Material - ABS or ASA (I used ASA as it's less likely to fade in sunlight than ABS). The printed parts will need to have the extra material broken away. Any rough bits should be sanded smooth. The shiny surfaces are produced by leaving the printed knob in acetone vapour for a few hours. I used a modified honey jar, as shown in the photo. (Bolt is M6 x 60mm, with nut and washer on the inside.) At the bottom of the jar is a piece of sponge, held in place by magnets (one inside, one outside). The sponge is for the acetone. The jar is used upside down. Be very careful when removing the jar from the lid. The shiny surface will continue to get smoother as the acetone dries out. The prints were done using a 0.6mm nozzle, layer height 0.2mm, no supports.