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Re: [mill_drill] fenner belts installed, surface finish improved, but...

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  • figNoggle
    hi rick- thanks for your comments. please see below: MetalWorkingFAQ.NET - Over 50 content sites! CNC, Plans/Kits, 8x12 Lathe,
    Message 1 of 26 , Feb 2, 2007
      hi rick-

      thanks for your comments. please see below:


      MetalWorkingFAQ.NET - Over 50 content sites! <http://www.metalworkingfaq.net>
      CNC, Plans/Kits, 8x12 Lathe, Mini-Mill, How-Tos <http://www.fignoggle.com>
      Sieg X3/Super X3 Mill Information, HF/Enco Coupons <http://www.superx3.com>

      On Thu, 1 Feb 2007 rgsparber@... wrote:

      > David,
      >
      > I read in your last article that you were running 10 to 15 IPM. That seems
      > VERY fast to me.
      >

      i may have overstated it. even at lower snail's pace movements on the
      order of a few ipms, the surface finish didn't quite improve as i had
      hoped. i didn't mention that a fly cutter was also used to see if the
      finish could be improved over the initial test. it was - but not to our
      liking. even our little x2 mini-mill makes a mirror-smooth finish..

      > I was chasing 2 thou of cut error today with my new link belts after
      > thinking the problem was solved. After spoiling yet another part, I figured out the
      > problem was feed rate. At max speed (maybe 6 IPM), I got an OK surface finish
      > but the cutter seems to have pulled the head down about 2 thou or the
      > vibration of the head was up and down 2 thou. Slowing down to 1.5 IPM gave me a
      > wonderful finish plus an agreement between intended cut via DRO and measured
      > result via mic of less than 0.5 thou. My finished thickness was off 0.3 thou.
      >
      > Independent of feed rate, if you are getting strange sounds from your
      > spindle, I would pull the bearings, flush them out, closely inspect them for wear,
      > and if they are otherwise OK, repack them. If they are damaged, buy new ones.
      > I did this once and don't recall it being difficult once I got the pulley
      > off. Be careful as you remove the pulley because it is easy to crack. I ended
      > up nudging it up with a block of wood under it. I tried using a puller but it
      > was clear to me that the pulley would crack before it would come off.
      >
      > When you run the mill at a high spindle RPM, do the bearings get hot? That
      > can be a sign of too much tension on the bearings, loss of lubricant, or dirt
      > in the ball race.
      >

      no heat to the touch. the spindle makes noise under two conditons: 1. when
      the quill lock is tightened (kind of a light crunching sound?) and 2. when
      the motor's shut off and things wind down.

      can the spindle pulley be removed without a puller? haven't checked
      yet, but it looks like after that large nut's removed, there must be a
      keyway in the pulley?

      thanks!
      david

      > Rick Sparber
      > rgsparber@...
      > web site: http://rick.sparber.org
      >
    • figNoggle
      hi malcom- MetalWorkingFAQ.NET - Over 50 content sites! CNC, Plans/Kits, 8x12 Lathe, Mini-Mill, How-Tos
      Message 2 of 26 , Feb 2, 2007
        hi malcom-


        MetalWorkingFAQ.NET - Over 50 content sites! <http://www.metalworkingfaq.net>
        CNC, Plans/Kits, 8x12 Lathe, Mini-Mill, How-Tos <http://www.fignoggle.com>
        Sieg X3/Super X3 Mill Information, HF/Enco Coupons <http://www.superx3.com>

        On Fri, 2 Feb 2007, Malcolm Parker-Lisberg wrote:

        > I think that the spindle bearing is the root of all
        > the problems. The vibration is caused by the spindle
        > not by the motors or belts. I am prepared to be proved
        > wrong.
        >

        the motor does vibrate (like a low frequency rumble), but the only other
        thing to isolate would be the spindle, so that's going to be removed and
        inspected soon. :) will report back.

        i also wonder if the stand is contributing to the vibration. it's a pretty
        nice welded unit of decently thick quage sheet metal, but perhaps bolting
        hte mill down to a workbench with substance may help a bit. this will be
        the last resort.

