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RE: [mach1mach2cnc] Re:noise problem. Not solved

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  • Jeffrey Birt
    ... that ... No, that is NOT the right way to do things. The confusion comes about as we use the term ground to mean many things. First consider a simple
    Message 1 of 14 , Jul 22, 2013
      >>So you wire one wire from the switches to the BOB inputs and the other to
      >>the star ground with all the shields and the mains earth... have I got
      that
      >>right?



      No, that is NOT the right way to do things. The confusion comes about as we
      use the term 'ground' to mean many things. First consider a simple battery
      powered flashlight (torch). The battery will have a "+" terminal and a "-",
      in common parlance we might refer to these "positive" and "ground" (or
      "negative"). In fact this ground has nothing to do with the Earth nor is it
      negative w.r.t. anything else. It would be more accurate to call this the
      'common' terminal.

      In an AC mains system is it typical practice to tie/bond one side of the AC
      power to Earth or to "ground it". This is where the term 'grounding' comes
      from. In your CNC machine control box you have a power supply that takes the
      mains voltage and gives you DC. The output of the power supply will be
      labeled "+" and "-", the "-" however is NOT to be confused with Earth
      Ground. (Inside the power supply the "-" may be bonded to Earth Ground but
      you should not do so elsewhere unless the manufacturer directs you to do
      so.)

      The "-" terminal on your power supply is the "common" it is the return path
      for your DC circuits. Anything that the power supply is providing power for
      should be connected to the power supply "-" terminal. The Earth Ground
      should NEVER be used as a return path for DC circuits. To do so is to
      invites noise into your control and much frustration into your life.



      Jeff Birt

      Soigeneris.com
      _____

      From: mach1mach2cnc@yahoogroups.com <mailto:mach1mach2cnc%40yahoogroups.com>
      [mailto:mach1mach2cnc@yahoogroups.com
      <mailto:mach1mach2cnc%40yahoogroups.com> ]
      On Behalf Of qconvers@... <mailto:qconvers%40aol.com>
      Sent: Monday, July 22, 2013 3:19 PM
      To: mach1mach2cnc@yahoogroups.com <mailto:mach1mach2cnc%40yahoogroups.com>
      Subject: Re: [mach1mach2cnc] Re:noise problem. Not solved

      Nope, with the X axis limit switch detached from the BOB completely, Mach
      keeps getting tripped by the E stop. At one point it was reset, trip, reset,

      trip, reset, trip...

      I've re routed the LPT cable so it's not near any high voltages.. no good.
      I've disconnected all the inputs to the BOB now and I'm kind of hoping it
      will trip.

      So you wire one wire from the switches to the BOB inputs and the other to
      the star ground with all the shields and the mains earth... have I got that
      right? I've had each switch across and input and GND on the board. I
      thought all those wires stuffed into one small screw terminal might be
      wrong.
      So do I connect the GND to the star point too? It's funny that this thing
      has worked so well for so long.

      I'm going to order an Opto Isolated BOB and a new LPT cable and walk away
      from this tomorrow. Just to get some work done.

      I ran the driver test and it says my system is excellent...

      Slowly losing it, Dave

      In a message dated 22/07/2013 07:47:23 GMT Daylight Time,
      jiminwoodstock@... <mailto:jiminwoodstock%40gmail.com>
      <mailto:jiminwoodstock%40gmail.com> writes:

      Additional info...
      My limit switches are wired from ground to the interface board inputs. The
      interface board is configured so that +5v is present until the switch is
      closed which will bring the input to 0V. This way any possible noise on the
      wire is shunted to ground by the normally closed switch.

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

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





      [Non-text portions of this message have been removed]
    • Andy Wander
      Good luck, Dave! Intermittent stuff, and things that suddenly start happening with no apparent cause, can be the devil to track down. Sometimes they get fixed
      Message 2 of 14 , Jul 22, 2013
        Good luck, Dave! Intermittent stuff, and things that suddenly start
        happening with no apparent cause, can be the devil to track down. Sometimes
        they get fixed without us really knowing the cause!



        The board you linked to might be great, or it might be a piece of junk, it
        is really hard to say without seeing a circuit diagram, and having some
        experience with it.



