[vacpress]

teilhardo- yah. Ef the man! that bastard.


as for how this thing would make pictures. with 1 cololr its fairly simple - fill in the grid. with 4 colors its much more complex. it becomes: fill in the grid by spraying the right CMYK colors.

To do this, a few pieces of software need to be adapted\written. One piece has to breakdown a bitmaped raster image, convert it into values such as x,y,color. Then it needs to transmit that information to the "print engine"

the print engine needs to be able to:

1) read the x,y value of each pixel and locate the apropriate print nozzle over than location.
2) decide what color to spray out to achieve the desired color. so, yes, lots of software and possibly 1 piece of hardware needs to be developed for this...

the easiest way to do this is probably with a "post processor" style arrangment. basically you would

1)load your fullcolor, highquality image into the processor engine.
2)the engine will break the image into a grid, and assign a color value for each coordinate location.
3)the engine will control the print mechanism as it plots these color values.

this is why the wirejet uses those steppers and wires - to maintain an accurately metered, yet very minute amount of paint. The wirejet has 3 nozzles that direct the each paint drop to the work material. someone should work on this.. i have found other companies use the sme concept as wirejet, so that means it must be valid to dopt their idea, as it may be more universal than they make it sound on their site. I checked out their pattents, and the drawing of their nozzle array could prove usefull.


if someone would begin to do real research on the software, while i constuct this hardwae, that would be really cool.. A place to start is finding out exactly what a "RIP engine" does.

Best Regards

[vacpress]

something else worth persuing is the same wheeled ganty idea for VERY large vinyl sign making. Using my design as a starting point, a 24foot wide gantry could be constructed... hmmmm..... tarps for sign material... hmmm...

worth mentioning - such a device can also cut nylon fabric very accurately by holding a soldering iron type heated cutting element.

if i remember correctly, there is some smple math to keep a knife's cuttong edge perpindicular to your cutting direction - i saw it over on luberths site a year or so ago...

The xylotex can be cheaper unipolar drivers - but then the thing will go slower


pulitime-did you read my .rtf?

[vacpress]

ok. here is a quickish 4-color printhead concept. the PCB is a db25 breakout board i figured could do double as a wire distro point on the printhead carriage. not modeled yet are the steppers or solenoids that control the brake cable, also not modeled. Maybe soon. Anyone got a model of a Xylotex Board? or do i have to do everything?




all these transparent parts are acrylic. i am making them different colors for clarity. acrylic is nice because when machined, it can attain tight tolerances.




next up : a swivel knife assembly, and a hot knife assembly. for cutting paper & vinyl, and synthetic cloths respectively.

[Bloy2004]

Vac! You astound me with your renderings...and the quickness!
They sure look like they will work, but then I only dreamed of these type of machines after visiting pixilation....
How do you do it? Is the control and machanics basically a glorified printer-operating with much higher volts and amps?
...and yes, I've been dreaming of toolchangers, and laser digitizers, and variable speed spindles, and....etc..etc...etc...

P.S. the pics are still huge....are you using low res files? they sure don't appear to be.

[tachus42]

I used to a printer tech so I've got a few thoughts.
Don't try and angle your nozzles to try and hit the same spot. The dot shape from each nozzle will be differrent and one color will bleed out from under another. For example a green dot made from cyan and yellow will be cyan on one side green and the middle and green on the other. Space the nozzles apart a interger number of pixles apart and handle the offset in software.

You might want to check out Ghostscript, www.ghostscript.com its a open source postscript interperter (RIP) which as well as all the standard printer drivers can also output simple bit map files with the required pixel on/off type of format.

[vacpress]

tachus-good point - the angle affecting dot shape. i am probably not going to build anything like that 4 color printhead. i am allready looking at a system that will allow much smaller amounts of paint to be delivered to much smaller spaces. possible a thin plastic or metal 3" ring being driven through a pool of paint, and past some very small nozzles. with 3-4 nozzles, i can make much smaller circles.

if i try to use HP RTL, how do i take the info from a generic driver and store it, and then print it? can i emualte all that in software?

i am a fairhand at "PicBasic" style microcontroller programming..

for now i am going to just build the roving gantry, as i have all the parts on my table.. just gotta take the time to do it right or it will go in circles! any slop in build on this guy will show after a foot or so of movement.

[tachus42]

Vac, Just saw from you post in another thread that you are already looking a ghostscript, here is a link which might be helpfull if you havn't aready found something similar http://www.ghostscript.com/doc/gnu/7...s.htm#Uniprint
It looks like you could make a custom upp file and have it output a sun raster file which could then have the head movement commands spliced into it by a simple script.

[vacpress]

tachus- yes i am discussing this with someone in anothe thread - the script would read the raster iamge pixel by pixel, line by ine, and move the printhead to these locations.. any elaboration on this script would be lovely

what is this process called? where can i find an example? who else has done this? how hard is it?

the uniprint document looks very promising. one question.. if i define all theis information for the machine in this driver, what actually takes the pixel\colro data, and gets the mechanical system to spit it out? i like how you can set offsets between print nozzles with unidriver.. thats something we will need.....
i am gonna start building the gantry in a few hours. I may try my "chepa linear bearing" idea since i have really never used my lathe for much other than making model components, and making motor couplers. printing the templates out of solidworks is so obnoxious when it takes 3 pages of 81/2x11 all cutup nd taped together.

[kcoaks]

Vac, you mentioned using PIC basic...have you settled on a particular PIC? Just curious. I'd lend a hand with the PIC code, but my experience is strictly PIC assembly, and probably more limited than yours. But I'd be happy to lend a coding hand, if need be.

I know people keep saying this, but those drawings are incredible! You're pretty handy with the 3D.

