Concept The Cube: ~16L steel mATX case

Clamor

Minimal Tinkerer
Original poster
New User
Jun 27, 2020
3
0
I. GOALS

I was searching for a good, small and cheap mATX case for my portable PC build. And...I didn't found case till now that accommodates all my needs. Goals of this case are:
  1. Smallest volume possible for mATX case;
  2. Simplicity and cheapness in manufacturing;
  3. Compatibility with standard parts;
  4. Durability and high mobility;
  5. Ability to use powerful CPU and GPU without overheating.

II. SPECIFICATIONS


Technical:
Dimensions (H x W x D)​
255mm x 255mm x 255mm​
Volume​
~16.58L​
Material​
Steel​
Weight​
~4.5kg​

Compatibility:
Motherboard support​
mATX or smaller (245mm x 245mm)​
PSU support​
ATX or smaller (length may vary)​
CPU radiator support​
Up to 145mm​
GPU support​
Height: Up to 155mm​
Length: Up to 245mm​
Storage support​
2.5": four drives on the bottom via included bracket​
Cooling support​
Two 80mm fans on back panel.​

III. STATUS & ACHIEVEMENTS


The Cube's frame and base plate are made of 2mm steel. Which should give good rigidness to all construction. Frames are the most complicated parts. It is really a challenge to manufacture them, so I made 3 models, which include bending and welding in different proportions.


Drive brackets have four mounting spots for 2.5" drivers. Most of case parts are made by simple cutting and involve no additional work. All external panels have dust filters. Case can be manually assembled and disassembled. Front and side panels are held by magnets, while other parts are assembled with screws and bolts. This fact allows to create DIY kits with volume much smaller than actual case and therefore have less shipment cost.

The Cube is one of few cases where motherboard lays flat, which gives less tension due to massive cooler or GPU. Case features 2 horizontal divisions: bottom for PSU and drive bracket, top for motherboard, GPU and CPU with it’s cooler.

Button division: PSU has it's own fresh air circulation (bottom -> back), drive bracket is cooled by 80mm fan with airflow back -> front. There is a big chunk of free space behind PSU which allows to use non-modular PSU and have good cable management. Length of PSU isn't strictly limited and limiter bracket can be removed.

Top division is divided into 2 chambers with GPU, so they both have separate airflow. GPU takes fresh air from left side and moves it through front and back panels. CPU chamber allows radiator with height ~140-145mm. Air is taken from back panel with 80mm fan.

This planning allows using of powerful CPU and GPU with barely no overheating.

IV. COMPROMISES


Such a small case of course has some compromises in design. First of all is absence of 3.5" and 5.25" mounting points. There might be space for 3.5" drive, but personally I find this form-factors outdated. We have to move to 2.5" and, of course, M2 form-factors. Next is lack of water cooling radiator. This might be improved, but water cooling is frequently overestimated and pricy comparing with air cooled radiators. Case has no separate I/O. All panels are clean and have only perforation on them. Only back panel has all connections on it, including power button.
 

Valantar

Shrink Way Wielder
Jan 20, 2018
1,890
1,822
2mm steel? Isn't that going to be absolutely ridiculously heavy? And can't that safely be reduced to at least ¼ without really losing any rigidity? Steel isn't soft like luminium after all.

Beyond that the design looks good, though IMO cube layouts aren't the best in terms of space utilization - unless you are planning to stuff it full of 3.5" HDDs and the like of course.
 
Last edited:
  • Like
Reactions: Clamor

Clamor

Minimal Tinkerer
Original poster
New User
Jun 27, 2020
3
0
2mm steel? Isn't that going to be absolutely ridiculously heavy? And can't that safely be reduced to at least ¼ without really losing any rigidity? Steel isn't soft like luminium after all.
Here I agree, initially I planned to use full aluminium, but after some research steel looked so much more simple in work, and I decided to switch material. 2mm steel is used only for frames and base plate. Else is made of 1mm (or even thinner) steel or maybe aluminium.

IMO cube layouts aren't the best in terms of space utilization
Smallest motherboard form-factor for me is mATX, mini-ITX boards currently can't give me functionality I'd like to have, require liquid cooling with powerful hardware and cases have restrictions with sizes and non-standart parts. And I couldn't find small enough case with horizontal motherboard mounting.

P. S. Thanks for your reply.
 

Valantar

Shrink Way Wielder
Jan 20, 2018
1,890
1,822
Here I agree, initially I planned to use full aluminium, but after some research steel looked so much more simple in work, and I decided to switch material. 2mm steel is used only for frames and base plate. Else is made of 1mm (or even thinner) steel or maybe aluminium.

Smallest motherboard form-factor for me is mATX, mini-ITX boards currently can't give me functionality I'd like to have, require liquid cooling with powerful hardware and cases have restrictions with sizes and non-standart parts. And I couldn't find small enough case with horizontal motherboard mounting.

P. S. Thanks for your reply.
No problem!

2mm steel is still way too thick though. You aren't building something for use on a workshop floor here, right? For comparison, the Cerberus uses .9mm (20 gauge) steel for its frame. Thicker steel will make bends far more difficult, it will drive up the weight of the case dramatically, and it will increase cost. If you want this to be even somewhat portable I would reduce the thickness of the steel frame (though obviously you should do some modelling around this - I'm not a mechanical engineer).

