One Cube, One Solution — Verified Polycube Puzzle

The dissection is original: I generated tens of thousands of random ways to split a 3×3×3 cube into six pieces, counted the solutions of each, and kept this one. It has exactly one solution — not "about one", not "we think it's unique". One.

That number is the whole point. Most puzzle listings guess at difficulty. Here it's a measured quantity, and the counter that produced it was validated first: run it on the classic Soma cube and it returns 11520, which is precisely the known answer (240 essentially different solutions × 24 cube rotations × 2 mirror images). Only then did I trust it on my own dissection.

Six pieces, one cube, one way in. It's genuinely hard — expect a good while on your first attempt, and the satisfaction to match.

What's included

• Six puzzle pieces (three of five blocks, three of four)

• A tray to build in and store it, with thumb cut-outs to lift the pieces out

Details

• 18 mm blocks with 2.2 mm rounded edges — no sharp corners anywhere

• Assembled cube 54 × 54 × 54 mm; tray 61.4 × 61.4 × 22 mm with 1.4 mm clearance

• About 62 g of pieces plus 17 g of tray, roughly 4 hours for the whole set

• Every piece is too large to pass the small-parts cylinder (Ø31.7 × 57.1 mm) — the smallest is 18 × 36 × 36 mm. Suitable from age 3 with the usual supervision, though the puzzle itself will keep adults busy

Print settings

• No supports. Each piece has a designated orientation in the file; four of the six have zero overhang at all, the other two have a single 70 mm² patch that bridges without trouble

• 0.2 mm layers, 15% infill, 3 walls

• PLA is fine — the pieces get handled, not loaded

• Print each piece in a different colour. It transforms the puzzle: children can see which blocks belong together, and it makes the solved cube look far better than a single-colour print