I have an old habit from my days of PEAD (Pencil & Eraser Aided Design): draw a skeleton of what you want with a bunch of hairlines with appropriate offsets and trace what you need with a thicker pencil. Mark hole centers etc same way.
Today I need to create my first own footprint totally from scratch.
I have a DS for the part with a bunch of dimensions and I was hoping to repeat the technique.
But where is “Add dimension” button in footprint editor?
Or there is something that I am missing on the concept level of footprint editor?
I don’t think there is such a thing in the Footprint Editor.
What you can do is use the “User” layers to add some lines to help a bit with alignment.
Or indeed the good old paper and pencil to make a sketch.
Dimensions in the Footprint Editor are often a bit different from shown in the datasheet. For example, the Footprint Editor likes to know the center locations of pads, while datasheets may specify the edges of pads. Pre-calculating the numbers KiCad likes and writing them down beforehand make it easier to focus on entering the right numbers in the right locations in the Footprint Editor.
A completely different option is to use the “StepUp” workbench in FreeCAD. It has quite a learning curve, and I mention it more for completeness then as a suggestion.
There’s a Micrometer Tool in the toolbar in the footprint editor. The dim’s disappear after clicking away from the placed dim’s but, it is somewhat useful… somewhat…
After a bit of looking at .kicad_mod file it came to me that it would be easier to create&edit such files manually. Or, maybe, taking something close to desired footprint and modify it.
Hacking with a text editor is a valid way to modify stuff in KiCad.
It used to be quite common, but as the functionality of KiCad itself increases over the years, it becomes less necessary to do so.
Schematic file format has changed completely in KiCad-nightly V5.99 (soon to become V6) Other file formats may also have changed a bit, but much less dramatic.
At least in v5 the kicad internal options were too limited to be of use. Which is why i always used external tools to make the drawings needed for checking contributions to the official library. I documented my workflow here Tutorial: How to check footprint correctness?