        thanks!
        david


        >
        >
        >
        > --- figNoggle <david@...> wrote:
        >
        > >
        > > hi all-
        > >
        > > this post follows rick's recent posts about his
        > > installation of the fenner
        > > belts. surface finish is much improved!
        > >
        > > here are some posted pictures and videos of the
        > > outcome after installing
        > > the fenner belts, but would like to get some insight
        > > into this noise
        > > that's coming from the spindle cartridge. we're
        > > going to take this apart
        > > soon and perform a clean-up and adjustment to
        > > rule-out spindle looseness,
        > > but wanted to get some advice as well.
        > >
        > > in this recent post, we talk about the belt upgrade
        > > improving surface
        > > finish:
        > >
        > > <http://tinyurl.com/35lqfa>
        > > or
        > >
        > <http://www.fignoggle.com/machines/round-column-mill-drills/standard-v-belts-vs-fenner-power-twist-plus-adjust-a-link-belts.htm>
        > >
        > > at the bottom of the page is a video titled "spindle
        > > noise?". what's the
        > > sound after the motor's shut off and the spindle
        > > winds down?
        > >
        > > thanks!
        > > david
        > >
        > >
        > > MetalWorkingFAQ.NET - Over 50 content sites!
        > > <http://www.metalworkingfaq.net>
        > > CNC, Plans/Kits, 8x12 Lathe, Mini-Mill, How-Tos
        > > <http://www.fignoggle.com>
        > > Sieg X3/Super X3 Mill Information, HF/Enco Coupons
        > > <http://www.superx3.com>
        > >
        >
        >
        >
        >
        > ____________________________________________________________________________________
        > Food fight? Enjoy some healthy debate
        > in the Yahoo! Answers Food & Drink Q&A.
        > http://answers.yahoo.com/dir/?link=list&sid=396545367
        >
      • rgsparber@aol.com
        Some confusion here. My machine is well behaved now. It was solved with the new belts, better shimming, and slower feed rate. I now get a great finish plus
        Message 3 of 26 , Feb 2, 2007
          Some confusion here. My machine is well behaved now. It was solved with the new belts, better shimming, and slower feed rate. I now get a great finish plus decent accuracy.
           
          Rick Sparber
          rgsparber@...
          web site: http://rick.sparber.org
        • rgsparber@aol.com
          In a message dated 2/2/2007 10:51:55 A.M. US Mountain Standard Time, david@fignoggle.com writes: can the spindle pulley be removed without a puller? haven t
          Message 4 of 26 , Feb 2, 2007
            In a message dated 2/2/2007 10:51:55 A.M. US Mountain Standard Time, david@... writes:
            can the spindle pulley be removed without a puller? haven't checked
            yet, but it looks like after that large nut's removed, there must be a
            keyway in the pulley?
            I used a block of pine, rubber mallet, and a gentle touch to move the pulley up and off the taper after removing the large nut. I don't recall any keyway.
             
            As for "acceptable finish", that is in the eyes of the beholder. With the finish I get now using a 5/8" end mill, I can remove all tooling marks with about 10 passes on 600 grit emery cloth that is resting on my surface plate. Does that help?
             
            Rick Sparber
            rgsparber@...
            web site: http://rick.sparber.org
          • n5kzw
            To kill vibration, one of the best tools is something that absorbs the vibrations in an inelastic manner. Steel is very elastic. Wood and sand are very
            Message 5 of 26 , Feb 3, 2007
              To kill vibration, one of the best tools is something that absorbs the
              vibrations in an inelastic manner. Steel is very elastic. Wood and
              sand are very inelastic. A bunch of sand bags in the base may improve
              the vibration problem.

