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Re: [Inkjet_PCB_Construction] Re: Let's make our own Open Source 2D ink printer for print on paper, wood, clothes, PCB, etc.

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  • Slavko Kocjancic
    ... Nice... As I see that works but... Trace seems a way to wide. For PCB I think 0.2mm is max alowed.. So the nozzle should be aprox 0.08 as spot is over 2
    Message 1 of 21 , Aug 9, 2010
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      casainho pravi:
      > Here is a video of the "piezo print head" printing: http://vimeo.com/13973877
      >
      > Read the wiki page to get all the information: http://reprap.org/mediawiki/index.php?title=Scratchbuilt_Piezo_Printhead
      >
      >
      >
      Nice...
      As I see that works but...
      Trace seems a way to wide. For PCB I think 0.2mm is max alowed.. So the
      nozzle should be aprox 0.08 as spot is over 2 times larger than orfice.
      The other 'thing' is that I see continous stream. Is it capable to make
      only one drop? Ie is it reliable if you apply only one electric impulse
      and got spot?
      for DOD system the head should use separated drops (pulses) and that
      can't be done with PWM. (unles is in MHz range). I make test's and used
      ULN2804 under microcontroller controll. I put pieco in bridge
      configuration to be able to power pieco in both direction.
      The chip is nothing more than 8 npn darlingtons. I get 4 to make one leg
      and other 4 for other leg to make a H bridge.
      So the upper two vertical's of H is just 1k resistor the horizontal of H
      is pieco and Each of lower part of H is 4 transistors (outputs of ULN)
      with different resistors in series. I use 20,40,80,160 ohm to have
      chance to change speed of charge. I drive the pieco with 35VDC and
      'swing' is same as to use 70V. The piezo is esentila capacitor so using
      right resistor in series we can control the speed of bending. And
      different resistors in both leegs can do different thing.
      Im my 'research' I got best single fire with folowing sequence.
      Apply +DC trought largest resistor to piszo make chamber with more volume.
      Rest about 15uS.
      Apply -DC trought smalest resistor to squeze ink out from chamber
      rest about 3-5uS
      Energize all transistors to pull both ends of piezo to GND (discharge as
      fast as possible) Piezo gone to midle rest position
      about 10uS later I deenergize all transistors so both ends of piezo goes
      to Vcc (piezo stay in middle)
      Wait at least 150uS to ink settle.
      With that you can fire 5000 drops per second.
      .... but ... again but... I'm have succes to firing isopropil alcohol
      only. The watter is unsucesful. I don't know why. Can be surface tension
      problem, the water tend to leave some air bubles in chamber and air is
      compressible so any air buble is no go. As I have wish to apply solder
      resist onto PCB with that and this stuff is like honey I realize that
      with that system is not plausible to do it. Maybe if I make two check
      valves to make a pump like device ... maybe

      and maybe little help how to 'drill' so small holes... I tested two
      variant and both works well.
      Dril a hole with smalest drill you have. 1mm is good point. (I use brass
      material) then pick a piece of thinnest enameled wire (in some relays
      the wire is under 0.05mm) and pass it trought hole. Then QUICK fil hole
      with solder. You must do that quick to not destroy enamel of wire. Then
      in one side (outside) flatten the 'blob' of solder and wire with very
      sharp chisel. You can polish that too. After that pull out wire from
      opposite side and you got finest hole. If you can't find so thin cooper
      wire you can try with glass too. I do sucesfuly under 0.1mm. Break some
      glass jar and pick thin scrap of it. Then heat it with torch to red hot
      and then with two tweezers quick pull out of fire and stretch. You can
      get very fine fiber and use same solder pour method as above. But this
      method is little harder as fibre can very easy break when pull it out
      from hole. I didn't test it but I think that single carbon fibre out of
      some carbon cloth can do the best. Is stronger and can't be burned (as
      enamel on cooper). Just don't have piece to check thicknes.

      Slavko.
    • Casainho
      ... I would like to get 0.1mm. If you are doing such work, why don t you document it? -- you can write on this wiki page:
      Message 2 of 21 , Aug 9, 2010
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        > Trace seems a way to wide. For PCB I think 0.2mm is max alowed.. So the
        > nozzle should be aprox 0.08 as spot is over 2 times larger than orfice.

        I would like to get 0.1mm.

        If you are doing such work, why don't you document it? -- you can
        write on this wiki page:
        http://reprap.org/wiki/Scratchbuilt_Piezo_Printhead, or start another.
        You can also use the RepRap forum.


