Thank you :) I want to understand the charging and charge measuring process better. A year ago I tried to just put the piezo nozzle, charge electrode and charge sensor together and tried to measure the charge, but it did not work very well and when I broke one amplifier I also saw that the result was not repeatable with other amplifiers. Now I want to try it step by step, starting with large drops at low frequency and a simple setup. My plan is to build my own amplifier next for measuring these drops and if everything works well I want to increase the drop frequency and reduce the drop diameter until ultimately ending up at 0.1mm drops at 40000 to 60000 drops per second for the CIJ printer. What I learned so far is that shielding seems to be very important to not pick up noise like the mains frequency with your charge sensor on the way to the amplifier.
Hi Michael, I'm trying to figure out what I have to pay attention to when charging and measuring drops. At the moment I try out a bunch of AD620 amplifier modules to make sure that the reading is repeatable, because last year I did a similar test and I later found out that I only got the reading with one of the amplifier boards (after I broke it 🤦). When I can get the same readings with all boards I want to try building a more optimized amplifier, try out different charge sensor designs and later I want to try out detecting smaller drops with higher frequency for finally getting a reliable charge sensor for my CIJ project.
Wow this can both the wire edm and sinker edm? Like one can machine a copper piece and use it to shape steel? That would be a DIY home tools gamechanger
Maybe it could work, but you would need more powerful piezos or maybe something driven by an electromagnet, since solder paste has a much higher viscosity than water + ink.
Hi, thank you :) I just learned about it while doing it. When I find a project I want to do, I search online for everything I can find about it and try to understand it well enough to get it done. I'm really not that smart, just motivated 😅
Yes, I want to build something like a small hydraulic setup with this valve keeping the pressure stable while the pump can continuously run. The unused ink should get feed back into the reservoir tank as well as the return line from the printhead.
I can't see a voltage divider in your EDM. Also, can't see stepper motor where is connected ( I see you have both arduino nano and mega but mega). Thanks!
For this circuit I used an ACS712 current sensor for detecting when the electrode touches the workpiece, instead of using a voltage divider for that. I used stepper motors for the X and Y axis and another one similar to a 3D printer's direct extruder for moving the electrode. The Arduino Mega is running Marlin for driving the stepper motors and receiving GCODE and the Arduino Nano is just used for generating a square wave for the MOSFET of the EDM circuit.
Hi, the ink stream is broken up by a piezo on the nozzle into droplets which are evenly spaced apart so that they have no electrical connection to each other. The nozzle has a ground connection so that the ink stream is at ground potential until it breaks up into droplets. At the position where it breaks up there is an electrode (brass block with a slit) located. When the droplet breaks loose from the ink stream it gets a negative electrostatic charge from a positive voltage (312V in this test). When the charged droplet now passes the angled high voltage electrode (with 4.4kV in this test) it gets attracted to it and leaves it's straight flight parth. In this test I flipped the switch that powers the 312V supply to show that the stream of charge ink droplets gets deflected. The ultimate goal would now be to deflect only single droplets with exactly the needed charge to form characters and pattern for printing, but there is more work to do to make this happen. Here in the details section is a diagram of it: hackaday.io/project/178762-cij-printer Thanks for your interest :)
Hi @OfficialSeccour, I haven't dared to make commentated videos, yet, because I have not much experience in speaking English, so it would likely sound weird. But maybe I can make a project summary with a text to speech app for the next major update. Until then I write a buildlog for every update on Hackaday: hackaday.io/project/178762-continuous-inkjet-printing/details Thank you for your interest in my project :)
Hi @Unmannedair, I'm working on a Continuous Inkjet Printer like they use in the industry for printing the expiry date on food and doing other product labeling. The goal of the project is to build a useful (fast + good quality) inkjet printer at home that needs no parts from commercial inkjet printers/printheads so that you can build your own inkjet projects like part labeling machines or binderjet/polyjet 3D printers as private or even commercial project based on it.
@@dominik_meffert that's fair. Also don't worry about your spoken English you can only progress as you try :) My only issue with the updates is that it's a bit difficult (at least for me) to really link what I see on the video and the things you detailed in writing. Maybe inserting more pictures next to the relevant text would make things easier ? Anyway I like your project as I'm planning to either modify or current printer or build one from scratch to print on our packagings
This one is testing the timing of the droplet charger, in sync with the new piezo driver circuit, to make sure that with the new driver circuit generating the CIJ droplet stream, he can still get the charging plate to affect the droplets' charge reliably.
