I need help to curve a shape like this into the middle where the circle is flat but the rest of it has a smooth curvature to it. I also need it to have a thickness of 2mm and the difference in height is 15mm. This is the closest i can get but there are visible grooves where it isn't entirely smooth. I did this using the loft tool then shelling it out from the bottom to get the 2 mm thickness, is there a better way? Thanks!