        Andy Wander

        _____

        From: mach1mach2cnc@yahoogroups.com [mailto:mach1mach2cnc@yahoogroups.com]
        On Behalf Of qconvers@...
        Sent: Monday, July 22, 2013 4:39 PM
        To: mach1mach2cnc@yahoogroups.com
        Subject: Re: [mach1mach2cnc] Re:noise problem. Not solved





        Thanks Andy,

        I'm putting off opening another can of worms, fitting the SS just now. So
        I've got my eye on this...

        http://www.diycnc.co.uk/optoboardV3.pdf

        It's the most expensive I've seen, but it looks well built and the guy
        sounds like he knows what he's talking about. With no switches attached,
        there's no problem. So far.

        The sun has gone down here and I've spent the whole day messing with it.

        Regards Dave


        In a message dated 22/07/2013 21:25:27 GMT Daylight Time,
        ohawiseguyeh@... <mailto:ohawiseguyeh%40gmail.com> writes:

        I would use the GND terminal on the BOB. Keep the switch wires together as
        much as possible,

        Andy Wander

        _____

        From: mach1mach2cnc@yahoogroups.com <mailto:mach1mach2cnc%40yahoogroups.com>
        [mailto:mach1mach2cnc@yahoogroups.com
        <mailto:mach1mach2cnc%40yahoogroups.com> ]
        On Behalf Of qconvers@... <mailto:qconvers%40aol.com>
        Sent: Monday, July 22, 2013 3:19 PM
        To: mach1mach2cnc@yahoogroups.com <mailto:mach1mach2cnc%40yahoogroups.com>
        Subject: Re: [mach1mach2cnc] Re:noise problem. Not solved

        Nope, with the X axis limit switch detached from the BOB completely, Mach
        keeps getting tripped by the E stop. At one point it was reset, trip,
        reset,

        trip, reset, trip...

        I've re routed the LPT cable so it's not near any high voltages.. no good.
        I've disconnected all the inputs to the BOB now and I'm kind of hoping it
        will trip.

        So you wire one wire from the switches to the BOB inputs and the other to
        the star ground with all the shields and the mains earth... have I got
        that
        right? I've had each switch across and input and GND on the board. I
        thought all those wires stuffed into one small screw terminal might be
        wrong.
        So do I connect the GND to the star point too? It's funny that this thing
        has worked so well for so long.

        I'm going to order an Opto Isolated BOB and a new LPT cable and walk away
        from this tomorrow. Just to get some work done.

        I ran the driver test and it says my system is excellent...

        Slowly losing it, Dave

        In a message dated 22/07/2013 07:47:23 GMT Daylight Time,
        jiminwoodstock@... <mailto:jiminwoodstock%40gmail.com>
        <mailto:jiminwoodstock%40gmail.com> writes:

        Additional info...
        My limit switches are wired from ground to the interface board inputs. The
        interface board is configured so that +5v is present until the switch is
        closed which will bring the input to 0V. This way any possible noise on
        the
        wire is shunted to ground by the normally closed switch.

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

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

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

        www.machsupport.com - Web site AccessYahoo! Groups Links

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





        [Non-text portions of this message have been removed]
      • studleylee
        I m jumping in w/o fully reading this thread, but my 2cents: 1)for a test,right at the contacts that the limit switches are being read my Mach, put some .1uf
        Message 3 of 14 , Jul 23, 2013
          I'm jumping in w/o fully reading this thread, but my 2cents:

          1)for a test,right at the contacts that the limit switches are being read my Mach, put some .1uf caps to gnd( gnd that the limit switch is referenced to ) see if behavior changes.

          2) What I eventually did to resolve: I had this exact condition and it drove me crazy until I added optocouplers to the limit circuits. There was an induced fast glitch that was hard to capture happening.
          -Lee Studley


          --- In mach1mach2cnc@yahoogroups.com, "Andy Wander" <ohawiseguyeh@...> wrote:
          >
          > Good luck, Dave! Intermittent stuff, and things that suddenly start
          > happening with no apparent cause, can be the devil to track down. Sometimes
          > they get fixed without us really knowing the cause!
          >
          >
        • quadconversions
          Hi Lee, Thanks for the input. I happen to have a load of caps, resistors etc. that someone gave me. Thinking I knew what to do with them. I don t. I ve got
          Message 4 of 14 , Jul 23, 2013
            Hi Lee,

            Thanks for the input. I happen to have a load of caps, resistors etc. that
            someone gave me. Thinking I knew what to do with them. I don't. I've got
            some that say 65V 1uf on them, would these do? And can you get them the
            wrong way round?

