This is a LONG going project of mine, I had been wanting a better homelab setup for some time but didn't have the space or the money for rack servers, and as I am constantly moving yearly I didn't want to constantly be setting up multiple devices together and re-configuring them.

After seeing this post about a 3d printed mini server rack for Pi's. I loved it and seemed to resolve my issues, small enough to fit, cheaper then rack, modular and a single moveable unit although there where some design choices i wanted to change. I have since built MONTY, a simple fully contained mini network and server rack, this is being produced to answer questions and provide files from the post: https://www.reddit.com/r/homelab/comments/lqr1gy/monty_3d_printed_mini_rack/

NOTE

This is not a guide or instructions, other then the base rack it will be tricky to simply print these parts for your own. The rack will have brief hardware lists and design instructions however the units will not unless something needs to be explicitly explained as being odd. This is due to some parts being designed to accommodate my 3D printer inaccuracies. Also the components used here are uncommon formats and a miss-match, the TFT screens in all Units are annoyingly different dimensions and therefore likely wont fit yours. It's possible to use the CAD files to alter a unit to match your own TFT screen or boards though, I have no issue with people taking and altering the designs to fit their own needs and servers, just post them to /r/homelab for us to enjoy your designs.

ZIP file

The ZIP file contains all the FreeCAD files + unused/WIP designs, ALL STL's, brief documentation (MD) and any code required for parts of MONTY. This is due to the fact MONTY was created for personal use and not intentionally designed for others to use, therefore all these files are given as reference to create something based of monty or customise the files to meet your needs.

Design

Overall goal was to be a single contained unit, that was somewhat module for easy changes with minimal external dependencies. MONTY only requires 1 power plug and 1 Internet ethernet connection to function, all other services are internal such as Router, DNS, etc.

Size

The length/width is 7" to accommodate many devices including Intel NUC's for more power, any larger would become expensive and difficult to print. 1U height is 30mm again to comfortable accommodate Pi's and Intel NUC's. I wanted the design to use nuts rather then the nutless type design to prevent wearing them out over changes.

Unit

Each unit consists of three parts, Body, Frontplate and Backplate, the backplate slides into the body with no bolts, the front is mounted with at least 2 bolts and nuts. This design meant each unit required at minimum 2 bolts, the design has no roof as it didnt seem necessary and I didnt want to waste printing it. Each unit can be installed half way slide into the rack and bolted into the rails, this is bolted half way into the unit and front of the rack itself and slide the rest of the way in, where the ears are bolted to the front for extra support.

Rack

The rack uses T-slot aluminium extrusion as the base with corners joints and T-slot winged nuts for rack ear mounting and side mounting, the size being 7"x7"x50cm, Yes the mix in metrics is annoying. The width/height is fairly fixed but the height can be easily altered as nothing requires the 50cm, so a 30cm mini mini version easily possible.

Power

MONTY is powered by a 24v 24A switching PSU mounted on the side, with a DC-DC buck convertor to supply the correct power to each unit.

Cooling

The side cooling on the right side is a ESP8266 with a restful API server that controls the PWM pin on PST PWM fans. The microcontroller can controller all 5 PWM fans via 1 pin, the speed is controlled over the API by a service that queries influxDB to get the average temperature of the entire rack.

Dimensions

Total Size

Width: 7"
Length: 7"
Height: 46cm/50cm (-4cm due to frame)
Bolts consistent gap 32mm (2mm buffer for printer inaccuracies)

Unit Size

Width: 13.7cm (5.4")
Length: 17cm (6.6")
height: 3cm (1.18")

Note this is the Unit size not the internal useable size.

Rack Hardware

Hardware Required for Rack ONLY

V-Slot Linear Rail 2020 50cm X 4
- https://ooznest.co.uk/product/v-slot-linear-rail-20x20mm-cut-to-size/
- Note these can be ANY height, however may need to print custom 2020 fillers
V-Slot Linear Rail 2020 13.7cm X 8
- https://ooznest.co.uk/product/v-slot-linear-rail-20x20mm-cut-to-size/
3-way 2020 Series End Corner T Slot Bracket Aluminum Extrusion Connector X 8
- https://www.ebay.co.uk/itm/4x-3-way-2020-Series-End-Corner-T-Slot-Bracket-Aluminum-Extrusion-Connector-Set/383788662355?hash=item595b963e53:g:v4MAAOSwq1tfnVez
Drop in T-nuts 2020 M4 X (Height - 4cm) * 12
- https://www.ebay.co.uk/itm/M3-M4-M5-2020-Drop-In-Tee-nut-Hammer-T-Nut-Slot-6mm-20series-Extrusion-Profile/174346020777?hash=item2897d527a9:g:XHIAAOSwIXxf7grR
- The amount depends on the size of rack going for, 50cm is: (50-4) * 12 = 180
- This is because each column is filled every 3cm for 3 sides on all 4 columns
M4 Countersunk Bolts 6mm X 32 https://www.ebay.co.uk/itm/M4-M5-M6-M8-A2-STAINLESS-COUNTERSUNK-SOCKET-SCREW-ALLEN-KEY-BOLTS-SCREWS-DIN7991/321229079336?hash=item4acabec328:g:Wp0AAOxyWmxSXEh-
- For the 3 way corner mounts, more are like needed for other components if going further

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