner to clean up inside the spindle. I
                                  found that the head of the drawbar made a good tool to wrap the rag
                                  around. The first couple of swipes around got what might have been some
                                  swarf, or it might have been on the rag. I did not grab a completely new
                                  clean rag for this project. But I was getting dirt out of the spindle.

                                  Try the collet again, clean some more, try the collect, tap it with
                                  plastic faced dead blow, and it goes in.. YA!!. Tap it back out with the
                                  drawbar, there is some gunk - dirt on the collet shank, clean it off,
                                  clean the spindle.

                                  SOOO, all told, I have come to believe that the previous owners had a
                                  dirty spindle and might have been sanding or stoning down the collets to
                                  make them fit. With the spindle cleaned up the new 3/8 collet fits
                                  close, as in light machine oil and tap it a little to get it in and tap
                                  it a little to get it out.

                                  The drill arbor slides in place because the boss on it is .948 which is
                                  actually under spec, but for a drill chuck I have to wonder.

                                  And, my readings for run out just blow me away. I ran the indicator on
                                  the smooth shank of the end mill and turned the belts by hand and the
                                  indicator did not even move.. I double checked my setup to make sure the
                                  finger was against the shank and that I had not bumped it, etc. I know
                                  under power there are other forces placed on the spindle, so I ran it
                                  with a test motor to see and the run out is less than .0001.

                                  I have an old plunger type indicator that also does .0001 and I'm going
                                  to retest. That just seems crazy to me seeing how the machine was
                                  neglected..

                                  So, Ah, NO probably did NOT spin the collet in the spindle, or at least
                                  the spindle is not worn....

                                  Scott Dunt
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