Diesel Engine (ITX / SFF / Console) - COMPLETE!

Chris Howell

Trash Compacter
Original poster
Diesel Engine
Jan 17, 2016
44
122


Final Pics of the three consoles that I made in the end. Scroll to Page 4 for more Final Pics!






-------------------------------------------------------------

Hello everyone - Welcome to my build log for my current project, a scratch-built PC / Games Console designed for the living room.

About the Build:
After my previous project was primarily built from used components and recovered materials, I wanted to design and build something new and bespoke, with materials sourced for the purpose of the build. The move to smaller cases and living room PC's was also an area that I've found really interesting recently; lots of great designs from both big manufacturers and modders alike. So this is my attempt at the same challenge. I'll be including as much of the design process as I can, as well as the actual building (the design phases pre-build were very important!)

The Build Spec - Primary Requirements:
- Powerful enough to play games and compete with other living room systems
- Small enough to fit in a unit under the TV and not look out of place (i.e. flat)
- Quiet enough that it doesn't ruin the gaming/TV experience
- The design must represent a visual showcase, one that provides Diesel Engine with a unique and clear identity.

Secondary requirements:
- The software must boot directly into a gamepad-navigable state. No Keyboard + Mouse
- The case must not light up like the sun (this is very distracting when sitting under the TV)
- The case should not use or require any specialist or custom hardware
- Be able to support both 1080p and 4K system setups
- Not require an external power brick

Oh... (and this should go without saying) but the build shall not call itself an "ITX case" and still support full size ATX hardware and all the trimmings.


Concept Artwork

I drew and modelled a range of concept pieces first, free from any technical limitations, just so I could see where the art style was heading. Once the style was chosen, only then would I start to figure out if the design was technically feasible.


A similar half and half design to the Xbox One and PS4, which have matt and gloss surfaces.
A chunky hexagonal design in copper plate also sounded great




A very slim, long and simple design. Minimising or hiding all controls and inputs from the front



I explored some of the same shapes and colours in 3D, using Sketchup to create some quick and dirty mockups



By this point I was aware of the size of ITX and SFF components and had a rough case size in mind.
This helped me work with some units when modelling





Technical Design

I decided to pursue and modify Concept 2#, it was a simpler design and there were areas of Concept 1# would be technically more difficult to implement. I needed to determine what parts of the design were feasible and the layout of the components within the case. There were three main parts of the design up for negotiation: orientation of the graphics card, form factor of the power supply, choice of supported components and airflow solutions.

It's worth mentioning here that I had also started investigating materials and fixtures. Like many cases, sheet steel construction would provide the strength and simplicity that I required for the inner shell. I planned on using premium materials to cover the steel shell and where possible, be fixed from the inside of the case so that no screws would be on show. My technical designs started to consider how the pieces would be made from bent sheel material and fit together.

I had experience using graphics card riser cables, so I knew that I would be able to re-orientate the card how I liked. Many other HTPC cases that I had seen use rigid risers and have the card fan facing downwards. I really didn't want this, it was important that performance cards get fresh air from outside the case so I wanted the fan to be as close to the console lid as possible. I planned to incorporate a design into the lid that provided direct airflow to the components.

I built a bunch of scale models to check the real-size of components. SFX and Flex ATX power supplies here.
I'd recommend this technique since 3D models can sometimes detach you from the relative size of objects.





An ITX motherboard and a SFX/short graphics card.
Side note: the questionable meatballs are NOT mine ;)





I chose the Flex ATX form factor for its tiny height, just 40mm! The SFX power supplies were around 80mm and up. I started modelling and worked on translating my concept designs into a technical design




I decided the simplest layout of positioning the components next to each other would allow me to keep the case in a flat console style.




I explored a bunch of different front port options




Investigating ways that the Graphics car mounting would work in the simplest way




I started mapping the mounting holes for Flex ATX PSUs




The front panel assembly for the USB's + power button was something that I would have to create.
This was an early solution I came up with.