            I've called a couple of guys that sell Opto isolated BOBs today. The first,
            selling cheap ones on Ebay put me onto the other one. I think he could
            tell I was a serious CNCer. Following their advice I've reinstalled Mach
            (upgrading it to the version Jeff recommends for an Ethernet SS) No good.

            It's like any of the cables going out to switches can trigger a limit or E
            stop. It's like the machine it'self is omitting spikes. It is grounded,
            I've had a circuit tester between the machine and the plug in the wall today.

            It even does it without power to the steppers. The model board I machine
            does create a lot of static, but I've machined skip loads of the stuff no
            problem.

            I was reluctant to go Opto isolated until I had found the cause, but I'm
            beyond that now. I'll have a Opto board by the end of the week.

            Regards Dave


            In a message dated 23/07/2013 19:27:08 GMT Daylight Time,
            indigo_red@... writes:


            I'm jumping in w/o fully reading this thread, but my 2cents:

            1)for a test,right at the contacts that the limit switches are being read
            my Mach, put some .1uf caps to gnd( gnd that the limit switch is referenced
            to ) see if behavior changes.

            2) What I eventually did to resolve: I had this exact condition and it
            drove me crazy until I added optocouplers to the limit circuits. There was an
            induced fast glitch that was hard to capture happening.
            -Lee Studley


            --- In mach1mach2cnc@yahoogroups.com, "Andy Wander" <ohawiseguyeh@...>
            wrote:
            >
            > Good luck, Dave! Intermittent stuff, and things that suddenly start
            > happening with no apparent cause, can be the devil to track down.
            Sometimes
            > they get fixed without us really knowing the cause!
            >
            >




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

            www.machsupport.com - Web site AccessYahoo! Groups Links






            [Non-text portions of this message have been removed]
          • Dave
            Call me a nag... but have you undone ALL changes you made recently to your previously running system? Have you swapped out the BOB, LPT card, LPT cable, and
            Message 5 of 14 , Jul 23, 2013
              Call me a nag... but have you undone ALL changes you made recently to
              your previously running system?

              Have you swapped out the BOB, LPT card, LPT cable, and computer?

              You need to make one change at a time, and then evaluate.

              If you start installing the E Smoothstepper you might just dig yourself
              another rabbit hole...

              Dave



              On 7/22/2013 3:18 PM, qconvers@... wrote:
              >
              > Nope, with the X axis limit switch detached from the BOB completely, Mach
              > keeps getting tripped by the E stop. At one point it was reset, trip,
              > reset,
              > trip, reset, trip...
              >
              > I've re routed the LPT cable so it's not near any high voltages.. no
              > good.
              > I've disconnected all the inputs to the BOB now and I'm kind of hoping it
              > will trip.
              >
              > So you wire one wire from the switches to the BOB inputs and the other to
              > the star ground with all the shields and the mains earth... have I got
              > that
              > right? I've had each switch across and input and GND on the board. I
              > thought all those wires stuffed into one small screw terminal might be
              > wrong.
              > So do I connect the GND to the star point too? It's funny that this thing
              > has worked so well for so long.
              >
              > I'm going to order an Opto Isolated BOB and a new LPT cable and walk away
              > from this tomorrow. Just to get some work done.
              >
              > I ran the driver test and it says my system is excellent...
              >
              > Slowly losing it, Dave
              >
              >
              >
              > In a message dated 22/07/2013 07:47:23 GMT Daylight Time,
              > jiminwoodstock@... <mailto:jiminwoodstock%40gmail.com> writes:
              >
              > Additional info...
              > My limit switches are wired from ground to the interface board inputs.
              > The
              > interface board is configured so that +5v is present until the switch is
              > closed which will bring the input to 0V. This way any possible noise
              > on the
              > wire is shunted to ground by the normally closed switch.
              >
              > [Non-text portions of this message have been removed]
              >
              >



              [Non-text portions of this message have been removed]
            • quadconversions
              Hi Dave, Yes, I ve put the RAM back to 512 Mb with no effect. I ve ordered a new cable as I didn t have one. I don t have a spare BOB but I m about to order
              Message 6 of 14 , Jul 24, 2013
                Hi Dave,

                Yes, I've put the RAM back to 512 Mb with no effect.

                I've ordered a new cable as I didn't have one. I don't have a spare BOB but
                I'm about to order one. I've got a Gecko 540 but I believe that won't
                handle Nema 34s at 4.2 amps...