        > As I have wish to apply solder
        > resist onto PCB with that and this stuff is like honey I realize that
        > with that system is not plausible to do it. Maybe if I make two check
        > valves to make a pump like device ... maybe

        Did you try to print with ink, other than try using water and alcohol?

        Slavko, please join us! or at least write blog messages with your
        findings. People do it at RepRap, using free blogspot.com blog, like
        mine: http://casainho-emcrepstrap.blogspot.com/
      • Slavko Kocjancic
        ... Hmm with 0.1mm I be wery happy. ... Hmm take to much time ... I don t want to publish scrap but to do work well I need to much time. ... and to write some
        Message 3 of 21 , Aug 9, 2010
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          Casainho pravi:
          >> Trace seems a way to wide. For PCB I think 0.2mm is max alowed.. So the
          >> nozzle should be aprox 0.08 as spot is over 2 times larger than orfice.
          >>
          >
          > I would like to get 0.1mm.
          >

          Hmm with 0.1mm I be wery happy.

          > If you are doing such work, why don't you document it? -- you can
          > write on this wiki page:
          > http://reprap.org/wiki/Scratchbuilt_Piezo_Printhead, or start another.
          > You can also use the RepRap forum.
          >
          >
          >

          Hmm take to much time ... I don't want to publish scrap but to do work
          well I need to much time.
          ... and to write some quick message is plausible... just to share
          information.

          >> As I have wish to apply solder
          >> resist onto PCB with that and this stuff is like honey I realize that
          >> with that system is not plausible to do it. Maybe if I make two check
          >> valves to make a pump like device ... maybe
          >>
          >
          > Did you try to print with ink, other than try using water and alcohol?
          >

          No. I discover that nozzle is important part and should be short as
          possible (from chamber) and orfice to be as short as possible. In other
          side the input pipe need to be just right dimension and length. It's way
          easy to get continous stream (like in video posted here) but hard to get
          start/stop and single droplet's.
          I think the surfacee tension is the problem. The fluid can just run out
          of the nozle if not ok or not going trought at all. The head is just so
          sensibile to media used. Of course if head is cheap we can have
          different head's for different media. I have done a lot of engraving for
          input capilar but none works as should. After many times I got very
          cheap and very easy available input pipe/capilar. And work nice.. Just
          strip a piece of insulation from some wire. If the wire is hardcore
          (single 'rod') the insulation can be striped in long length and work
          just perfect. I do all the work with 20mm diameter buzzer and have
          enougth displacment. As I want Single drop on demand the displacment
          doesn't need to be big as single drop has small volume. The 200mm buzer
          displaces aprox 4mm long colon of fluid in capilare of aprox 0.2mm
          diameter.

          You can observe that singl drop with near all cannon powershot cameras.
          Great tool for all for testing/observing DIY jet heads.

          Check
          http://stereo.jpn.org/eng/sdm/index.htm

          The 'thing' is intended for stereo photography (need to capture photo
          with two camera in same time) Near no hardware is required. It's like
          remote switch. Just put 5V to USB connector and remove it when need to
          fire shutter. The delay is about 10uS and is pretty constant. With right
          background light and manual macro focus is possible to see drop in fly.


          ... and as I already write I want that just for making PCB. Toner
          transfer work good for me so I want Solder resist at 1'st. (there the
          resolution of 0.5mm is stil good) after that if succes the more precise
          layout can be printed. For single (prototype) board the price is to high
          but over 10 pieces the easyest and best is to put board to PCB house to
          manufacture it. ...but sadly 95% of board I make is 1 or 2 piece run.


          > Slavko, please join us! or at least write blog messages with your
          > findings. People do it at RepRap, using free blogspot.com blog, like
          > mine: http://casainho-emcrepstrap.blogspot.com/
          >
          >

          .. asy I write. So many ideas so little time. Maybe in winter...
        • Casainho
          ... Do you think we could print the head? Take as example what is being printed here: http://www.thingiverse.com/ Would be nice if we could print the head, and
          Message 4 of 21 , Aug 9, 2010
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            > The head is just so
            > sensibile to media used. Of course if head is cheap we can have
            > different head's for different media.

            Do you think we could print the head? Take as example what is being
            printed here: http://www.thingiverse.com/

            Would be nice if we could print the head, and just need to work the nozzle.
          • Slavko Kocjancic
            ... Probably... But the time need to make head is X to make the nozzle is X*100. So the nozle is expensive part.
            Message 5 of 21 , Aug 9, 2010
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              Casainho pravi:
              >> The head is just so
              >> sensibile to media used. Of course if head is cheap we can have
              >> different head's for different media.
              >>
              >
              > Do you think we could print the head? Take as example what is being
              > printed here: http://www.thingiverse.com/
              >
              > Would be nice if we could print the head, and just need to work the nozzle.
              >
              >
              Probably...
              But the time need to make head is X to make the nozzle is X*100. So
              the nozle is expensive part.
            • Casainho
              Probably... ... Right, but if we can divide the work/cost for a few developers, then we have more changes to achieve the objectives. My main example of success
              Message 6 of 21 , Aug 9, 2010
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                Probably...