              Regards,
              Ed

              --- In mill_drill@yahoogroups.com, figNoggle <david@...> wrote:
              >
              >
              >
              > hi malcom-
              >
              >
              > MetalWorkingFAQ.NET - Over 50 content sites!
              <http://www.metalworkingfaq.net>
              > CNC, Plans/Kits, 8x12 Lathe, Mini-Mill, How-Tos
              <http://www.fignoggle.com>
              > Sieg X3/Super X3 Mill Information, HF/Enco Coupons
              <http://www.superx3.com>
              >
              > On Fri, 2 Feb 2007, Malcolm Parker-Lisberg wrote:
              >
              > > I think that the spindle bearing is the root of all
              > > the problems. The vibration is caused by the spindle
              > > not by the motors or belts. I am prepared to be proved
              > > wrong.
              > >
              >
              > the motor does vibrate (like a low frequency rumble), but the only other
              > thing to isolate would be the spindle, so that's going to be removed and
              > inspected soon. :) will report back.
              >
              > i also wonder if the stand is contributing to the vibration. it's a
              pretty
              > nice welded unit of decently thick quage sheet metal, but perhaps
              bolting
              > hte mill down to a workbench with substance may help a bit. this will be
              > the last resort.
              >
              > thanks!
              > david
            • rgsparber@aol.com
              In a message dated 2/3/2007 3:13:42 P.M. US Mountain Standard Time, n5kzw@arrl.net writes: To kill vibration, one of the best tools is something that absorbs
              Message 6 of 26 , Feb 3, 2007
                In a message dated 2/3/2007 3:13:42 P.M. US Mountain Standard Time, n5kzw@... writes:
                To kill vibration, one of the best tools is something that absorbs the
                vibrations in an inelastic manner.  Steel is very elastic.  Wood and
                sand are very inelastic.  A bunch of sand bags in the base may improve
                the vibration problem.
                Ed,
                 
                What do you think of filling the column with sand?
                 
                Rick Sparber
                rgsparber@...
                web site: http://rick.sparber.org
              • rmskutertrash@aol.com
                Rick- If your bench could support it, lead shot would be best Richard
                Message 7 of 26 , Feb 3, 2007
                  Rick- If your bench could support it, lead shot would be best <G>
                  Richard
                • rgsparber@aol.com
                  In a message dated 2/3/2007 5:27:28 P.M. US Mountain Standard Time, rmskutertrash@aol.com writes: Rick- If your bench could support it, lead shot would be
                  Message 8 of 26 , Feb 3, 2007
                    In a message dated 2/3/2007 5:27:28 P.M. US Mountain Standard Time, rmskutertrash@... writes:
                    Rick- If your bench could support it, lead shot would be best <G>
                    I would prefer not to handle lead plus it is my understanding that lead shot is not that common anymore. What about using cement?
                     
                    Rick Sparber
                    rgsparber@...
                    web site: http://rick.sparber.org
                  • rmskutertrash@aol.com
                    The cement might be a little irreversible. One thing about the sand, it would be cheap. Perhaps there is some form of like a 2 part foam out there with
                    Message 9 of 26 , Feb 3, 2007
                      The cement might be a little irreversible. One thing about the sand, it would be cheap. Perhaps there is some form of like a 2 part foam out there with vibration damping qualities. More Googling I guess.
                      Richard
                    • rgsparber@aol.com
                      Richard, I found foams that might work but they are expensive and possibly even harder to remove than concrete. I think I will try filling the column with
                      Message 10 of 26 , Feb 4, 2007
                        Richard,
                         
                        I found foams that might work but they are expensive and possibly even harder to remove than concrete.
                         
                        I think I will try filling the column with sand since I have that on hand. If it does not work, I can remove the bottom stopper and let gravity do the work of removing it.
                         
                        My son-in-law is a civil engineer. He suggested using 3000 psi grout cement but also warned, as you have, that it would not be fun to remove later.
                         
                        Rick Sparber
                        rgsparber@...
                        web site: http://rick.sparber.org
                      • rmskutertrash@aol.com
                        I like simple cheap empirical experiments. The sand idea certainly fits into that realm. Of course, that will need to expand into a sand type/quality/grain
                        Message 11 of 26 , Feb 4, 2007
                          I like simple cheap empirical experiments. The sand idea certainly fits into that realm. Of course, that will need to expand into a sand type/quality/grain discussion <G>. I do believe our Arizona sand would be superior to lesser grades LOL
                          Richard
                        • Malcolm Parker-Lisberg
                          It my reasoning that only if things were wildly out of balance would any vibration make its way to the spindle and to the cutter or you hit alternatively when
                          Message 12 of 26 , Feb 5, 2007
                            It my reasoning that only if things were wildly out of
                            balance would any vibration make its way to the
                            spindle and to the cutter or you hit alternatively
                            when you hit the natural mechanical resonant frequency
                            of something. The flexibility of the belts would
                            absorb impulse vibrations and would be most unlikely
                            to manifest themselves at the cutter. The belt is an
                            elastic medium and will tend to smooth out any
                            variations. The cutter must be moving axialy, either
                            in twist ie. side to side, or up and down to be
                            detectable in the cut. With the spindle locked,
                            healthy spindle bearings and the correct preload
                            should take care of any tendency to do that.


