Hi Art, I've attached a version that's been simplified, a couple of areas that had fragmented faces have been combined into a single larger face and I sliced off a sliver with an angled cutting plane to make just one single plane in place of 2 fragments that had a shallow meet-up angle.

This version should work better with Chamfer.

- Michael

Michael this is super helpful for understanding how this works. And now I'm trying to recreate how you got that cutting plane to line up the way you have it in the file in the first place. I tried three point plane on surface but it doesn't extend past the points I select. Was this a re-oriented plane or C-plane view method?

Hi Art, that was a 3 point plane that was then scaled, here's a demo:



- Michael

Ah, nice. Thankyou!

Hi Michael, after some practice, some test prints and your tips I went and remade the initial cutting solid over again in a few min with a simpler method of a few planes and blended edges. I am happy with the smooth interior result and this boolean cut is obviously the last step before exporting. fillets/chamfers done prior to cutting out the large cavity space.