Epson 3800 - those starwheel trails of dots again

[inkonpaper]

I’m new here, so stand by for basic questions .  .  . Proud owner of Epson 3800, printing on Somerset Enhanced Satin 330gsm using the rear manual feed, and getting those darned trails of white spots (not scratches) from the starwheels in areas where a lot of ink has been laid down, so I guess the paper is swelling that bit more in those areas and the wheels are picking the ink off  –  yes, they are white dots, not just indentations, and next to the wheels I can see black dust. (It happens to a much lesser extent with Epson Somerset 225gsm. I shall be sending samples with Epson paper to Epson.) I have tried the front manual feed which is allegedly for paper between 1.5mm and 2mm which my paper is nowhere near. In this mode the starwheels are lifted off and I don’t get the marks, but now I’m getting ink sprayed around, manifesting itself as a pale coloured ‘wash’ at the edges, like a halo effect. This is presumably because when I engage the front manual feed the platen gap opens right up, expecting thick paper, and the heads are now a mile from the paper. In this mode you can’t (/I can’t see how to) reduce the platen gap as the menu options are not now available on the printer. I’ve had a look at the forum archives but couldn’t see much on this. I have not yet tried one suggestion of running board through to take the shine off the starwheels but this feels a bit more basic. I also saw suggestions about removing the starwheels but I want to check first that I haven’t omitted a setting or something obvious somewhere. All help/suggestions gratefully received.

[Conner999]

Common issue with 3800 (or any pizza wheel printer) and glossy papers - especially in heavy black areas.

Have same issue with my 3800 when doing B&W prints on 13x19 + Harman FB Al and IGFS if it has a heavy black/ink area. The heavy ink area starts to swell and slowly arches up in some spots to JUST kiss the bottom of a pizza wheel(s). Matte papers are no issue. Color 13x19 or 17x22 prints of IGFS with no heavy ink areas are no problem using the rear feeder. The more a given paper swells when inked and or the more flex it has, the worse the issue. HBFAL tends to swell more than IGFS (which is also stiffer), so former causes more issues (for my printer).

The problem varies by printer and paper, I suspect due to manufacturing tolerances, etc.  

It's interesting to watch happen. If you do a heavy-black-area print on a problematic paper using the front feeder, take a flash light and observe the paper vs the wheels as it emerges. You can see it starts out ok - nice and flat and well clear of any sharp bits.  But as the ink builds up, the top side of the paper gets saturated and takes on an almost 'M' shape -- and creeps up towards the wheels, paper guides, etc.   The result are some marks starting about 3-4" from the start of the heavy ink area and extending the length of that area. Sometimes it catches enough to turn the wheels, sometimes it just kisses the b*****ds.

Only workable solution for me (there are a number) is as Eric Chan suggests on his site for the 3800: http://people.csail.mit.edu/ericchan/dp/Epson3800/index.html

Use the front feeder as you tried, but put a price of cardboard or thin matte under the paper. I use the protective cardboard sheet that comes in a box of IGFS (about 0.02" or 0.51mm thick). Just line them up nicely, slide in thru the front feeder to the line and hit the feed button as normal. No marks on my 'acid test' print (a 13x19 sheet about 1/3 or which is SOLID black) and no apparent acuity issues. Works for IGFS or HBAL. I tried thicker stock (about 0.8mm) but it was JUST thick enough to allow a kiss as the paper swelled.

My next printer is  vacuum hold-down unit. Sick and #$%^ tired of scratch patrol on glossy papers. I'll keep the 3800 for matte.

Have actually started removing the problematic pizza wheels from mine. I only feed single sheets anyway. I use a set of surgical forceps (the type that lock) and long tweezers - both with small rare earth magnets taped to them. The springs and teeth steel and the magnets help ensure nothing goes missing. The printer is out of warranty and as for resale - the shipping costs would kill any resale value - and I'll just use it along with any 4800, for whatever I print less of (mat or gloss) to save on ink swaps. The 3800's only shortcoming for the price is the lack of vacuum paper retention, so if I can remedy the #$%^& scratch issue with large glossy sheets, no reason not to keep it until it blows up.

[madmanchan]

The phenomenon you describe is consistent my experiences, described here:

http://people.csail.mit.edu/ericchan/dp/Ep...eels_workaround

[dgberg]

Eric,
"EPSON 3800: PRINTER FAQ"
I have scanned your 3800 report in the past but never took the time to read it in its entirety. This morning I spent an hour reading from front to back. Excellent work and required reading for all 3800 owners. Thanks for this great paper.

[madmanchan]

Glad you found it useful, Dan.

[Conner999]

Update. After trying every known fix under the sun re; wetting back, platen gap, wide vs wider, 1440 vs 2880, etc, etc, got fed up and removed the pizza wheels from my 3800 (a non-reversible process).

Modest improvement in scratches on IGFS and Harman FBAl, but it's obvious that other sharp bits (of which there are many, many candidates) within the 3800 are also causing issues when paper swells, not just the pizza wheels.  Have also tried the front feed + underlay trick and still getting them (albeit fewer) if paper not FLAT. One sheet can be fine, next scratched.

13x19 or larger Harman was always an issue and while IGFS used to be fine, starting a month or so ago, 50/50 hit rate. Cleaned rollers, etc - no avail.

Matte prints fine.  So, other than now limiting my ability to print with shallow margins on matte, have accomplished nothing. Given VFA is my fave paper, it's not the end of the world, just a real PITA.

The 3800 produces great IQ, but for me, has been shelved for non-matte use. If it had vacuum bed, it would be ideal for a low-volume printer like myself who likes to mix matte and gloss printing without wasting too much $$.

Other users are fine which I suspect is due to manufacturing variances copy by copy and other external factors (humidity, paper stock, etc).  Given the tolerances were talking about, it wouldn't take much by way of additive 'slop' between the manufacturing tolerances of the printer chassis, paper, the effects of humidity plus the ink requirements of the print, etc, etc, etc., to cause an issue (or not). In an ideal world where papers stayed flat when inked, the PW system with the proper platen gap and thickness setting would work fine. But it's not an ideal world - especially as paper makers strive to make papers that are more darkroom-like in look, feel and acuity. The result being increasingly delicate surfaces and in many cases, papers more prone to swell/distort when wet.

In my case, just too much wastage from gloss/SG prints being ruined. Hate the idea of $$$ for having to move to 4880 (or successor) with new profiles, etc., for the sake of vacuum assist (with other benefits as well), but looks like only future option.