                            --- figNoggle <david@...> wrote:

                            >
                            >
                            > hi malcom-
                            >
                            >
                            > MetalWorkingFAQ.NET - Over 50 content sites!
                            > <http://www.metalworkingfaq.net>
                            > CNC, Plans/Kits, 8x12 Lathe, Mini-Mill, How-Tos
                            > <http://www.fignoggle.com>
                            > Sieg X3/Super X3 Mill Information, HF/Enco Coupons
                            > <http://www.superx3.com>
                            >
                            > On Fri, 2 Feb 2007, Malcolm Parker-Lisberg wrote:
                            >
                            > > I think that the spindle bearing is the root of
                            > all
                            > > the problems. The vibration is caused by the
                            > spindle
                            > > not by the motors or belts. I am prepared to be
                            > proved
                            > > wrong.
                            > >
                            >
                            > the motor does vibrate (like a low frequency
                            > rumble), but the only other
                            > thing to isolate would be the spindle, so that's
                            > going to be removed and
                            > inspected soon. :) will report back.
                            >
                            > i also wonder if the stand is contributing to the
                            > vibration. it's a pretty
                            > nice welded unit of decently thick quage sheet
                            > metal, but perhaps bolting
                            > hte mill down to a workbench with substance may help
                            > a bit. this will be
                            > the last resort.
                            >
                            > thanks!
                            > david
                            >
                            >
                            > >
                            > >
                            > >
                            > > --- figNoggle <david@...> wrote:
                            > >
                            > > >
                            > > > hi all-
                            > > >
                            > > > this post follows rick's recent posts about his
                            > > > installation of the fenner
                            > > > belts. surface finish is much improved!
                            > > >
                            > > > here are some posted pictures and videos of the
                            > > > outcome after installing
                            > > > the fenner belts, but would like to get some
                            > insight
                            > > > into this noise
                            > > > that's coming from the spindle cartridge. we're
                            > > > going to take this apart
                            > > > soon and perform a clean-up and adjustment to
                            > > > rule-out spindle looseness,
                            > > > but wanted to get some advice as well.
                            > > >
                            > > > in this recent post, we talk about the belt
                            > upgrade
                            > > > improving surface
                            > > > finish:
                            > > >
                            > > > <http://tinyurl.com/35lqfa>
                            > > > or
                            > > >
                            > >
                            >
                            <http://www.fignoggle.com/machines/round-column-mill-drills/standard-v-belts-vs-fenner-power-twist-plus-adjust-a-link-belts.htm>
                            > > >
                            > > > at the bottom of the page is a video titled
                            > "spindle
                            > > > noise?". what's the
                            > > > sound after the motor's shut off and the spindle
                            > > > winds down?
                            > > >
                            > > > thanks!
                            > > > david
                            > > >
                            > > >
                            > > > MetalWorkingFAQ.NET - Over 50 content sites!
                            > > > <http://www.metalworkingfaq.net>
                            > > > CNC, Plans/Kits, 8x12 Lathe, Mini-Mill, How-Tos
                            > > > <http://www.fignoggle.com>
                            > > > Sieg X3/Super X3 Mill Information, HF/Enco
                            > Coupons
                            > > > <http://www.superx3.com>
                            > > >
                            > >
                            > >
                            > >
                            > >
                            > >
                            >
                            ____________________________________________________________________________________
                            > > Food fight? Enjoy some healthy debate
                            > > in the Yahoo! Answers Food & Drink Q&A.
                            > >
                            >
                            http://answers.yahoo.com/dir/?link=list&sid=396545367
                            > >
                            >




