01/17/2020 at 00:40 •
Here I want to write down some ideas for the printer software.
I think besides CMYK printing it should have a mode for assigning a color to a printhead. E.g. if you have a svg graphic with areas in RGB Colors, black areas are assigned to printhead 0, pure red areas are assigned to printhead 1, pure green areas are assigned to printhead 2 and blue areas are assigned to printhead 3.
It should also have an option to print black and white with all four printheads for faster printing like I planned before for the 10 nozzle printhead instead of CMYK.
More ideas will follow.
01/05/2020 at 12:05 •
The last few weeks I changed a few things on the printer so that I can try CMYK printing. It would be a dream if it works out.
I removed the 36V power supply, 3 L298Ns, the step down converter, the shift register, the WAGO clamps and the pump speed controller and added a 12V power supply, 3 more pumps, a much heavier speed controller and a step up converter.
The printhead is now a 4 nozzle, single piece, height adjustable printhead for 4 different colors.
The T fitting has been replaced by a SLA printed block for 4 different colors.
I ordered cheap inkjet ink which I would mix with water for testing, but today I saw there is even cheaper ink out there which I could use without mixing it with water.
The printer is now ready for testing, but I don't have any software to create the GCODE yet.
I will try to write one in Python with a GUI so that you can select a picture and the settings and it will create a preview and the GCODE.
This maybe take a while because I haven't done something like that before.
12/07/2019 at 15:52 •
I tried to print a few pictures using water mixed with color. Since the last test with color I've increased the speed by optimizing the software and driver electronics and I solved the issue of continuous ink supply with a closed ink supply cycle and a peristaltic pump.
The resolution has not changed since then.
The next thing I will try is building a better printer design for 4 color/cmyk printing and writing the software for it.
Some things to add/test in the future:
- Increase the resolution with the use of a smaller nozzle and optimized piezo control
- Simplifying the piezo driver electronics
- Building a system to print with melted wax like:
- Continue working on a multi nozzle design for increased printing speed.
12/01/2019 at 14:52 •
I've added a Closed Cycle Material Supply System in form of a T fitting with some hose connectors, a Nema 17 stepper motor driven peristaltic pump, an extern stepper driver, a check valve and some silicon tubes to solve the problem of continuous material supply.
The pump pumps the material to the T fitting, which is mounted in the correct hight, so that the printhead neither leaks nor runs dry. In the top of the T fitting is a hole drilled, so that the pump not influences the pressure between the T fitting and the printhead. A small amount of the material is used for printing, but the majority of it flows back to the tank.
This way there is always enough material in the T fitting to print until the tank is empty and besides of once setting up the right hight of the T fitting and refilling the tank when it's empty there is no additional maintenance needed.
I use a peristaltic pump, because that way the pump has no direct contact with the material which maybe could damage the pump or contaminate the material.
I changed the stepper motor pump to a 12V DC motor pump & speed controller from amazon because a stepper motor is not necessary for just pumping the fluid continuous through the system.
11/19/2019 at 15:41 •
Here is a test with all 10 nozzles online and speed optimized post processing script.
I noticed an offset in the Y direction and missing drops in the middle of the star.
I will check the software whether it can be fixed but maybe a single CNC machined/ laser cut nozzle plate, at which each offset is exactly the same could be better for a multi nozzle setup.
I've tested a single nozzle setup and the offset is still there. Must be a issue in the post processing script.
I think I've found the issue.
In the picture above the printhead is only moved to the positions where it should print and not "raster-moving" the whole area.
I think that way should be better and saves time too.
A short video of the single nozzle setup.
11/11/2019 at 11:10 •
A short test of my DIY Inkjet Printer to test the function of the printer, software and toolhead.
Nozzle 9 and 10 are offline in this test because I ran out of pins on the Arduino UNO .
The Nozzles are 0.4mm 3D printer nozzles which are maybe too big. I will later test smaller ones.
Now printing with 3600mm/min.
11/06/2019 at 18:44 •
YES, the printer and all 10 printheads are working. Now it's time to work on the software.
I have almost no coding experience besides of Arduino and the python script I wrote. So maybe it could take some time...
11/03/2019 at 01:42 •
Here is a new 10 nozzle toolhead based on the new SLA 3D printed design. The dimensions are 105*55*50mm + nozzles and push-in fitting. The nozzle to nozzle distance is 8mm and at its back is a 4020 aluminium profile for easy attachment.
10/29/2019 at 04:37 •
My new Elegoo Mars
In the last weeks I've tried to design a 3D printed toolhead to get the size and complexity down and here is my latest (successful) test:
2 Printheads (The SLA parts in the picture were not cured and so they bend at the sides I think when they are cured they should no longer bend that much)
Inner channels to prevent the buildup of air in the ink chamber
Features of the new toolhead:
- Dupont Connectors
- Smaller Size 30*50*8mm
- Nozzle to Nozzle Distance 8mm
- Extendable (You can stack as many as you want)
- No more venting (No build up of air in the ink chamber because in and output are at the top)
- Only One Ink Connection (The ink flows from one printhead to the next and venting is no longer needed)
The only problem that remains is controlling the pressure...
I've ordered pressure sensors for further testing.
10/19/2019 at 19:44 •
I've built a pressure control unit to keep the right pressure during printing.
I also ordered check valves to flush every printhead which should be delivered by Monday.
When I have everything together I will test the whole system and see whether it works but I think this attempt will be too complicated and expensive to be more than a prototype...
So the next thing I will test will be a printhead printed with a resin 3D printer to utilise the capillary effect and maybe smaller piezo discs.
Today I've ordered an Elegoo Mars so I can start working on 3d printed parts with small channels inside by next week.