[sdiy] KiCad early success: guide dots for drilling homemade PCBs

[Tim Parkhurst]

Nicely done, thanks for sharing! I haven't read all the info yet, but
you've presented some handy tips here. I've been using KiCAD for years
now (all my Magic Smoke boards were done in KiCAD). The process to add
new parts and footprints is a little clunky, but I've managed to work
with it (then again, maybe I need to read the docs again).

Tim (RTFP = Read The Frakking PDF) Servo
---
"Sire, the church of God is an anvil that has worn out many hammers."
- H.L. Hastings


On Mon, May 27, 2013 at 6:49 AM, Robin Whittle <rw at firstpr.com.au> wrote:
> I am exploring the open source Kicad schematic - PCB - Gerber system and
> so far am most encouraged by its ease of use, functionality and
> documentation:
>
>   http://en.wikipedia.org/wiki/Kicad
>   https://launchpad.net/kicad
>
> Thanks to Veronica Merryfield and others who wrote to this list about
> their KiCad experiences - including Eric Brombaugh who wrote a great
> comparison of KiCad and gEda, the two most prominent complete
> open-source schematic-PCB systems:
>
>   http://dropmix.xs4all.nl/pipermail/synth-diy/2011-February/030929.html
>
> It is my impression that the documentation is is well-written,
> well-illustrated and generally up-to-date with the software.   The
> documentation is in PDF files.  (Eagle documentation is all text - no
> graphics!  LabCenter Proteus is another commercial PCB system with
> documentation which I think is seriously lacking - just Windows help
> files which are very difficult to print, with no PDF versions.)
>
> I worked through most of the "Getting Started in Kicad" document and was
> able to make a schematic, with my own additional components, then a
> netlist and a single layer PCB design with my own additional footprints
> (PCB patterns of copper and holes).
>
> I just wrote to the authors of this guide with some suggestions for
> bringing the guide totally up to date with the current version of KiCad.
>  If anyone wants to use this guide I can send you my notes which might
> save you some headscratching.
>
> The guide only covers making Gerber files for an external company to
> make the PCBs.  I suggested they include a new section on home-brew PCB
> making and suggested they link to the Homebrew PCB Yahoo group:
>
>   http://tech.groups.yahoo.com/group/Homebrew_PCBs/
>
> Below is the rough text I suggested for a section which explains how to
> print or generate files for phototools or other home-brew toner transfer
> techniques.  Except for people with their own CNC drilling machines, we
> need a guide dot in the middle of each pad or via so we can center our
> drill bit.
>
>  - Robin      http://www.firstpr.com.au/pcb-diy/
>
>
>
> For making PCBs at home, it is necessary to generate phototools - or a
> similar pattern of toner or ink on the PCB itself as an etch resist -
> which are 100% final size and which have a small dot in the centre of
> each via and pad, to guide the manual drilling operation.
>
> Frequently it is desired to replicate a small PCB design several times
> on the one phototool.  This can be done in PCBnew by left-click dragging
> around the entire original design, moving the mouse cursor outside that
> area and right clicking to use the Copy option.  This can be repeated
> several times so the total design contains an array of exact copies of
> the original design.
>
> There are two ways of creating the desired artwork.  In these examples
> we assume that the board is single-sided, so only the B.Cu layer needs
> to be output.
>
> The first approach starts with File > Print with just the B.CU layer
> selected.  The X and Y scale adjustments which would normally be set to
> 1.0 but could be used to correct for printer scaling errors.  The "Black
> and White" and "1 Page per Layer" options should be selected.  "Mirror"
> can also be selected.  "Drill Pad Opt" should be set to "Small mark" to
> create the drill-bit aligning dot in each pad and via.   This drives the
> printer directly, though many systems have printer drivers which can
> create PDF files.  This approach does not directly allow the negation of
> the image, so it is not appropriate if white tracks are required against
> a black background.  (File > Export SVG has negation but lacks small
> drill marks.)
>
> The second approach allows this negation: File > Plot > SVG.  This can
> also be used to generate a Postscript file which can be processed with
> software such as Ghostscript to create a PDF file.  SVG files can be
> loaded into vector graphics programs - for instance Inkscape, which with
> suitable configuration can print them at exactly the right size, perhaps
> after further manipulation, tiling, addition of other images etc.
> There are options for Mirroring, Negative, and Small Drill Marks, but
> not for scaling.  This method can also be used to generate a drill file
> for home-based shops with CNC drilling facilities.
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy