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Re: Speed control lag

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  • Ian Foster
    Ray. Thank you OGTDA Regards Ian ... available ... of ... able ... things
    Message 1 of 17 , Oct 3, 2007
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      Ray. Thank you

      OGTDA
      Regards'
      Ian
      --- In GrizHFMinimill@yahoogroups.com, "Ray Livingston"
      <jagboy1964@...> wrote:
      >
      > Ian,
      >
      > The schematics for the mini-mill motor controller are
      available
      > in the "Files" section of this group. I downloaded them a couple
      of
      > years ago to aid in resurrecting mine after it blew up. I was
      able
      > to get it working much better than it did before by adjusting
      things
      > better than they apparently did at the factory.
      >
      > Regards,
      > Ray L.
      >
      >
      >
    • Ray Livingston
      Ian, I don t know how electronically inclined you are, but just in case - Be *VERY* careful messing with this controller, it is a very dangerous pile of parts.
      Message 2 of 17 , Oct 3, 2007
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        Ian,

        I don't know how electronically inclined you are, but just in
        case - Be *VERY* careful messing with this controller, it is a very
        dangerous pile of parts. It all runs directly off line power, with
        no transformer isolation, so touch the wrong thing, and you'll get
        zapped big-time. Connect an oscilloscope without an isolation
        transformer to it, and you'll blow a fuse, or worse.
        While you've got it out, I'd seriously consider doing a pre-
        emptive replacement of the FETs with better quality parts. The FETs
        are normally about the only thing that goes wrong with these, other
        than adjustment, and there are much more robust parts you can put in
        for about $5 each. I don't recall the part number, but if you drop
        an e-mail to Jim Rabid: rabid@... or www.unclerabid.com.
        Jim is *the* man on these controllers, a really nice guy, and *very*
        helpful. Better still, just send it to him, and let him fix it up.
        His prices are very reasonable.
        I used a couple of light bulbs as a dummy load when I was bench-
        testing mine. That made it alot easier than working with the actual
        motor.

        Regards,
        Ray L.



        --- In GrizHFMinimill@yahoogroups.com, "Ian Foster" <fosterscons@...>
        wrote:
        >
        > Ray. Thank you
        >
        > OGTDA
        > Regards'
        > Ian
        > --- In GrizHFMinimill@yahoogroups.com, "Ray Livingston"
        > <jagboy1964@> wrote:
        > >
        > > Ian,
        > >
        > > The schematics for the mini-mill motor controller are
        > available
        > > in the "Files" section of this group. I downloaded them a couple
        > of
        > > years ago to aid in resurrecting mine after it blew up. I was
        > able
        > > to get it working much better than it did before by adjusting
        > things
        > > better than they apparently did at the factory.
        > >
        > > Regards,
        > > Ray L.
        > >
        > >
        > >
        >
      • Ian Foster
        G day Ray. Your concern is well founded. OTHERS NOTE ALSO. If you look through old posts on the 7x12 group you will find that I have given others the same
        Message 3 of 17 , Oct 3, 2007
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          G'day Ray.
          Your concern is well founded. OTHERS NOTE ALSO.
          If you look through old posts on the 7x12 group you will find that I
          have given others the same counsel. Any power controller is
          dangerous because inherently it has to be at mains potential.
          I do have to work professionally on/too close to live equipment
          sometimes so I do take care.
          I hate CROs connected to power equipment. I have seen them standing
          in the middle of a shop on a rubber mat and live at 240V!

          I do not plan to work over the board for a while; I first have to
          work out the relation between the various adjustments.

          One thing I can see is that there is an over-current cutout which is
          separate from the current feed back loop. I also note that PE is not
          the same as GND, the current feed back circuit will not work if
          there is a connection between the two. There is a diagram in the
          7x12 mini-lathe group files which shows 12V V+ rail connected to the
          +90V motor rail.

          All this is hyperthetical, my machine is 240V!

          A bank of lights as a dummy load would be handy, particularly when
          setting up the current loop and over current cut out. You would need
          a few bulbs.

          As we both say "Take care!"

          OGTDA.
          Regards,
          Ian




          --- In GrizHFMinimill@yahoogroups.com, "Ray Livingston"
          <jagboy1964@...> wrote:
          >
          > Ian,
          >
          > I don't know how electronically inclined you are, but just in
          > case - Be *VERY* careful messing with this controller, it is a
          very
          > dangerous pile of parts. It all runs directly off line power,
        • moparado
          Oh man, you two guys are whimps! Being a surviving member of the 440 club and during my working career i worked on 2.4KV 3-phase motor controllers at 160
          Message 4 of 17 , Oct 3, 2007
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            Oh man, you two guys are whimps!
            Being a surviving member of the '440' club and during my working
            career i worked on 2.4KV 3-phase motor controllers at 160
            Amps/phase...Hot sticks, gloves and all, not to mention 600 VDC
            overhead crane controllers, 120 VAC ain't nothing! By the way, the
            initiation to join that exclusive '440' club is just plain shocking
            in case you're wondering!

