Re: gEDA-user: new footprint guidelines

[Armin Faltl <armin.faltl@xxxxxx>]

For all those, that follow the discussion from here or vaguely remember 
some other rotations:

Rick Collins wrote:
> I had to go through all this some time ago and recently I wanted to 
> iron out all the difficulties so that the assembly house could use my 
> XYRS file (location and rotation data) directly without alteration.  
> That ended up being a fool's errand, but I did learn a few things.  
> IPC has a standard for this which everyone "seems" to use.  For two 
> pin symmetrical parts, pin one is to the left.  For IC type parts, pin 
> one is in the upper left quadrant for parts with pin one in a corner 
> or for parts where pin one is in the center of a side pin one is on 
> the upper most side.  This is the zero degree rotation point for the 
> part.  All rotations are counter-clockwise from this position.
on 2010-08-15 Rick wrote in thread 'Specification of Rotations for Auto 
Assembly':
"I just found something that changes what I thought I knew.  I have a 
PDF of an IPC magazine from 2005 where they are touting a "leap forward" 
in land pattern generation.  An illustration showing pin 1 in the upper 
left for SOT components is what I used as my reference.  That and the 
post in the FreePCB forum of a normally very reliable source.  But I 
found a copy of IPC-7351 and it clearly says that for SOT and most other 
IC parts, the original rotation is with pin 1 in the LOWER left.  That 
is what FreePCB does in the library editor by default. "

This isn't Ricks fault: reading the 2005 IPC-7351 I can confirm this, 
while the 2009 IPC-7351B says,
that pin 1 is in the upper left corner ;-)
Shall I comment on this ? I'll just use upper left...



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