Homebrew PCBs

In metal working and in woodworking that concept is used quit 
frequently, so for me to get it was easy.  It is a tough one to 
grasp because it is hard to visualize that the printing will be 
square to the one edge - regardless of what the other three edges 
look like.  In reality, this could be accurate to within .003" 
depending on a couple of things...

1) The locating or reference surfaces are clean - dust has thickness!

2) The center mark is precise - don't try to line up a magic marker 
line with a pencil line.  Rather, use a razor blade to make both 
refernce marks (on the fixed stop and on the PCB).  With a fine line 
like that, accuracy with the naked eye is very easily done (even 
with my horrible eye sight).

3) The PCB does not move while printing (relative to the carrier 
jig).

4) The printer can sense the leading edge of the board (or jig) 
within .003"

It really should be difficult.  In reality, I think it will be more 
accurate than we can do with toner transfer or photo-imaging.  With 
the ink jet process, you eliminate two problem areas:

1) End to end miss-alignment as you will be bumped against a fixed 
point.

2) Rotational miss-alignment as you can have the board rotated if it 
is tight against the stop.

Even the third variable - side-to-side alignment can be very 
accurate too depending on the method used there.




--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan" 
<stefan_trethan@...> wrote:
>
> On Sun, 16 Apr 2006 17:20:39 +0200, lcdpublishing  
> <lcdpublishing@...> wrote:
> 
> > Well, not really. Right now you cut the PCB material to size then
> >
> > transfer & etch.
> >
> >
> > Rather, you have your "leading" or "reference" edge cut straight 
and
> >
> > you mark the center point on that edge.  You then print one side,
> >
> > flip, print opposite side.  Now the artwork is square to that 
same
> >
> > edge and aligned from face to face.
> >
> >
> > Etch the board, then trim the rest to size.
> >
> >
> > I believe that will work out okay.
> 
> 
> At least one got it! fantastic...
> 
> ST
>