The tolerances were going to be tight. I learned that folding very near holes in the sheet would likely compromise the shape of the hole, so I had to redesign some sections several times.




I was having the same problem with the graphics car supports and was unsure if they would still hold thier shape after being bent

 
Last edited:

Chris Howell

Trash Compacter
Original poster
Diesel Engine
Jan 17, 2016
44
122
Final Design



I combined the learnings from my technical design investigation and produced a final concept design of what the case was going to look like and how it was going to work. The final design includes ventilation in the lid, mounting for all components, a front panel assembly and cable management solutions. I was also able to find solutions that would allow me to construct the case from the inside, hiding nearly all of the screw heads.

Having a solid technical design also allowed me to go back and design the asthetic parts of the console, knowing that it would be feasible to create. I had started searching online to see what kinds of parts were freely available: thin panels of real wood, thin and affordable premium metal panels, fixtures.














....And there you have it! During the design of the final concept I also nailed down a lot of the technical details that you see in the images above. I'll go into more detail about the shell design next post and explain the role the of the spacers and also why I chose to separate the case into several different pieces. Other small decisions like the position of the power button were finalised, I really liked the idea and look of cutting the corner off the case.

I also began using CAD software to translate my sheet designs into something that can be fed into a machine and made. I have many tips and learning from that exercise that I can share here.





Before I leave the first post, I should probably show some work in progress right? Oh okay, can you tell what it is yet?

 

confusis

John Morrison. Founder and Team Leader of SFF.N
SFF Network
SFF Workshop
SFFn Staff
Jun 19, 2015
4,197
7,187
sff.network
I am SO looking forward to this, great to see the design as it progressed. I may have missed it - why did you move from copper to brass accents?
 

Phuncz

Lord of the Boards
SFFn Staff
May 9, 2015
5,858
4,914
Interesting ! It's always nice to see people try out different materials than the standard metals. Very nice patterns and shapes incorporated too. Keep us updated !
 

FCase

SFF Lingo Aficionado
FCase
Dec 20, 2015
142
92
Awesome design. Its good to see someone else that believes pc cases can be more than just metal or plastic.
One question: How does the hot air from the cpu escape? The gpu and psu have their own exhaust, but you do not mention how the cpu air exits the case, only how it enters.

Mal
 

Chris Howell

Trash Compacter
Original poster
Diesel Engine
Jan 17, 2016
44
122
Thanks for the positive reception guys :)

I started off designing with copper, but soon realised lots of fittings already existed in solid brass (like the M8 hex bolts) at reasonable prices. The copper panels themselves were also more expensive than brass. In the end I wanted to keep the accent consistent, so I switched it all to brass. I've ordered some 2mm brass plates cut to size and they're looking great. I also having some brass ageing formula, which I will apply to make the metal parts look really weathered and steampunky.

The CPU exhaust question is a good one. I don't have a solid solution at the minute, but I need to investigate the use of slim fans for lid as ell as some temperature tests. I'll let you know how it goes!

Edit: also, It's great to be here on smallformfactor.net! :)
 
  • Like
Reactions: Phuncz

iFreilicht

FlexATX Authority
Feb 28, 2015
3,243
2,361
freilite.com
Very cool, I absolutely love the design and the materials you're using! The CPU exhaust question was already mentioned, but depending on the thickness of the case, you could add small exhaust vents directly above the Mainboard I/O like the NFC S4 Mini.

Another small concern is the GPU mounting. I like the idea of having just two simple bends there, but normally PCIe brackets are screwed in from the opposite side, so you'll probably need washers between the bracket and the bend in your case. The cutouts for the mounting tabs are indeed very close to the bend, but you could also extend them to end directly on the bend line, that way you'll get no distortion and can still use the tabs perfectly fine.

You say you can use 200mm FlexATX PSUs in this case, so I guess it is about 220mm deep on the inside, right?

