Chamber Fan Duct for P1P/P1S - no supports

Just a quick remix (of the 38mm version) to be able to print the duct with no (or pretty much no) supports. Print it vertically and the only places where you can add minimal support are insert slots, I printed mine with no supports at all and they worked well, but one of the inserts is not perfectly flush with the duct. It still works perfectly well, but if you want inserts flush, you can add some supports. You don't have to glue the inserts. when the duct is screwed in, there's no way for it to loosen up because the inserts will hold it in.