                > But the time need to make head is X to make the nozzle is X*100. So
                > the nozle is expensive part.
                >

                Right, but if we can divide the work/cost for a few developers, then we have
                more changes to achieve the objectives. My main example of success and
                colaborative work is the 3D printer RepRap.


                [Non-text portions of this message have been removed]
              • Slavko Kocjancic
                ... I think that 1 st someone need to have few working examples to prove design. After that the coproduction is plausible. Till that just sharing information
                Message 7 of 21 , Aug 9, 2010
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                  Casainho pravi:
                  > Probably...
                  >
                  >
                  >> But the time need to make head is X to make the nozzle is X*100. So
                  >> the nozle is expensive part.
                  >>
                  >>
                  >
                  > Right, but if we can divide the work/cost for a few developers, then we have
                  > more changes to achieve the objectives. My main example of success and
                  > colaborative work is the 3D printer RepRap.
                  >
                  >
                  >

                  I think that 1'st someone need to have few working examples to prove
                  design. After that the coproduction is plausible.

                  Till that just sharing information and result is (by my mind) best approach.
                  So some 'coordinator' need to make plan/list of needed examples/tests
                  Then user's pick the test and report result
                  than all discuse results and try new branch of experiment till working
                  example is made.

                  as sending semifinished parts over world isn't good idea in developing
                  phase. After that if someone makes 1000 nozzles and someone other 1000
                  bodies and someone other then makes packages for 'coutry es' then
                  shipping cost can be low. other is just to expensive and to slow to do
                  job in separate places. (of course if few people in same area (town)
                  work together is just other thing.

                  Slavko
                • Casainho
                  If everyone could print the head body, buy on local shop the piezo and assembly on head body, and make his own nozzle. Also the electronics can be prototyped
                  Message 8 of 21 , Aug 9, 2010
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                    If everyone could print the head body, buy on local shop the piezo and
                    assembly on head body, and make his own nozzle. Also the electronics can be
                    prototyped with Arduino and that can work with actual RepRap Mendel. As for
                    software, printing can be the same as extruding, so while extruder is turned
                    on, the piezo/circuit could print -- just start and stop printing and a
                    constant speed.

                    Many people have already his own RepRap Mendel and can work with the
                    Arduino, so I guess we can at least prototype a very simple printing head.


                    [Non-text portions of this message have been removed]
                  • Steve Greenfield
                    You can t have an unbroken column of liquid from the head all the way back to the fluid source if it is more than a cm or so. I wrote this quite a while ago
                    Message 9 of 21 , Aug 9, 2010
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                      You can't have an unbroken column of liquid from the head all the way back to
                      the fluid source if it is more than a cm or so.

                      I wrote this quite a while ago about adding bulk ink systems to printers, it may
                      help illustrate what I mean:
                      http://www.polyphoto.com/tutorials/bulkinksystem/ExtensiveThoughtsOnCIS.html

                      An excerpt:

                      Many people don't realize that you also need an air bubble inside the cartridge.
                      Yes, you need an air bubble. The air bubble acts as sort of a spring to buffer
                      ink flow from the bottles. Without it, when printing starts it is pulling on the
                      entire column of ink from the head back to the top of the bottle. Then when a
                      nozzle stops drawing ink, inertia keeps the ink going. Maybe you've heard this
                      in the past in old houses, it's called Water Hammer when the pipes make a Bang
                      as you shut off a faucet quickly. All houses now include a (wait for it) dead
                      end pipe with an air bubble in it.
                       
                      With the air bubble in the top of the cartidge, as the print head pulls out ink
                      the air bubble grows a little larger as it drops barely below ambient air
                      pressure. This creates a slight suction that pulls ink in from the bottles. If
                      the nozzle does a lot of heavy printing and gets some ink flowing, then stops
                      suddenly, instead of a column of ink 20 inches long slamming ink out the nozzle,
                      it simply compresses the air bubble a little and this then springs the ink back
                      slightly into the bottle until everything is again at ambient pressure.
                       
