kicad-developers team mailing list archive

[Jean-Paul Louis <louijp@xxxxxxxxx>]

Wayne,

Historically, the through-hole parts were always referenced of the pin 1, because through-hole IC placement machines did not have vision systems (we’re talking about 1970’s.

Only with the advent of SMT, placement machines started to use vacuum nozzles and later vision, so it became more prevalent to use the centroid of the part instead of the pin 1.

So TH parts are referenced from pin 1, and SMT parts are referenced from the centroid.

Just another extra $0.02 worth of info.

Jean-Paul
AC9GH


> On Oct 1, 2015, at 10:29 AM, Wayne Stambaugh <stambaughw@xxxxxxxxx> wrote:
> 
> While I was fixing the broken 3D models on the interf_u demo, I noticed
> that reference point (0,0) for many if not all of the through hole
> footprints and models is now pin 1 of the footprint instead of the
> physical center of the footprint.  When did this change take place?  I'm
> pretty sure reference point used to be the physical center of the
> footprint because I had to recenter (and rotate some) many of the
> through hole footprints on the interf_u demo.  I thought that I
> mentioned this before about announcing library changes like this to a
> least the developers list.  I don't use through hole components very
> often but I also don't like being blindsided by unexpected changes.  In
> the future, when there are policy changes to the library structure or
> footprint defaults that effect users, please give everyone (this
> probably should include users) a heads up.
> 
> Thanks,
> 
> Wayne
> 
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