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Subject: Re: Produce Quick & Cheap PCBs with a CNC paper cutter

From: "Leslie Schwartz" <lhs_emf@...>
Date: 2012-06-15

Do you have any recommendations for a pen plotter machines?

I have seen a lot of large and some small format pen plotters on ebay, for
which I think it would be hard to find drivers, even if they are
comparatively inexpensive.

I also have an old Epson 3000 stylus which is a medium size flatbed inkspray
printer which might work for a direct resist print method, but not sure it
would accommodate a pcb thickness.

We are sort of coming back around to the plotter / laser method where a
small size solid state laser is placed into the pen holder and the software
starts and stops the laser and moves it through the production of a pcb.

-----Original Message-----
From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
On Behalf Of David Mitchell
Sent: Friday, June 15, 2012 12:06 PM
To: Homebrew_PCBs@yahoogroups.com
Subject: Re: [Homebrew_PCBs] Re: Produce Quick & Cheap PCBs with a CNC paper
cutter

I have a number of cricuts that I got broken from ebay for $20 or so,
shipped, and repaired myself. Some are much easier to fix than others, but
if you're handy as I suspect most on this list are, pretty much all are
repairable.

I like the vinyl etch method, but had problems with it floating off when I
was using the "metal salt" etch on aluminum.

Not to get too far off the topic of PCBs, I got around the edge leakage
issue by cutting a positive mask from vinyl (vinyl goes where you want the
metal removed), transfer to the metal, and spray-paint over it. Then peel
off the vinyl. The spray paint works as a much more effective etch resist.

The "pcb plotter" method using a ultra-fine tip industrial sharpie works
much better for PCBs IMHO since the ink makes for a pretty effective etch
resist, no weeding necessary, and there's no "offset" problem using the pen
instead of the blade. In this case, the resolution is limited mostly by the
size of the pen point, but you do get some jaggies in diagonal or curved
lines which increases the minimum space between traces in those areas.

I use the "Make the Cut" software to plot via the Cricut, but you'll need
the driver plugin to go this route, and its gotten a bit difficult since
ProvoCraft has repeatedly sued MTC to eliminate support for the Cricut
machine.

One other way to plot to the cricut from your PC is through the Licut
library at http://sourceforge.net/projects/licut/


-David


On Fri, Jun 15, 2012 at 10:37 AM, Tony Smith <ajsmith1968@...> wrote:

> ∗∗
>
>
> > Interesting topic. Instead of cutting the copper directly, how about
> cutting some
> > vinyl or maybe masking tape? Then transfer the cut vinyl or tape to
> > a
> copper
> > clad FR4 board. Or maybe better yet, bond the tape or vinyl to the
> > copper
> clad
> > FR4 and then cut. Remove the unwanted vinyl or tape and etch the
> > board. I have not tried this technique exactly, but have done a few
> > boards with
> hand cut
> > tape. If the etchant doesn't leak under the tape or dissolve the
> > tape, it
> works
> > fairly well. The trick might be to find the right tape, perhaps
> > Kapton
> tape, or
> > wide electrical tape?
>
> Ordinary sign vinyl would work for the usual through hole size stuff,
> you'd have trouble on really fine tracks.
>
> That's how a lot of etching (on glass etc) is done, cut the pattern,
> stick it on whatever you're etching, and then apply the etchant or sand
blast it.
> (The sign vinyl is quite thin, the stuff used for sand blasting tends
> to be
> thicker.)
>
> It'd be a bit easier than toner transfer, apart from picking out all
> the unwanted bits.
>
> Tony
>
>
>


[Non-text portions of this message have been removed]



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