I originally designed this as a mini ornament. It looks great at that size (1X), but looks even better at 1.5X and 2X. At 1X, it's about the size of a golf ball. At 1.5X, it's a standard Christmas ball size. At 2X, it's about the size of a grapefruit. It will scale up even more if you want to. I assume most people will print this at 1.5X, so that's what I've used the the time estimate.

The cover photo shows it at 2X.

I've provided a couple versions of the ball - in 2 pieces and in 1 piece (not including the cap). I recommend printing it as 2 pieces. It's a lot smoother that way and the ball prints without supports. I've provided my PrusaSlicer 3MF files and MK3S+ GCODE for the 2 piece print at all 3 sizes. I've provided the ball as 1 piece mostly in case someone wants to experiment with cutting it in a different place or you want to print the ball as 1 piece using a 3 color filament.

Print SettingsPrinter brand:Prusa

Printer:I3 MK3S

Rafts:NoSupports:Doesn't MatterResolution:0.15mmInfill:Only in certain spotsFilament brand:MatterHackers Quantum

Filament color:Raspberry Gold

Filament material:PLA

Notes:You might think this needs infill everywhere, but it really doesn't. I used height range modifiers in PrusaSlicer to add a few layers of infill (25 - 30%) in 5 places where something starts to print unsupported. It printed really well and it's light. Printing the 1.5X ball with 25% infill everywhere increases the final weight by 50% and adds 2.5 hours to the print time.

I printed most of the ornament with just 1 perimeter. At the bottom of each half, where the halves later get glued together, I used 2 perimeters. I used 2 and the top of the top half and 3 at the top of the bottom half. The cap is printed with 2 perimeters everywhere.

I printed the 1.5X and 2X balls with supports to get a cleaner print on the dome, but that part of the print is just about impossible to see when the ornament is glued together. I'm just a perfectionist.

I used custom seams to put as many as I could on the inside of the ball where they don't show.

I printed the 1X ball with 0.1mm layer height and the other sizes at 0.15mm.