PCB laser printer
I am attempting to modify a laser printer to print toner directly to copper clad board. I'm quite excited about it, because it could be better than quite a few things...
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Things are progressing rather slowly as my 3rd year project takes up more time. I was on the brink of keeping the printer happy through a complete print when suddenly the transfer belt lift clutch, cleaning roller cam clutch and feed motor all stopped working! I looked at the paper feed PCB, to which they are all connected and saw a small axial component the size of a standard resistor but without colour bands with "FU101" on the silkscreen.
Submitted by jeff on Sat, 04/07/2007 - 15:47. categories [ ]
I discovered a piece of software called Scribus. It is an open source desktop publishing program, and it allows one to work in CMYK space. I made a document with a black square made from 100%K and a "400% black" square, made from 100% of C,M,Y and K. Scribus allows you to use ICC colour profiles and display what your printer will actually print. I downloaded the 4550's colour profile from HP, plugged it into Scribus and sure enough the black square was lighter than the 400% black square.
Submitted by jeff on Sat, 03/24/2007 - 17:24. categories [ ]
I decided to buy a colour laser printer to experiment with, as I suspected that I could print blacker with one. They print four times (CMYK) onto a transfer belt, then transfer the image from the belt to the paper (circuit board). So potentially I can have four layers of toner deposited without any alignment problems.
Submitted by jeff on Thu, 03/22/2007 - 16:18. categories [ ]
Submitted by jeff on Thu, 03/15/2007 - 16:02. categories [ ]
As discussed last time, I needed to get some more solid data for the alignment. Here it is:
Submitted by jeff on Tue, 03/13/2007 - 17:20. categories [ ]
I need to get some idea of what's causing the vertical misalignment (I'm calling the driven axis vertical, as in a portrait page). Last night I did some tests. I printed a horizontal line near the top of the board and measured the distance to the edge. Measurements were performed with a vernier caliper to a measuring accuracy of about +-0.02mm. I performed the test with and without a second guide fence, and with the edge sensor mounted to look at the trailing edge of the board, to eliminate variation at the point where the leading edge mashes into the imaging rollers. The numbers are distances in mm from the board edge to the image. The standard deviations are given in bold after the rule.
Submitted by jeff on Fri, 03/09/2007 - 15:21. categories [ ]
Much has happened since my last blog post since, though published only minutes ago, it was written a few days back. This lag between life and blog is largely the fault of flickrfs.
Submitted by jeff on Thu, 03/08/2007 - 16:44. categories [ ]
Fortunately the search for a new fuser unit was short. I asked around campus for old laser printers, and in discussion with the ECS helpdesk people it transpired that they had a brand new fuser unit on the shelf that they were never going to use.
Submitted by jeff on Sun, 03/04/2007 - 19:50. categories [ ]
On monday evening I connected up the various parts of the printer and managed to get it to print for the first time since it was dismantled.
The printer is bristling with sensors to check that the various hatches are installed, the cartridge is in, paper isn't jammed, and so on. They all have to be fooled correctly to get it to print.
Submitted by jeff on Thu, 03/01/2007 - 18:19. categories [ ]