            OK, that said, 120VAC can and does kill.
            It only takes a handful of milli-amps through the heart to stop it
            cold and 120VAC is certainly capable of doing just that under the
            right conditions.

            As Ian and Ray said, be careful poking around with these controller
            boards!

            Ken

            ----------------------------------
            "Ian Foster" <fosterscons@...> wrote:
            I have given others the same counsel. Any power controller is
            dangerous because inherently it has to be at mains potential.
            > I do have to work professionally on/too close to live equipment
            > sometimes so I do take care.
            > I hate CROs connected to power equipment. I have seen them standing
            > in the middle of a shop on a rubber mat and live at 240V!
            >
            > All this is hyperthetical, my machine is 240V!
            > As we both say "Take care!"
            >
            > OGTDA.
            > Regards,
            ----------------
            > Ian
            "Ray Livingston" <jagboy1964@> wrote:
            > >
            > > Ian,
            > >
            > > I don't know how electronically inclined you are, but just in
            > > case - Be *VERY* careful messing with this controller, it is a
            > very
            > > dangerous pile of parts. It all runs directly off line power,
          • Ray Livingston
            Ken, That s nothing. I spent ten years working on electric vehicles, including a 21-passenger transit bus with 3600 pounds of batteries. You haven t lived
            Message 5 of 17 , Oct 4, 2007
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              Ken,
              That's nothing. I spent ten years working on electric vehicles,
              including a 21-passenger transit bus with 3600 pounds of batteries.
              You haven't lived until you've seen several square inches of 1/2"
              steel plate and four foot sections of #0000 welding cable vaporized
              in front of your eyes when something goes wrong! :-)

              Regards,
              Ray L.



              --- In GrizHFMinimill@yahoogroups.com, "moparado" <kenwm2@...> wrote:
              >
              > Oh man, you two guys are whimps!
              > Being a surviving member of the '440' club and during my working
              > career i worked on 2.4KV 3-phase motor controllers at 160
              > Amps/phase...Hot sticks, gloves and all, not to mention 600 VDC
              > overhead crane controllers, 120 VAC ain't nothing! By the way, the
              > initiation to join that exclusive '440' club is just plain shocking
              > in case you're wondering!
              >
              > OK, that said, 120VAC can and does kill.
              > It only takes a handful of milli-amps through the heart to stop it
              > cold and 120VAC is certainly capable of doing just that under the
              > right conditions.
              >
              > As Ian and Ray said, be careful poking around with these controller
              > boards!
              >
              > Ken
              >
              > ----------------------------------
              > "Ian Foster" <fosterscons@> wrote:
              > I have given others the same counsel. Any power controller is
              > dangerous because inherently it has to be at mains potential.
              > > I do have to work professionally on/too close to live equipment
              > > sometimes so I do take care.
              > > I hate CROs connected to power equipment. I have seen them
              standing
              > > in the middle of a shop on a rubber mat and live at 240V!
              > >
              > > All this is hyperthetical, my machine is 240V!
              > > As we both say "Take care!"
              > >
              > > OGTDA.
              > > Regards,
              > ----------------
              > > Ian
              > "Ray Livingston" <jagboy1964@> wrote:
              > > >
              > > > Ian,
              > > >
              > > > I don't know how electronically inclined you are, but just
              in
              > > > case - Be *VERY* careful messing with this controller, it is a
              > > very
              > > > dangerous pile of parts. It all runs directly off line power,
              >
            • moparado
              Ray, YIKES!! I always wondered about those electric vehicles when something goes wrong like a bad accident causing a direct short from B+ to the battery
              Message 6 of 17 , Oct 4, 2007
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                Ray, YIKES!!
                I always wondered about those electric vehicles when something goes
                wrong like a bad accident causing a direct short from B+ to the
                battery return. Lets hope at least they put the fuse links in the
                right place. But i suppose they said the same thing about the dangers
                of gasoline when those first model T's rolled off the line.

                By the way, those 1000+HP 2.4KV motors i mentioned were used to drive
                turbine pumps for a petroleum pipeline Co. i worked for years ago.
                Maximum throughput was around 7000 Barrels/hour with the max pressure
                safety limit set to 1200 PSI....all through a 16 inch steel pipe.

