Designing a Custom Server Rack

Posted Feb 15, 2025

By scxrp

7 min read

Introduction

A server rack is incredibly useful—it turns a mess of computers and equipment into a neat and organized setup. At least, that’s what I’ve been trying to achieve over the past five years. Here’s my current setup:

My Racks Area

Close-Up View of my Server Rack

Warning: Be careful when screwing directly into the legs—it doesn’t hold up well.

Remaining VHB Tape from the Right Rack

Yes, both racks are held together with VHB tape… I’m not proud of it. But when you don’t have wood screws or a drill, you have to get creative. I did manage to screw the wheels in by hand, though.

I got the idea of making a rack with an IKEA Lack table while shopping at IKEA. Ironically, I only discovered the “IKEA Lack Hacks” community two months after building my first rack.

Nowadays, I mostly use them for storage rather than an actual server rack, but that needs to change. As you can imagine, this was not my first attempt, and once again, it failed because screwing into the IKEA Lack legs isn’t the greatest idea. So, I searched for a better solution and found this design along with these cage nuts. However, I wasn’t happy with their designs, so I decided to create my own from scratch.

Sketching the Concept ✏️

Before diving into CAD software, I started with hand-drawn sketches to visualize:

The overall structure of the rack.
Mounting points for screws, brackets, and rails.
How the cage nut adapter would be printed.

Here’s an early concept:

Initial Hand-Drawn Sketch

Materials & Tools Needed 🛠️

Tools	Materials
Writing Instruments and Paper	3D Filaments
Extrait de Normes 2022 (VSM)	M6x25 or M6x30 Screws
Measuring Tools (Ruler, Caliper)	M6 Cage Nuts
CAD Software	M6 Nuts
Google Machine	Rack Rails 18HE (18U)
3D Printer	IKEA Lack
Screwdriver	Optional: Casters
Optional: Drill	(requires 16 wood screws)

Designing & Prototyping 🖥️

Key Design Considerations:
✔ Sturdy adapters that support the equipment’s weight.
✔ Precise dimensions for mounting and cage nut adapters.
✔ Simplified assembly, avoiding too many different 3D-printed parts.
✔ Easily reproducible without requiring special tools.
✔ Visually appealing design—no ugly hacks.

I referenced the Adam Hall 19-inch rack rails datasheet for standard dimensions:

Note: Pay attention to the cotation on the bottom-left, the vertical one it’s a 9 not 6.

With this reference, I created the rack rail and cage nut adapter design while adhering to mechanical standards.

Here are the main sketches:

Main Sketch of the M6 Nut Adapter with Sequential Bridging Highlighted

Pro Tip: Design a Sequential Bridging instead of using supports when possible. Check out this video tutorial from Maker’s Muse.

Lack Leg Mounting Holes Sketch

Pro Tip: Use Linear Pattern instead of manually copying repeating elements.

And here’s the result:

ISO Section View of Lack Leg Adapter

M6 Cage Nut Adapter

View of the Sequential Bridging

Pro Tip: When applying a Fillet or Chamfer, select an edge, then right-click RMB → Select → choose either Equal Length/Radius Edges or Parallel Edges to automatically select matching edges, rather than manually selecting each one.

Prototypes & Adjustments

Below is the final assembly, along with key alignment and clearance checks:

Final assembly ISO View

Bottom Hole Alignment Check

Mid Hole Alignment Check

Top Hole Alignment Check

Clearance Check

Clearance Check for Radius

Note: The IKEA Lack uses an R2 radius for both the legs and the tabletop.

3D Printing Settings

Setting	Value/Parameter
Print Material	PETG
Layer Height	0.2 [mm]
Infill Density	15%
Infill Pattern	Cross Hatch
Wall Count	6
Top Layers Count	3
Bottom Layers Count	3
Support Structures	NO
Brim or Raft	NO

Note: PLA can also be used, but PETG offers better durability.

Here are the printed pieces:

Cage Nut Adapter

IKEA Lack Rack Rail Mount

Final Assembly & Installation 🔩

Attach the Leg Adapters using screws.
Stack and align the IKEA Lack tables.
Insert the Pins into the adapter holes to secure both tables.
Mount the Rack Rails onto the adapters.
Optionally, attach the Casters to the bottom table.

Assembly Mid-Section

Once assembled, it’s time to install the cage nut adapters:

Cage Nut Assembly Section View

Post-Assembly Adjustments & Fixes 🛠️

Once one side was fully assembled, I tried to install my Custom 19” Rack Mount for my audio interface, but I quickly encountered an issue:

The screw holes didn’t align—the rack spacing was insufficient because I didn’t check in the CAD file before launching the print jobs.

