I recently finished building my 9U mini rack and populated it with networking and compute equipment.

Rack Construction

The rack itself is constructed from 20x20 aluminum extrusions and off-the-shelf rack rails. This approach was quite cost-effective, with the total cost coming in at under €65:

• €31 for the machined extrusions
• ~€20 for the rack rails and cage nuts
• ~€2–3 for miscellaneous hardware
• ~€10 for the panels

The design uses blind joints, the method of choice for Voron Design printer frames. If you haven't seen one being assembled before, here are two short videos:

• Voron Frame Assembly Video 1
• Voron Frame Assembly Video 2

Parts List

• 8x 260mm extrusions (both ends tapped M5)
• 4x 445mm extrusions (clearance drilled on both ends)
• 4x 9U rack rails
• 16x M5x16 BHCS
• 6x M5 T-nuts
• 6x M5x6 BHCS
• 2x 274mm x 418mm panels
• 1x 274mm x 274mm panel

The uprights can be easily adjusted to accommodate different rail lengths using the formula: 44mm + (44.5mm * U), rounded up. Depth can be adjusted by changing 4 of the 260mm extrusions to the desired lengths.

Populated

This is how I filled it:

Front Configuration

• Raspberry Pi 4 (8GB), 2x JetKVM (pending delivery) in a LabStack Mini
• White-label managed switch (8x 2.5G, 1x SFP+)
• Asus NUC 14 Pro (NUC14RVH, Intel Core Ultra 5 125H, 96GB RAM, 4TB local storage, 1TB shared storage)
• Intel NUC 13 Pro (NUC13ANHI7, Intel i7-1360P, 64GB RAM, 4TB local storage, 1TB shared storage)
• Intel NUC 13 Pro (NUC13ANHI7, Intel i7-1360P, 64GB RAM, 4TB local storage, 1TB shared storage)

Rear Configuration

• 4x 80mm fans
• 2U blanking plates
• 2x 4-port Schuko PDU
• 1x tray for power adapters

Networking & Cooling

Interconnect is handled via Thunderbolt Networking, using the Thunderbolt 4 ports on the devices in a ring topology. This network handles migration, replication, and intra-cluster application traffic using VXLAN. External connectivity is provided via 2.5G Ethernet and the SFP+ uplink.

Airflow follows a front-to-back configuration, as the NUCs exhaust towards the rear. The PWM-controlled fans help maintain low noise levels.

Future Upgrades

• Replacing the PWM fan controller with a temperature-controlled system. Planning to build one using an ESP32 and a boost converter, controlling PWM fans is rather trivial.
• Relocating the networking to the back of the enclosure and upgrading it to include more SFP+ ports.
• Adding a 2U flash/SSD-based NAS with Thunderbolt and SFP+ connectivity. Currently researching hardware but haven’t found the right fit yet.