                            ____________________________________________________________________________________
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                          • corey renner
                            The motor vibrates in synch with the 60Hz power that s driving it. A Three phase motor is smoother and provides a better surface finish on the parts as a
                            Message 13 of 26 , Feb 5, 2007
                              The motor vibrates in synch with the 60Hz power that's driving it.  A Three phase motor is smoother and provides a better surface finish on the parts as a result.  I too was skeptical of the claims of improved finish with a fenner belt, so I did an experiment with a block of 6061.  One pass with the rubber belt, changed belt, then another pass with the fenner next to the first.  Same speed, same feed, same lube, same direction of feed, moments apart.  The fenner belt gave a better finish.  It wasn't an enormous difference and other factors were much more important (speed, feed cutter, etc.) but the two passes were definitely different and you could easily see that one was a little better than the other.  The downside to the fenners that I haven't seen anytone mention is that on small-diameter pulleys they slip much more readily than solid rubber belts.  On a 6"+ dia pulley, they transmit power well, but when trying for large speed reductions, I've tried them on small (maybe 3") pulleys, and had a lot of slip, enough that I had to go back to solid rubber belts to complete that particular operation.

                              cheers,
                              c

                              On 2/5/07, Malcolm Parker-Lisberg <mparkerlisberg@...> wrote:

                              It my reasoning that only if things were wildly out of
                              balance would any vibration make its way to the
                              spindle and to the cutter or you hit alternatively


                            • Malcolm Parker-Lisberg
                              Split Phase motors (capacitor start/run) do not transmit much 60 Hz vibrations, only that due to the magnetostrictive properties of the laminated iron core and
                              Message 14 of 26 , Feb 5, 2007
                                Split Phase motors (capacitor start/run) do not transmit much 60 Hz vibrations, only that due to the magnetostrictive properties of the laminated iron core and that is small. Most of the vibration is at a low frequency, a few Hz, due to the difference in speed from the synchronous speed required to produce the load torque. A three phase motor runs at synchronous speed. 3600 rpm for a two pole 3 phase and 1800 rpm for a four pole.
                                I still maintain that a good set of spindle bearings will be independent of the belt. Think of the old leather flat belts with metal joining staples used on lathes that go klunk as the joint travels over the pulley.


                                corey renner <vandal968@...> wrote:
                                The motor vibrates in synch with the 60Hz power that's driving it.  A Three phase motor is smoother and provides a better surface finish on the parts as a result.  I too was skeptical of the claims of improved finish with a fenner belt, so I did an experiment with a block of 6061.  One pass with the rubber belt, changed belt, then another pass with the fenner next to the first.  Same speed, same feed, same lube, same direction of feed, moments apart.  The fenner belt gave a better finish.  It wasn't an enormous difference and other factors were much more important (speed, feed cutter, etc.) but the two passes were definitely different and you could easily see that one was a little better than the other.  The downside to the fenners that I haven't seen anytone mention is that on small-diameter pulleys they slip much more readily than solid rubber belts.  On a 6"+ dia pulley, they transmit power well, but when trying for large speed reductions, I've tried them on small (maybe 3") pulleys, and had a lot of slip, enough that I had to go back to solid rubber belts to complete that particular operation.

                                cheers,
                                c

                                On 2/5/07, Malcolm Parker-Lisberg <mparkerlisberg@ yahoo.com> wrote:
                                It my reasoning that only if things were wildly out of
                                balance would any vibration make its way to the
                                spindle and to the cutter or you hit alternatively



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                              • figNoggle
                                hi all- with the spindle lock loose and the spindle retracted, a quick push/pull of the spindle with one hand on the spindle and one hand on the drawbar (but
                                Message 15 of 26 , Feb 5, 2007
                                  hi all-

                                  with the spindle lock loose and the spindle retracted, a quick push/pull
                                  of the spindle with one hand on the spindle and one hand
                                  on the drawbar (but only the hand on the spindle doing the push/pull
                                  along the Y and X axes), a bit of play could be felt most noticably at the
                                  drawbar end.

                                  pushing/pulling along the z-axis yielded no play.

                                  it sounds like the cartridge needs to be taken apart and the bearings
                                  checked for play, no? that clicking sound in the video is probably the
                                  ball bearings in need of grease, but could also be the play that's allows
                                  it to move excessively.