                My last project there was to install and program a SCADA telemetry
                system to control the entire pipeline from a central location which
                eliminated a dozen or so manned booster and switching stations.
                The old timer operators at the time were also extremely skeptical at
                the thought and dangers of starting 3 or 4 cascaded 1000 HP turbine
                pumps a couple hundred miles away!

                (All this might be a little off topic as i'm sure Barry will remind
                us of sooner or later!!)
                Ken

                --------------------------------------------

                "Ray Livingston" <jagboy1964@...> wrote:
                > Ken,
                > That's nothing. I spent ten years working on electric
                vehicles,
                > including a 21-passenger transit bus with 3600 pounds of
                batteries.
                > You haven't lived until you've seen several square inches of 1/2"
                > steel plate and four foot sections of #0000 welding cable vaporized
                > in front of your eyes when something goes wrong! :-)
                >
                > Regards,
                > Ray L.
                >
                > --- In GrizHFMinimill@yahoogroups.com, "moparado" <kenwm2@> wrote:
                > >
                > > Oh man, you two guys are whimps!
                > > Being a surviving member of the '440' club and during my working
                > > career i worked on 2.4KV 3-phase motor controllers at 160
                > > Amps/phase...Hot sticks, gloves and all, not to mention 600 VDC
                > > overhead crane controllers, 120 VAC ain't nothing! By the way,
                the
                > > initiation to join that exclusive '440' club is just plain
                shocking
                > > in case you're wondering!
                > >
                > > OK, that said, 120VAC can and does kill.
                > > It only takes a handful of milli-amps through the heart to stop
                it
                > > cold and 120VAC is certainly capable of doing just that under the
                > > right conditions.
                > >
                > > As Ian and Ray said, be careful poking around with these
                controller
                > > boards!
                > >
                > > Ken
                > >
                > > ----------------------------------
                > > "Ian Foster" <fosterscons@> wrote:
                > > I have given others the same counsel. Any power controller is
                > > dangerous because inherently it has to be at mains potential.
                > > > I do have to work professionally on/too close to live equipment
                > > > sometimes so I do take care.
                > > > I hate CROs connected to power equipment. I have seen them
                > standing
                > > > in the middle of a shop on a rubber mat and live at 240V!
                > > >
                > > > All this is hyperthetical, my machine is 240V!
                > > > As we both say "Take care!"
                > > >
                > > > OGTDA.
                > > > Regards,
                > > ----------------
                > > > Ian
                > > "Ray Livingston" <jagboy1964@> wrote:
                > > > >
                > > > > Ian,
                > > > >
                > > > > I don't know how electronically inclined you are, but
                just
                > in
                > > > > case - Be *VERY* careful messing with this controller, it is
                a
                > > > very
                > > > > dangerous pile of parts. It all runs directly off line power,
                > >
                >
              • Barry Young
                Hi Ken: I was letting it go until someone complained. What you guys have done fascinates me. Barry ...
                Message 7 of 17 , Oct 8, 2007
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                  Hi Ken:

                  I was letting it go until someone complained. What you
                  guys have done fascinates me.

                  Barry



                  --- moparado <kenwm2@...> wrote:

                  > Ray, YIKES!!
                  > I always wondered about those electric vehicles when
                  > something goes
                  > wrong like a bad accident causing a direct short
                  > from B+ to the
                  > battery return. Lets hope at least they put the fuse
                  > links in the
                  > right place. But i suppose they said the same thing
                  > about the dangers
                  > of gasoline when those first model T's rolled off
                  > the line.
                  >
                  > By the way, those 1000+HP 2.4KV motors i mentioned
                  > were used to drive
                  > turbine pumps for a petroleum pipeline Co. i worked
                  > for years ago.
                  > Maximum throughput was around 7000 Barrels/hour with
                  > the max pressure
                  > safety limit set to 1200 PSI....all through a 16
                  > inch steel pipe.
                  >
                  > My last project there was to install and program a
                  > SCADA telemetry
                  > system to control the entire pipeline from a central
                  > location which
                  > eliminated a dozen or so manned booster and
                  > switching stations.
                  > The old timer operators at the time were also
                  > extremely skeptical at
                  > the thought and dangers of starting 3 or 4 cascaded
                  > 1000 HP turbine
                  > pumps a couple hundred miles away!
                  >
                  > (All this might be a little off topic as i'm sure
                  > Barry will remind
                  > us of sooner or later!!)
                  > Ken
                  >




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