If you are using these in the sun (as a mailbox usually is) try using a tougher more UV resistant plastic such as ABS or PETG. Many of my outdoor PLA prints have failed due to the exposure to nature. I find PETG to be a great mix of affordability, toughness, and colors.
I would agree - as a test, I printed my first set (both side of the mailbox) in PLA - they have now been up for more then six months - all summer, rain, and now snow! They are holding up amazingly well. I am going to add current photos of the numbers as they stand now - The will deteriorate over time - my second set will be in PETG!
Nice design! Mine wobbles a little when spinning, but I used the 3d printed bearing instead of the recommended one so there is some room for tinkering.
Made the regular sized one. Then I wanted a smaller version where the sides were not so sharp in your hand. I imported the stl into Fusion 360, and chamfered the sides, and printed it at 75%. Worked pretty well. Thanks for sharing.