Designed with one goal in mind: build the smallest possible 4-bay NAS.

This compact, vertically stacked system is powered by a Raspberry Pi 4 Model B and takes design inspiration from the Xbox Series X to maximize space efficiency and airflow. 

Supports up to 4× 2.5” SATA drives via USB 3.0, all powered from a single 12V input with onboard step-down conversion. The vertical layout enables efficient cooling using an 80mm fan, while keeping the footprint minimal.

Fully 3D printable, modular, and built using off-the-shelf components.

Key Specs

* Smallest form factor target for 4× 2.5” drives

* Raspberry Pi 4 (4GB recommended) all the pis can be fitted (Raspberry Pi 1B+, 2B, 3B, 3B+, 4B, and 5) but you have to use low profile heatsink

* USB 3.0 → SATA storage (shared bandwidth)

* Gigabit Ethernet

* 12V DC input + 5V buck converter

* Active cooling (80mm fan ≤25mm thick)

* Magnetic vent cover

* Standard M2/M3 hardware

Use Cases 

NAS, Media Server, Backup, Homelab, Self-hosting

Minimum size. Maximum storage density. Full control.

Parts List (BOM)

Core Components

* Raspberry Pi 4 Model B (4GB recommended)

[https://rpishop.cz/raspberry-pi-4/1598-raspberry-pi-4-model-b-4gb-ram.html?currency=EUR](https://rpishop.cz/raspberry-pi-4/1598-raspberry-pi-4-model-b-4gb-ram.html?currency=EUR)

* Copper heatsink (4mm, full base cooling) 

[https://a.aliexpress.com/_EwsMUGI](https://a.aliexpress.com/_EwsMUGI) 

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Storage

* 4× SATA to USB 3.0 adapters (2.5” drives, up to 6Gbps)

[https://a.aliexpress.com/_EwDeBgS](https://a.aliexpress.com/_EwDeBgS)

* 2.5” HDD/SSD (up to 4TB per drive, optional) (example: Western Digital Blue or similar)

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Power System

* 12V 5A power supply (5.5×2.1mm)

[https://a.aliexpress.com/_EulLgl0](https://a.aliexpress.com/_EulLgl0)

* DC barrel jack (panel mount, DC-022B)

[https://a.aliexpress.com/_Exzr9h4](https://a.aliexpress.com/_Exzr9h4)

* DC-DC step-down converter (12V → 5V, ≥8A)

[https://a.aliexpress.com/_Eyd1Tbo](https://a.aliexpress.com/_Eyd1Tbo)

* USB-C power cable (for Raspberry Pi)

[https://a.aliexpress.com/_EHUloj8](https://a.aliexpress.com/_EHUloj8)

* SPST rocker switch (ON/OFF, panel mount)

[https://a.aliexpress.com/_Ev1bRuK](https://a.aliexpress.com/_Ev1bRuK)

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Connectivity

* USB 3.0 hub (4-port, compact)

[https://a.aliexpress.com/_EIH5BEm](https://a.aliexpress.com/_EIH5BEm)

* RJ45 Ethernet extension cable (panel mount)

[https://a.aliexpress.com/_EuB6phy](https://a.aliexpress.com/_EuB6phy)

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Cooling

* 80mm fan (80×80×25mm max height) 

[https://www.amazon.com/ARCTIC-P8-80-Pressure-Optimised-Noise-Level/dp/B07XL9QJHF](https://www.amazon.com/ARCTIC-P8-80-Pressure-Optimised-Noise-Level/dp/B07XL9QJHF) 

* JST connector cables (for fan wiring) 

[https://a.aliexpress.com/_EzmS3ui](https://a.aliexpress.com/_EzmS3ui)

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Mechanical & Assembly

* 6×2 mm magnets (for magnetic vent cover)

[https://a.aliexpress.com/_EHyRunG](https://a.aliexpress.com/_EHyRunG)

* Anti-slip pads / rubber feet

[https://a.aliexpress.com/_EHeWjCi](https://a.aliexpress.com/_EHeWjCi)

* M3 screws (for HDD mounting)

* M2 + M3 screws (general assembly)

* Heat-set inserts (M2 + M3)

* Wires / cables for internal connections

⸻

Printing * PLA or PETG filament

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Notes

* Raspberry Pi 4 (4GB) is sufficient

* Fan height must be ≤25mm

* SATA drives connect via USB (shared bandwidth)

* Basic soldering required

* You have to cut the SATA to USB cables and solder them back to the board again to fit them in the case