Thank you :) I tried capturing a feedback signal from the stream of ink droplets. The piezo breaks the stream of ink into equal sized droplets and a test signal is applied to the charge electrode which these droplets pass after breakup. The test signal are 16 pulses with each having a different phase shift to the piezo drive signal. The purpose of this signal is to find out which of the 16 phase shift settings leads to the highest charge on the droplet. When a charged droplet passes the phase detection electrode there is a pulse visible on the oscilloscope. It's alway 16 readings/droplets and a pause. The yellow signal is only for triggering. In this video I tried changing the output voltage of the piezo driver with a potentiometer and saw that it also changes the feedback signal. So, it changed which phase setting gives the best droplet charge. I still have to work a lot on this... Normally the feedback signal should only be positive and also more stable 😅
Hi, no I'm still working at it. Last week I replaced all lines, valves and fittings with either stainless steel, rubber or plastic to prevent corrosion which was a big problem with brass and copper. I'm currently testing ink made out of Ethanol + PVB which has a higher viscosity than pure ethanol (like a clear varnish). The higher viscosity ink required some modifications, but now it's working and the ink can be used to actually print things that will not evaporate (like pure ethanol). Next, I want to work on the viscosimeter for keeping the viscosity constant at all times. Then on a corrosion resistant printhead design, the piezo driver, the charging + phase detection electronics, the code for phase detection and the code for actual printing. I guess it will still take a long time until this project is finished.
What are all the various tubes for, is this intended to be some sort of Continuous Sensor? Either way really neat project, it would be great for my dream of an Open Source Materials Science Lab!
It's going to be a CIJ printer when finished. The tubes are lines for ink, vacuum and pressurized air. The ink flows in a cycle across the system and only some droplets will be deflected out of the ink stream for printing. The ink stream is ejected from the nozzle and enters a vacuum tube to be recycled over and over again.
Yes, thats right. The machine I'm building uses a piezo at the nozzle to split the ink stream into equal sized droplets which then get a charge to deterimine their deflection angle. After charging they pass a high voltage electrode that attracts them out of the straight flight path of the ink stream. When everything works I can try out labeling with it first and if that works I want to use it as a printhead for 3D printing on powder.
This is really great progress for DIY metal 3D printing! maybe passing the wire through a hollow stirring tool made of a heat resistant alloy or ceramic to enable forging the as printed material onto previously built layers? and using a bit less heat? Would love to learn more about this adventure!
Thank you very much :) Nice idea. At the time I built this project I did know almost nothing about electronics and I think with a better built power supply + the stirring tool it could work much better.
Any chance from changig gcode mode into a regular printer like behaviour? Meaning Paper just comming through once, with all the dots on the right spot.
Hm, do you mean so that it appears to windows like a real desktop printer or just a software that operates the machine like a printer without the need of writing a windows compatible printer driver?
@@dominik_meffert both ideas are great. Mainly my idea was, to improve efficiency by forwarding paper only in one direction. Easyest would be, I guess, to sort the point locations in x, y axis and let it run then in g code. But a windows pri ter compatibility wouöd be great. Next step would be to reduce the droplets and gwt an open source printer going. Everyvody is building 3d printer and cnc machines. Nobody is getting rid of those drm infested printers.
I'm currently working on a CIJ Printer prototype. If I can get it to work it will get some software for printing all sort of things with. Unfortunately, the machine will be far more complicated and expensive than the piezo pump printer, but in return it should be possible to make it more precise, reliable and faster.
Was this inspired by the iro3d? I only ask that because I was working on something almost identical to this at the time you uploaded this video. Ender 3, graphite crucible etc. I was using a two separate heads with syringes for dispensing though.
nice, it looks to me one coil being energized and turn off fast, maybe sparks from motor? the yellow line have positive and negative voltages at same rate...looks like a coil with capacitor being energized
@@daviperes Here is another test: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-OI_NzipObTI.html The ink droplets are measured (as far as I know) by capacitive coupling when they pass the sensor.
@@dominik_meffert very hard to think on. the droplet is flying? or is that 0.1mm on wire? if it is on the wire, you measure the whole wire, in the air maybe only can be measured if they do not stick on wall?. sry
I'm currently working on a Continuous Inkjet Printer like the ones who print the expiration date on food. The ink stream flies from the nozzle into a vacuum return line for recirculation if it is not used for printing, so there is an inkstream present at any time. The 0.1mm stream is broken up into equal sized droplets which get charged by a testing signal (blue waveform) to find the perfect "phase" for charging. The yellow waveform is the signal from the charged droplets. I just took another video where the signal is much cleaner: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-BN4DvKIaSE4.html
I'm currently working on another DIY printer project that aims to get a higher resolution in the end: hackaday.io/project/178762-cij-printer Unfortunately it will be a lot more complex than the single piezo pump printhead. Maybe moving the piezo pumps directly to the printhead and then using a smaller nozzle and a well adjusted pulse could make a higher resolution possible.
Thank you :) In this video I tried to charge the ink stream by turning on the 312V, so that it gets attracted by the high voltage electrode for altering it's flight parth.