In the CAD file, you can measure it more accurately than in real life.

Insufficient Spacing

Center Distance Issue

Parallel Distance Alignment

It should be 465.12mm, but it is 454.602mm.

There are two ways to calculate the offset:

Center-to-Center Distance Measurement
\[465.120 - 454.602 = \mathbf{10.518} \text{ mm}\]
Parallel Distance Measurement
\[\begin{gather*} 464.100 - 9.50 = 454.60 \text{ mm} \\ 465.12 - 454.60 = \mathbf{10.52} \text{ mm} \\ \implies \boxed{10.518 \text{ mm} \approx 10.52 \text{ mm}} \end{gather*}\]

Now back to the drawing board:

Concept Fix

With the concept clear now, we can go back into CAD and design the two versions of the fix.

Solution 1: Symmetric Design

Requires x16 of the same piece.
Thinner screwing thickness → slightly weaker connection.
Shorter screws needed.

Solution 1 ISO View

Solution 2: Asymmetric Design

Requires x8 of each piece (x8 green and x8 blue).
Same thickness for screw mounting.
25mm or longer screws needed.
More careful assembly required (due to asymmetry).

Solution 2 ISO view

Solution 2 Top View

With the design fix in place, we can verify the spacing in the assembly view.

Solution 1 Verification

Assembly - Solution 1

Spacing - Solution 1

Center Distance - Solution 1

Solution 2 Verification

Assembly - Solution 2

Here’s how to assemble the multiple pieces. It does complicate the assembly slightly, but this reference image makes it clearer:

Assembly - Solution 2 ISO View

Spacing - Solution 2

Center Distance - Solution 2

\[465.122 \approx 465.120\]

There is only 2μm of difference between the two solutions. This difference is so small it can be considered zero.

Print Settings Adjustments

The print settings remain the same.
For Solution 1, the Wall Count increases from 6 to 7 for extra strength.

Here’s the completed server rack, featuring Solution 2 for added strength and stability:

Left Final Rack Assembly, Right Rack in its home

Cost Breakdown 💰

Item	Quantity	Unit Cost	Total Cost
3D Filaments	876.04 g	CHF 30.00/kg	CHF 26.28
Cage Nuts Adapter	270 g	CHF 30.00/kg	CHF 8.10
Pins	0.88 g	CHF 30.00/kg	CHF 0.85
(2nd Iteration Solution 1	765.04 g	CHF 30.00/kg	CHF 22.95)
2nd Iteration Solution 2	869.56 g	CHF 30.00/kg	CHF 26.09
Rack Rails	4	CHF 8.30	CHF 33.20
M6x25 or M6x30 Screws	min. 48, max 264	CHF 0.20	CHF 9.60 or CHF 52.80
M6 Nuts	min. 48, max 264	CHF 0.10	CHF 4.80 or CHF 26.40
M6 Cage Nuts	max. 216	CHF 0.60	CHF 129.60
IKEA Lack	2	CHF 9.95	CHF 19.90
Optional: Casters	4	CHF 2.4875	CHF 9.95
Optional: Woodscrews	16	CHF 0.15	CHF 2.40
Grand Total			CHF 293.52 or CHF 305.87
			CHF 195.60 or CHF 205.97

Explanation of Grand Total (1):

This total includes:

Total 3D Filaments (for the leg adapter and pins, solution 2 and with the first iteration)
Rack Rails
M6 Screws (max quantity)
M6 Nuts (min quantity)
M6 Cage Nuts
IKEA Lack
Optional: Add cost for casters and woodscrews.

Explanation of Grand Total (2):

This total includes:

Total 3D Filaments (for all parts, solution 2 and with the first iteration)
Rack Rails
M6 Screws (max quantity)
M6 Nuts (max quantity)
IKEA Lack
Optional: Add cost for casters and woodscrews.

Summary:

Grand Total (1): CHF 267.24 or CHF 278.59 (with casters and woodscrews without the first iteration)
Grand Total (2): CHF 167.34 or CHF 179.69 (with casters and woodscrews without the first iteration)

Conclusion 🎯

This was a rewarding project—yes, it was expensive, but now I have an awesome custom rack 😎.

If you’re attempting something similar, remember:

Research first—you might find existing solutions.
Stay objective—don’t let emotions rush your process.
Test measurements in CAD before printing.

homelab, hardware

CAD DIY

This post is licensed under CC BY 4.0 by the author.