Mini 2x2 FTO puzzle

This is a fully 3D-printable 2x2 FTO (Face-Turning Octahedron) twisty puzzle. You do not need an AMS or any additional hardware (like screws or springs) for printing and assembly. Mechanically, it can be described as a Skewb with moving tips attached to the centers. You can choose between three versions: monocolor, stickerless, or tiled. For each version, you can also choose if you want a standard puzzle or a keychain variant with a hole (designed for a 25mm diameter keyring). This puzzle was designed for the BONBON Capsules Design Contest hosted by @Pipin.World - 皮皮世界. The standard FTO was added as an official WCA (World Cube Association) event this year (2026). This 2x2 version is a simpler, more approachable variant. Just as the 2x2 Rubik's Cube is a simplified version of the standard 3x3, this 2x2 FTO is the simpler counterpart to the standard FTO. Print Settings: (Using the provided print profile is recommended) Material: PLA is recomended (for caps you can also use PETG) Layer Height: 0.12mm Infill: 15% (Gyroid) Supports: NO (for stickerless version), YES (for monocolor [center_fixed] and tiled version [center_fixed, center_movable]) Brim: Recommended for small parts (center_bonds, core_bonds, tip_bonds) Wall Loops (Perimeters): 3 for the small parts (center_bonds, core_bonds, tip_bonds) Performance Notes: The puzzle turns smoothly. While it may feel a little loose, it does not pop. Assembly & Post-Processing Tips: Brims and supports: Clean the parts thoroughly after 3D printing. Make sure no leftover brim or support material is sticking out, as this can negatively affect the movement of the puzzle. Lubrication: For smoother turning, you can apply lubricant to the internal mechanism (this step is optional). Assembly instructions: Step 1: Insert the smaller end of the tip_bond into the edge. Step 2: Place a tip on top of the inserted tip_bond. Repeat Steps 1 and 2 six times Step 3: Pass the smaller end of the center_bond through the center_fixed. Repeat this st