Arc, Circles and Curves Manipulation in PCB Edge


Hi all,

Recently I was tasked with the design of a PCB with an odd shape. Broadly, it was a circle with 3 circular arcs on the “edge cut” spaced 120 degrees apart. The board in question also had to have circularish cutouts located elsewhere on the board for a rare kind of mechanical fitment. This was very tough for me to do in KiCAD (I use version 4.0.4). I managed it using trigonometry as I didn’t want to use other programs / software (like inkscape / freecad / corel, etc) to design the outline and then export and import to KiCAD. Even after that, it was very difficult to draw it out on the edge cuts layer.

I’d like future versions of KiCAD to have a much stronger arc and circle manipulation capability. This way odd board shapes can also be possible within KiCAD itself. I hope this not an unreasonable request.


P.S.: KiCAD’s really come a long way and has become a really useful tool. Please don’t let KiCAD go down the same path Eagle did and commercialize it!


The best way to do is to draw the outline with a CAD program designed for the job, but unfortunately you have rejected that option. I think there has to be a better justification than “I don’t want to use other programs”.

Perhaps you don’t realize that KiCad is an Open Source mainly run by volunteers, it does not have a company behind it. It is considered reasonable to spend some of your own time finding a solution before asking others to spend some of their spare time.

You can create graphics using Python scripts, but I guess you don’t want to learn that either. :slight_smile:

Hmm, I’m wondering if KiCad should actually charge $5 per download…


Actually I saw one of Chris’ latest uploads ( on YouTube. That’s when I learned there’s a road-map for versions 5 and 6 with so much good stuff coming soon. So I just thought, if KiCAD’s gonna get more optioned and feature rich, then why not have arc and circle manipulation as well. Despite KiCAD having so many features now and many more to come, going elsewhere just for a board outline seems a bit frivolous really.


We’re working on improving 2D drawing tools. I can’t promise it will happen before V5, but sooner or later will be in the nightly.



This is known by long time…
Moreover for complex shapes where BSplines are needed it is better to develop the PCB edge outside KiCad or in general ECAD sw…

this is in fact a good position because of the following…

probably you don’t need a mechanical integration in your designs, otherwise you will stand for an edge design in MCAD environment as already suggested above…
just for an example of what is done in the world have a look at the latest integration between Eagle and Fusion360

There you can see that in a complex project the Edge has to be designed in a mechanical environment…

A similar option is also available if you use FreeCAD and KiCad together

but you need to change the way of designing the pcb


I’m trying to supplement KiCad drawing tools with KiCommand. Have a look at it, especially the commands in the Draw category. Let me know if you have ideas about how to improve or add to KiCommand for your needs.


Thank you maui, gotcha!