Rack Snap-in system (8 bay Raspberry Pi Cluster)

A snap‑in rack module that lets you mount up to 8 devices (most commonly Raspberry Pi 4/5) into a 10‑inch rack, and with an easy “push‑to‑lock / pull‑to‑release” workflow.

This is part of the KWS Rack system

if you’re building a compact homelab rack

make sure to check the main KWS Rack model and the rest of the ecosystem modules.

 

 

 

Why this module exists

I wanted a clean and fast way to mount a small “cluster” of things in a 10" rack:

• 8 snap‑in slots (this module holds up to 8 devices like Raspberry Pis - while other modules hold up to 7)
• Each slot takes a Snap‑In Carrier: insert, click, done
• Carriers have two side handles that act like springs - push them in, the carrier locks; squeeze/pull to release
• Designed to be remix‑friendly: I’m including a blank carrier STEP so you can design mounts for your own devices and share them in print profiles

 

Build Options

Option 1 - Front‑Only Module (fits all 10 inch racks)

Best if you only need a clean snap‑in rack front and you’ll power things elsewhere.

Print:

• Front Slot Panel (non‑expandable) (no shelf connection holes)
• Your chosen Snap‑In Carriers + Snap Handles

Note: I still recommend printing the expandable front panel if you think you might upgrade to Option 2 later.

 

Option 2 - Power + Cooling Extension (full build) - for KWS Rack ONLY

Best if you want this module to be a self‑contained cluster bay with tidy power distribution and active cooling.

Print (fits KWS Rack only):

• Front Slot Panel (expandable)
• Extension Shelf (supports a Mean Well power brick + optional power distribution blocks)
• Rear Power + Fan Panel
• Fan Grill Assembly (x1):
  • Fan Grill Spacer (keeps the net offset from the fan blades)
  • Fan Grill Net (3D printed mesh)
  • Fan Grill Frame (mounts the net/spacer to the rear panel)
• Your chosen Snap‑In Carriers + Snap Handles

What it holds / supports (Option 2):

• A Mean Well power brick mounted to the shelf
• A Mean Well PDU held in place by the rear panel
• 4× 40mm fans above the PDU for exhaust/airflow
• Optional: 3× PTFIX power distributors mounted to the shelf

 

Bill of Materials

Required

• M4×6mm screws ×4 + M4 nuts ×4 (to mount the Extension Shelf to the Front Slot Panel (expandable))
• M4 screws ×2 (20–24mm length) (to mount the Mean Well to the PDU / power assembly as designed)

Optional

• 0.91" OLED screens ×4 (for the optional 1/3U OLED Display Strip add‑on panel)
• 40mm fans ×4 (if you want active cooling on the back plate)
• Mean Well PDU (model: LRS-200, 5V)
• PTFIX power distributors ×2 (optional)
• Fan screws (often included with fans, otherwise M3 depending on the fan type)
• Cable connectors / ferrules / terminals (depending on how you wire your Mean Well & PTFIX)

 

Printing Recommendations

Material: PETG is recommended for the Snap Handles (and ideally the carriers) because the snap mechanism benefits from a bit of elasticity.

 

Assembly Overview

1) Assemble each Snap‑In Carrier

1. Mount the device into the Device Mount Insert (method differs per device carrier)
2. Snap the two handles into the carrier - they should click in firmly

2) Insert carriers into the Front Slot Panel

• Slide the carrier in from the front
• Push until it clicks
• To remove: squeeze/pull the handles

 

3) Option 2 only - build the Power + Cooling Extension

1. Attach Front Slot Panel (expandable) to the Extension Shelf using 4× M4×6mm screws + 4× M4 nuts
2. Mount the Mean Well power brick to the shelf
3. Install optional PTFIX blocks (x3)
4. Attach the Rear Power + Fan Panel
5. Mount 4× 40mm fans
6. Install the Fan Grill Assembly (Spacer + Net + Frame)

 

 

Remixing & Community Expansion (please add yours!)

I’m intentionally treating this as a mini snap‑in ecosystem.

• I’m including a blank carrier STEP so you can create mounts for new devices
• If you design a new carrier: please share it in your print profile (and ideally upload the STL/STEP in your remix) so the system grows into a library of snap‑ins

 

Ideas for the community:

• NVMe/USB enclosures
• Zigbee / Thread dongles
• SBCs (Orange Pi / Rock Pi / etc.)
• Audio DACs, small amps, KVMs

all the community remixes can be found HERE

 

Designed for the KWS Rack ecosystem

This module is part of the KWS Rack v.2 modular ecosystem

Check out the full rack system here

 

 

 

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