Re: Printed Circuit Board Supplies

An old flat bed plotter works great for making boards. That is what I used
for 4 years a while back. The Z axis worked fine as-is. What's required is
a special holder made to hold an extra-fine Sharpie by a friction fit and
duplicate the standard plotter pens on the outside. With the pen up, slide
the friction fit pen up to clear the board by about .015 to .020" . Too
much clearance will beat the tip of the pen flat and create a wider line
than desired. The extra-fine Sharpie has kinda' a nylon tip, so it is
pretty durable. I only trusted each pen for one side of an average (6" X
10") board. Small boards could probably be done several per pen. It's not
good when a pen runs out of ink on the second side of a large board,
although lacquer thinner can make the board re-plottable again. The lost
time doesn't come back though.

Ward M.

ward@...

----- Original Message -----
From: "hansw" <hansw@...>
To: <CAD_CAM_EDM_DRO@onelist.com>
Sent: Wednesday, February 09, 2000 2:58 PM
Subject: Re: [CAD_CAM_EDM_DRO]Printed Circuit Board Supplies


> From: hansw <hansw@...>
>
> Doug,
> The iron film is about as good as useless
>
> "Harrison, Doug" wrote:
>
> > From: "Harrison, Doug" <dharrison@...>
> >
> > Digi Key has an iron on transfer sheet that is developed by running it
> > through a copier. Perhaps it works for small boards, perhaps it works
once
> > you get the hang of it, but I was not at all impressed. Ended up paying
> > $400 to have the boards made for me.
> >
> > Does anyone know of a good tutorial or source of info on routing PCB's?
> > This seems like a good approach for prototypes. Another method I have
> > considered is putting an etch-resist pen in the spindle of a CNC mill
and
> > letting the machine draw the pattern on the board. Has anybody tried
this?
> > Still another possibility is using my old HP7475 plotter with etch
resist
> > ink.
>
> HP used to make a flat bed plotter, and if you ever get on of those, it
could be easy to attach
> "something" to either draw or route the boards. It would need a job on the
Z axis. The flat bed can handle
> "B" size paper... Can't remember the Model Number..
>
> Etch resistant pens are sold by many electronic stores, in fact you can
buy the same thing at Office Depot for a lot less,
> It's Sanford "Sharpie" also known as Laundry marker...
>
> hansw
>
>
> > The HP7475 moves the paper and I'm not sure it would handle the extra
> > inertia of clad board. Comments?
> >
> > Doug
> >