70 mm Cratered Moon Sphere2

A roughly 70 mm ball pitted with 60 craters of uneven size and placement, so it reads as a moon rather than a clean sphere. The craters run from about 4 mm to 14 mm across and 0.5 mm to 1.5 mm deep, scattered across the whole surface — a few sit on the underside, so the face changes as you turn the part. A 3 mm blind hole enters from the front and stops at the centre, leaving the back solid; it runs 35 mm deep and takes a thin wire or cord pushed in from one side.

The ball is a hollow shell with a 3 mm wall, so there is no interior to fill — the hole opens into a sealed cavity that is otherwise closed. That keeps the weight and material down, but the top of the cavity is an overhang: it may need supports or it may sag slightly inside, where only you will see it. The outside still touches the build plate at a single point, so print it with supports or a wide brim, or split it at the equator into two hemispheres that each print flat-side down and join afterwards. The crater field is surface detail, so almost nothing here is locked in.

Remix hooks

• Diameter — about 70 mm on all three axes. The crater field and wall thickness scale with it; much past 200 mm and you are into split-and-glue territory on most beds.
• Wall thickness — 3 mm as it stands. Thinner walls save material but print shakier; thicker walls swallow the crater depth, so deepen the craters if you go up.
• Crater count and size range — 60 craters from 4 mm to 14 mm across. Raise the count and tighten the range for a finely pocked surface, or drop to a couple of dozen large ones for a few big basins.
• Crater depth — 0.5 mm to 1.5 mm. Shallower craters print cleaner overhead and read best under a wash; deeper ones catch more shadow but want slower overhangs — and they must stay well under the wall thickness.
• Minimum gap — a pair or two still meet, which the gap check misses because the cut widens slightly on the curved surface. Widen the spacing and count each crater's true surface width if you want every bowl cleanly separate; expect slightly fewer craters as a result.
• Wire hole — 3 mm wide, 35 mm deep, blind, entering from the front and ending at the centre. Scale it with the wire you have. Running it all the way through gives a threaded bauble; moving it off-axis gives one that hangs tilted.
• Cavity openings — the shell is sealed apart from the wire hole. A drain hole or a screw cap turns the hollow into a container.
• Distribution and split point — bias the scatter toward one hemisphere for a near-side/far-side look; cut at the equator for two support-free halves, or off-centre for a shallow cap and deep bowl, with a locating lip to register the halves.

Obvious variants

• A flat-bottomed version that stands on a shelf or glues to a base without supports.
• A solid version when weight matters more than material, with the full-depth craters of the earlier build.
• A scaled-down single-piece print when you want the cratered shape without the support hassle.

Pairs with

• A thin wire or cord pushed into the 3 mm blind hole for a hanging decoration, with a dab of glue to hold it.
• A socketed ring or base if you add a flat, for a stand-up display.