Modelling issue or bug?

HI All,

When I join or boolean these surfaces, strange things happen.

Is there an issue with the surfaces?


For some reason the cone surface is invalid (bad object), it has a bad edge… don’t know how it got that way.

In this case, if you temporarily hide the other part, then use _Untrim on one of the outer edges of the cone, that fixes it. Then you can show the other part again and join the two.