3D Printed Raspberry Pi 4 Case with Fan Mount

The Raspberry Pi 4 runs noticeably hot under sustained load — thermal throttling begins above 80 °C. This printable case adds a 30 mm fan on the top lid that pulls air over the SoC, keeping temps under 55 °C even during heavy use. The two-part snap design opens without tools for easy access. GPIO header, camera ribbon slot, and all ports are accessible through precise cutouts.

What You’ll Need

• FDM printer (Ender 3 or similar) + PLA filament — ~70 g
• Raspberry Pi 4 (any RAM variant)
• 30 mm × 30 mm 5 V DC fan
• 4 × M2.5 × 10 mm screws and nuts (for Pi mounting)
• 4 × M2 × 10 mm screws (for fan mounting)
• 2-pin JST connector or solder for fan wires
• Ultimaker Cura for slicing

Step-by-Step Instructions

1. Download or design the case: Search Printables for “Raspberry Pi 4 case fan” or model your own in FreeCAD. Ensure the design has: 85.6 × 56.5 mm mounting hole pattern, 30 mm fan hole in the lid, and all port cutouts (USB-A ×4, USB-C power, HDMI ×2, 3.5 mm audio, Ethernet, GPIO slot).
2. Slice settings: 0.2 mm layer height, 30% gyroid infill, 3 walls, no supports if the overhangs are 45° or less. Print base and lid separately.
3. Print and post-process: Clean any stringing with a heat gun set to low. Test-fit M2.5 nuts in the hex recesses — heat-set inserts give a stronger hold if your slicer supports the recess geometry.
4. Mount the Pi: Place Pi into the base. Secure with M2.5 screws through the Pi’s mounting holes into printed standoffs or captured nuts.
5. Wire the fan: Connect the fan’s 5 V and GND wires to GPIO pin 4 (5 V) and pin 6 (GND). This runs the fan at full speed constantly. For PWM control, use GPIO pin 18 and a transistor.
6. Snap the lid: Press the lid onto the base. The snap tabs should audibly click into place. Fan should be blowing INTO the case (sticker side up = blowing down).

Safety Notes

• Never power the Pi while the board is loose on a conductive surface — always in the case or on a non-conductive mat.
• Ensure the fan spins freely before closing the case — a stalled fan can draw excess current.

Tips & Troubleshooting

• Monitor temperature with: watch -n 2 vcgencmd measure_temp
• If the case runs hot even with the fan, check the fan is positioned to exhaust over the SoC (SOC is the large square chip near centre of board).
• PETG is better than PLA for this project if the Pi sits in a warm environment — PETG has a higher heat deflection temperature.