                      Note that flexible sidewalls can substitute for this air bubble, for instance
                      the C8x and C6x series of Epsons have a thin plastic "sticker" that seals one
                      side of the cartridge and this can flex in and out in place of an air bubble.

                      It might seem strange that a column of ink 20 inches long "slams" into the
                      nozzles but gently compresses an air bubble. The difference is volume. 64
                      nozzles smaller than a human hair versus a bubble that may be 20 times the
                      diameter of the hose. Turn on your shopvac. Put a funnel over it, small side
                      out. You get a jet of fast moving air. Now put a large funnel over it (or make
                      one out of cardboard) that expands the size. Slow moving air.


                       Steve Greenfield AE7HD
                      http://www.linkedin.com/in/stevenjgreenfield


                      >
                      >From: Slavko Kocjancic eslavko@...

                      >No. I discover that nozzle is important part and should be short as
                      >possible (from chamber) and orfice to be as short as possible. In other
                      >side the input pipe need to be just right dimension and length. It's way
                      >easy to get continous stream (like in video posted here) but hard to get
                      >start/stop and single droplet's.
                      >I think the surfacee tension is the problem. The fluid can just run out
                      >of the nozle if not ok or not going trought at all. The head is just so
                      >sensibile to media used. Of course if head is cheap we can have
                      >different head's for different media. I have done a lot of engraving for
                      >input capilar but none works as should. After many times I got very
                      >cheap and very easy available input pipe/capilar. And work nice.. Just
                      >strip a piece of insulation from some wire. If the wire is hardcore
                      >(single 'rod') the insulation can be striped in long length and work
                      >just perfect. I do all the work with 20mm diameter buzzer and have
                      >enougth displacment. As I want Single drop on demand the displacment
                      >doesn't need to be big as single drop has small volume. The 200mm buzer
                      >displaces aprox 4mm long colon of fluid in capilare of aprox 0.2mm
                      >diameter.
                      >
                    • Slavko Kocjancic
                      The position of air bubble is important. The bubble in piezo compression chamber is 100% no go!!! I learned that input to the chamber need to have at least 10
                      Message 10 of 21 , Aug 9, 2010
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                        The position of air bubble is important.
                        The bubble in piezo compression chamber is 100% no go!!! I learned that
                        input to the chamber need to have at least 10 higher resistance of orfice.
                        And I implement that with aprox 8cm long capilar (actualy thin pipe with
                        0.7mm hole) and put little reservoar there. Filling that reservoar probably
                        need some air buble to isolate other installation. But we are try to
                        implement head 1'st after that the CIS system come in action... (if nedded
                        at all) filling with syringe is quick enought for me.

