Homebrew PCBs

--- In Homebrew_PCBs@yahoogroups.com, "Andrew Thornber"
<andrew.thornber@...> wrote:
>
> Hi,
> 
> I have been lurking on this site for a while now, and thought I
might throw
> in a few of my experiences.
> 
> I used to be a printer/proofer engineer and worked on many similar
machines
> if not a bit larger than your acerage home machine.
> 
> All of the DOD style printer I worked with were made by the company that
> also manufacture Epson print heads.

What is "DOD style"?

> The way that has always worked for me was to get a good look at the
nozzles
> and use either a lint free cloth soaked in Isopropyl alcohol and
just press
> it gently against the underside of the head.  This almost always
worked.  It
> may take a little time but will get there.

I found that isopropyl did not dissolve all the ink. See my pages for
a mixture including ammonia that seems to cut even very dried ink:
http://www.polyphoto.com/tutorials/PrintHeadCleaning/

> The other way was to use a cotton bud dipped in isopropyl alcohol
and clean
> the nozzles.  Then wipe the head with a lint free cloth to get rid
of all
> the bits of cotton.

I try to keep cotton as far away from the heads as possible, as you
point out you must take special care to remove all left-over fibers.
Any little bits left on the head or park pad cause recurring clogs and
deflected nozzles.

> Running cleaning cycles is about a much use as shouting at it if you
have
> some subborn nozzles.  When the head is clamped into the cleaning
station
> then it is sucking on all nozzles at the same time.  If one is
blocked and
> the others are clear all it will do is suck the ink from the clean
nozzle!

Yes! Which is why I recommend the procedure above, and patience, lots
of patience.

> Isopropyl alcohol is a standard solvent available from most places.
 In the
> UK we used to by it from RS Components but I think if you have a
chat with a
> chemist they can get it for you.  It is, if memory serves me
correctly, very
> similar chemically to the solvent used in epson inks.  (Which is why
we used
> it!)

I think some variety of alcohol is used in Epson inks, possibly
isopropyl. As are some glycols. I'm told that ammonia works so well at
dissolving the ink because rather than just dissolving it, it
chemically tears it apart. Not very scientific. I just know it really
works well!

The cleaner used by Epson, also sold by some on eBay and at
fixyourownprinter.com is a surfactant. Very gentle, but that's not
necessarily a good thing with a very dried clog. For those who don't
know, a surfactant is a wetting agent. It just kind of facilitates the
water getting the surface (or ink clog) wet.

> Any way, enough of me.  Sorry if I have been teaching any one to
'suck eggs'
> I just thought I might help out a little.

Better too much information than too little!

Steve Greenfield