We mean the rubber (cover) part .The diaphragm cover I've 3d printed in TPU with success... not as pretty as silicone, but functional:
I've cast a usable T in silicone out of 3d printed molds, but it's still a work in progress.Scubapro 108/109 Diaphragm cover by James1979
Rendering of diaphragm cover, modeled in Freecad. will be attempting to print in TPU, but I have concerns about supports... will update as it progresses.Edit#1 Support worked out surprisingly well. Thickness of outer ring was too much to assemble the reg, and the overall stiffness was a bit...www.thingiverse.com