"Precisely" define Filled Zone Outlines


Of course the filled zone function works for me. It is not a great thing, but one question confuses me:
All the examples I have seen are created with some kind of “free hand” drawing. Depending on steady hand, it is a nice straight line and after editing all 4 sides of PCB, a nice rectangle. Or a shaky polygon.
How to define the shape exactly?
For example, when defining the PCB shape, I can specify exactly the positions of the start/end point per line, and thus the corner points of the PCB.
With the zone fill function I don’t see the possibility.
Am I missing something? How do you do it?


I don’t have any problems when placing or editing zones “precisely”. Go to preferences and see snaping options, h/v/45deg drawing modes, also, change grid as needed per current situation. Talking about v6 of course, I don’t know what are you using.

Also, using spacebar to reset xy coordinate counter on statusbar, and turning on “full width” cursor crosshair (found in left toolbar) are agreat helpers to draw preciselly.

Hello poco,

Tried your hint. Although I’m using 5.10, it works a treat!
I think, changing grid was the point.

Thanks a lot!

I usually draw zones in some weird pentagon shape around the PCB.

This has two reasons:

  1. KiCad clips the edge of the zone from the PCB, so it’s less coordinates to worry about or things to try to get “just right” which speeds up development a little bit.
  2. The weird pentagon shape makes it immediately obvious if something has gone wrong during for example creation of Gerber files and a last inspection is done before sending them to a fabhouse.

Trying to align a zone with Edge.Cuts takes more time, and can lead to suble mistakes which are not easily spotted.

In older KiCad versions, a zone could only be selected by clicking on it’s edge (Which I much prefered above the current situation where a zone can be selected anywhere. The PCB is already far to crowded to add that too). In the older version, the weird pentagon shape also made sure that zones are easily selectable. Drawing zone edges over each other (especially if it’s everywhere) did make the correct zone hard to select at some times in those older KiCad versions.

I do exactly the same :grinning:. Essentially because it was super easy to select appropriate zone depending on the layer in v5 (see different out-of-the-board shapes with different colors). This is not so important now in v6, because v6 supports multi-layer zones (add a single zone and assign any layers you want for zone to be on). And yep, misaligning GND zone contour from with board outline brings debugging capability, faster development, and error-free selection (there is no ambiguity to when trying to select board outline or zone outline when clicking).

Makes sense only if you want zone at whole PCB.
I have read that to avoid standing wave zones should not be rectangles and zones at different layers should not be the same shape to not make an open end waveguide reflecting the wave into the PCB.

Hello paulvdh, Piotr,
I have tried the pentagon. It also looks somehow activated far away from the edge of the PCB (I had always been irritated by that) - But: It works fine.
Thanks for that!

I’ve also found that turning on full screen crosshairs helps me line the pointer up horizontally and vertically to elements on the opposite side of the screen. YMMV

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