I decided to move my octoprint screen form the printer front panel ( https://www.thingiverse.com/thing:3863115 ) to external case. This allows for lots of space for active cooling of your raspberry pi 4, the temperature of raspberry pi stays around 60'C even when printing and wirelessly streaming Full HD camera video. I wanted the usb connectors to be on the left, it forced the screen to be upside down. You will find the how to rotate at the bottom of the description.

Parts needed:

• Gpio stacking header https://www.amazon.com/Adafruit-Accessories-GPIO-Stacking-Header/dp/B00TW0W9HQ I didn't have any so I used random 2.54 goldpin ports to extend the gpio.
• Stepdown converter: https://www.amazon.co.uk/POLOLU-2865-Step-Down-Voltage-Regulator-D24V60F5/dp/B01IMERSI2
• Radiator: https://www.amazon.co.uk/MakerHawk-Raspberry-Aluminium-Radiation-Protection/dp/B07M7M53LT/ref=sr_1_12?keywords=raspberry+pi+4+radiator&qid=1583187633&s=lighting&sr=8-12
• Some kind of power port and a plug, the hole is 8mm wide.

The cable that goes from step down converter to raspberry pi needs to be quite thick. I got under voltage warnings when using a bjc connectors with thin wires. I connected the 5V to Pin 2 and GND to pin 6, and added a small capacitor just for extra stability. No more warnings since.

The case don't require any screws. The snap-in fittings were beefed up to withstand a little abuse. The best way to put everything together is to:

1. Install the screen back plate into the frame.
2. Install the screen into the screen back plate.
3. Install all 3 parts to the front part of the box, the screen GPIO connector needs to be on the side without ventilation!
4. Slowly install the raspberry pi on top of the screen.

25.06.2021 Changed Fron_box.stl to withstand more side force applied to usb ports.