Path: utzoo!attcan!uunet!aplcen!samsung!brutus.cs.uiuc.edu!usc!jarthur!uci-ics!truesdel
From: truesdel@ics.uci.edu (Scott Truesdell)
Newsgroups: comp.sys.mac
Subject: Re: Imagewriter trouble & possible replacement
Message-ID: <256CEB6C.13797@paris.ics.uci.edu>
Date: 24 Nov 89 07:19:08 GMT
References: <6234@shlump.nac.dec.com> <869@maytag.waterloo.edu>
Lines: 78

>>I'm having trouble with my Imagewriter II: It frequently scrunches up
>>lines during a printout. 12 point comes out looking like 4 point!  :-(.
>>
>If you think that is bad, imagine a 3 hour lab with 50 Mac II's used by
>first year computer science students, With 9 ImageWriter II's.  Each 

>Does anyone know of a decent solution to this problem with ImageWriter II's.

I have a similar situation (13 hours per day, 60 Mac Pluses, 8
ImageWriter IIs). I have thought about this problem (sort of) a lot and
don't have any long term solutions but do have some observations.

First: I resent being held hostage by Apple with substandard printers.
As much as I prefer the Mac over other personal computers, the absence
of decent low-cost printers is really bad. The WAY overpriced Image-
Writer II is an embarrasment. It should cost around $275-300 and it
should have a decent paper transport mechanism. IBM's low cost printers
are vastly superior to Apple's offering(s).

Second: the "push" tractor feed is always going to be a problem on any 
printer. It sort of works on the ImageWriter pretty much based on luck.
If one has the friction roller on there will be a mismatch of feed rates
eventually resulting in torn or crumpled paper. If one has the friction
roller off, as it should be, it is still dependant on friction to move
the paper along the path. This "sort-of" friction is nearly impossible 
to maintain correctly.

Third: Any contamination of the platen causes the "sort-of" friction
paper feed scheme to fall on its face even worse than when the scheme
it operating as well as possible (which is none too). Contamination is 
usually from (a) accumulated small amounts of ink bleed-through, which,
over time, saturates the platen and slickens the "sort-of" friction.
This can take years. And (b) paper coatings, usually in the form of
manufacturing artifacts, also slicken the platen.

Fourth: Older ImageWriter IIs with the mechanical paper-out detectors
(a black prism about 1cm by 4cm at the left edge of the platen) are
more prone the "sort-of" friction failure than ImageWriters with the 
newer optical paper-out sensors. This could be meerly a symtom of 
age and contaminant build-up.

Fifth: The cleaner the platen, the better the performance. One poster
mentioned sandpaper. If done sensibly and uniformly, this is probably 
a great idea. I haven't tried it and don't recommend it. It COULD
work well if done sensibly. 

Xylol works very well to clean the platens. This used to be marketed
under the name of Fedrol. It is carcinogenic, toxic, and a heavy
environmental polutant. It is also currently illegal (thank goodness).
One of the reasons Xylol works so well is that it is a VERY effective
solvant for the ink contaminants on the platen.  It's even a good
solvent for the platen itself, which, in small doses, is just what the,
er, doctor ordered. However, we shouldn't use this substance, I suppose
:^)

Sixth: Alcohol will work in a manner of speaking. Its chief benefit
is its low toxicity. I have found that even a dozen cleanings with 
alcohol within a 30 minute period barely begins to start the cleaning
process thoroughly enough to be beneficial. The first several cleanings
show almost no ink on the cleaning cloth. Eventually the cloth starts
to blacken and, verily, it seems that once started, the cleaning
process could continue almost indefinitely, each time removing a bit
more ink. It is tedious, no doubt, but it does help.

Conclusions:

1) Shame on Apple. It's been how many years?
2) The cleaner the platen, the better.
3) A slight roughness, or tooth, to the platen seems like a good idea.
   However, too much roughness will definitely adversly effect print
   quality (don't laugh, it's relative).
4) We need ongoing research into better safe solvents for the contaminant
   build-up. I think that this is the key.

  --scott
 
--
Scott Truesdell