Scratch Build Acronym

[Achron]

Click HERE for the final pictures!






Acronym - m-ITX HTPC

Hello everyone!

Long time reader (5+ years) and first time poster here. I must first start by saying that everyone here has some real artistic and mechanical talent. There are very few mods or builds I have come across that don't leave my jaw open. For that, I have the utmost respect for this community.

As I'm coming to the end of my career as a full time master's student in the next 4 months, I decided to build an HTPC for the non-existent HDTV that I own . The plan is to have it finished around the time I graduate (March), or sooner. As I'm sure everyone here knows, it's hard to keep a consistent log as a student, let alone finish a build, but I'll do my best.


Specifications:

Currently Bought:
Motherboard: Zotac Geforce 9300-ITX WiFi
Processor: Intel C2D E7400 2.8GHz
Memory: 2GB Kingston DDR2 800
Hard Drive: Western Digital Scorpio Blue 2.5" 80GB
Operating System: Ubuntu 9.10 with XBMC

Future Purchases: (Too poor right now!)
Optical Drive: Slimline Blu-ray Player
CPU Heat Sink: Undecided...It's between the Thermolab Nano, Silverstone NT07, and Zalman VF2000 (due to height restrictions of <45mm).


Purpose:

Since everyone has a different purpose for their HTPC, I figure I'll state mine up front. It won't be storing any media locally, as I have a NAS set up with the goods already. I want an attractive, convienent front end to show my media, stream 1080 content, and the option to occasionally play a Blu-ray right from the computer itself.

I looked up several pre-boxed HTPC's, but none really caught my eye. After this failed reconnaissance mission, I decided to design my own.


Design:

I really have no idea what influenced me on this project. It had to be small. Barely big enough to fit the mini-itx board. It also had to fit all of the components snugly. It also had to look sexy enough for my taste.

Without further ado, here are some drawings. Solidworks was my program of choice, since I've been using it for 5 or so years.

You can see in these drawings I measured everything out and modeled the components so everything can fit nicely. If anyone has any questions as to the logistics of how the case will go together, ask me, and I may have an answer (or I may not know yet ).

Quick rendering in Solidworks


Wireframe View - Front


Wireframe View - Side


Wireframe View - Top



Machining:

For the past year or so, I've been working in the machine shop on campus here. I've had machining experience before this, but working here has given me the chance to improve on this. We have a HAAS 3-axis vertical mill, which I adore ( no 4-axis). Most of the work will be done on the CNC due to the complex shape that the case takes, since I like things to be oh-so-easy.

Also, a note. This won't and can't (with my budget and limited machines) be machined from a solid piece of material. The plan is to divide the case into sections and machine them individually, then connect them together to make the full case. Think of one of those foam Millennium Falcon jigsaw puzzles, only this time it's aluminum . I plan on machining all of the insides first, lining everything up, then machining the outside all at once.

Frontplate:

The frontplate was the easiest starting point of this whole project. Flat, thin, and not much to it (if I had a nickel...). Unfortunately, I won't have any process pictures for a few sections, since I'm an idiot and kept forgetting the camera. It's simple, however. Take a slab of 3/8" aluminum, cut to size, face with a sick nasty multi-head cutter, take drawing, import to Mastercam, voila!

Here's a snap of the half-completed frontplate. Again, I'm saving the contour for the very last. Mmm shiny.

Wireframe:


Front:


Back:


You'll notice the ends of the piece aren't as smooth as the middle. The clamp in the CNC is only so wide, so the ends tend to chatter a little when the tool goes over those parts. It's still smooth to the touch, but what you're seeing is probably 0.001-0.005" variations. Nothing a little sandpaper can't fix .

The big oval hole is for some IR-visible plexiglass. I don't like anything external, so I hacked apart a MCE receiver and it will be mounted behind this opening. The two holes on the ends are for vandal switches, one for the power switch and the other for the Blu-ray eject (probably). The slot...well the slot is for ejecting the money that I sank into this project .

Top Chassis Lid:

This piece is a bit more difficult than the last. First, finding a 1" thick piece of aluminum 100mmx200mm is a tedious task. Not to mention that the shape of this piece is...well, complex. As I'm writing this log on a Friday night, the part has been running since 4ish PM today. Projected time to completion, 20ish hours. That may have something to do with the fact that to smooth out the 'scallops' left by the roughing toolpath, I had a small ball end mill (1/8") make very small steps. If anyone doesn't know much about CNCing, feel free to ask and I will do my best to answer. Disclaimer: I am by no means an expert!

Here's a solid model shot of the piece. I started off by facing each side, then cutting the groove in the sides. Then, the CNC took the spotlight and drilled the holes on the underside of the piece, followed by roughing and finishing.

Solid - Top:


Solid - Bottom


Unfortunately, I don't have a roughing shot (dammit)...so here's what comes out of a 24 hour long CNC marathon .

Oops! You'll have to wait a day . To be continued tomorrow.


#Tag: Devin Spratt

[skunkmunkey]

this is one of those projects where you read the first post and the only thing you can say is wow. Amazing rendering skills there mate and nice work on the machining

[jrs77]

This will be interesting

Another cooler you could use is this one -> http://www.thermaltakeusa.com/Produc...C=1148&ID=1862 but it's 47mm in height, so I don't know if it will still fit.

