My toughest thing in creating this myself is centering the stem.
It is a high pressure air valve for an air rifle; 2k.psi. The OE poppet does exactly as you suggest, and it distorts, and loses its seal (suggested as black delrin - white ebing the preferred for the guys doing their own replacements). I've tried all of the things I can think of in alternate fixes, and, have gotten some to hold for short term. But, repeated cycles breaks down my efforts rather quickly. Then its another 100 pumps with my hand pump, and, sweat.
I'm hoping that the company comes to the rescue, but, am also doubtful, as they'd have to admit to a faulty design, and I am just out of warranty (but this is the third valve failure in a year and a half). Their warranty tech is a sharp guy, and has a complete machinist shop available to him. I have a message out to him, but, am still looking for alterrnates.
where are my manners?
thanks for the primer on 3D printing!