Also, make sure you've got enough space for the PCIe riser you're planning to use, it is often underestimated how much space their connectors can take up, especially on the GPU side.

I'm very excited to see this project, good luck!
 

Chris Howell

Trash Compacter
Original poster
Diesel Engine
Jan 17, 2016
44
122
Thanks Dude :)

I know what you mean about the exhaust vents above the Motherboard I/O, I saw the holes in the S4 mini. Sadly, I don't think I'll have any room there. There are a LOT of vents in the lid though, I'll have to do some tests where the CPU fan is in both Push and Pull configurations.

RE: The Flex ATX PSU. That note is a little confusing. I actually have 200mm of space internally, so that space includes room for the cables when I say "20cm PSUs". Which I admit is not that clear. But it's enough room, I've picked up a FSP 400W PSU that is 150mm x 81mm x 40mm which should do the trick. More details on my PSU investigation to follow in future updates, soon! :)

I took lots of great knowledge and research you did on the LiHeat risers that have the 90 degree end connector - so thanks for that. I did indeed do lots to make sure I had enough room at the end of the case to accommodate that. Will update details of exact dimensions soon.
 

Soul_Est

SFF Guru
SFFn Staff
Feb 12, 2016
1,536
1,928
Very well done so far, @Chris Howell . I look forward to seeing your progression. It has also motivated me to continue a design that I am currently working on.
 

iFreilicht

FlexATX Authority
Feb 28, 2015
3,243
2,361
freilite.com
I see, so it's really space for a 150mm PSU plus cabling. I guess you're talking about the FSP400-60FGGBA?

No problem, we've got to help each other out. Especially with PCIe risers, little information is available, somebody's gotta fill that gap.
 

Chris Howell

Trash Compacter
Original poster
Diesel Engine
Jan 17, 2016
44
122



CAD Packages & Sheet Metal Design

As I started to reach a final design for the case, I needed to think about what software I was going to use to translate my Sketchup model into a sheet metal design that could be read by a machine somewhere to manufacture. I didn't really consider creating the case by hand, the design was going to be tight and required the precision that only a laser or CNC can provide. I needed the confidence that I could create the parts separately and know they would come together and fit perfectly. Part of the process was defining how the case was going to be fixed and compare the benefits of having the case as 1 large folded piece or made up of several smaller and simpler pieces.

After a broad internet search I came across an American company called eMachineShop that actually have thier own softwate which can model sheet metal bends and also privide instant pricing and ordering from within the software. I didn't actually buy anything from them in the end, but I found the software and simulation of bends very useful.

An early attempt into creating a CAD design of the case pieces



I explored different layouts within the software to evaulate the price difference for the part.
This design was never going to work! Not sure what I was thinking... :D




Here's the design coming together a bit more. You can define bend lines & give them an angle.
I also added tons of notes for myself and the machinist




A 3D render shows the parts after being bent. A useful instant-visualisation



This is my final design in CAD format. The 4 panels, the brackets for securing the shell to the wooden base,
the SSD bracket and the Front I/O assembly bracket



The 3D render of those parts






There is definitely something to be said about modelling the bends of individual pieces to check thier position after being bent. A 100mm sheet strip for example, bent across 90 degrees, doesn't give you two 50mm lengths (measured on the outside of the angle) because of the radius of the bend itself. If you're still interested, keep reading :p. After a bit of searching, it turns out every type of bending material has a "K-Factor" which is a value applied depending on the material and the thickness of that material, to calculate the length of material needed before being bent, so that your measurements (screw holes etc..) remain correct after the material has been bent. This effect is magnified the thicker the material.

I used a tool to calculate the sheet material required so that it would be correct after being bent.
You can see an example of the calculation and values for this below.
Note that to get 50mm after being bent, each length needs to be slightly less than 50mm (49.045mm etc..)