As for your mATX requirement, that is understandable, but this design still has some issues that need resolving to varying degrees.
- No space whatsoever for bringing cables up from your PSU basement. The 255x255x255 size means a few mm of clearance on all sides of the motherboard - there's no way you're getting a 24-pin through that. That tiny cutout at the front isn't sufficient.
- Poor utilization of space in the basement.
-Relatively limited GPU support compared to the overall volume of the case.

One possible solution: ditch the basement entirely, extend the case a bit towards the front, move to SFX (-L) PSU support either overhanging the front of the motherboard (above the RAM) or rotated perpendicular to the motherboard, just in front of the RAM. That would allow you to mount your drive cages in the front of the case next to the PSU if your GPU and other AICs aren't too long, while reducing the complexity of the build by quite a lot and still keeping a relatively small overall footprint with the motherboard horizontal.

If not, you're going to need to extend the case towards the front by at least 10mm to allow cables to pass through.
 

Clamor

Minimal Tinkerer
Original poster
New User
Jun 27, 2020
3
0
2mm steel is still way too thick though
As I told before, I agree with this statement, moreover, I have an idea how to decrease amount of frame metal and yes, decrease thickness to 1mm. Currently, I don't have enough time to rebuild and recalculate all measurements.

- No space whatsoever for bringing cables up from your PSU basement. The 255x255x255 size means a few mm of clearance on all sides of the motherboard - there's no way you're getting a 24-pin through that. That tiny cutout at the front isn't sufficient.
If motherboard is precisely 245mm wide, than gap will be 6mm, if less - 16 mm. If I adjust thickness I might increase gap to 10mm.

One possible solution
Actually you propose to recreate Cerberus case, only difference is that it has legs on side and lays horizontally.
 

Valantar

Shrink Way Wielder
Jan 20, 2018
1,890
1,822
As I told before, I agree with this statement, moreover, I have an idea how to decrease amount of frame metal and yes, decrease thickness to 1mm. Currently, I don't have enough time to rebuild and recalculate all measurements.

If motherboard is precisely 245mm wide, than gap will be 6mm, if less - 16 mm. If I adjust thickness I might increase gap to 10mm.

Actually you propose to recreate Cerberus case, only difference is that it has legs on side and lays horizontally.
Well, you might say that, but the Cerberus is quite a lot bigger - even bigger than your cube in terms of volume (319mm x 172mm x 358mm, 19.64 l). It does after all have a decent amount of space added all around for fan and radiator support, the top handle, etc. You've stated that your goal is the smallest possible mATX case and that you don't care much for radiator support, and your cooling design seems centered around a negative pressure, exhaust only setup with perforated panels all around for air ingress, so that way you could still keep quite a unique design even without the basement. The Cerberus also focuses on aesthetics with the solid front panel, window option, etc., while you are clearly going for a more pragmatically oriented frame+panels design.

It's good that you're working on reducing the frame thickness though, that will make this much more portable no matter what direction you go with the final design :)

For the cable cutouts, 16mm is definitely on the slim side if you're talking a somewhat high powered system - the cutout in your renders is definitely less than 100mm wide, so you'd need to pass your 24-pin, 1-2 8-pin EPS cables and however many PCIe power cables you need through there, plus SATA cables for your drives. That is going to get cramped very quickly. 6mm would only work with a very well managed ribbon-style cable harness with relatively few cables. Depending on your choice of side panel material and thickness, any excess cabling going through here would most likely cause the panel to bulge given that the cutout is near the middle of the panel. This is part of why I suggested ditching the basement design - it bypasses the need for space around the board for passing cables through altogether, bypassing this problem.

Extending either the front or left side of the case (when seen from the front in a typical horizontal "desktop" setup) to fit a vertically mounted SFX PSU would end up in a size of ~255mm x ~325mm x ~172mm*, 14.25 l compared to your current design: ~255mm x 255mm x 255mm, ~16.58 l. The 2 l difference can likely be attributed entirely to the removal of the unused space in front of the PSU and drive bracket. The same extension could also allow for mounting an SFX PSU along the top front of the case, overhanging the 24-pin and RAM, but leaving plenty of space below for cables, drives, etc. - though it might limit CPU cooler compatibility somewhat. A front mounted PSU of course needs an extension cable, but one mounted below the PCIe slots wouldn't. This would result in a surprisingly "traditional" layout, but a very space-optimized one, still leaving space for a compact 2.5" drive rack next to the PSU. There wouldn't be much space for stowing cables, but given the short cables of most SFX PSUs I don't see this being an issue.

*I used the width of the Cerberus as a guide for height here, your design may of course differ.

Of course there might be other arguments in favor of the cube layout (or you might just prefer it, which is obviously entirely up to you) - I'm just trying to give some feedback on what I am seeing in your design and presenting some suggestions to how some challenges might be overcome. One additional benefit of keeping your current design but extending it by ~15mm in the front to make for better cable management would be possibly allowing for the mounting of some slim 120mm intake fans in the top chamber, as that 80mm fan would otherwise be tackling a potentially big job (and not helping with GPU heat at all given its position).
 
  • Like
Reactions: khanate and Clamor