Low elevation 3D printing

Powder and inkjet printing
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DDDoug
Posts: 6
Joined: Fri Feb 05, 2016 11:57 pm

Low elevation 3D printing

Post by DDDoug »

I have an Epson workforce printer that I am trying to hack. We want to print low elevation shims with the printer in a continuous mode for about 30 seconds. The print head is set up originally to raster back and forth during printing. The turn around time gives the printer time to build up memory. Since I want to print continuously (30s), I need to use my own micro-controller.
Here is what I think I know.
Nearly all new Epson printers use the same print head design called precision core... some use many heads.
The smaller work force printer has a single head with two rows of nozzles. 400 black and 384 CYM. Each in a 128 nozzle segment.
The print head has 20 pins. I would guess about 8 are ground pins.
The print head uses synchronous data with a clock pin and several data pins as well as possibly a few others for drop size.
I would guess that the the data stream consists of about four bits per clock cycle. The print head could be partially loaded up to 7 times where each load cycle corresponds to a different drop size. (It would take 50 clock cycles for each partial load if using 4 bits.) During the "fire" operation, The piezo component of each head would vibrate 1 to n times to determine the amount of liquid for each nozzle. My internet reading tells me that the head fires at 10 kHz when data has changed at each fire.
If anyone knows anything about these printer heads and would supply usable information on the needed wiring configuration, I would be forever grateful.
Thank you in advance.
ezrec
Posts: 112
Joined: Sat Aug 15, 2015 1:31 pm

Re: Low elevation 3D printing

Post by ezrec »

Things you should look for:

* EPSON patents on the specific printhead you have in your machine (what model, by the way?)
* The EPSON service manual for your printer (supposedly available at https://www.tradebit.com/G/manuals/2038-epson - a quick google for 'espon workforce service manual' brought up)

If it's a recent (and cheap) model (< $75 USD) I may be willing to get one to experiment alongside you.
DDDoug
Posts: 6
Joined: Fri Feb 05, 2016 11:57 pm

Re: Low elevation 3D printing

Post by DDDoug »

ezrec,
Thank you for your response. The printer that I am using is the WF-2540. I bought a used model for testing on ebay for $26 including shipping. I tried to purchase a new 2540 directly from epson for $49 including shipping and instead, they sent me a 2650. It has a larger cabinet but it looks to be similar. I looked at service manuals for other workforce printers and all I saw was block diagrams. I have an older 9800 that we use every day and I found the service manual for it and it shows a diagram but this print head has about 60+ wires on two ribbon cables.
Where are you located? I am in Charlotte, NC.
I have not yet tried mapping with my o-scope. I also have one of those Saleae logic analyzers. The board on the 2540 is against a metal plate that is next to the carriage. The circuit board also has what looks like a non-contact mechanical switch linked to the carriage mechanism making it difficult to do a pin out test.
I like the new generation print heads due to their high density and by having only two lines of nozzles make it easy to add material on curved surfaces.
I may be able to help with your costs. You can reach me at ian1*1*9*6 (remove asterisks) at my hotmail.com account
ezrec
Posts: 112
Joined: Sat Aug 15, 2015 1:31 pm

Re: Low elevation 3D printing

Post by ezrec »

I will. Expect an email from 'Jason McMullan'.
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dragonator
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Re: Low elevation 3D printing

Post by dragonator »

If you can get it working your own code it would be amazing. Bubblejets can only be used for simple binders and are only useful for 3DP printers. Epsons are piezo electric printheads. They can be made into a lot of things. Polyjet printers (like Objets), wax printers (For lost wax models and PCB making) and better, more reactive binders for 3DP.
ezrec
Posts: 112
Joined: Sat Aug 15, 2015 1:31 pm

Re: Low elevation 3D printing

Post by ezrec »

I picked up a XP-320, and EPSON has an excellent open-source ESC/P-R driver for it that means I don't have to try to reinvent the wheel for controlling the printhead.

Like the 'A5 Powder Bed Printer' http://reprap.org/wiki/A5_Powder_bed_printer, I plan to drive the printer across the top of the powder handler:

For the XP-320 project, I am going to keep as much of the printer intact as possible (including the capping station). The intent is to have it ride on rails over the print bed, "believing" that it is actually printing pages.

It looks like the maintenance station runs off of the reverse motion of the main drive.

With that in mind, my current mechanical setup theory is:

1) Remove rod that runs between paper drive and maintenance station
2) Add a small DC motor onto the maintenance station (separately controlled by Arduino)
3) Remove everything else below the paper path on the printer
4) Switch the paper-out and start-of-page sensors via transistors to my Arduino.

Per-layer powder deposition will be as follows, assuming the printer is over the start of the feed area

1) Drop part bin by 1x layer height, raise feed by 1.25x layer height
2) Set PAPER_START: FALSE, send MAINT_NOZZLE ESC/P-R command
3) Printer will now rotate the paper feed system backwards, moving the printer to the end of the part bin and spreading powder
4) Lower the part bin and feed bin by 1mm (so roller will clear on return pass)
5) Set PAPER_START: TRUE, and send PRINT_RASTER (printer will use paper handling system to ride along the bed during print)
6) At end of the end of the printable area, set PAPER_START: FALSE, and send FORM_FEED
7) When printer is as start of feed bin, set PAPER_START: TRUE - this stops the printer
8) If on layer > 20 or time > 5 min, send PARK_HEAD, turn on the extra DC motor on the capping station, and send MAINT_NOZZLE - this will run the printer across the bed, and clean the nozzles at the capping station. Go back to 6.
9) Raise part and feed bins by 1mm.
10) If not last layer, go back to 1.
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