Origami Time

The next part of the journey was to create a version of my shell in card to check that it was going to fit together and to try out my card-components that I had made. Now, this method turned out really well (and I consider this a top tip actually :D) but I searched and found a CAD package that allowed me to print the CAD design at real scale onto paper, which I then glued to card and cut out with a craft knife. For the printing I used DraftSight.



The print didn't fit on one A3 sheet, so I had to improvise!


Glued on...


Cut... and assembled with some tape


You can see the relative height of the case shell. Those meatballs again...


I set about placing the components in the shell


I got out an old bracket and tried the fit. Pretty chuffed that it was spot-on


An old I/O Shield. The card broke at the thinnest parts, but it was enough to verify the fit was solid


The mounting holes for the PSU - lined up like a dream too


And the USB ports! ... very important that a comfortable fit was made




Seriously, all this was great to build confidence in the measurements before I put any money down to have the case made. Nothing worse than being disappointed.


Dimensions!

Additionally, you might be wondering about the measurements for the all of the screw and I/O apetures. I created the design based from a small selection of technical specs that I saved from various sources. They are here if you want to check them out. The Motherboard one was particularly important because it not only defines the size of the apeture, the the relative position and mounting holes for the motherboard itself - which is usually fixed to another part entirely and needs to line up perfectly.

- The Motherboard I/O Apeture
- The double height PCI bracket dimensions
- SSD Mounting positions
- Flex ATX Power Supply Mounting holes

An illustration of the dimensions.







That's all for now...
 

iFreilicht

FlexATX Authority
Feb 28, 2015
3,243
2,361
freilite.com
Nice to see a paper prototype!

I'm a bit surprised you're doing K-Factor calculations yourself, what CAD program are you using that you have to do that?
 

Chris Howell

Trash Compacter
Original poster
Diesel Engine
Jan 17, 2016
44
122
Thanks guys! :D Progress is good, I was able to spend a bunch more time on it this weekend. I'll post more updates soon.


Nice to see a paper prototype!

I'm a bit surprised you're doing K-Factor calculations yourself, what CAD program are you using that you have to do that?

I'm working in the eMachineShop software and exporting as DXF format. Essentially, after chatting to a few sheet metal manufacturers, the less work that needs to be done by the manufacturer to setup the file and the design, the cheaper the cost. As a result, I did all of the design work and took all the responsibility for the fitting etc.. I found there were 3 main options

- most expensive: you provide a 3D model or non-technical drawing. The company re-creates the design in 2D CAD and translates your idea into a complete product
- average cost: you provide CAD designs that require tweaking /modification before manufacture. The company products the final product
-lowest cost: You proved exact CAD designs that require no additional work. The company doesn't build the product, but just produces the finished parts
 
  • Like
Reactions: Soul_Est and K888D

iFreilicht

FlexATX Authority
Feb 28, 2015
3,243
2,361
freilite.com
I'm working in the eMachineShop software and exporting as DXF format. Essentially, after chatting to a few sheet metal manufacturers, the less work that needs to be done by the manufacturer to setup the file and the design, the cheaper the cost. As a result, I did all of the design work and took all the responsibility for the fitting etc.. I found there were 3 main options

- most expensive: you provide a 3D model or non-technical drawing. The company re-creates the design in 2D CAD and translates your idea into a complete product
- average cost: you provide CAD designs that require tweaking /modification before manufacture. The company products the final product
-lowest cost: You proved exact CAD designs that require no additional work. The company doesn't build the product, but just produces the finished parts

Didn't know about eMachineShop, I guess they will manufacture your design as well? Their CAD software seems pretty limited in terms of sheet metal capabilities. Of course you'd always want to provide a manufacturer with exact technical drawings, but pretty much every CAD software can export to .dxf, and most of them (AutoCAD, Inventor, Fusion 360, CATIA, Solidworks, FreeCAD with sheet-metal plugin) do all the calculations to convert the folded model to a flat pattern for you.

But hey, whatever works :)
 
  • Like
Reactions: Soul_Est