> -----Original Message----- > From: [EMAIL PROTECTED] [mailto:geda-user- > [EMAIL PROTECTED] On Behalf Of Mark Rages > Sent: Monday, February 12, 2007 5:29 PM > To: gEDA user mailing list > Subject: Re: gEDA-user: Re: LED 100 != 5mm LED ? > > On 2/12/07, Kai-Martin Knaak <[EMAIL PROTECTED]> wrote: > > > > I trust only footprints I made myself and triple checked for consistency > > with the specs. Is this bizarre? > > > > It seems wasteful for all gEDA users to be doing this. > > Wouldn't you find this bizarre: "I print only with fonts I made myself > and triple checked for consistency." If I said that, you might > consider me a control freak with too much time on my hands. For > similar reasons, I think a board design application should come with a > tested library of popular footprints. Now, having been burned a > couple times by broken footprints in pcb, I now check closely before > sending the board off. I think we can agree that this is an > undesirable situation. (I also realize that footprint library > maintenance is hard work, and I'm not volunteering.) >
Assuming you created a perfect footprint for your PCB application with zero errors, does not equate to that same footprint being exactly perfect for my application. Depending on board population techniques, there could be a wide variance into what an acceptable pad excess should be. If I am soldering at home without a microscope, I may want 50-80 mils of excess pad to help facilitate soldering. If I have access to my company's scopes, then 10-40 mills might be needed depending on the pitch of the part. Pick and place and I may want no excess to help pack parts. Bottom line, its tough to come up with a one size fits all footprint IMHO. _______________________________________________ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user