Certainly hoped to have made more progress by the Semifinalist round deadline. Kind of seems to have gone backwards, but the real job got in the way. Interestingly, the problems with the current code gave me an idea to simplify the model and make it a form that will print better. I can't see any reason the main tube of the cannula needs to be cylindrical. So am thinking I could optimise the form to simplify the intersection of the nares cylinders and the base form (cylinders intersecting with flat surface) and optimise it for 3D printing (minimise unsupported overhangs). Something that in cross section is something like the image below. Should be more Processing friendly and 3D printer friendly...so time to start over.