Like my other TwistedFlutes designs the outside if this part a Loft surface made from 10 vertically stacked and twisted plane curves, and the inside is a Loft surface made from 10 stacked circles. My original design was about 30% smaller, but this resulted in the top area being too thin to print properly. So to keep the proportions right I made the entire piece thicker and larger.

This part printed in 13 3/4 hours using a print speed of 80 mm/sec and a layer height of 0.200 mm.