Scratch Build – In Progress Diesel Engine (ITX / SFF / Console)

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



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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





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.

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....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 learnings 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?

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Interesting!

Can't wait to see how the meatballs figure into the design though. Does it heat them up?

More seriously, I'm looking forward to seeing this take shape.

 

200W Flex ATX is going to cover a graphics card? That PSU will be seriously noisy.

Most graphics cards - even short ones - don't have connectors on the end, only on the side. I think you've underestimated the PSU connector sides and cable bending radius in general and I don't see how you'll fit an SSD in there. M.2 is more likely.

I love the design but I think you've been too casual on the hardware mock-ups and you'll hit problems very quickly without an IRL layout check. Make a card(board) box the same size and stick the hardware in it. Get to know how hot it will be before committing to the cuts. Fire up a game on that and you'll have ~65W? of CPU, ~150W of Graphics (assuming even a modest GTX 960) circling air internally and not exhausting + some effect of PSU in a tiny box. I've made a similar sized box years ago with a ~30W chip and two HDD; they get warm even doing very little!

EDIT: Consider dividing the CPU and GPU areas from each other and working on an airflow strategy. You've got intakes, but no defined exhaust. Consider flipping the fan on the CPU to exhaust via roof and make it draw cool air inwards instead; this is how most ultra-slim devices and consoles work for example.

 

Awesome design work sir.

Like mentioned above but asked more nicely, I see how you plan to draw air in for the cpu, but you don't mention how the now hot air will escape? The gpu and psu have their own exhaust, what did you come with for the cpu?

Mal

 

Thanks for the feedback guys I did a bunch of investigation into PSU options that I'll share in a future post, as well as how I arrived at a size for the case that would work internally.

The power supply that I've purchased is actually a 400W model from FSP. It's 150mm x 81mm x 40mm. They also have 500W units that aren't available as single units at the minute, but the specs illustrate the potential of the form factor in the future. It's a fair amount more than you would get from power brick based PSU's (Pico PSU / HD-PLEX). Like you mention, even if the higher power isn't required, it will allow the PSU to run cooler and not throttle itself.

You're totally right about the cable sizes, but I have done exactly what you describe and made a paper case and places the paper components inside. Again, I'll share the details of this soon

I don't have a solution for the CPU exhaust hot air at the minute. I'm looking into the potential use of thin (10mm) fans for the lid and/or investigation to see how hot the CPU gets. My main heat concerns were the graphics card, then the power supply. I will aim to be a graphics card that is an exhaust type.

 

Look forward to it

That's true enough. What 80Plus power efficiency rating is it though?

Very difficult to find in ITX sizes. Most of them are a large center fan that spews air everywhere.
ASUS do a slightly longer than ITX GTX 970 Turbo with exhaust style.

 

What are the case dimensions?

Btw I'm glad I'm not the only person who wants a case where the GPU isn't upside down!

 

Similar to Lian Li's O series - the graphics card is on a flexible riser.

 

Not cheap though

 

FSP do a range of different rated power supplies, but this one is 80 plus Gold rated. You can get slightly cheaper supplies from them that don't have a rating or are Bronze rated too though.


...I did see those O series. They look pretty, but the price is high and they're still pretty big dimension-wise.

 

Awesome start. I was hoping to see an etch/cut pattern in wood when I saw the concept.

It was refreshing to see Bindi throwing text walls at a mod too.
@Deano5 - You can order the risers straight from Li-heat on E-bay. Expensive, but they work great.
Which reminds me: Don't underestimate the amount of space the riser takes up. They are really stiff and have bulky connections. Take that into consideration when choosing the length of cable.
...Think I had this convo with Chris already.

 

I don't think $38 usd is too bad for a foot extension that actually works. The $24 shipping for one is rough though. I'm gonna order a few extra to get my money's worth on the shipping.

 

Welcome!
I'm pretty much exclusively interested in SFF mods these days. I do very much like the design here.

 

How did you come up with the name?
I mean, I've looked at a few Diesel Engines and I really fail to make the connection.

 

Thanks Cheaps - More wood laser etching and cutting to come. The test cuts that I've done so far are looking sweeeet.

Yeah, user iFreilite did a bunch of research and contacted Li-heat about the space tolerances with their risers, particularly because their risers have the handy 90 degree bend at the end. This image was useful in identifying how much space is required both vertically and horizontally within the case.




@Xir - RE: The name! It's not a direct association to actual diesel engines but instead reflects the industrial style of the case and the simplicity of the layout. It's also in the same ballpark as 'Steam Engine' and other steampunky type stuff. Much like clean, plastic cases have names like Razor and X-Series Turbo 2000 Ultra XXXX (OK, I'm exaggerating, but you get the idea )

 

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...



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



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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 . 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 ) 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


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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 apertures. 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 aperture, 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 Aperture
- 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...
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Now you say that those meatballs are not yours, but this being the second time they got featured I ask: how can we trust you...?

 

Very nice! Love the checking work.

What GPU are you using exactly?

I've got one of these in 2GB model: http://www.galax.net/GLOBAL/960_oc_4gb.html It's 172mm long, semi passive and very low power. There are some mini cards from ASUS/MSI iirc too - up to GTX 970. I don't think you'll have the thermal capacity for say a R9 Fury Nano tbh.

 

It'll be interesting to see what AMD and Nvidia bring to the table this upcoming generation. They're supposed to sip power. I wouldn't be surprised if more Nano type cards pop up since SFF is becoming so popular.

BTW Chris, I didn't say it before, but I'm liking the look of this!

 

Not a fan of smart price meatballs but I have to say I have a soft spot for their spag boll

Oh yeah, this build rawks