                I've been going round in ever decreasing circles and I'm convinced it's one
                of the items you mention.

                I have X limits and X home on the same pin. I can enable the home, but
                enabling either limit will cause immediate, constant limit trip now, but with
                no LEDs on. Even with them disabled I've seen other LEDs flash and
                completely physically removing the switches does not solve the problem.

                I'm sure replacing LPT cable and BOB will solve it. I'll let you know
                when they turn up.

                Thanks for your concern, it's nice just to share the problem as I don't
                know anyone else here that has a clue what I'm facing.

                Regards Dave




                In a message dated 24/07/2013 04:55:52 GMT Daylight Time, dc9@...
                writes:

                Call me a nag... but have you undone ALL changes you made recently to
                your previously running system?

                Have you swapped out the BOB, LPT card, LPT cable, and computer?

                You need to make one change at a time, and then evaluate.

                If you start installing the E Smoothstepper you might just dig yourself
                another rabbit hole...

                Dave



                On 7/22/2013 3:18 PM, qconvers@... wrote:
                >
                > Nope, with the X axis limit switch detached from the BOB completely, Mach
                > keeps getting tripped by the E stop. At one point it was reset, trip,
                > reset,
                > trip, reset, trip...
                >
                > I've re routed the LPT cable so it's not near any high voltages.. no
                > good.
                > I've disconnected all the inputs to the BOB now and I'm kind of hoping it
                > will trip.
                >
                > So you wire one wire from the switches to the BOB inputs and the other to
                > the star ground with all the shields and the mains earth... have I got
                > that
                > right? I've had each switch across and input and GND on the board. I
                > thought all those wires stuffed into one small screw terminal might be
                > wrong.
                > So do I connect the GND to the star point too? It's funny that this thing
                > has worked so well for so long.
                >
                > I'm going to order an Opto Isolated BOB and a new LPT cable and walk away
                > from this tomorrow. Just to get some work done.
                >
                > I ran the driver test and it says my system is excellent...
                >
                > Slowly losing it, Dave
                >
                >
                >
                > In a message dated 22/07/2013 07:47:23 GMT Daylight Time,
                > jiminwoodstock@... <mailto:jiminwoodstock%40gmail.com> writes:
                >
                > Additional info...
                > My limit switches are wired from ground to the interface board inputs.
                > The
                > interface board is configured so that +5v is present until the switch is
                > closed which will bring the input to 0V. This way any possible noise
                > on the
                > wire is shunted to ground by the normally closed switch.
                >
                > [Non-text portions of this message have been removed]
                >
                >



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



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

                www.machsupport.com - Web site AccessYahoo! Groups Links






                [Non-text portions of this message have been removed]
              • chuck
                Dave, just an off the wall guess but is it possible the ribbon cable inside the pc to the PP connector was knocked lose while you were inside? if the PP socket
                Message 7 of 14 , Jul 24, 2013
                  Dave,
                  just an off the wall guess but is it possible the ribbon cable inside the pc to the PP connector was knocked lose while you were inside?
                  if the PP socket is directly on the mother board than disregard my guess.
                  Chuck

                  ----- Original Message -----
                  From: qconvers@...
                  To: mach1mach2cnc@yahoogroups.com
                  Sent: Monday, July 22, 2013 3:18 PM
                  Subject: Re: [mach1mach2cnc] Re:noise problem. Not solved



                  Nope, with the X axis limit switch detached from the BOB completely, Mach
                  keeps getting tripped by the E stop. At one point it was reset, trip, reset,
                  trip, reset, trip...

                  I've re routed the LPT cable so it's not near any high voltages.. no good.
                  I've disconnected all the inputs to the BOB now and I'm kind of hoping it
                  will trip.

                  So you wire one wire from the switches to the BOB inputs and the other to
                  the star ground with all the shields and the mains earth... have I got that
                  right? I've had each switch across and input and GND on the board. I
                  thought all those wires stuffed into one small screw terminal might be wrong.
                  So do I connect the GND to the star point too? It's funny that this thing
                  has worked so well for so long.

                  I'm going to order an Opto Isolated BOB and a new LPT cable and walk away
                  from this tomorrow. Just to get some work done.

                  I ran the driver test and it says my system is excellent...

                  Slowly losing it, Dave



                  In a message dated 22/07/2013 07:47:23 GMT Daylight Time,
                  jiminwoodstock@... writes:

                  Additional info...
                  My limit switches are wired from ground to the interface board inputs. The
                  interface board is configured so that +5v is present until the switch is
                  closed which will bring the input to 0V. This way any possible noise on the
                  wire is shunted to ground by the normally closed switch.