                        2010/8/9 Steve Greenfield <alienrelics@...>

                        > You can't have an unbroken column of liquid from the head all the way back
                        > to
                        > the fluid source if it is more than a cm or so.
                        >
                        > I wrote this quite a while ago about adding bulk ink systems to printers,
                        > it may
                        > help illustrate what I mean:
                        >
                        > http://www.polyphoto.com/tutorials/bulkinksystem/ExtensiveThoughtsOnCIS.html
                        >
                        > An excerpt:
                        >
                        > Many people don't realize that you also need an air bubble inside the
                        > cartridge.
                        > Yes, you need an air bubble. The air bubble acts as sort of a spring to
                        > buffer
                        > ink flow from the bottles. Without it, when printing starts it is pulling
                        > on the
                        > entire column of ink from the head back to the top of the bottle. Then when
                        > a
                        > nozzle stops drawing ink, inertia keeps the ink going. Maybe you've heard
                        > this
                        > in the past in old houses, it's called Water Hammer when the pipes make a
                        > Bang
                        > as you shut off a faucet quickly. All houses now include a (wait for it)
                        > dead
                        > end pipe with an air bubble in it.
                        >
                        > With the air bubble in the top of the cartidge, as the print head pulls out
                        > ink
                        > the air bubble grows a little larger as it drops barely below ambient air
                        > pressure. This creates a slight suction that pulls ink in from the bottles.
                        > If
                        > the nozzle does a lot of heavy printing and gets some ink flowing, then
                        > stops
                        > suddenly, instead of a column of ink 20 inches long slamming ink out the
                        > nozzle,
                        > it simply compresses the air bubble a little and this then springs the ink
                        > back
                        > slightly into the bottle until everything is again at ambient pressure.
                        >
                        > Note that flexible sidewalls can substitute for this air bubble, for
                        > instance
                        > the C8x and C6x series of Epsons have a thin plastic "sticker" that seals
                        > one
                        > side of the cartridge and this can flex in and out in place of an air
                        > bubble.
                        >
                        > It might seem strange that a column of ink 20 inches long "slams" into the
                        > nozzles but gently compresses an air bubble. The difference is volume. 64
                        > nozzles smaller than a human hair versus a bubble that may be 20 times the
                        > diameter of the hose. Turn on your shopvac. Put a funnel over it, small
                        > side
                        > out. You get a jet of fast moving air. Now put a large funnel over it (or
                        > make
                        > one out of cardboard) that expands the size. Slow moving air.
                        >
                        >
                        > Steve Greenfield AE7HD
                        > http://www.linkedin.com/in/stevenjgreenfield
                        >
                        >
                        > >
                        > >From: Slavko Kocjancic eslavko@...
                        >
                        > >No. I discover that nozzle is important part and should be short as
                        > >possible (from chamber) and orfice to be as short as possible. In other
                        > >side the input pipe need to be just right dimension and length. It's way
                        > >easy to get continous stream (like in video posted here) but hard to get
                        > >start/stop and single droplet's.
                        > >I think the surfacee tension is the problem. The fluid can just run out
                        > >of the nozle if not ok or not going trought at all. The head is just so
                        > >sensibile to media used. Of course if head is cheap we can have
                        > >different head's for different media. I have done a lot of engraving for
                        > >input capilar but none works as should. After many times I got very
                        > >cheap and very easy available input pipe/capilar. And work nice.. Just
                        > >strip a piece of insulation from some wire. If the wire is hardcore
                        > >(single 'rod') the insulation can be striped in long length and work
                        > >just perfect. I do all the work with 20mm diameter buzzer and have
                        > >enougth displacment. As I want Single drop on demand the displacment
                        > >doesn't need to be big as single drop has small volume. The 200mm buzer
                        > >displaces aprox 4mm long colon of fluid in capilare of aprox 0.2mm
                        > >diameter.
                        > >
                        >
                        >
                        > ------------------------------------
                        >
                        > Yahoo! Groups Links
                        >
                        >
                        >
                        >


                        [Non-text portions of this message have been removed]
                      • Donald H Locker
                        Many years ago, I made very small pipettes by drawing a heated glass tube out. This would be similar to making a glass fiber like you speak of, but because
                        Message 11 of 21 , Aug 10, 2010
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                          Many years ago, I made very small pipettes by drawing a heated glass tube out. This would be similar to making a glass fiber like you speak of, but because you start with a tube, the fiber ends up hollow over portions of its length.

                          By using a strong magnifier, you can find the position in the micro-pipette where the bore of the tube is the right size for a nozzle and break that section away from the rest of the tube. This micro-pipette must be supported to work as a nozzle - I suspect an epoxy resin would work well to glue it into the hole of the piezo head.

                          Donald.
                          --
                          "Plain Text" email -- it's an accessibility issue
                          () no proprietary attachments; no html mail
                          /\ ascii ribbon campaign - <www.asciiribbon.org>

                          ----- Original Message -----

                          > From: "Slavko Kocjancic" <eslavko@...>
                          > To: "Inkjet PCB Construction" <Inkjet_PCB_Construction@yahoogroups.com>
                          > Sent: Monday, August 9, 2010 4:25:26 AM
                          > Subject: Re: [Inkjet_PCB_Construction] Re: Let's make our own Open Source 2D ink printer for print on paper, wood,
                          > clothes, PCB, etc.
                          >

                          [snip]

                          >
                          > and maybe little help how to 'drill' so small holes... I tested two
                          > variant and both works well.
                          > Dril a hole with smalest drill you have. 1mm is good point. (I use brass
                          > material) then pick a piece of thinnest enameled wire (in some relays
                          > the wire is under 0.05mm) and pass it trought hole. Then QUICK fil hole
                          > with solder. You must do that quick to not destroy enamel of wire. Then
                          > in one side (outside) flatten the 'blob' of solder and wire with very
                          > sharp chisel. You can polish that too. After that pull out wire from
                          > opposite side and you got finest hole. If you can't find so thin cooper
                          > wire you can try with glass too. I do sucesfuly under 0.1mm. Break some
                          > glass jar and pick thin scrap of it. Then heat it with torch to red hot
                          > and then with two tweezers quick pull out of fire and stretch. You can
                          > get very fine fiber and use same solder pour method as above. But this
                          > method is little harder as fibre can very easy break when pull it out
                          > from hole. I didn't test it but I think that single carbon fibre out of
                          > some carbon cloth can do the best. Is stronger and can't be burned (as
                          > enamel on cooper). Just don't have piece to check thicknes.
                          >
                          > Slavko.
                          >
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