If you have an Intex PureSpa portable hot tub and need to cap off the blower inlet, this is for you.
The blower inlet has a check valve internally, but mine started leaking and I don't have the OEM filter assembly installed anymore.
The thread is 2.375"-12, scaled 98.5% X/Y and 118.3% Z for a good fit and matching thread pitch. I've uploaded a pre-scaled version so this is already done.
I also hand-cut a 58mm circle of 1/16" silicone gasket I bought in sheet form on Amazon, as the cap doesn't seal well enough without it. The second model included is a ring you can put on top of the sheet then step on to press a cut line you can then follow with scissors.
I printed mine in black ASA for outdoor longevity and chlorine tolerance, but you do you.
Update 3/11/24: I uploaded a new version of the cap. It's got slightly thicker walls, as my original started splitting along the layer lines where the walls are under tension holding the seal.
I recommend you slice this with extra perimeters, maybe 4 or 6, for good thickness in the load bearing sections.
For more info: https://www.alexwhittemore.com/intex-inflatable-spa-plumbing-caps/