Push/Pull creating "extra" geometry?

I have an object I’ve made which I’ve sliced into smaller shapes, then inset faces.
My intent was to push/pull the faces through to create a frame.
However, I’m finding that some of the push/pull operations result in geometry being created rather than eliminated.

As you can see here, the top row of shapes operated properly, but push/pull created an “extrusion” of something in the second row:

On a hunch, I found that the perimeter faces work, and the interior faces don’t. Here’s a pic :

I am attaching the file with a 2nd copy of the frame before the misbehaving push/pull.


frame-push-pull.3dm (1.5 MB)

The offending pieces are not part of a closed polysurface:

You can heal it by joining the right part first.
Then PushPull will work as expected.

In this case PushPull is cumbersome.
I would extrude the outline, the necessary edges are all there.

1 Like

Thanks Charles -

“The offending pieces are not part of a closed polysurface”

As far as I can tell, creating the shapes this way should result in each “piece” being identical, i.e. they are all created the same way (inset) and are all surrounded by the same border geometry.

What makes the interior shapes different? Hmmm…

In the meantime I can certainly extrude / subtract.