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

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  • Gle Tha
    If you want to make a single nozzle print head that will take almost any ink or paint then you will want to go with a pressurized system. They are easy to make
    Message 1 of 21 , Aug 4, 2010
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      If you want to make a single nozzle print head that will take almost any ink or
      paint then you will want to go with a pressurized system. They are easy to make
      and easy to expand to multiple nozzle systems. A few years back I did a system
      that had seven nozzles. I think your trying to put this on a CNC system. If this
      is the case then the spacing of each color nozzle will be the offset in your CNC
      program. You going to start with one head so you will not have an offset. Here
      is how the simple printer and head is made. Get a plastic bottle and drill two
      holes in the lid then put fitting in the holes so hoses can be connected to
      them. On of the fitting will also have a metal tube connected to it that will
      reaches to the bottom of the bottle. Now get a Loveshaw Cpjl00-001-0 micro valve
      and connect a plastic tubing from the bottle fitting that has the metal tubing
      that goes to the bottom of the bottle to then in port of the micro valve.
      Connect a plastic tubing to the out port of the micro valve to a nozzle and to a
      nozzle. The nozzle is nothing more then a small pipe that will fit into the
      plastic tubing that has been filled with epoxy while having a wire in the center
      of it the desired nozzle orifice size that has been waxed. When the epoxy is
      cured pull the wire out and that is your nozzle. The last thing that you need to
      do is connect a few pounds to air pressure to the other fitting on the bottle. 3
      to 5 PSI is goof don’t use more then 7 PSI. The micro valve works on 5 VDC. When
      5VDC is applied to the micro valve the pressure will push ink or paint from the
      bottle. One more note the Plastic tubing between the micro valve and the nozzle
      should be as short as possible. If you want to get a supply of these micro
      valves your best be would to buy a Marsh print head off of eBay. The print head
      would give you seven micro valves, seven plastic tubing print nozzles.




      [Non-text portions of this message have been removed]
    • Casainho
      ... Thanks. I am recording this info and sending to others so we can think about it. thanks ;-) [Non-text portions of this message have been removed]
      Message 2 of 21 , Aug 4, 2010
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        On Wed, Aug 4, 2010 at 3:25 PM, Gle Tha <tegtronics@...> wrote:

        >
        >
        > If you want to make a single nozzle print head that will take almost any
        > ink or
        >
        Thanks. I am recording this info and sending to others so we can think about
        it. thanks ;-)


        [Non-text portions of this message have been removed]
      • Gle Tha
        The attached file is how a basic single nozzle printer is made using a CNC with a pulse to step drives. If your drives step on any pulse high or low then
        Message 3 of 21 , Aug 5, 2010
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          The attached file is how a basic single nozzle printer is made using a CNC with
          a pulse to step drives. If your drives step on any pulse high or low then you’ll
          need a different circuit. If the CNC step commands are 5vdc then this circuit
          works if it is more then 5vdc then a voltage divider will be needed for each and
          gate input. The voltage divider is nothing more then two resisters.  I used the
          Atmel microprocessor to do all the controlling back when I did my project a few
          years ago. The microprocessor allows you to send all the enable step and
          direction commands to it before it send them to the drives. This allows you to
          write the printer valve delays in to the microprocessor code. Here is the big
          hint how to add delays in a stream of pulses coming to the microprocessor.
          Everything goes into shift registers. This allows you to insert and remove bits
          states to turn on and off the printer valve. Every time a bit state changes on a
          microprocessor pin you shift index the shift registers with the new valve. If no
          action has accrued in a set amount of time make sure you turn off the printer
          valve. I hopes this helps with your project.


          ________________________________
          From: Casainho <casainho@...>
          To: Inkjet_PCB_Construction@yahoogroups.com
          Sent: Wed, August 4, 2010 7:12:25 PM
          Subject: Re: [Inkjet_PCB_Construction] Let's make our own Open Source 2D ink
          printer for print on paper, wood, clothes, PCB, etc.