[Sheiken]

Cant wait to see how this one turns out

[Botn3vik]

Looking good! Love the solidworks drawings or sketches (L)

[Bindibadgi]

Originally Posted by Sheiken

Cant wait to see how this one turns out

+1

[Bullitdodger]

Originally Posted by Bindibadgi

+1

+ 1 more....

[Jipa]

Gotta love crazy designs. Looking forward!

[stuartwood89]

I'll be watching as well.

[ringo]

very cool case design.

[Achron]

I figured I would provide a picture of the shop I work in, and where this case will (hopefully) come to life. Also, a nice view of the CNC machine is shown.

Machine Shop


Haas CNC



Top Chassis Lid:

Although I have no progress pictures of this piece, here is the finished bottom of the lid. If you're wondering, this piece took 1.5 hours to rough cut, and ~8 hours to finish.

Finish Pass


Close Up


Another Close Up


Long Shot


Some of you may wonder what the protrusions and holes are for. The long rectangular protrusion is for the hard drive mount, which can (sort of) be seen in the Solidworks drawings in my previous post. The circular and goofy looking shape is for my IR receiver circuit board! The board looks like so:

IR Circuit Board



Top Slices:

Since this case can't be comprised of a single block of aluminum, I chose to separate it into sections. It's basically an inch slice from the top of the case, which results in 2 separate pieces.

Solidworks Top Slices


Solidworks Top Slices


The piece starts out as such...just a simple block of aluminum.

Aluminum Block


Then, off to facing and edging the piece so everything is level.

Multi-head Cutter


Fly Cutter


End Facing


Then, off to Mastercam!

Mastercam Toolpaths


Absolutely nothing visible through the filthy plastic windows and coolant.

Coolant Shot


After the roughing paths, this is what is left. Then, we finish it with a smaller ball end mill.

Finished Roughing


Halfway through the finishing process.

Half Finished


Finished!


Even if it may not look smooth, I assure you, you can feel no ridges. Just to get a sense of why the process takes so long, I'm using a 1/8" ball end mill making 0.1mm paths. So, for every line the mill takes, it moves over a step of 0.1mm and does the next one. This piece took ~4 hours total in the CNC.

Next up? The other top piece, which I left to run overnight again. More updates soon!

[Achron]

Originally Posted by jrs77

This will be interesting

Another cooler you could use is this one -> http://www.thermaltakeusa.com/Produc...C=1148&ID=1862 but it's 47mm in height, so I don't know if it will still fit.

It's still up in the air as to what the exact clearance number is. I projected it around 45mm initially, but things have changed. That's the last thing I'll buy, but I'll keep the cooler in mind, thanks!

[Oreon_237]

CNC machines are awesome!
loving the design. for the CPU heatsink, would the scythe shuriken fit?

[Achron]

You know, I've read several reviews of that heatsink and none have nothing bad to say about it. It pretty much blows all of the competition out of the water at the low profile height. However, the heatsink itself is 64mm and add a fan in there, another 12-15mm, so it's definitely way too high.

[haakon.t]

Epic first post, + rep

[The_Gnu]

Sweet, cnc + alu = subscribed.

Looking relly nice. I was wondering about one thing though. I can only see a couple of ventilation holes on the top and on the back. Will those be enough for that setup? Looks like the air might have some trouble. One thought would be to use the alucase itself as a kind of passive cooler to assist the aircooling.

Looking good so far.

[Achron]

Originally Posted by The_Gnu

Sweet, cnc + alu = subscribed.

Looking relly nice. I was wondering about one thing though. I can only see a couple of ventilation holes on the top and on the back. Will those be enough for that setup? Looks like the air might have some trouble. One thought would be to use the alucase itself as a kind of passive cooler to assist the aircooling.

Looking good so far.

That really is the million dollar question. The only fan that is currently planned to be in the case is the CPU heatsink fan. Whether or not that will suffice after playing HD video is beyond me. I'm messing around with finding a place for a 40mm fan somewhere in the case, but it's looking to be a long shot.

[Idioteque]

Bah, wish I had access to CNC equipment... Great mod, love the design! subbed.

[Achron]

So this really isn't a work update, I simply can't make up my mind as to what I want the case to look like! I wanted to add a little life and depth to the case, since it looks kind of bland simply with the anodization on the aluminum. So, here are a few case designs that I would like some feedback on. I have a preference in mind, but I won't reveal that until later! The transparent pieces in this case are acrylic, and the black is obviously the anodized aluminum.

Original


Design 1


Design 2


Design 3


Design 4



Also, for those that were wondering how in the world this was going to get machined, you can see the sections that I chose in the renderings. These should limit most pieces to less than an inch thick (material gets very expensive above this), with an exception to the two side pieces.

Also, does anyone have any experience with components such as this in a small enclosed space with only the CPU fan? For some reason I don't see it being a problem, but I would hate to come back and machine things after the piece has already been done.

What do you think?

[stonedsurd]

I like design 1 the best. Simple and elegant.