                                  what's actually preventing play of the spindle cartridge in the head? are
                                  there adjusting screws or something? there was one slotted set screw
                                  with a lock nut (which looked like it had never been adjusted) on
                                  the left side of the head close to the spindle lock lever..

                                  thanks!
                                  david


                                  MetalWorkingFAQ.NET - Over 50 content sites! <http://www.metalworkingfaq.net>
                                  CNC, Plans/Kits, 8x12 Lathe, Mini-Mill, How-Tos <http://www.fignoggle.com>
                                  Sieg X3/Super X3 Mill Information, HF/Enco Coupons <http://www.superx3.com>

                                  On Mon, 5 Feb 2007, Malcolm Parker-Lisberg wrote:

                                  > Split Phase motors (capacitor start/run) do not transmit much 60 Hz vibrations, only that due to the magnetostrictive properties of the laminated iron core and that is small. Most of the vibration is at a low frequency, a few Hz, due to the difference in speed from the synchronous speed required to produce the load torque. A three phase motor runs at synchronous speed. 3600 rpm for a two pole 3 phase and 1800 rpm for a four pole.
                                  > I still maintain that a good set of spindle bearings will be independent of the belt. Think of the old leather flat belts with metal joining staples used on lathes that go klunk as the joint travels over the pulley.
                                  >
                                  >
                                  > corey renner <vandal968@...> wrote: The motor vibrates in synch with the 60Hz power that's driving it. A Three phase motor is smoother and provides a better surface finish on the parts as a result. I too was skeptical of the claims of improved finish with a fenner belt, so I did an experiment with a block of 6061. One pass with the rubber belt, changed belt, then another pass with the fenner next to the first. Same speed, same feed, same lube, same direction of feed, moments apart. The fenner belt gave a better finish. It wasn't an enormous difference and other factors were much more important (speed, feed cutter, etc.) but the two passes were definitely different and you could easily see that one was a little better than the other. The downside to the fenners that I haven't seen anytone mention is that on small-diameter pulleys they slip much more readily than solid rubber belts. On a 6"+ dia pulley, they transmit power well,
                                  > but when trying for large speed reductions, I've tried them on small (maybe 3") pulleys, and had a lot of slip, enough that I had to go back to solid rubber belts to complete that particular operation.
                                  >
                                  > cheers,
                                  > c
                                  >
                                  >
                                  > On 2/5/07, Malcolm Parker-Lisberg <mparkerlisberg@...> wrote: It my reasoning that only if things were wildly out of
                                  > balance would any vibration make its way to the
                                  > spindle and to the cutter or you hit alternatively
                                  >
                                  >
                                  >
                                  >
                                  >
                                  >
                                  >
                                  >
                                  >
                                  >
                                  >
                                  > ---------------------------------
                                  > Sucker-punch spam with award-winning protection.
                                  > Try the free Yahoo! Mail Beta.
                                • SupportOurTroops - Skip
                                  Does anyone but me have experience with the high efficiency Goodyear FHP belts, raw rubber machined sides for super smooth running and less torque loss? All
                                  Message 16 of 26 , Feb 5, 2007
                                    Does anyone but me have experience with the high efficiency Goodyear FHP belts, raw
                                    rubber machined sides for super smooth running and less torque loss? All the advantages
                                    of links without the disadvantages of wearing out your aluminum pulleys and the slipping
                                    on small pulleys? All rubber v belts are not created equally. In my opinion they beat link
                                    belts hands down in all applications except industrial ones where disassembly down time
                                    is a big problem. Plus, they are much cheaper than link belts.

                                    Skip Campbell
                                    mkctools.com
                                    Ft. Worth, Texas



                                    corey renner wrote:

