Hi All, Please try out this parametric CAESES model of a volute for a blower. The basic shape is controlled by a function (red) to control the offset of the outer shape from the inner circle. If you switch off the visibility of the trimesh (named volute, click on its icon in the object tree) you can see the surface topology behind it. If you are a bit experienced, such a model is set up in 15 min from scratch. Have fun!volute1.fdb