[vacpress]

kcoaks- ive used PBP to make robots and stuff with PIC16f84A s


and the drawings: thanks! i love compliments, as its something I hav tried very hard to get good at..

[turmite]

Vacpress I can see already this adoption thing I proposed is not gonna work! These folks are not gonna let you go.

I have a couple of commets and only hope to help what little I can on this open source thing.

1. It looks to me that the paint guns you have drawn are in reality jamb guns or touch-up guns instead of airbrushes.

2. While thinking about your project I envisioned a huge, yet lightweight frame that could be mounted vertically and programmed with the layout of the front of a house and viola or whatever that word is.....a cnc house painting machine.

I agree with everyone else here that for a young person that has tons of talent you also seem to have a bigger heart.

Mike

[vacpress]

<smile>
i think im just an MIT wannabe... im in art school. it somtimes leaves me craving math..

the paintguns are in fact "detail" guns, or touch up guns. on the package it said "detial airgun for..." in some bad asian translation...

I am going to move to something much more like pixation is doing when i move from a pen for testing upto a "printhead" i am actually about to go walk into the shop to start building this, after i print a few cut templates out of solidworks. sucks, i dont have a bandsaw here. im gonna try and do it with a scroll saw, if that dosent workout, i am just going to machine some motor couplers and maybe give the v-bearing idea a shot. (see holy grail thread).

its odd so many of the "gurus" here have remained silent on this. i was hoping for some really rigorus criticism and saugestions..


thanks for the input so far though! i will photograph and post my evenings progress. i only hve like 3 or 4 hours before i gotta go see my girlfriend.. darn.

[ynneb]

I am so jealous. If only I could draw like Vac in Solidworks.

Keep those concepts rolling in, its soooo inspiring.

I still want to see a CD coater launcher design from you Mr Vac.
That neighbours cat would make a great target.

[vacpress]

I am currently building a 1/2 scale model of foamcore and balsa, since i have decided to wait and use a bandsaw to do the main body cuts isntead of my crappy scrollsaw. Heres the first picture of several i have prepared this evening.

I also posted about 15 messages in various yahoo groups looking for a programmer to help me with the "raster to step\dir" problem.


http://www.interinar.com/BSD-01.htm @$26 this driver may work great for the 3 steppers that need microstepping.

[vacpress]

solidworks is easy to learn if your a graphics freak like i am.. the first time i used it was like a revelation - something like the first time i played with legos...

to really learn solidworks takes a year though.. my first projects didnt look like this.. if anyones really curious, i can start a thread "the 2 year development of solidworks mastery" or something.. show some images from my first projects... its inspirational for me at least to see people go from suck - to success..

[publitime]

vac

I think HyperXpress will be intressting to RIP an image and thene import it into a CAD program.

[vacpress]

publitime - checkout the "free rip" program on the pixelation site. it may provide a key also..

and searching on the perl GD libraries is also very usefull, and someone recomended reading something called the "comp.graphics faq" so im gonna hunt that down for bedtime reading.

gotta do this homework... whats HyperXpress?

[jeffterm]

I FINALLY found this thread again! hope I can add to the game.

I recently wrote a VB program converting a BMP into gcode for 3d engraving on our bridgeports here at work. Your coordinate system does not need to be complicated since your going to run through your entire image sequentially. i.e do complete first row - return home - goto next row - do complete row - return home. Yes you can add complexity if you want to print bi-directionally - but lets walk first - run later;-)

Keeping this Raster frame of mind eliminates the x,y issues, but keeps you color mixing at the print head. Since all graphic images are broken down into pixel grids all you need is to take the color values at each location and time the 'spray' based upon its value. The value is relative to the sprayer and will need to be fine tuned during assembly.

My 3d engraver used the color density to determine depth on the z. Your case would have to send all 3 parameters separately for each color. Very do-able in my mind.

[publitime]

jeff

can you give littel more info about how you see the controller for the printer?
What electrical components are needed to run.
With what program will you run the whole thing

[vacpress]

jeffterm - thats what i am comming to realize. i am also building a prototype. i was going to use acrylic, but have been forced to compromise the design because acrylic costs to much. so sad, but the 4 pieces i need will aparently cost me $40. i am far to poor to spend $40 on acrylic. The guy who I normally see wasnt at the plastic shop today. SOO, i gotta either find a cheaper source for some 1/2" acrylic or, change to MDF or something.

the software you describe sounds interesting. i have decided basically to try and get a 48" wide gantry up by the weekend and on wheels. i have a tiny computer im about to put an array of DOS CNC software on to test the thing. I just need to order 2 more xylotex drivers, but have some 1-pulse/step unipolars i made that will allow me to get the thing moving as long as i use unipolar motors. im gonna try and make it have auniversal nema mounting scheme tho..

jeff- for the latest software scoop goto:

www.luberth.com and checkout cstep - thats gonna be for the vector mode. AND
www.pixation.com goto the downloads site and checkout the "Free RIP" program. that may be for the image prep. Or ghostscript. Then it needs to be decoded and printed: custom perl script, maybe even in an IC, with a windows style driver that sends the program and parameters to the board.

You may have an easier solution - a simple G code scheme with a seperate command for each color, and a good post processor application that generates the code?

there is a GCODE in a chip opensource Atmel project. I bet that could be customized very easily to work specifically with the program you created. The program you made needs a few thing smost likely to be just right : output resolution, output size.

Tell me more!

SO. Axrylic:

$195 for a 4x8' sheet
roughly 7$ sq/ft

its wierd, last time I went there, the guy who i delt with was really cool, gave me lots of stuff for $10. this guy wanted me to pay $45 for a 1/3 sheet. sooo. i said no thanks.