Build your own large format printer?

[rackbox]

This is JUST A THOUGHT i have been meddling with for a couple of years. Haven't really researched on this, but might be possible - and might even be very easy! I don't know.

My thought is, simply, to modify an existing inkjet (office type) making it wider and perhaps fitting a CIS system on it.

Would it be possible just to "enlarge" the sideways movement by putting in a longer brushed iron bar and a longer gear belt? Of course the driver (and possibly the firmware?) would need to know to print wider.

I disassembled one of my own printers and found out, there is a sensoe registering when the printhead i in either side of the printable area. Also, there is a paper sensor. Much more than this, I don't know.

Anyone up for the challenge?

[andyew]

yeah, i was thinking the same and coming here to find answers/solutions, but i could only see question like you hv posted...

anyway, i'm thinking of changing the sensor resolution to a lower value one, eg. let's say original is 180dpi, reducing to by 5 fold becoming 36dpi. It'll cheap the printer to printer 5 times wider, almost 5 feet! Of course, the picture u send to print has to be distorted in a way that it'll print in a right proportion (eg. original pic WIDTH shrunk by 5 times). Then, the picture width resolution will also be sacrificed by 5 times, example original resolution is 5760dpi x 1440dpi, then after "cheating" it, it'll b reduced to 1152dpi x 1440dpi....

how does this hypothesis sound? anyone any voice??

thanks,
Andy

[ViperTX]

Andy....nice hypothesis......I suspect that you have discovered that if you walk around the base of a tree.....you can walk along time before you get to the other side.

Look at a print head.....it has a matrix of ink jets.......you don't have to change the sensor resolution of anything......the edge of paper sensors are merely there so that the printer knows where to print........you don't want it printing an envelope on an 8x11 or 8x14 or 8x17.....you want it to notice the envelope....

Anyway....think about it....rackbox has the right idea...at some point the limits of the printing software will be reached....not sure what those are....

[kram242]

Im in

[greybeard]

Andy - It occurs to me that you'll have to do something about the amount of ink delivered per dot.
Otherwise the image will be 1/25(?) as bright.
John

[kram242]

Heres a cool idea using an airbrush (I think)
http://www.magicairbrush.ca/Printers.htm

[foxesfarm]

And some printers have an encoding strip that looks like a thin strip of celluloid. This lets the print head know exactly where it is all of the time, width wise. Without the strip, it's useless. It's a trick I've learned as a computer repairman to wipe down a dead printer's encoder strip with gauze and distilled water. It's a miracle, it now works! Sometimes.

[epineh]

That little strip is a linear encoder if you look closely enough it has little "stripes", the optical pickup reads these as it passes by, counts and works out it's position. It is the same principal as a servo, except a servo uses a rotary encoder.

I for one will be watching your progress with this, you have probably seen the direct PCB printing thread :

http://www.cnczone.com/forums/showth...199#post246199

If not it might help a little with the machanics, and sorry but it is a LONG read...

I have thought something similiar, the best I could come up with was to totally dissassemble an existing printer, and re-mount the print head, control board onto a working CNC router. The hard part is going to get it to work properly (or at all), speeds, software, print driver and a heap of things I haven't thought of. But it would be cool!!!

Russell.

[max_imum2000]

ok now here is something i think i am an expert in
i have been working with plotters and inkjet machines for 7 years now.
from repair, refilling and even devlopment of inkjet cartridge with printhead for hp printers.
i dont know exactly what are you trying to do here, but if you are thinking in inventing a plotter from the start, you will go into a lot of problems
like writting down a driver, hardware in to drive the printhead, image anaylss etc..

if you want to modify a printer to make it print in paper rolls for example, again you will have to deal with the driver and so on.

in my opinon its not for DIY or at least its not easy

the best thing to do , is to buy a cheap chinnese plotter, disassemble it and make it print on any thing you want (walls, paper, etc)
they usually use printheads called XAAR, and usually encad compatible
their price range from 600$ to 3000$, and they work really well.

[andyew]

John, in fact if the driver can be hacked, the separated dots of the ink could be "adjusted" thru the color profile... thus, except that the dots are now coarser (further apart) than original, since the resolution is sacrificed for the larger width, otherwse it shud look fine if proportional is rite...

BUTTT, there's a problem with the acceleration and velocity of the printhead carriage! the speed is not constant from start to the other end and so forth, thus, the ink being jetted out with another speed (controlled by the board, higher voltage faster the ink flies). these 2 elements (carriage n ink speeds) have to b tuned correctly to avoid distortion or misalignment "vertically" (vertical banding prob..). this is the speed profile which has to be synchronized very well in order to produce correct printout to our eyes...

As for the driver hacking, i have been thinking, ya.. thinking... about the available linux open source stuffs... i hv taken a peep on these open source driver n it looks like possible to change the width, color profile and mayb speed as well... not very sure yet.. any LINUX EXPERT here to guide for this driver thingy? well, i m targeting at Epson inkjet since piezoelectric printhead has more practical uses compared to other brand of small printer like hp, canon, lexmark etc etc.... which r the stpid bubblejet.... sensitive with ink type...

MAX_imum2000, xaar is pretty coarse and oso costly as well... while encad is the bubblejet which is not very flexible with most of the ink... piezo choice left for epson only, since it's widely avail n cheap... forget bout roland, mutoh and mimaki... these r expensive toy n they'r oredi built in large format, no need for modification...any more suggstion?

[Hombre Verde]

Hi, I've heard about people who have converted a inkjet interior wide format printer plotter into solvent. Do any one know about this?

Thanks in advance.

[foxesfarm]

I bought a wide format printer from China, and the manual was so poorly translated that I bought the wrong ink for it. Assembled it on a Friday, worked beutifully on anything I put in it, then I went home.

Came back monday, thought, wow, that's pretty strong smell for low odor solvent ink!

Not only did the 1/2 liter ink tanks disolve, but so did the feed lines and the print heads.

Changing the ink tanks and lines to a solvent proof plastic seems easy enough, but how do you change the print heads? The heads of solvent printers are huge in comparison, so the print head width is wrong, and the colors wouldn't register. It could be done easily enough if you wanted to just print single color jobs, as the cheap china printers aren't smart enough to be constantly checking back and forth with their printheads to make sure you're not using a generic, or to tell you it's time to order a new one. Before completely rebuilding the one I got, I tried just installing 1 printhead and inktank/line. Printed in red alone just fine.

Nice thing about a brand new melted printer? I got to tear it apart right away without anyone nagging at me for it. Bad thing, well, I melted a new printer, and have been ribbed about it ever since.

Good luck,
Kathy