Space Invaders – Modular Pixel Art

Backstory: 

After releasing my modular TETRIS project and still riding the nostalgia wave, I wanted to create a new pixel-art challenge: three iconic Space Invaders you can assemble, customize, and stick onto any metal surface.

Concept: 

You can print one or all three invaders. Each one is made of modular pixels that snap into place with a quarter-turn bearing system, while the underlying structure can be magnetized to stick to metal surfaces. Change individual pixels, mix colors, or print a single set of pixels and swap structures (Squid, Crab, or Octopus) — total freedom. 

How it Works: 

Each invader consists of two printed parts: 

• pixel: the colored visible surface. 

  • squid: 2 eye pixels + 36 body pixels 

  • crab:2 eye pixels + 46 body pixels 

  • octopus: 4 eye pixels + 60 body pixels 

• STRUCTURE: the structural layer. 

  • squid: 4 magnets 

  • crab: 6 magnets 

  • octopus: 8 magnets 

Featuring several print-in-place bearings and slots for cylindrical magnets (Ø10 × max 4 mm). 

Note: These numbers represent the maximum number of magnet slots. 
At first I wasn't sure how many magnets would be needed to support the structure and pixels, so I added several possible positions. It also works with fewer magnets, so you can choose how many to use and where to place them. 

Once printed, the bearings rotate freely after loosening them with the included tool. Each bearing receives a pixel secured with a quarter-turn screw action. 

Two small TOOLS are provided: 

• tool_1: to free the bearing if it’s too tight after printing. 

• tool_2: clips into the first tool to create a compact screwdriver for assembling pixels onto the structure. 

Note: After tightening hundreds of bearings during testing, I noticed slight deformation on tool_2. This can happen if a bearing isn’t fully freed before assembly, or if the bridge under certain pixel parts wasn’t printed cleanly. For convenience, you may want to print two copies of tool_2. 

Additional Materials: 

• Magnets Ø 10×3 mm (max 4mm)

Technical Specifications: 

• Printer used: Prusa Core one 

• Nozzle: HF 0.4 mm (extrusion width: 0.45 mm) 

• Filaments used:  

  • Polymaker Polyterra PLA: for the colorful tops (nice matte finish) 

  • Polymaker Poylite PETG: for the structures and tools 

Printing Instructions: 

pixel (color – PLA) 

• Layer height: 0.15 mm (first: 0.2 mm) 

• 3 perimeters | 5 bottom layers (1 mm) | 5 top layers (1mm) 

• Infill: 15% Gyroid 

• Ironing: ON 

• Scarf joint placement: Everywhere 

• Scarf joint around entire perimeter: ON 

STRUCTURE: squid – crab – octopus (transparent – PETG) 

Personnaly, I use translucide filament for more discretion. 

• Layer height: 0.15 mm (first: 0.2 mm) 

• 3 perimeters | no bottom/top layers 

• Infill: 0%  

TOOLS: tools_1 & tools_2 (PETG) 

• Layer height: 0.15 mm (first: 0.2 mm) 

• 3 perimeters | 5 bottom layers (1 mm) | 5 top layers (1mm) 

• Infill: 15% Gyroid 

Assembly Instructions: 

1. Use the Bearing release tool if needed, loosen and activate the bearing’s motion. 

2. Insert 10mm cylindrical magnet into the available slots (check polarity — all magnets should face the same way). 

3. Attach each pixel to the STRUCTURE using the printed screwdriver. A ¼-turn clockwise locks it in place. 

4. Enjoy customizing your pixel art! I started with the “classic” designs, but feel free to get creative and invent your own colour patterns. 

Note: A full step-by-step assembly video is available.