Homebrew PCBs

Hot dog, sounds like you are making some great progress!  

The puddling is a very strange problem I don't understand yet.  With 
the crude tinkering I did with the inks a few months back, I recall 
seeing that problem.  But it seems as though the puddling looks more 
like "Fish-eyes" that are seen when paint is applied over a surface 
with silicone contaminates on it.  So, I am not sure it's the amount 
of ink causing that puddling as it may be a contaminate causing it.  

But in any case, I saw it with my crude tests, I believe Steve ran 
into that problem, and now you.  If it is a contaminate of some 
sort, it is common to all of us.

Thanks for the suggestions on that paper sensor.  I will have to dig 
out that other printer and give it a go again. 




--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan" 
<stefan_trethan@...> wrote:
>
> I put the thing together today, the printer works fine now, 
currently  
> fiddling with the settings.
> Etched a test PCB early on, but could already see there were 
problems on  
> the printout.
> Some nozzles were not firing, i can see breaks where they where. 
Also i  
> had some significant puddling of ink on the ground area.
> 
> I've cleaned the head, all nozzles are firing properly now, but 
i'm still  
> struggling with the puddling.
> Tried all 15 possible combinations of paper type and print 
quality, while  
> the results seem to vary there's some puddling on every setting.
> 
> The brightness/contrast settings do not seem to work to adjust the 
ink  
> amount. No change between 0 and +2, and over that there is no ink 
at all.  
> Maybe i would need to use a grey image or something instead of 
black.
> 
> The puddling may not be a problem for my normal PCBs, i made kind 
of a  
> challenging test pattern. The larger structures of the main text 
came out  
> well.
> 
> Well, some more tinkering needed to get it just right. But i could 
do a  
> PCB with it right now, and i'm sure after fine-tuning it will be 
much  
> better than the best toner transfer.
> 
> Also, a lot of work is needed on the curing issue. I think i can 
use that  
> old clothes iron upside down for that. I have calibrated the dial 
in  
> degrees some time ago. my gut feeling is the curing is only about 
driving  
> all the water out and not very critical, but i guess that is to be 
seen. I  
> expect tests with a few different temperatures and curing times 
are  
> required.
> 
> Oh, one more thing, the transparency setting does not use any 
black cart  
> ink at all. Only color ink. Some of the pther paper settings have 
a black  
> ink only option.
> 
> Chris, about the paper sensor: I think i know how you can fix 
that, it got  
> into the same situation.
> My solution is to mount the paper sensor so it will "see" the 
carrier  
> plate directly by mounting it so the edge passes through. But the 
printer  
> expects a certain time delay from when it starts eating paper to 
when the  
> sensor should see it. So i cut out a notch from the side of the 
carrier  
> that will alow about 6cm of feed before the sensor is activated. 
The  
> procedure is to put the leading edge of the carrier into the 
printer  
> manually so the feed roller grabs it, before you send the print 
command.
> I experimented for the ideal distance between sensor and the end 
of the  
> notch, and found the printer is quite tolerant (maybe from 2cm to 
10cm or  
> so will work. Simply stick some tape to the side of a sheet and 
manually  
> feed it varying distances before starting the printing process.
> 
> ST
> 
> 
> On Fri, 07 Jul 2006 23:45:30 +0200, lcdpublishing  
> <lcdpublishing@...> wrote:
> 
> > Good luck Stefan!!!
> > Please post some photos of your progress and achievments.  I have
> > out-of-town guests in for the weekend so my ink-jet nightmare 
will
> > be on hold for another couple weeks or so.
> > I am still upset about that jam-up - dumb,dumb,dumb.
>