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





                  [Non-text portions of this message have been removed]
                • Dave
                  If you set the current limit on the G540 to the max 3.5 amps (I think that is no resistor - as I recall) it should be able to drive those nema 34 s at reduced
                  Message 8 of 14 , Jul 24, 2013
                    If you set the current limit on the G540 to the max 3.5 amps (I think
                    that is no resistor - as I recall) it should be able to drive those nema
                    34's at reduced power. Make sure you PS voltage is not too great for
                    the G540.
                    I've driven Nema 34s with a G540 before.. You may have to run at
                    reduced accel/speed but at least you can eliminate your existing BOB as
                    a concern or confirm that it is bad.

                    Dave

                    On 7/24/2013 7:30 AM, qconvers@... wrote:
                    >
                    > Hi Dave,
                    >
                    > Yes, I've put the RAM back to 512 Mb with no effect.
                    >
                    > I've ordered a new cable as I didn't have one. I don't have a spare
                    > BOB but
                    > I'm about to order one. I've got a Gecko 540 but I believe that won't
                    > handle Nema 34s at 4.2 amps...
                    >
                    > I've been going round in ever decreasing circles and I'm convinced
                    > it's one
                    > of the items you mention.
                    >
                    > I have X limits and X home on the same pin. I can enable the home, but
                    > enabling either limit will cause immediate, constant limit trip now,
                    > but with
                    > no LEDs on. Even with them disabled I've seen other LEDs flash and
                    > completely physically removing the switches does not solve the problem.
                    >
                    > I'm sure replacing LPT cable and BOB will solve it. I'll let you know
                    > when they turn up.
                    >
                    > Thanks for your concern, it's nice just to share the problem as I don't
                    > know anyone else here that has a clue what I'm facing.
                    >
                    > Regards Dave
                    >
                    >
                    >
                    >
                    > In a message dated 24/07/2013 04:55:52 GMT Daylight Time,
                    > dc9@... <mailto:dc9%40dc9.tzo.com>
                    > writes:
                    >
                    > Call me a nag... but have you undone ALL changes you made recently to
                    > your previously running system?
                    >
                    > Have you swapped out the BOB, LPT card, LPT cable, and computer?
                    >
                    > You need to make one change at a time, and then evaluate.
                    >
                    > If you start installing the E Smoothstepper you might just dig yourself
                    > another rabbit hole...
                    >
                    > Dave
                    >
                    > On 7/22/2013 3:18 PM, qconvers@... <mailto:qconvers%40aol.com> wrote:
                    > >
                    > > Nope, with the X axis limit switch detached from the BOB completely,
                    > Mach
                    > > keeps getting tripped by the E stop. At one point it was reset, trip,
                    > > reset,
                    > > trip, reset, trip...
                    > >
                    > > I've re routed the LPT cable so it's not near any high voltages.. no
                    > > good.
                    > > I've disconnected all the inputs to the BOB now and I'm kind of
                    > hoping it
                    > > will trip.
                    > >
                    > > So you wire one wire from the switches to the BOB inputs and the
                    > other to
                    > > the star ground with all the shields and the mains earth... have I got
                    > > that
                    > > right? I've had each switch across and input and GND on the board. I
                    > > thought all those wires stuffed into one small screw terminal might be
                    > > wrong.
                    > > So do I connect the GND to the star point too? It's funny that this
                    > thing
                    > > has worked so well for so long.
                    > >
                    > > I'm going to order an Opto Isolated BOB and a new LPT cable and walk
                    > away
                    > > from this tomorrow. Just to get some work done.
                    > >
                    > > I ran the driver test and it says my system is excellent...
                    > >
                    > > Slowly losing it, Dave
                    > >
                    > >
                    > >
                    > > In a message dated 22/07/2013 07:47:23 GMT Daylight Time,
                    > > jiminwoodstock@... <mailto:jiminwoodstock%40gmail.com>
                    > <mailto:jiminwoodstock%40gmail.com> writes:
                    > >
                    > > Additional info...
                    > > My limit switches are wired from ground to the interface board inputs.
                    > > The
                    > > interface board is configured so that +5v is present until the switch is
                    > > closed which will bring the input to 0V. This way any possible noise
                    > > on the
                    > > wire is shunted to ground by the normally closed switch.
                    > >
                    > > [Non-text portions of this message have been removed]
                    > >
                    > >
                    >
                    > [Non-text portions of this message have been removed]
                    >
                    > ------------------------------------
                    >
                    > www.machsupport.com - Web site AccessYahoo! Groups Links
                    >
                    > [Non-text portions of this message have been removed]
                    >
                    >



