The new Raspberry Pi 4 consumes draws more power and generates more heat than before. But the official Pi4 case does not come with a cooling fan nor vents for ventilation.
This results in thermal throttling after a few minutes of moderate workload.

I have analysed thermal images of Pi4s under load.
With the relevant information in hand, I made a decent case with 40mm fans to help alleviate the problem.

NOTE:
A heatsink is beneficial.
But use one of max height 5mm.
Slightly taller heatsinks may fit, but not guaranteed.

IMPORTANT:

1. Use support blocker on Cura along the vent holes at the back, "Raspberry Pi 4" lettering and Raspberry logo.
2. The ports section of the case is recessed 1mm to allow access to the HDMI and USB-C ports. This section "might" need supports. Check preview on Cura.
3. Use 4Gx6mm (x4) screws to mount Pi 4 to case bottom piece.
4. Use M3 bolts and nuts to mount 40mm fan to case top.
5. Use 4Gx6mm (x4) screws to mount case top to case bottom.

Approximate Print time

• 8 hours for case bottom piece
• 2 hours for case top piece

Feel free to contact!

Happy Printing

Sumit

Update:1
The cutouts for the HDMI ports were misaligned and undersized in old STL file.
Old STL file hence deleted and replaced with new STL file.
19/09/2019

Update:2
The vent holes on the back of the unit has been resized and realigned.
New vents added beside the USB and Ethernet ports.
1/10/2019