@dpd First I just extruded the base vertically. Second attempt I added a step. Copied the top arc and placed it as seen in the second image, scaled to fit and extruded. I think this is the money shot. [image: 1762857783243-extrude-base-vertically-resized.jpg] [image: 1762857800233-extrude-base-vertically-additional-step-arc-resized.jpg]