Homebrew PCBs

Steve, or anyone,  I suspect that the distance between the print head 
and the PCB is critical.  I suspect most folks are like me, you use 
the PCB material you can get and lately I have been buying off E-Bay 
at really good prices.  However, the thickness varies. 

So, I am planning my mechanical conversion to be adjustable to 
accomodate the various thickness PCB materials.  I suspect this could 
add a lot of complexity in the conversion process, but if I have time 
I want to do it.  I just don't have any idea what would be the 
acceptable range between that print head and the PCB material being 
printed - anyone?

CHris

many printers have a lever to adjust height. If that can be kept in a  
working state it can solve the problem.

"Back then" when i did that useless HP conversion i simply planned on  
putting another PCB below the one to be printed. If i wanted to print 1mm  
this shim PCB would be 0.5mm, for 0.5mm 1mm.

ST

On Mon, 24 Apr 2006 17:12:14 +0200, lcdpublishing  
<lcdpublishing@...> wrote:

> Steve, or anyone,  I suspect that the distance between the print head
>
> and the PCB is critical.  I suspect most folks are like me, you use
>
> the PCB material you can get and lately I have been buying off E-Bay
>
> at really good prices.  However, the thickness varies.
>
>
> So, I am planning my mechanical conversion to be adjustable to
>
> accomodate the various thickness PCB materials.  I suspect this could
>
> add a lot of complexity in the conversion process, but if I have time
>
> I want to do it.  I just don't have any idea what would be the
>
> acceptable range between that print head and the PCB material being
>
> printed - anyone?
>
>
> CHris

Ah, excellant suggestion!  Get the range to work and accept thick 
boards, and pass two through at the same time to make up the 
difference beyond adjustment - Great idea!

Chris



--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan" 
<stefan_trethan@...> wrote:
>
> many printers have a lever to adjust height. If that can be kept 
in a  
> working state it can solve the problem.
> 
> "Back then" when i did that useless HP conversion i simply planned 
on  
> putting another PCB below the one to be printed. If i wanted to 
print 1mm  
> this shim PCB would be 0.5mm, for 0.5mm 1mm.
> 
> ST
> 
> On Mon, 24 Apr 2006 17:12:14 +0200, lcdpublishing  
> <lcdpublishing@...> wrote:
> 
> > Steve, or anyone,  I suspect that the distance between the print 
head
> >
> > and the PCB is critical.  I suspect most folks are like me, you 
use
> >
> > the PCB material you can get and lately I have been buying off E-
Bay
> >
> > at really good prices.  However, the thickness varies.
> >
> >
> > So, I am planning my mechanical conversion to be adjustable to
> >
> > accomodate the various thickness PCB materials.  I suspect this 
could
> >
> > add a lot of complexity in the conversion process, but if I have 
time
> >
> > I want to do it.  I just don't have any idea what would be the
> >
> > acceptable range between that print head and the PCB material 
being

> >
> > printed - anyone?
> >
> >
> > CHris
>

On Mon, 24 Apr 2006 17:58:27 +0200, lcdpublishing  
<lcdpublishing@...> wrote:

> Ah, excellant suggestion!  Get the range to work and accept thick
>
> boards, and pass two through at the same time to make up the
>
> difference beyond adjustment - Great idea!
>
>
> Chris


I really believe some sort of flat table must be constructed to allow for  
second side alignment.

Thinking about it now it seems to me a printer with bend-over paper path  
might be best for that, since the table can ride over the large central  
roller. With the semi-straight path printers the paper passes below the  
drive rollers i would expect. maybe one can only use two narrow rollers at  
the side so there is space for a PCB in the center.

ST

Well,

I got started on the modifications and it ain't pretty so far.  
Right now I am cutting away a lot of the sheet metal framing to get 
the path clear for "Straight through" feeding.  My first goal is to 
get to that point where I can get a PCB to pass through it.

Then, the next step is to figure out where to re-locate the logic 
board.  Some of the flat cables are pretty short and won't allow me 
to move some parts very far.  Once I get to that point, I am going 
to start looking at how I can get the PCB to feed straight and to 
handle two sided printing.  

I found the one switch for the paper sensor - working with that will 
be key to getting double sided printing to work good.  There is 
another sensor on the printer which seems to be in the paper feeder 
section.  Not sure what that is for yet.  It seems to sense the 
position of the cam that grabs the paper from the stack.  If it is 
for that, I believe that one won't be much a problem.

Will report any further findings as I move along with this thing.

By chance, Stefan have you started on your printer yet (that is if 
you have it in hand yet)?

Chris

Hmmm, getting more difficult with the 850...

I have managed to cut away all the metal in the way of the PCB path.  
Then I started watching as I was pushing a PCB through the printer to 
see what problems and clearences and such are needed and where. Got 
all the obstructions out of the way and have clearance between the 
print head and the PCB now.

Now the problem is getting the PCB to feed through.  The main feed 
roller on this printer is the metal roller with the rough surface on 
it - not a rubber roller.  There just isn't enough friction between 
that and the rollers above and the PCB to pull the PCB through.  There 
is a second set of rubber rollers on the outfeed side. Once I get the 
PCB to that point, it might feed okay.

Getting a carrier board in there is the next direction for me to start 
looking.

what about some silicone rubber on the rough metal roller ?

On 24/04/06, lcdpublishing <lcdpublishing@...> wrote:
>
> Now the problem is getting the PCB to feed through.  The main feed
> roller on this printer is the metal roller with the rough surface on
>

- Looking for early starwars (episode 4, original starwars)
recordings, even pirate
-
- I dont need your originals just some information about running time
- and scene cut points
-
-
- also looking for a car, silver or white, 4 doors -
- diesel with a bosch pump, abs and pas  -
- aircon would be nice, and not a ford       -