                    [Non-text portions of this message have been removed]
                  • quadconversions
                    Hi Chuck, It s directly on the mother board. It hasn t tripped for over an hour now with the X axis limits un-enabled... but then it s tripped before with
                    Message 9 of 14 , Jul 24, 2013
                      Hi Chuck,

                      It's directly on the mother board. It hasn't tripped for over an hour now
                      with the X axis limits un-enabled... but then it's tripped before with them
                      completely disconnected....


                      Regards Dave


                      In a message dated 24/07/2013 13:38:01 GMT Daylight Time,
                      chuckels@... writes:

                      Dave,
                      just an off the wall guess but is it possible the ribbon cable inside the
                      pc to the PP connector was knocked lose while you were inside?
                      if the PP socket is directly on the mother board than disregard my guess.
                      Chuck

                      ----- Original Message -----
                      From: qconvers@...
                      To: mach1mach2cnc@yahoogroups.com
                      Sent: Monday, July 22, 2013 3:18 PM
                      Subject: Re: [mach1mach2cnc] Re:noise problem. Not solved



                      Nope, with the X axis limit switch detached from the BOB completely, Mach
                      keeps getting tripped by the E stop. At one point it was reset, trip,
                      reset,
                      trip, reset, trip...

                      I've re routed the LPT cable so it's not near any high voltages.. no good.
                      I've disconnected all the inputs to the BOB now and I'm kind of hoping it
                      will trip.

                      So you wire one wire from the switches to the BOB inputs and the other to
                      the star ground with all the shields and the mains earth... have I got
                      that
                      right? I've had each switch across and input and GND on the board. I
                      thought all those wires stuffed into one small screw terminal might be
                      wrong.
                      So do I connect the GND to the star point too? It's funny that this thing
                      has worked so well for so long.

                      I'm going to order an Opto Isolated BOB and a new LPT cable and walk away
                      from this tomorrow. Just to get some work done.

                      I ran the driver test and it says my system is excellent...

                      Slowly losing it, Dave



                      In a message dated 22/07/2013 07:47:23 GMT Daylight Time,
                      jiminwoodstock@... writes:

                      Additional info...
                      My limit switches are wired from ground to the interface board inputs. The

                      interface board is configured so that +5v is present until the switch is
                      closed which will bring the input to 0V. This way any possible noise on
                      the
                      wire is shunted to ground by the normally closed switch.

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





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



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

                      www.machsupport.com - Web site AccessYahoo! Groups Links






                      [Non-text portions of this message have been removed]
                    • quadconversions
                      That s good to know Dave. But my Gecko is on my bench top machine and all wired up with DB9 plugs.. I ve been promised a next day delivery on the new BOB. My
                      Message 10 of 14 , Jul 24, 2013
                        That's good to know Dave. But my Gecko is on my bench top machine and all
                        wired up with DB9 plugs.. I've been promised a next day delivery on the new
                        BOB.

                        My Z axis weighs close to 20KG.. it takes all the amps it can get at any
                        speed :0)

                        Regards Dave


                        In a message dated 24/07/2013 14:06:38 GMT Daylight Time, dc9@...
                        writes:

                        If you set the current limit on the G540 to the max 3.5 amps (I think
                        that is no resistor - as I recall) it should be able to drive those nema
                        34's at reduced power. Make sure you PS voltage is not too great for
                        the G540.
                        I've driven Nema 34s with a G540 before.. You may have to run at
                        reduced accel/speed but at least you can eliminate your existing BOB as
                        a concern or confirm that it is bad.