           
          On Wed, Aug 4, 2010 at 3:25 PM, Gle Tha <tegtronics@...> wrote:

          >
          >
          > If you want to make a single nozzle print head that will take almost any
          > ink or
          >
          Thanks. I am recording this info and sending to others so we can think about
          it. thanks ;-)

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







          [Non-text portions of this message have been removed]
        • Casainho
          Hello :-) Sorry, I got none attachment files, looks like the yahoo groups removes all the files. Can you please send to my e-mail? Thanks. ... -- Cumprimentos,
          Message 4 of 21 , Aug 5, 2010
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            Hello :-)

            Sorry, I got none attachment files, looks like the yahoo groups removes all
            the files. Can you please send to my e-mail?

            Thanks.


            On Thu, Aug 5, 2010 at 4:58 PM, Gle Tha <tegtronics@...> wrote:

            >
            >
            > The attached file is how a basic single nozzle printer is made using a CNC
            > with
            > a pulse to step drives. If your drives step on any pulse high or low then
            > you�ll
            > need a different circuit. If the CNC step commands are 5vdc then this
            > circuit
            > works if it is more then 5vdc then a voltage divider will be needed for
            > each and
            > gate input. The voltage divider is nothing more then two resisters. I used
            > the
            > Atmel microprocessor to do all the controlling back when I did my project a
            > few
            > years ago. The microprocessor allows you to send all the enable step and
            > direction commands to it before it send them to the drives. This allows you
            > to
            > write the printer valve delays in to the microprocessor code. Here is the
            > big
            > hint how to add delays in a stream of pulses coming to the microprocessor.
            > Everything goes into shift registers. This allows you to insert and remove
            > bits
            > states to turn on and off the printer valve. Every time a bit state changes
            > on a
            > microprocessor pin you shift index the shift registers with the new valve.
            > If no
            > action has accrued in a set amount of time make sure you turn off the
            > printer
            > valve. I hopes this helps with your project.
            >
            > ________________________________
            > From: Casainho <casainho@... <casainho%40gmail.com>>
            > To: Inkjet_PCB_Construction@yahoogroups.com<Inkjet_PCB_Construction%40yahoogroups.com>
            > Sent: Wed, August 4, 2010 7:12:25 PM
            > Subject: Re: [Inkjet_PCB_Construction] Let's make our own Open Source 2D
            > ink
            > printer for print on paper, wood, clothes, PCB, etc.
            >
            >
            >
            > On Wed, Aug 4, 2010 at 3:25 PM, Gle Tha <tegtronics@...<tegtronics%40yahoo.com>>
            > wrote:
            >
            > >
            > >
            > > If you want to make a single nozzle print head that will take almost any
            > > ink or
            > >
            > Thanks. I am recording this info and sending to others so we can think
            > about
            > it. thanks ;-)
            >
            > [Non-text portions of this message have been removed]
            >
            > [Non-text portions of this message have been removed]
            >
            >
            >



            --
            Cumprimentos,
            Jorge Pinto


            [Non-text portions of this message have been removed]
          • Casainho
            Thanks! I am being sharing this info on the forum message we started: http://forums.reprap.org/read.php?153,52959,54160#msg-54160 [Non-text portions of this
            Message 5 of 21 , Aug 5, 2010
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              Thanks! I am being sharing this info on the forum message we started:
              http://forums.reprap.org/read.php?153,52959,54160#msg-54160


              [Non-text portions of this message have been removed]
            • Gle Tha
              I wrote some code so you will get an idea of how a shift regesters works. You said it was going to be open source so I wrote it in Bascom-AVR. Basis is easy or
              Message 6 of 21 , Aug 5, 2010
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                I wrote some code so you will get an idea of how a shift regesters works. You
                said it was going to be open source so I wrote it in Bascom-AVR. Basis is easy
                or everyone to learn and you can download a free version of bascon-avr from
                MCSelec.com . This code is not complete, I wrote it to give everyone an idea of
                how to write there own code.



