QTR-Quadtone RIP

The head-alignments do not fix head-direction micro banding. Head alignments fix miss-timed fires that create vertical moire-style banding (perpendicular to the head direction).  Do all tests at 2880dpi UniDirection with the QTR 8ink file in Calibration mode. It’s normal to see some micro banding even then when testing with this file (even on good heads).

however,...

The LM is most likely causing most of micro-banding in-print. You probably have nozzles dropping out during the print-process most likely due to old damper assembly with particulate in it that is limiting the head-pressure during the print. Dampers only last a few years if the printer was used a lot. They have very tiny screens in them that are last-resort filters before the ink goes into the head. These fill up. They also are covered by a very thin plastic film air-seal that can get holes in it over time and let small amounts of air into the system (although when that happens you will often see either leaks or full channel dropping out). They can also be miss-aligned to the ink inlets on the head itself. It could be the end-of-road for the head as well if it has particulate in its intake manifold or (god forbid) inside of its piezo-channels.

I can’t attest to the quality of the ink, it’s age or if you let it sit around, or if the bottle it is stored in had particulate matter, or the quality of the cartridge if not IJM’s, but these are all long-run factors. However, I’ve seen this happen often enough with only Epson OEM ink . . .

Best,
Walker




> On Apr 11, 2016, at 8:33 AM, rdeloe1@... [QuadtoneRIP] <QuadtoneRIP@yahoogroups.com> wrote:
> 
> A bag of expired Epson cartridges I picked up for the chips to use in refillables carts for my Epson 3880 came with a bonus: an Epson 3800 with a lightly clogged Light Magenta channel, but no other obvious issues. Clogged channels are fixable, and this one is only missing a few ticks on the LM nozzle check. All the other channels are fine on the nozzle check.
> 
> I hate to see a good printer get landfilled, and it will be a good backup for my 3880. But, before I get serious about up the LM channel I need to know if another issue is related and fixable.
> 
> I made a few prints and noticed some micro-banding on prints in certain tones. An automatic head alignment followed by a manual head alignment did not improve things. The micro-banding is quite obvious in a QTR calibration print. It's parallel to the direction of the print head when the ink was laid down. The banding is very noticeable in Cyan and Magenta, and noticeable in Light Cyan and Light Magenta. It's barely noticeable in Y, LK, LLK, and practically invisible in K. 
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> I'm using Paul Roark's Eboni-Variable Tone ink formula, so the Y channel is the toner, LLK is the same ink as LM, and LK is the same ink as M. The ink is WJ1082 from STS (a fresh bottle). The cartridges are refilled Epson OEM carts. Carts hold pressure and do not leak. 
> 
> Prior to loading the Eboni-VT ink in the refilled Epson OEM carts, I ran a cleaning solution from cleaning carts through the printer until all lines printed clear. I lightly cleaned the print head, and I thoroughly cleaned the capping station using the techniques in the excellent Inkjetmall videos. There may still be dried ink and paper dust under the head (I haven't done overnight soaks of the head yet). As I said above, I also ran automatic and manual head alignments. 
> 
> So... what might be causing this micro-banding in the calibration chart? More to the point, is it worth putting more time into this printer, or could I be dealing with something that isn't fixable?  Rob
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