Scratch Build – In Progress The A3 Media PC: "the box is probably worth something too" Finished 22th Feb

Concept and Design​

Hiya all.

My old pc (1.3Ghz duron) is currently sitting un-used in a beige box. I'd like to turn this into a low-power media server / folding machine / something similar. Therefore it needs to be quiet, and fairly inconspicuous.

When I built my current system I only had one case, so put the old system in a cardboard box (aka boxputer) during the transition. Amazingly I managed to fit it all into a cardboard box some of the components came in. This gave me the idea for the layout for this new case - except the PSU won't be resting on the PCI slots! (pics: here and here)

The new case I'm going to build will follow similar principles, by seperating the boxy components (DVD drive, HDD, and PSU this time) on a lower deck from the more cooling-critical motherboard and parts on the top deck. Playing about in Rhino3d, I came up with the following plan:

Front -


Rear -



Looking at the dimensions for this plan, I realised it needed a base size only a couple of cm smaller than a sheet of A3 paper - which is pretty convenient, as I could find 5mm thick A3sheets of perspex online quite easily.

I decided to go with an A3 sized foot-print as it also minimised the number of cuts I needed. The roof would be set to standard A3 size (ie 420x297mm), and the height of the cuboid was set at 280mm, which gave 125mm height for the bottom deck (enough for 3 HDD stacked with room for airflow) and 140mm for the top deck, enough for full height PCI cards. The remaining 15mm would be the bottom and top, plus another 5mm sheet for the MB tray.

Using these dimensions I planned a layout of the sheets which involved only 11 cuts, and would keep these edges to the bottom or rear of the case. The best tool for cutting I had available was my Dad's circular saw, so I was concerned I wouldn't get very straight/accurate cuts and wanted to hide these.

I'd also considered cutting the edges at 45 degrees, so they'd line up with a seamless edge... but while the circular saw could do this it wouldn't have been pretty, let alone easy. Getting an accurate, straight edge suitable for building with is probably going to be impossible without a laser cutter.

Anyway, after some feedback from a thread I posted in the Modding section, I revised my cooling layout. Previously I'd had 2x120mm either side, and the negative pressure from the 80mm fan in the PSU would suck down some air. But, everyone giving me feedback on the thread seemed concerned about the welfare of my poor 32GB HDDs.

The solution:





Two Antec 200mm Big Boys - I have one of these in the top of my Antec Nine Hundred, and for the 80cfm it pushes at low speed, it's pretty much silent. You need to hold your ear against it to hear any buzz noise from the blades, and the noise you hear from a distance is just the airflow through the grill. I'm going to get some AC Ryan Mesh to cover up the intakes, which should be a bit more stylish than the old school fan grills.

One fan will pull in, one push out, and this will push some of the airflow through the bottom shelf as well. I've got a Zalman MFC1 fan controller, the black aluminium bezel can be removed so I'll drill holes for the 6 control knobs in the rear panel for control over all the fans. This will replace one of the DVD drives, but I doubt I'd need two.

I'll also have to invent some 200mm dust filters. The primary function of this case could actually be to remove dust from the air in my room, not actually house a computer system.

Now if this all seems like madness, fear not! Having the footprint of an A3 sheet of paper, I stuck two A4 together and tried fitting it all together. I used a spare bit of A3 clear perspex to support the mb. It all fitted together and I wired it up fine, only the thick rigid IDE cables caused some bother. I'll need to extend the 20pin power supply cable too if it's going to go round the front, but I'd rather make a hole in the corner for a cleaner upper deck





I had planed to make the corner joints from brass inserts and cubes of perspex, but as you wont be able to see them I might just use metal corner brackets.

My beige box could become a donor for a spare I/O bracket. For the PCI slots, I've not decided if I'm going to hack the rear section of my beige box and mount it in, or just cut holes in the perspex as required. Incidentally, all the functional parts will be mounted to the rear (inc DVD drives, which will be rarely used), leaving the front panel completely clean. I might mount a LCD/matrix display at a later date, if can think of a use for it. Really, this case is a blank canvas.

 

Cutting the Perspex​

At the weekend I went back up to Aberdeen to use my Dad's circular saw. Earlier in the week I ordered 8 sheets of A3 Black Perspex, 5mm thick. Strictly I only need 7 (6 sides and the MB tray) but I got a spare one too. I bought it from here, who were nice enough to give me some lovely cell-cast stuff when I phoned up and asked.

Because the perspex was pre-cut to A3 size, we only had to make 11 cuts with the circular saw. The finest blade available had about 2 teeth per inch, I was a bit concerned but the first test cut came out really well, with some scratching on the cut edge but otherwise clean. The edge was a bit wobbly though, so we clamped on a T-ruler I had to give a very straight edge. From then on the only inaccuracies in the cuts were where I'd drawn the lines a bit squint! But, you lot will never see these as they'll be at the back and lower edges of the base...