                                    > The motor vibrates in synch with the 60Hz power that's driving it. A Three phase motor is smoother and provides a better surface finish on the parts as a result. I too was skeptical of the claims of improved finish with a fenner belt, so I did an experiment with a block of 6061. One pass with the rubber belt, changed belt, then another pass with the fenner next to the first. Same speed, same feed, same lube, same direction of feed, moments apart. The fenner belt gave a better finish. It wasn't an enormous difference and other factors were much more important (speed, feed cutter, etc.) but the two passes were definitely different and you could easily see that one was a little better than the other. The downside to the fenners that I haven't seen anytone mention is that on small-diameter pulleys they slip much more readily than solid rubber belts. On a 6"+ dia pulley, they transmit power well, but when trying for large speed reductions, I've tried them on small (maybe 3")
                                    > pulleys, and had a lot of slip, enough that I had to go back to solid rubber belts to complete that particular operation.
                                    >
                                    > cheers,
                                    > c
                                  • leasingham_connelly
                                    ... Hz vibrations, only that due to the magnetostrictive properties of the laminated iron core and that is small. Most of the vibration is at a low frequency,
                                    Message 17 of 26 , Feb 6, 2007
                                      --- In mill_drill@yahoogroups.com, Malcolm Parker-Lisberg
                                      <mparkerlisberg@...> wrote:
                                      >
                                      > Split Phase motors (capacitor start/run) do not transmit much 60
                                      Hz vibrations, only that due to the magnetostrictive properties of
                                      the laminated iron core and that is small. Most of the vibration is
                                      at a low frequency, a few Hz, due to the difference in speed from
                                      the synchronous speed required to produce the load torque. A three
                                      phase motor runs at synchronous speed. 3600 rpm for a two pole 3
                                      phase and 1800 rpm for a four pole.
                                      > I still maintain that a good set of spindle bearings will be
                                      independent of the belt. Think of the old leather flat belts with
                                      metal joining staples used on lathes that go klunk as the joint
                                      travels over the pulley.
                                      >
                                      >
                                      > corey renner <vandal968@...>
                                      wrote: The motor vibrates in synch
                                      with the 60Hz power that's driving it. A Three phase motor is
                                      smoother and provides a better surface finish on the parts as a
                                      result. I too was skeptical of the claims of improved finish with a
                                      fenner belt, so I did an experiment with a block of 6061. One pass
                                      with the rubber belt, changed belt, then another pass with the
                                      fenner next to the first. Same speed, same feed, same lube, same
                                      direction of feed, moments apart. The fenner belt gave a better
                                      finish. It wasn't an enormous difference and other factors were
                                      much more important (speed, feed cutter, etc.) but the two passes
                                      were definitely different and you could easily see that one was a
                                      little better than the other. The downside to the fenners that I
                                      haven't seen anytone mention is that on small-diameter pulleys they
                                      slip much more readily than solid rubber belts. On a 6"+ dia
                                      pulley, they transmit power well,
                                      > but when trying for large speed reductions, I've tried them on
                                      small (maybe 3") pulleys, and had a lot of slip, enough that I had
                                      to go back to solid rubber belts to complete that particular
                                      operation.
                                      >
                                      > cheers,
                                      > c
                                      >
                                      >
                                      > On 2/5/07, Malcolm Parker-Lisberg <mparkerlisberg@...>
                                      wrote: It my reasoning that only
                                      if things were wildly out of
                                      > balance would any vibration make its way to the
                                      > spindle and to the cutter or you hit alternatively
                                      >
                                      Split phase motors can be bought with capacitor start only or
                                      capacitor start and run. In the first type the capacitor is only
                                      used to set the direction of rotation when power is first applied,
                                      in the second the capacitor gives a small rotation to the magnetic
                                      field from the stators to maintain that rotation if the motor speed
                                      drops. In both cases the force on the rotor is applied as a series
                                      of overlapping torque pulses that are not linear. The result is a
                                      ripple of torque that manifests itself as vibration and noise from
                                      the motor. The frequency is a function of the applied voltage
                                      frequency, the motor rpm and the number of windings on the rotor the
                                      number of segments on the comutator). As long as the motor is fixed
                                      to the mill head some of the vibration will be transmitted to the
                                      cutting tool. The vibration is often referred to as cogging.

                                      Three phase motors use their three phases to create a rotating
                                      magnetic field. The rotor is not powered directly but has a squirrel
                                      cage construction. The rotating magnetic field induces a current in
                                      this squirrel cage and Lenz's law states that the direction of
                                      current opposes the field which created it. The result is an induced
                                      magnetic field in the rotor that causes it to be pulled round by the
                                      rotating field of the stator. In order for this field to be produced
                                      there must be slip between the rotating magnetic field and the
                                      stator so these motors are not synchronous and the speed is usualy
                                      about 95% of synchronous speed under load. As there is no pulsing
                                      torque produced by a comutator the output of a 3 phase motor is far
                                      smoother and quieter than a split phase single phase motor.

