kicad-developers team mailing list archive

[Vesa Solonen <vsolonen@xxxxxxxxx>]

On Thu, 12 Aug 2010, Alex G wrote:

> BTW, is the naming of the footprints acceptable?

I think so. It's the easiest to change if needed :)

> I've set it at 0.5mm. What value should I increase it to; 1mm? If I
> change the radius, I'll also have to adjust the footprint, as a minimim
> clearance of 4.4mm from the base of the package to the bend is recommended.

Google "to-220 lead bending radius" found a good International Rectifier 
application note: http://www.irf.com/technical-info/appnotes/an-1031.pdf
So it would work out to 1.2mm, which is on the safe side. Also bent stress 
relief vertical option might be nice, but that may add too many varables.

> Alright, I'll remove the numbering from the mounting hole. I'll leave
> the pad outer radius at 6mm, as that is necessary to sufficiently
> accommodate an M3 screw.

Now that you said it I had to check M3 nut max width and it says 6.4mm. So 
maybe 6.5mm is big enough with tolerances. Please don't get mad at me ;)

> Sure. I have the S202S02 in front of me. The missing pins are there,
> except that they are cut from the base of the package. It is possible
> that this may become a standard package (TO-somenumber), or that we will
> see more parts with this package in the future, with the missing pins.
> Numbering the missing pins will provide consistency should that happen.
> If you believe I should ignore the missing pins, and just number
> existing ones 1,2,3,4, I have no objection.

Someone wiser than me shoud comment here. I'd make numbering conform to 
exact pin count this time, but I can see problems coming from various DIP 
packages with partial pin count. Schematic wise it's a bit mess as multi 
part packages come to mind when one sees larger pin numbers than pin 
count.

> I am excited about this, and at times, it may be difficult to be
> patient. I'm waiting to get my hands on the Perl script that generates
> the libs so that I can play around with it. I'll suggest to Oydvind that
> we create a branch in Kicad-Newlib for his work.

:D I know. Best luck to the cooperation. I'm sure this will bring 
something good.

> I'm glad you like them. I drew the 3D packages in Inventor with the
> exact dimensions from the datasheet. I want to get any glitches cleared
> ASAP, so I'm willing to work on this literally 24/7 (minus
> sleep/eat/drink time).

Thank you for your enthusiasm. Take your time, reaching perfection may 
need infinite time, but we just need something thats always good ;)

> I've also created a branch in Kicad-Newlib here:
> https://code.launchpad.net/~mr-nuke-me/kicad-newlib/footprints_misc
> I'll submit the footprints there once I figure out how to use bzr; and
> I'll just ping here.

Great to see you getting along :)

-Vesa