Hot Tub/Spa Filter Cap/Retainer

prusaprinters

ADDENDUM : When I originally made these in Aug. 2022 I had some concerns that PETG might not hold up well in hot chlorinated water. As I write this in March 2024 I can report that that the prints still look as good as when I originally made them, even though they have been immersed in 104°F (40°C) water treated with “chlorine granules.”END ADDENDUMThis was made to fit a Hot Spring model “spa” or hot tub, but will likely work with other models of hot tub that use a similar filter cartridge. This is a replacement part which can be purchased for around $6 each, but why do that when you can print it for $1.25?For reference, the cylindrical part of this print has a diameter of 48.8mm and a length of 66mm; the internal threaded part is 4.5 TPI.I should note that I printed these in PETG, and I do not know how well it will stand up to the heat and chlorine of a hot tub. It's also worth noting that the original filter caps (after many years of use) show significant deterioration and “flaking” (which is why I made replacements - see photos). The cap is printed in two parts so as to avoid the need for supports. The grip simply snaps into the cap.Notes on choice of filament :I chose PETG because it has a higher glass transition temperature than PLA (likely a poor choice). ABS might be a better choice. Print InstructionsPrint in PETG using the gcode and 3mf files provided. Otherwise :2 perimeterscap : 10% rectilinear infill grip : 0% infillCADThe OnShape 3D CAD files for this are here :https://cad.onshape.com/documents/2ffdfd2db112fe2df58b3e8a/w/fc1e45d3234ece46ecdb7a31/e/d5a96075759c5133d6d35ffb