Hi, from time to time I need to move the zone cutout when I relocate component blocks. Is there any way to move it keeping its shape, or just corner by corner/edge by edge? If I select the cutout and attempt to move it, the whole Zone moves with it. Seems like I’m unable to select the cutout only. Do I miss anything?
Just select and move with M. That’s it.
No, it doesn’t move the cutout inside the zone. It moves the whole zone. The problem is that the cutout is integral part of the zone as much as the outer edges. AFAIK there’s no way to handle it as an independent item.
However, you can define an independent keepout zone which makes a hole in the copper zone.
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In a case of a ‘cutout’ being part of a zone this should not be called a cutout!
As eelik said a cutout should be just that, namely a separate cutout. Otherwise it ain’t no cutout!
Why not? It’s a zone’s cutout. It’s part of the zones’ polygonal outline. Not a cutout in anything else. It’s a hole in that polygon.
I agree with eelik here. I see the cutout just as integral to the zone as for example chamfered corners, which are also part of the polygon.
KiCad is not a mechanical design program. For more complex zones, creating them in a mechanical program and then import from DXF is a good alternative. (And is probably implemented by now, (have not tested lately)).
Yet another alternative is to use multiple nested zones and use zone priorities.
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This is an interesting idea, take a zone with integrated cutouts and split it into individual keepout zones (and maybe vice versa). I’m working on the area/zone handling of KiCommand and will look at implementing this feature. Will post here when available (if no one objects).
What would changing between these methods add to a design?
With stuff like this it’s usually best to experiment with a very simple project, untill you get your workflow right, and then draw it in your real PCB in the right way.
Just for fun I made a GND plane with 2 cutouts in a dummy project.
The slanted outline is the outline of the GND zone. I always make these crooked so it is easy to spot if for example Gerber generation goes wrong with the edghe holdoff. It also give easy handles if you have multiple zones.
The 2 vertical slots are keepout zones on the same layer.
Keepout is not an option for me, as there are some places I need to have another Copper zone located there. Zones priority also does not solve all the issues a Cutout does, as I want to control the area.
An example it happens in my designs are the areas near the “Hot” (high di/dt) nodes for Buck converters. To reduce EMI, as many IC manufacturers suggest, I do keep the GND copper away. But then I do need my planes for certain features of the SMPS design. So the natural choice is a cut-out. It works for me great, the only issue is when I try to move it due to some re-design of the PCB.
Moreover, maybe these two features (cut-out and keep-away) could be merged into a single feature. Zone cutout seems just like a special, “selective” mode of Keep-away: keep away copper fill but only for a specific Net. These two have confused me many times anyway.
An alternative may be to define a special net class for your “Hot” nodes with a very wide clearance to lower capacitance to “adjacent stuff”. If you then put them on the same layer as your zone, they create their own dynamic cutout.
I once experimented with this for a crystal oscillator, where currents and noise in the GND plane under the crystal can cause deviations.
Setting a clearance for a Net class will try to enforce these clearances also between several “hot” nodes which is not necessary.
Anyway, current solution with the “Cutout” does the trick, and only becames cumbersome if it comes to change things.
you may consider to approach StepUp… you can push and pull Edge.Cuts layers and also Fillzones and Keepout zones…
kicad StepUp wb few enhancements
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