In total we made 11 cuts, and it was all over. A quick bit of taping later and it was coming together.



Back home in Glasgow, another quick test, this time putting in the components too:



I'm still going to need to cut the MB tray to make room for the fans, and the cabling, the plan being as follows:

 

Some Test Sanding...​

"What's that awesome looking hardware?" I hear you say. The system specs are as follows:

1.3Ghz Amd Duron
MSI KT3 Ultra
Geforce 4 MX 440 (AGP)
Generic 300W PSU
Generic SDRAM (2x256mb and 1x512mb) - dunno what speed.
32Gb and 40Gb IDE hard disks
Soundblaster Audigy something something.

This is where the throw-aways from my dad's computers go. Nonetheless, it's been a great little setup for playing Civ 3, Starcraft and Transport Tycoon Open for the past 5 years. It's not fast but it's solid.

Moving on, I lined up the front, rear and side panels, which are all the same height - or should be!



Hmm.

After an hour sanding with 240, 480 and 600 grit, then some random attacks with a half-moon file, I've got things a bit more uniform:



Still, not perfect. The original edges of the A3 sheets are much better though (and square!) so I'm going to use these for all the construction edges - part of my sneaky design.


The edges come up quite well after sanding. Obviously it's going to take plenty of polishing, but pic this shows a sanded circular saw cut (top), an original A3 edge (middle), and a fresh edge cut with the circular saw:



If I can think of a more intelligent way of sanding a flat, straight edge I'll certainly give it a go - for now it's more or less by eyeball. I'd be happy to knock a couple of mm of the height of the case if I can sand down all the sides to a uniform height somehow.

 

Corner Brackets​

After a trip to B+Q (most of which was spent umm-ing and err-ing at screws) I came back with these beasts:



I'd really like the corner screws to be aligned square... eg the same distance from the corner on all three panels - obviously this bracket isn't aligned like that. The side holes are about 15mm down and 13mm in from the sides. Can I live with that...? It could drive me insane...

Anyway, I drilled a new hole in the flat edge in line with the holes in the side (13mm in). Time for test set-up





And testing with one of the offcuts from the side panels...



I don't think that will torment me for the rest of my life... square alignment would obviously be great. The next step is to drill all the 24 corner holes in the perspex, and the remaining 7 new holes in the brackets. The screws I've got aren't especially glamorous, I'd rather go from something with a phillips head, but anything stylish that's 4mm would be good. Also, i'm not keen on the nuts on the inside, as these easily come loose and will be a nightmare when opening and closing the case... somehow I need to attach something threaded to the brackets - I may end up with perspex cubes and brass inserts after-all.

I'm also going to have to make sure the edges are nicely lined up when I drill. There's no going back from there. Atleast I'll have plenty of time to sit and think about my mistakes while my crappy 12V drill recharges...

 

there nothing to cool,i've had this processor with the same cooler and 120 fan on it with 5V supply and everything has been perfectly cooled.
i like that box,the computer was in good looking paper-style modding

 

Yeah sure, I agree, the cooling is totally overkill.

Anyway, update time -

HDD Cage​

Yesterday I bashed together the hard drive enclosure. The bottom deck will be 125mm high, so I used the offcuts from the side panels to build the sides of the cages. With 4 metal brackets (costing a mighty 14p each from my local hardware shop) I put two cross-bars on making the cage slightly wider than the drives themselves. This was so I could put insulating foam on the edges of the drives - the sort of stuff you'd use to seal your windows and doors.





The fit is pretty tight, with both drives wedged in you can pick it up and shake it and they don't move! Nonetheless I wanted to add elastic to hold the drives vertically, as they may slip down over time. Originally I had wanted to have them suspended entirely by elastic, but the drive cage would then have had to been quite wide (about 5 inches) to have enough room to twist the elastic to hold the bays laterally - the foam idea came about because there's limited space on the bottom deck, this holds the bays laterally whilst still giving reasonable vibration insulation.



Wired up with some spares


Plugged into my main system - the noise that the 32Gb drive was making was almost as loud as my entire Antec nine hundred! Unforutately that's just to noise of the drive - is was built in 1999. The drive cage certainly worked though, I'd left it on top of a spare piece of perspex and the vibrations through it were minimal. I might replace the 32GB with a spare 160GB (still IDE though) drive sitting about, and do a clean install of windows - and possibly a dual-boot with some useful linux type thing.

 

the hdd bay is similar to those used in Antec cases.well done! i subscribed this thread and i'm looking forward to see more of this case soon

 

You know, you can plane perspex.