                '---------axas Tracking using shift
                registers---------------------------------------
                           If axaspins <> oldaxaspins Then
                                printflag = 1
                                Shift xtrack , Left , 1
                                Shift ytrack , Left , 1
                                Shift ztrack , Left , 1
                              If xaxaspin = 1 then
                                  xtrack = xtrack + 1
                              End if
                              If yaxaspin = 1 then
                                  ytrack = ytrack + 1
                              End if
                              If zaxaspin = 1 then
                                  ztrack = ztrack + 1
                              End if
                          End If

                '----------x axas----------------------------------------------------
                          xstate = 32768 And xtrack
                          If xstate = 32768 Then
                                 Portc.4 = 0                                'z on
                          Else
                                 Portc.4 = 1                                'z off
                          End If
                '----------y axas----------------------------------------------------
                          ystate = 32768 And ytrack
                          If ystate = 32768 Then
                                 Portc.3 = 0                                'y on
                          Else
                                 Portc.3 = 1                                'y off
                          End If
                '-----------print valve------------------------------------------------
                          If printflag = 1 then                            'print flag is what
                enables the print valve to turn off if there isn't axas movement
                               printstate = 8192 And printtrack            '32768  bit 16, 16384
                bit 15, 8192 bit 14,  4096 bit 13, .... (on time before step)
                               printflag = 0
                               If printstate = 8192 Then                 
                                  printtime = 3                             'print time (one
                time after step)
                               End If
                          End If

                          If printtime > 0 Then
                                 Portc.5 = 0                                'print valve on
                                 Decr printtime
                                Else
                                 Portc.5 = 1                                'print valve off
                                End If
                          End If

                 



                ________________________________
                From: Casainho <casainho@...>
                To: Inkjet_PCB_Construction@yahoogroups.com
                Sent: Thu, August 5, 2010 1:30:40 PM
                Subject: Re: [Inkjet_PCB_Construction] Let's make our own Open Source 2D ink
                printer for print on paper, wood, clothes, PCB, etc.

                 
                Thanks! I am being sharing this info on the forum message we started:
                http://forums.reprap.org/read.php?153,52959,54160#msg-54160

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







                [Non-text portions of this message have been removed]
              • Casainho
                Don t worry, we have some medium knowledge in electronics and ARM microcontrollers. I think the most difficult part for us is the mechanical part of the
                Message 7 of 21 , Aug 5, 2010
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                  Don't worry, we have some medium knowledge in electronics and ARM
                  microcontrollers.

                  I think the most difficult part for us is the mechanical part of the inkjet,
                  and do it to be DIY, simple and cheap.

                  Maybe later we can even have some difficult on software control of the
                  RepRap Mendel*, however we will try to re-use actual software tools.

                  We are also taking advantage of RepRap Mendel, and we will design and print
                  any needed piece in plastic.

                  http://reprap.org/wiki/Main_Page


                  [Non-text portions of this message have been removed]
                • Cristian
                  ... me too, please Cristian [Non-text portions of this message have been removed]
                  Message 8 of 21 , Aug 6, 2010
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                    At 08:13 PM 8/5/2010, you wrote:
                    >Hello :-)
                    >
                    >Sorry, I got none attachment files, looks like the yahoo groups removes all
                    >the files. Can you please send to my e-mail?

                    me too, please
                    Cristian

                    [Non-text portions of this message have been removed]
                  • Casainho
                    ... I put all the info and images online, here: http://forums.reprap.org/read.php?153,52959 [Non-text portions of this message have been removed]
                    Message 9 of 21 , Aug 6, 2010
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                      > At 08:13 PM 8/5/2010, you wrote:
                      > >Hello :-)
                      > >
                      > >Sorry, I got none attachment files, looks like the yahoo groups removes
                      > all
                      > >the files. Can you please send to my e-mail?
                      >

                      I put all the info and images online, here:
                      http://forums.reprap.org/read.php?153,52959


                      [Non-text portions of this message have been removed]
                    • casainho
                      Here is a video of the piezo print head printing: http://vimeo.com/13973877 Read the wiki page to get all the information:
                      Message 10 of 21 , Aug 8, 2010
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                        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
                      • 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 11 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 12 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 13 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 14 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 15 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 16 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 17 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 18 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 19 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 20 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 21 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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