I couldn't find a model here or any other site I checked that would screw on the waste port on our Intex sand filter. After some hair-pulling (Intex seems to use an oddball thread) in Fusion and several iterations, I now have an adapter. I can use the 1.25" pool hose from the vacuum to route the discharge water (draining, backflushing, etc) away from the pool area to a more convenient area.

The thread OD is 60mm, 10TPI, angle (best I can tell) is 60deg, thread ID is about 57.5mm.

Recommend PETG since this is an outdoor use item. Supports not needed if printed as shown in the pic. I chose that orientation to get a smooth surface for the rubber seal on the port. Used a brim just in case, but that depends on your bed adhesion strength.