cmyk slicing

[3dphamster]

Hi,

first big thanks for publishing the great work on powder based diy printers.

i see that you are trying to hack cmyk printheads to make the Plan b work in full color. For that reason i searched the whole internet to find out how to slice a full color OBJ or WRL file with its color information and export them as images in SVG, BMP etc. to printable cmyk 2D images. Unfortunately i did not find anything useful, although i looked to some software like blender etc. i could not find a solution. All i found is that slicing is only possible with STL and monochrome.

@dragonator: How do you plan to slice & print in cmyk? Is there already a script/software on the net, that can do the color slicing?

I would love to see somebody pointing me to a script/software that can achieve this already. Actually it just needs to convert the wrl file to layers. Easy talled, but i know its for sure a lot of work…

[dragonator]

I do not yet know of any slicer that is capable of doing that. i have had contact with a few people who say they can make one and are willing to do so. So I do have a plan for when I am ready to print in full color. There is only one issue so far.

There is no CMYK printhead that we can use for the next 3DP printer. Until that problem is fixed, there is no real incentive to make a full color slicer. If you do find something on the internet, please let me know, it could be useful.

[wonko]

I have written one that can do it. It basically calculates a negative hull around a 3D object. Each color pixel is then converted into a thin long box, creating a very detailed 3D model where every box has a single color. Those can then be easily sliced, and the result is a monochrome filled slice with an arbitrarily thick shell in color. I use parts of OpenGL to calculate and render that, so the output is fast. My test model has a few thousand facets and renders a slice in under 3 seconds. I’ll be happy to share the code, but first I want to see a working 5-color printer 😉

[3dphamster]

Thats good news!
Did you write it in Phyton? I was also trying to write some code. But did not figured out yet how to find the intersection points of the z-axis. Do you mind sharing the code with me? I would love to learn how you did this calculating.

[dragonator]

@Wonko, That is good to hear, that is the colour slicing problem having a solution. On the topic of 5 colour printhead. Is there still anyone working on that, or has that died down a bit.

[wonko]

I will put the code online that I have so far. I’ll let you guys know. It’s very rough, but I was able to do some slicing already.

As for the printhead, yes and no. I have receive the parts to implement the differential data lines, but I simply have no time to put it all together. Same with the printer itself. But my goal is still to get a full color powder based printer going at some point in the near future.

[wonko]

Alright, so here is the code for my machine that is remotely based on Pwdr. I was able to get a few models out of it, but choosing wood was idiotic, and the Y axis kept jamming. I am looking forward to get Plan B assembled and get much more time to try out powders instead of fixing the hardware over and over 😉

https://github.com/MatthiasWM/IotaSlice

PS: the software uses FLTK as a UI. The FLTK binaries for OS X are included, but the package can also be compiled for Linux and MSWindows. Note the fixed path to the .3ds file. Sorry about that – still lots of work to do.

Here are some videos of the machine:

[3dphamster]

@wonko:
Thanks so much for publishing your code!
I was expecting just a script but hey, you published the whole Printer code!! This is just amazing as you put so much effort & time on this. Thanks again for making it public.
The last days i was trying to run a slice but unfortunately i’ve never used FLTK and just can’t get it to work on windows nor on my mac. :(((
Guess it will take weeks or months until i get this to run and learn how to compile everything right without errors etc..

[wonko]

Well, I hope we can get something working for this machine or whatever 3D printer comes after it.

Yeah, the code is very rough around the edges. FLTK should compile just fine from their archives: http://www.fltk.org . It comes with Xcode and VisualStudio setups (no command line required). Maybe I missed posting some code? Also, there is a fixed path to a 3ds file in the reader, which must be changed to whatever you have on your machine.

You can also send me build issues and error messages directly, and I will try to guide you through a build: mm(AT)matthiasm.com

[3dphamster]

Thanks for your offer. I will definitely drop you an email in a couple of days. Cheers!

[3dphamster]

Can the Plan b print white parts? What ink/binder solution mix is needed for that purpose?

[dragonator]

In theory, yes. The reason why all parts are colored is because of remaining ink. This is also why it is very hard. If you can manage to remove all ink from the printheads, there is nothing stoping you from printing in any color. Any binder that is commonly used (Zcorp binder, pure alcohol, sake or vodka) is already clear.

[3dphamster]

So i don’t have to use zcorp binder and can use just pure alcohol in the print head?

[dragonator]

From what I heard, rice wine (sake) and vodka are better for the printhead, and it is not a perfect replacement, but look at the page linked here:

http://open3dp.me.washington.edu/category/formulas/

It has quite a few recipes tested on a Zcorp machine. There are all sorts of powder recipes and a few binder recipes that might be interesting. Original Zcorp binder has no alcohol in it, but if you understand what the binder has to do (temporarily melt the powder so it fuses with itself, then vaporize and re-solidify the powder), Alcohol mixes serve great. Pure alcohol might actually be worse. In all recipes described in the link, they actually dilute even the vodka they use. http://open3dp.me.washington.edu/2009/09/xb1-experimental-binder-1-400-class/

Pure alcohol does not dissolve most powders, it is the water that does the dissolving. Its the alcohol that helps the water to vaporize. Hope this information helps. I always wanted to experiment with powders myself, but it is the part I enjoy the least, and constantly swapping out powders on Plan B is laborious. (On the next printer I will fix this).

[3dphamster]

Thanks for the open3dp link. Definitely your information helped me a lot, for understanding the binder stuff.

“it is the water that does the dissolving. Its the alcohol that helps the water to vaporize”
That’s so true! Its just dumb from me, why i did not think about it before posting :)))

As i am thinking to build the plan b very soon i would like to ask you a couple of questions, which i think they are little private. Is there a way to contact you via email or chat somehow?

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