Uninformed user question:
Does KiCAD have any concept of a standard sizes table for a project, ie a table containing the pad sizes, hole sizes, track widths etc used within the project? Ie so you can set up some ‘standard sizes’ and just quickly select from those when defining footprints etc, to help sticking to some standards. I suppose one can maybe get some of that from the generated drill table after layout.
There is a thing called “net class” in: Pcbnew / File / Board Setup / Design Rules / Net Classes
A net class is a set of rules for track width, clearance & via size to be applied to a set of nets.
It’s normal practice to put the power nets into a net class for fat tracks and nets for signals in a design class with narrow tracks, and then when you draw the tracks, KiCad just follows the net class rules of the net you’re drawing.
There is no such thing for pads in footprints, and normally there is no need for such a thing either. If you want different sized pads on footprints however, then first copy a footprint to a personal library, and edit the footprint in the footprint editor.
Thanks. The logic behind a sizes table is that some PCB houses charge you extra if you go beyond a certain number of drill sizes or use ones that are not from a standard set of sizes. A table lets you see quickly what you are using.
Or at least, it used to be so, maybe I’m out of date.
If you generate a complete set of Gerber files (or just the drill file) then you can open it in a text editor and see how many drill sizes are used. You can also open the drill file in Gerbview, and different drill sizes get different D-codes. And there are probably more ways to check how many drill sizes are used.
If you want to reduce the number of drill sizes used, then start by reducing the the number of via drill sizes, or even set the via drill size to the same as a drill that is already used for THT pads. If you still have too many drill sizes, then identify in which footprints they are used, and modify the footprints.
The number of allowed drill sizes is these days a much smaller issue then it used to be (some 20 years ago). Machines are bigger with more drill spindles and auto tool changers.
Yes, I guess times have changed since I did a lot of this, although I just found this on the Olimex website (they did some boards for me about 10 years ago):
“Our standard drill tool rack is: 0.7 mm (0.028”), 0.9 mm (0.035"), 1.0 mm (0.039"), 1.1 mm (0.043"), 1.3 mm (0.051"), 1.5 mm (0.059"), 2.1 mm (0.083"), 3.3 mm (0.13").
If you are using non-standard drill sizes you will be charged additionally."
Providing a custom list for track widths is somehow easy; each entry needs just one value.
So even the very old Kicad which I still use (2010-05-05 BZR 2356) has such a list:
Design Rules Editor > Global Design Rules > Custom Track widths [8 tracks]
But each entry on a custom list for pads needs more than one value. So I wonder how it could be implemented.
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