Simple ashtray, has a hole in center for screwing a 3" wood screw to act as center post. You would need to round off tip after screwing it in so it won't damage anything.

Note on second and third picture, screw is modeled in. I gave away it before I could take picture and I don't use them so no printed picture. Works well, though you will need to back off screw sometimes as you screw it in, so it is easier.

Use default shells, 10% infill. I think 5% should work, but didn't test that.