@pilou said: a brute method Thx Fredo6 and its versatile Curviloft Kill surfaces and segments for keep only circular curves you can make the same with other if you want truncated conic volumes [image: like-thatt.jpg] Funny i have made a conic form few days ago for the free Simlab Composer Lite (max 1920 *1080) (geometric caterpilar curves + spheres ) [image: carterpilar.jpg] Thanks! I used the Skinning tool and that did exactly what I wanted; creating a surface along the arcs I created to get a smooth transition from the lozenge to the circle. Thanks so much for helping out. I am not back on track!