Edge 3d issue with arch


Hi, i have just moved from old stable version of Kicad to version 4.0…
It is very nice, I did a porting of my last project in very short time. I have just one issue I can’t fix. In the old project the board edge had rounded corners that I made with the arch function. When I visualize the 3D view I have a list of errors regarding the connections of the drawing…I did not have this problem with the old kicad. The 3D visualization shows just a rectangular board.

Any suggestion?



3D View of PCB errors:
Can't generate board outline in 3D view

The board edge must be closed. It complains if the end-points of the segments are too far away from each other. This is best observed at high zoom levels & best fixed in openGL mode.


thanks for the answer but it looks like my segments are overlapping so there is continuity. it looks like the tool wants each segment to end in another… I don’t know I did not have the problem with the old version. I will chcek openGL as well…thanks


I did some more check using OpenGL view and the segments are very well overlapped.
I have also added segments on the joint to make sure there is continuity…but the result is the same…any suggestions?


the new pcb has less tolerance for board edges…
overlapping should be avoided, also considering the ability to export the board edge to 3D mechanical CAD through IDF export menu.
you may find useful this post



The end-points MUST be very close (not more than 0.01mm) to each other. Simply overlapping the segments does not work.


It looks like segment start/end must be exactly the start/end of another. I spent a hour to do that and now it works. When I import a dxf with arches, I lose the arches but then I can recreate them knowing that the other segments are exactly placed. This way I can create arches with start and end points which are exactly matching the other segments connected. It is perfect but a bit heavy to do.


Best to start/end segments/arcs at the exact coordinates.

I’d first try to set a rough grid spacing… like 1mm or 0.5 mm and draw a simple rectangular outline and go from there… deleting/adding single segments/arcs as I go to keep it consistent, if you do your outlines in KiCAD (*)

*) alternatively you can draw up an outline in a CAD program of your choice that is able to export DXF, as the ability of KiCAD to do arbitrary arcs where start/end points meet other arcs/segments is very cumbersome. CAD programs have that one down as their main function :wink:
Naturally with simple 90deg arcs/segments you’d be faster in KiCAD still.


The segments must have ends which coincide. This is necessary because KiCad does not have geometry code to perform any trimming. Any seeming correct display in the past, given overlapping segments, was accidental. No overlapping - that’s bad geometry and is the reason kicad is getting confused; IDF export will also fail.


if you want to import dxf files with arcs and curves you have to follow some rules…
kicad can manage best dxf file if exported from LibreCAD in R12 version…
moreover it doesn’t support polyline

if you respect those rules, you can import very complex shapes

You may find these conversation useful:

and the kicad user manual, obviously
at the paragraph
6. Create and modify a board
6.1.2. Using a DXF drawing for the board outline