                        Dave

                        On 7/24/2013 7:30 AM, qconvers@... wrote:
                        >
                        > Hi Dave,
                        >
                        > Yes, I've put the RAM back to 512 Mb with no effect.
                        >
                        > I've ordered a new cable as I didn't have one. I don't have a spare
                        > BOB but
                        > I'm about to order one. I've got a Gecko 540 but I believe that won't
                        > handle Nema 34s at 4.2 amps...
                        >
                        > I've been going round in ever decreasing circles and I'm convinced
                        > it's one
                        > of the items you mention.
                        >
                        > I have X limits and X home on the same pin. I can enable the home, but
                        > enabling either limit will cause immediate, constant limit trip now,
                        > but with
                        > no LEDs on. Even with them disabled I've seen other LEDs flash and
                        > completely physically removing the switches does not solve the problem.
                        >
                        > I'm sure replacing LPT cable and BOB will solve it. I'll let you know
                        > when they turn up.
                        >
                        > Thanks for your concern, it's nice just to share the problem as I don't
                        > know anyone else here that has a clue what I'm facing.
                        >
                        > Regards Dave
                        >
                        >
                        >
                        >
                        > In a message dated 24/07/2013 04:55:52 GMT Daylight Time,
                        > dc9@... <mailto:dc9%40dc9.tzo.com>
                        > writes:
                        >
                        > Call me a nag... but have you undone ALL changes you made recently to
                        > your previously running system?
                        >
                        > Have you swapped out the BOB, LPT card, LPT cable, and computer?
                        >
                        > You need to make one change at a time, and then evaluate.
                        >
                        > If you start installing the E Smoothstepper you might just dig yourself
                        > another rabbit hole...
                        >
                        > Dave
                        >
                        > On 7/22/2013 3:18 PM, qconvers@... <mailto:qconvers%40aol.com> wrote:
                        > >
                        > > Nope, with the X axis limit switch detached from the BOB completely,
                        > Mach
                        > > keeps getting tripped by the E stop. At one point it was reset, trip,
                        > > reset,
                        > > trip, reset, trip...
                        > >
                        > > I've re routed the LPT cable so it's not near any high voltages.. no
                        > > good.
                        > > I've disconnected all the inputs to the BOB now and I'm kind of
                        > hoping it
                        > > will trip.
                        > >
                        > > So you wire one wire from the switches to the BOB inputs and the
                        > other to
                        > > the star ground with all the shields and the mains earth... have I got
                        > > that
                        > > right? I've had each switch across and input and GND on the board. I
                        > > thought all those wires stuffed into one small screw terminal might be
                        > > wrong.
                        > > So do I connect the GND to the star point too? It's funny that this
                        > thing
                        > > has worked so well for so long.
                        > >
                        > > I'm going to order an Opto Isolated BOB and a new LPT cable and walk
                        > away
                        > > from this tomorrow. Just to get some work done.
                        > >
                        > > I ran the driver test and it says my system is excellent...
                        > >
                        > > Slowly losing it, Dave
                        > >
                        > >
                        > >
                        > > In a message dated 22/07/2013 07:47:23 GMT Daylight Time,
                        > > jiminwoodstock@... <mailto:jiminwoodstock%40gmail.com>
                        > <mailto:jiminwoodstock%40gmail.com> writes:
                        > >
                        > > Additional info...
                        > > My limit switches are wired from ground to the interface board inputs.
                        > > The
                        > > interface board is configured so that +5v is present until the switch
                        is
                        > > closed which will bring the input to 0V. This way any possible noise
                        > > on the
                        > > wire is shunted to ground by the normally closed switch.
                        > >
                        > > [Non-text portions of this message have been removed]
                        > >
                        > >
                        >
                        > [Non-text portions of this message have been removed]
                        >
                        > ------------------------------------
                        >
                        > www.machsupport.com - Web site AccessYahoo! Groups Links
                        >
                        > [Non-text portions of this message have been removed]
                        >
                        >



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



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

                        www.machsupport.com - Web site AccessYahoo! Groups Links






                        [Non-text portions of this message have been removed]
                      • danmauch
                        If you use no resistor the current will be 3.5A but there is no auto current reduction. Use a 3.47K resistor for 3.47A and retain auto current reduction. Dan
                        Message 11 of 14 , Jul 25, 2013
                          If you use no resistor the current will be 3.5A but there is no auto current reduction. Use a 3.47K resistor for 3.47A and retain auto current reduction.
                          Dan

