Creating a cavity using combine

[milltechcm]

Hello

Thanks to all for the help getting this lens into a body.  Now I need to drop it into a cavity for position and to hold it to machine it.  When I drop it in and use combine, it cuts the shape out but leaves material on top.  I don't know how to extrude this 3d shape down into the fixture.  Thank you.

Brandon

[davebYYPCU]

With 4 fixture attempts, none has indicated what's needed.

The lens has some cuts and tabs, the project is fairly early, a few clues or photo of an similar one?

My initial thought is to position the lens, and then split the body in the correct way, for a top and bottom like a cavity mould, but ......