Homebrew PCBs

--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan"
<stefan_trethan@...> wrote:
>
> On Tue, 18 Apr 2006 16:52:41 +0200, Steve <alienrelics@...> wrote:
> 
> >
> >
> >
> > That sounds like you have ink but it is not getting pulled in.
> >
> 
> 
> Hmm, thinking about that, if there is a air bubble in the printhead
the  
> head itself has absolutely no way to pull ink in, other than gravity
and  
> luck, because the piezo head will not pump air... So the only way to
get  
> any air out is with a working vacuum pump and a cleaning cycle, right?
> 
> Seems obvious now, but i have never thought about it like that...

Exactamundo.

To add insult to injury: every time you take that cartridge out and
put it back in, it forces an air bubble up into the cartridge. Two
ways to clear that air: Run a lot of cleaning cycles, wasting a lot of
ink, or let it sit for a day (like 8 hours or more) so that the air
bubble can rise up away from the ink spike.

This is not a problem with brand new sealed cartridges if you give
them a "shake down". Hold with the ink feed hole down, bring your arm
down and stop abruptly. This should force any air bubble that may be
behind the plastic seal over the ink outlet to rise.

Of course you do this with an already broken seal, you end up with ink
all over and you still get an air bubble.

> I will make up your soultion and use lots of patience with the next  
> printer i get. It seems like you know what you are talking about....

JOAT, MON. Like to think MOS.

> No luck so far with the lintfree wipes. there are some medical
cellulose  
> pads on ebay which are supposed to be lint free, but i have severe
doubts  
> they are really lint free on the level i would need. I can get
cleaning  
> tissues for eyeglasses, but those usually are soaked in lotsa stuff
that  
> is meant to make them clean well and smell good.

Eyeglass tissues are good, usually. Let them dry out and wet them with
the cleaning solution. Just damp, not dripping.

What you said about the percentage of ammonia sounds right. You can
skip the IPA if you wish, but you should use filtered or distilled water.

"Purified" water is just tap water that has had clorine gas added or
been passed under UV to kill junk in it, but still has all the minerals.

Steve Greenfield