                          --- In mach1mach2cnc@yahoogroups.com, Dave <dc9@...> wrote:
                          >
                          > If you set the current limit on the G540 to the max 3.5 amps (I think
                          > that is no resistor - as I recall) it should be able to drive those nema
                          > 34's at reduced power. Make sure you PS voltage is not too great for
                          > the G540.
                          > I've driven Nema 34s with a G540 before.. You may have to run at
                          > reduced accel/speed but at least you can eliminate your existing BOB as
                          > a concern or confirm that it is bad.
                          >
                          > Dave
                          >
                          > On 7/24/2013 7:30 AM, qconvers@... wrote:
                          > >
                          > > Hi Dave,
                          > >
                          > > Yes, I've put the RAM back to 512 Mb with no effect.
                          > >
                          > > I've ordered a new cable as I didn't have one. I don't have a spare
                          > > BOB but
                          > > I'm about to order one. I've got a Gecko 540 but I believe that won't
                          > > handle Nema 34s at 4.2 amps...
                          > >
                          > > I've been going round in ever decreasing circles and I'm convinced
                          > > it's one
                          > > of the items you mention.
                          > >
                          > > I have X limits and X home on the same pin. I can enable the home, but
                          > > enabling either limit will cause immediate, constant limit trip now,
                          > > but with
                          > > no LEDs on. Even with them disabled I've seen other LEDs flash and
                          > > completely physically removing the switches does not solve the problem.
                          > >
                          > > I'm sure replacing LPT cable and BOB will solve it. I'll let you know
                          > > when they turn up.
                          > >
                          > > Thanks for your concern, it's nice just to share the problem as I don't
                          > > know anyone else here that has a clue what I'm facing.
                          > >
                          > > Regards Dave
                          > >
                          > >
                          > >
                          > >
                          > > In a message dated 24/07/2013 04:55:52 GMT Daylight Time,
                          > > dc9@... <mailto:dc9%40dc9.tzo.com>
                          > > writes:
                          > >
                          > > Call me a nag... but have you undone ALL changes you made recently to
                          > > your previously running system?
                          > >
                          > > Have you swapped out the BOB, LPT card, LPT cable, and computer?
                          > >
                          > > You need to make one change at a time, and then evaluate.
                          > >
                          > > If you start installing the E Smoothstepper you might just dig yourself
                          > > another rabbit hole...
                          > >
                          > > Dave
                          > >
                          > > On 7/22/2013 3:18 PM, qconvers@... <mailto:qconvers%40aol.com> wrote:
                          > > >
                          > > > Nope, with the X axis limit switch detached from the BOB completely,
                          > > Mach
                          > > > keeps getting tripped by the E stop. At one point it was reset, trip,
                          > > > reset,
                          > > > trip, reset, trip...
                          > > >
                          > > > I've re routed the LPT cable so it's not near any high voltages.. no
                          > > > good.
                          > > > I've disconnected all the inputs to the BOB now and I'm kind of
                          > > hoping it
                          > > > will trip.
                          > > >
                          > > > So you wire one wire from the switches to the BOB inputs and the
                          > > other to
                          > > > the star ground with all the shields and the mains earth... have I got
                          > > > that
                          > > > right? I've had each switch across and input and GND on the board. I
                          > > > thought all those wires stuffed into one small screw terminal might be
                          > > > wrong.
                          > > > So do I connect the GND to the star point too? It's funny that this
                          > > thing
                          > > > has worked so well for so long.
                          > > >
                          > > > I'm going to order an Opto Isolated BOB and a new LPT cable and walk
                          > > away
                          > > > from this tomorrow. Just to get some work done.
                          > > >
                          > > > I ran the driver test and it says my system is excellent...
                          > > >
                          > > > Slowly losing it, Dave
                          > > >
                          > > >
                          > > >
                          > > > In a message dated 22/07/2013 07:47:23 GMT Daylight Time,
                          > > > jiminwoodstock@... <mailto:jiminwoodstock%40gmail.com>
                          > > <mailto:jiminwoodstock%40gmail.com> writes:
                          > > >
                          > > > Additional info...
                          > > > My limit switches are wired from ground to the interface board inputs.
                          > > > The
                          > > > interface board is configured so that +5v is present until the switch is
                          > > > closed which will bring the input to 0V. This way any possible noise
                          > > > on the
                          > > > wire is shunted to ground by the normally closed switch.
                          > > >
                          > > > [Non-text portions of this message have been removed]
                          > > >
                          > > >
                          > >
                          > > [Non-text portions of this message have been removed]
                          > >
                          > > ------------------------------------
                          > >
                          > > www.machsupport.com - Web site AccessYahoo! Groups Links
                          > >
                          > > [Non-text portions of this message have been removed]
                          > >
                          > >
                          >
                          >
                          >
                          > [Non-text portions of this message have been removed]
                          >
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