Back massager attachment

As per the photographs, the original component that attached the ball to the spring had worn away over a prolonged use. I was asked whether I could fashion a new part so it could continue to be used. After a few hours of familiarising myself with Blender and exporting the .stl file to Bambu Studio and faffing about creating a negative part cylinder because I was getting non-manifold errors on the exported file, I managed to create this which secures the ball end. Two strips of parcel tape around the spring end to slot into the cylindrical part means it's securely held and won't fall out. Produced using PETG filament.