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Re: gEDA-user: How to make a foot print

On Wed, 5 Jan 2011 10:00:24 -0800
Colin D Bennett <colin@xxxxxxxxxxx> wrote:

>  [...]  
> Actually, I am impressed with the flexibility of your footgen.py
> script.  It looks like you've created many different types of
> footprints using it.

I think we miss-understood each other. Or let me say I wasn't clear enough.
footgen.py was written by Darrell Harmon. I'm just a user, who provided


> However, unfortunately for me at least, I cannot use it for "the
> majority" of my footprints.  Most of my custom footprints require
> individualized design.  For instance:
> - SMT LED footprints with special oversized pads as specified by
>   manufacturer for thermal dissipation.

A good point. Please share your footprints if you can!

> - FFC/FPC connector, proprietary 1.25 mm SMT header, etc. with special
>   extra pads for mechanical support, and silk screen indication of
>   reference pin (e.g., arrow for pin 1).
> - SMT aluminum electrolytic capacitors, two-pin polarized devices that
>   should have special silk screen including a beveled corner and "+"
>   symbol by one pad.

Well.. I became too lazy to do that. I put a "+" mark by hand to the layout,
when someone else solders the PCB. I, and the pick and place machine know the
polarity. :-)

> - Illuminated push-button, 5 pin through hole with non-standard pin
>   arrangement.
> My point is not to take away from the usefulness of your script, but
> to show that many footprints (I would even say "most") require manual
> design for the best results.  The tool, pcb, should make this easier
> and faster for users.

Yes. For example, I did footprints for the Tag-connector.


It was made by hand.

> For me, the most difficult part of drawing a footprint in pcb is
> getting various dimensions from part specifications into the pcb
> drawing as I create a footprint. If pcb had a dimensioning tool that
> could place dimension measurements on the drawing as one is working
> on it, then that would make my job much faster.  As it is, I always
> sketch the footprint by pencil on graph paper and figure out
> dimensions from there based on part specifications, then transfer
> these into pcb as I draw, making heavy use of the Ctrl-M measurement
> tool.

Yes. I too miss some GUI features, like "put this 2cm away", "copy that 10x
with 100mil spacing", etc.

> I will say that I am getting much more confident and much faster at
> creating footprints in pcb as I gain experience with it, and I'm no
> longer scared when I face a new part with an odd footprint. :-)

Yes! YES! That is the way! I am happy to hear that! :-)

Levente Kovacs

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