--- In
Homebrew_PCBs@yahoogroups.com, "Stefan Trethan"
<stefan_trethan@g...> wrote:
>
> On Mon, 02 Jan 2006 20:34:50 +0100, kennytrussell
> <kenneth.trussell@t...> wrote:
>
> >
> >
> > I have not done double-sided yet. I do have a question for someone
> >
> > about the "pouch". When you slide the board in, how do you assure
> >
> > that both sides of the pouch are still equally positioned? If the
> >
> > paper curvature is different for one side than the other where edge
> >
> > of the board meets the bound side of the pouch, wouldn't you get an
> >
> > ofset? (not sure I explained that well) For single sided boards, I
> >
> > trim my transparency or paper (whichever I am using) to just the
> >
> > outline of the board. Do you keep it a lot larger? Help from all
> >
> > appreciated.
>
>
> Yes, the curvature causes an error for me. If i put in in a
folded-over
> piece of thin cardboard the curve is much more gradual and not a
problem.
>
> ST
>
Using the Press n Peel I leave roughly 3/8inch overlap from the laser
print out. This is 3/8" larger than the board outline. (Diptrace will
print the board outline which is helpful to check alignment as you
assemble the pouch.) Again this is a rough idea I do it by eye and if
there is more because the board outline does not fit the press n peel
there may be more hanging over. ie press n peel is 8+ wide and I have
a board that is 3" I dont try to save the small amount of press n peel
that would be left over (2∗(3+(2∗3/8))) - gees John... I let the
rigidty of the pouch kinda self center the PC board Stock. Easier to
do than explain. After it comes out of the heated press and cold
water, the press n peel falls off, the board is dried and inspected.
If OK at that point then I will drill some small holes at the board
outline corner - usually .15. If these line up with the same point on
both sides of the board then the board is assumed to be in alignment.
Etch and enjoy. I have only had one time that this method failed and I
could attribute that to an error I made while closing the press.
Forgot my paper spacer and tried to open press and insert it... I will
be making some more in the next few days and will upload some pix if
you like
John