This is an ongoing project and I am still sketching, iterating, and printing so at some point I may need to go back and rework this whole thing!

This project wouldn’t have been possible without the support of the folks in the Reddit SFF community who were an excellent resource to learn from and acted as a sounding board for ideas. The idea of small form factor computers isn’t a new one, and there has been a community on the internet working together and sharing ideas for the better part of two decades. For most SFF hobbyists the goal is to squeeze as much processing power into as small of an enclosure as possible without catching on fire.

PC case design is an interesting and unique in that as a designer you’re not just designing a shell for users to put their parts into, you’re often creating a platform for the user to express themselves with. Many users take pride in systems they’ve built themselves and their choice in case is really important as it’s the most outward facing part.

Small form factor computers are broadly defined by being under 20 liters in total volume with some market examples going as small as 4 liters. The smaller you go the more limited and specific a user’s part selection becomes, with the smallest of cases not even allowing for a GPU. Generally, there are three main case layouts within SFF PCs:

Sandwich Layout

Pros:

• Having most of the components stacked in the same direction allows for a small footprint, meaning that the smallest SFF PCs are usually this layout.

• Most setups allow for full length GPUs.

• CPU/Mobo side is often thermally isolated from GPU side.

Cons:

• Airflow is difficult to manage as it is often obstructed by components and cables.

• Often requires a power supply extension.

• CPU coolers are very limited in height, so for higher performance systems water cooling is a must.

Power Supply Type: Can the case use a standard ATX PSU? If not then the user needs to install a SFX PSU. In some cases an even smaller, more specialized PSU must be installed to power the components. Generally, the smaller you go the less powerful the PSU.

CPU Cooling Solution: If the user wants to air cool their system then the case needs to allow for a decent amount of cooler height clearance. If they want to allow for water cooling then they need to give the user a place to mount radiators that is above the height of the pump.

GPU Dimensions: Does the user want to install a full length GPU? If so the case will need to be long enough in a dimension to allow the card to fit. PCI-E riser cables are often utilized in Sandwich and Vertical Stacked cases to make the GPU orientation more flexible.

Motherboard Dimensions: Most SFF PCs use a standard 170mm Mini ITX motherboard layout. These motherboards have most of the core features that a larger M-ATX or Full ATX board would have, with fewer slots and stricter component clearances.

The market for SFF PC cases and parts has seen an explosion in popularity in the last few years. This is evidenced by many more major hardware and case manufacturers producing SFF oriented cases and parts, and the growth in popularity of SFF builds on YouTube channels like OptimumTech, LinusTechTips, and HardwareCanucks. Historically most SFF hardware has come at a premium due to the nicheness of the audience, but as more parts and cases are produced they become more affordable.

In terms of production and market positioning my goal for this case is to be affordable to buy or free to produce by making all of the panels fully 3D printable and the hardware easily sourced from places like McMaster Carr.

From a feature set and function perspective I had a few main goals:

1. Make a case small and maneuverable enough to move from a desk to a home theater setup without the need for excessive adaptation and modification.

2. Air cooling for the sake of reliability and low maintenance, while remaining quiet under load. Some of the main uses for this PC will be for running Rhino CAD, KeyShot renders, and gaming. This will max out the CPU and GPU so the airflow and cooling must be well optimized.

3. Fit an ITX+ sized GPU with enough clearance for unrestricted airflow. I mainly game at 1080p at high framerates at my desk, and 1080p 60fps at my home theater, so an ITX+ GPU is sufficient for my needs.

Sketching and Prototyping

The 2D sketch exploration for this project was focused on user-facing convenience and movement features. Form factors were based roughly off of existing products, but when working around such specific size constraints the limits of 2D sketching were quickly reached. I settled on a few ideas to carry forward to the next phase.

Once a few options for form factors were established I began working in Rhino exploring how they could fit around the components. By jumping around from Rhino to foamcore to 3D printed parts I was able to quickly iterate and explore the real world scale of the options to get an idea of how the thermals were affected by changing the airflow.

I settled on a format that drew on some of the features of existing commercial products, but allowed me to specifically address compatibilities that I would need for my system.

Hover over the images for more info.

High Power Air Cooling Potential

The interior of the Compromise Cube can accommodate CPU coolers up 140mm in height. This allows an 8 core Ryzen 7 3700X to max at 72° C, and a 12 core Ryzen 9 3900X to max at 81° C during Cinebench R23.

Optimal Airflow Setup

In its current format a single NF-F12 Chromax static pressure optimized fan pulls air into the vents, across the motherboard, through the NH-C14S, and exhausts it out the top. On the GPU side it pulls air into the vents to feed the RTX 2070 OC’s fans. This keeps the acoustics of the system in check even under load. With an overclock to 1950 MHz the GPU never gets above 72° C.

Swappable Vent Panels

The intake inserts can be swapped between vented and solid panels. This allows the intake setup to be changed depending on user’s cooling needs. Currently, the panels are held on with small adhesive pads, but going forward I want to to a version that uses magnets. I also want to try to do some panels that have less visible vents but maintain the current cooling capacity.

Two Chamber Design

The upper and lower chambers are thermally isolated with separate intakes and exhausts. The PSU in the lower chamber connects to components in the upper chamber through holes in the floor. The space in the lower chamber allows for cable management and room for a 2.5” SSD. The front I/O and power switch are on the lower front panel.

Flat Packable, 3D Printable, & Easily Sourced

For the purpose of distribution I wanted to make this accessible to anyone with a 3D printer. The panels lay flat to aid with ease of shipping, and being PETG are light weight. The hardware necessary for construction is available on McMaster Carr. The 4/40x1/2 flat socket cap screws can be found here and the accompanying nuts here. The 3D printing files are available here.

This is an ongoing project and I am still sketching, iterating, and printing so at some point I may need to go back and rework this whole thing! Moving forward I want to continue exploring how much I power I can squeeze into this case. I recently upgraded CPUs from a 8 core Ryzen 3700X to a 12 core Ryzen 3900X and I think that I am pushing up against the ceiling of the NH-C14S’s cooling abilities. I am interested to see if water cooling could get better temps to push higher clocks on the new CPU. I also want to do more iterations of side panels to explore more visually discrete options for intake and exhaust vents while keeping the same simple panel construction.

I am open to any interest or discussion on this project and I would love to hear from you! If you have questions or comments shoot me an email at senuckels@gmail.com

Thank You!

back to work