                                      To give an idea of the difference in noise between single and three
                                      phase motor noise consider this. When my 3 phase equipped mill is
                                      running at slow speed with no load on the tooling I can hear the
                                      link belt squeaking as it bends and straightens in use. Before I
                                      replaced the motor the noise and vibration from the single phase
                                      motor was, to be kind to it, excessive.

                                      I have no experience of DC motors but if they have a comutator there
                                      must be some degree of cogging in them as well.

                                      I would think if you were trying to improve the finish then try 3
                                      phase. Maybe you could borrow something that would allow an
                                      experiment similar to the link belt trials.

                                      Martin
                                    • yahoogroups
                                      ... Skip, Can you recommend a source for the Goodyear belts? Fergus
                                      Message 18 of 26 , Feb 6, 2007
                                        > Does anyone but me have experience with the high efficiency Goodyear
                                        > FHP belts, raw
                                        > rubber machined sides for super smooth running and less torque loss?
                                        > All the advantages
                                        > of links without the disadvantages of wearing out your aluminum
                                        > pulleys and the slipping
                                        > on small pulleys?

                                        Skip,
                                        Can you recommend a source for the Goodyear belts?

                                        Fergus
                                      • Jerry Kimberlin
                                        ... I had to replace the original rubber belts on my Jet lathe after 10 years of working just fine. I replaced them with Fenner linked belts and that
                                        Message 19 of 26 , Feb 6, 2007
                                          SupportOurTroops - Skip wrote:
                                          > Does anyone but me have experience with the high efficiency Goodyear FHP belts, raw
                                          > rubber machined sides for super smooth running and less torque loss?

                                          I had to replace the original rubber belts on my Jet lathe after 10
                                          years of working just fine. I replaced them with Fenner linked belts
                                          and that experiment lasted about a month. The Fenner belts were the
                                          worst thing I ever used. So I went back to rubber belts and got the
                                          Goodyear type. They work well in an oily situation where the Fenner
                                          belts just slip and slip and slip and you can't get them clean again
                                          even with solvent soaking and degreasing. The good old rubber belts
                                          are far superior for lathe work. I don't have a belted mill/drill and
                                          the Fenner belts may work well there because of the lack of oil, etc.

                                          JerryK
                                        • babcockmill
                                          Goodyear BX series belts have been working very well on my Grizzly G- 1007. I replaced the china belts with Goodyear BX series belts and the noise and
                                          Message 20 of 26 , Feb 6, 2007
                                            Goodyear BX series belts have been working very well on my Grizzly G-
                                            1007. I replaced the china belts with Goodyear BX series belts and
                                            the noise and vibration went away. The BX belts have notched backs
                                            and transfer torque and negotiate small pulleys better than the
                                            plain smooth back Goodyear B series although they will also work
                                            quite well.

                                            Cheers...Ross

                                            --- In mill_drill@yahoogroups.com, Jerry Kimberlin <kimberln@...>
                                            wrote:
                                            >
                                            > SupportOurTroops - Skip wrote:
                                            > > Does anyone but me have experience with the high efficiency
                                            Goodyear FHP belts, raw
                                            > > rubber machined sides for super smooth running and less torque
                                            loss?
                                            >
                                            > I had to replace the original rubber belts on my Jet lathe after
                                            10
                                            > years of working just fine. I replaced them with Fenner linked
                                            belts
                                            > and that experiment lasted about a month. The Fenner belts were
                                            the
                                            > worst thing I ever used. So I went back to rubber belts and got
                                            the
                                            > Goodyear type. They work well in an oily situation where the
                                            Fenner
                                            > belts just slip and slip and slip and you can't get them clean
                                            again
                                            > even with solvent soaking and degreasing. The good old rubber
                                            belts
                                            > are far superior for lathe work. I don't have a belted
                                            mill/drill and
                                            > the Fenner belts may work well there because of the lack of oil,
                                            etc.
                                            >
                                            > JerryK
                                            >
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