Ahh, perfect. The mouseover text only says “change to isometric perspective” so I didn’t think to click it. Much better!
To add to these, the main reason I find myself opening CAD is some manufacturer models have a very bad origin that puts the object outside the 3D preview rendering volume. Something to bring the center of mass to the footprint would be nice.
Also, I think it’s a little more complicated than you make it out. IE in Paul’s example, to align a DIP pin to the holes, you need to mate the center of a circular hole to a rectangular solid, not just align vertices. I can do that easily enough in CAD, but it’s faster and just as good to eyeball it.
Yes, that’s even a bit of a pain in most CAD packages. Concentric mates are easy, rectangular to circular, less so. But possible. “Align the center of this surface to the origin” is probably workable, but it’s still something of an edge case.
Sure, you also need to be able to snap to edge centers and things like that. But, you don’t need dynamic constraints: once you get your model positioned, you are done.
Also, I agree that doing it by eye while zoomed in is often good enough.
There’s an argument to be made that people shouldn’t be relying on KiCad for mechanical layouts that are more sensitive than eyeballing can achieve - really should use a proper CAD for that.
But it would still be really, really nice to export a CAD model, import it into a full cad system, and have holes and similar features accurately referenced to the PCB features and components. I’ve been recreating a simplified PCB in my cad, using pads/holes as references, and it’s incredibly tedious (but accurate!).
One other thought, since we’re bantering - just display the centerpoint of each circular feature, so we can eyeball alignment much more accurately. A little + or something would be excellent.
But KiCad already does this quite well:
In KiCad’s internal 3D viewer you can easily obseve which 3D models work, and if there is trouble. All KiCad’s libraries (should) have perfect alignment and be dimensionally accurate (Trust, but Verify!).
Just yesterday I did:
Pcbnew / File / Export / Step / … and I imported the resulting board into FreeCAD. All parts on the PCB below are from KiCad’s default libraries.
You can also do some things the other way around.
You can for example create a complex board outline in a CAD program, and then import it as a 2d DXF file in Edge.Cuts layer.
For more complex interactions, there is the “KiCad StepUp” workbench in FreeCAD.
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I don’t know how that would work. Stepup is a plugin for FreeCAD. KiCAD doesn’t know it exists until it hits KiCAD’s Python API… I don’t know how that would be integrated as an official component of KiCAD. Maybe a mention in the download page and/or other documentation that installing FreeCAD and then it’s Stepup plugin is suggested. Maybe even put the suggestion in the installer like Wings3D used to be.
You haven’t installed KiCad on Windows since v4, have you? 
Not sure what you are getting at… I’ve been keeping up with the stable versions through v5 (installed v5.1.7 at home yesterday and at work today). That’s why I used the past tense about the Wings3D install suggestion. Now I see the FreeCAD prompt. I think I’ve just blown past that before. Maybe also mentioning installing the StepUp workbench there might also help?
Not sure if understand what you are doing well.
Using StepUp you can import footprint and 3D model into FreeCAD and then position 3D model against the footprint making some measurements if needed. And then export 3D model right positioned.
I’m old enough to not remember step by step how I have done that month ago 
but I managed to position 3D terminal block models I got from Wurth www that way.
I have also imported into FreeCAD the KiCad made PCB RFID antenna and positioned it and exported as 3D model used in another PCB. The problem was that tracks were visible at only one side of my antenna 3D. But as I have written about it then may be now it works.
The mechanical design is done in Solidworks. Typically I’ll make a native simplified cad model of the PCB, import component 3d models, and mate a hole feature on the PCB to a pin feature of the component model. This ensures perfect CAD accuracy, but requires me to make an extra PCB cad model.
It would be nice to just export the CAD of the populated PCB itself and use that, if I was sure it was accurate enough.
I have never used any mechanical program in my designs. I am starting to use FreeCAD to help me with 3D models in KiCad.
Using StepUp you can import KiCad PCB (with elements) into FreeCAD and save it as STEP and probably other formats. To make files smaller you can decide below each size element models to be ignored and if element models have to be accurate or just a boxes of right sizes. It is what I have read - never tried it.
I believe you get accurate files.
Yes, this should be quite accurate, as long as the footprints, alignment, and components models are perfect. I may start importing a STEP of my populated pcb into SW for enclosure design/alignment.
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