Don't go over the ends or you'll break the corners off, but you can go from one end in to the middle - and then the same from the other end. Good finish but needs the plane set up so you're taking off almost nothing - literally a thinner-than-paper paring.

 

Thanks for the tip, I'd been told you couldn't plane perspex. I'd give it a go but I don't have a plane (or much at all).

 

Progress recently has been slow, but steady.

Done:
- Main box structure
- Motherboard tray

To do:
- Cut holes for PSU, CD drive, and fans.
- Build internal structure to hold everything on the lower level.

For cutting the holes, I've done OK with a drill and hacksaw combo so far, but these will need to be curved cuts, a bit harder. I could invest in a dremel, or use my dad's jigsaw. I'm going away sailing in greece for a month from next week, so nothing is going to happen untill the end of August.

I'm planning on screwing the PSU onto the rear panel, as it would be in a normal PC. Otherwise it will just rest on the floor of the case. I'd wanted to insulate it from vibrations, but from something so big and heavy it's not going to be practical without screwing it to something.

I'm also reviewing the 200mm fan idea... They fit fine, but it's the cost that's the issue. At £15 each, I could get cheaper 120mm fans. It's a styling issue, really. I did take the Big Boy out of the top of my Antec Nine Hundred to check all the dimension. It's a beast. The only noise it really makes a low rpm is a little click from the bearings as it spins.

Design woes aside, here's some pics of recent progress.

Assembling the Box​

To drill holes to mount each of the corner brackets, I pushed the three sheets of perspex to be joined into the corner of a desk, then started the hole a bit with the drill. I took the sheets apart and completed the drilling.



In an ideal world, this would give the 3 sheets at each corner perfectly lined up... no. There are 24 holes to be drilled in total, and each one went ever so slighty wrong. I spent all of my Saturday night filing the holes in the metal brackets into oval shapes so the perspex sheets would line up just perfect.

This does leave me something of an upgrade path, though. If I ever get my grubby hands on some brass inserts and perspex cube, I might try something ala the awesome Phinix Cube.

 

Motherboard Tray​

I managed to drill out the rivets on an old case, and got hold of a nice ATX backplate. This will save a whole lot of hassle cutting holes in the rear.



Using the original holes in it, it then screws directly onto the motherboard tray (sheet).

I cut the motherboard tray to the right width, each Antec Big Boy is 30mm deep, and I took off an extra 2mm either end to allow for mesh and dust filters.


Again, a hacksaw gnawed it's way through the perspex to make the hole for the IDE cables


At first I planned to put threaded brass inserts into the motherboard tray to hold the standoffs, but after a bit of testing decided to just screw them straight in. Because perspex loves being threaded.

Marking the holes to be drilled later (with the motherboard removed!)



With the holes drilled right through, I began to screw in a standoff. I'll add a thread tap to the list of things I don't have but clearly need. Careful... careful!




And the inevitable. The A3PC - or "How Not to Build Your Own Case". Seriously, if you read anything in this log, don't use it on your mod. Even if it looks like I've come up with something clever, it's just a solution to a stupid problem which should never have arisen in the first place!


So, I drilled out the broken shaft of the standoff.


For the last few turns to get the standoff in, the perspex was seriously creaking, and my mighty brutish torque was obviously too much for the brass to handle. Hence, snap. The solution was to only screw the standoffs partly in, and I used rubber grommets to ensure they were all at the same height.


With the motherboard in place and backplate screwed on, it almost looks good.


I had to cut grooves where the bottom of each PCI bracket meets the motherboard tray... I had considered just cutting the ends off with a hacksaw.

And after some more hacksaw and drill action, I had something resembling a rear panel, albeit with wobbly cuts and poorly aligned panels.



And amazingly enough, all the hardware still works!



So, to summarise: please, please, please, promise me you will never make a case using any of the methods shown here. Just go buy a P182, it'd be much cheaper.

Untill next time, I'll leave you with a puzzle:

What does this connector on my PSU do? As a clue, the PSU was made in 2002. I've never seen anything this could power?

 

i believe that there should be 2 of those on the power supply and that is what was used to power the ancient motherboards when there was no ATX 20/24 pin connector...atleast that is what i believe it's for from my knowledge so correct me if i am wrong

Good job with the case. I might actually borrow your idea of using corner brackets because i want to make an acrylic shell for my case but want the light to come through all over (hence my want of not using aluminum bars)

 

It's a s423 aux connector. Had it on my P4 RAMBUS board. That was a setup there, I tell ya...

 

I have a PSU with two of those connectors, it came from an AT computer

That I'm now (Unsuccessfully) trying to mod

 

Nice so far. Hard luck for that mobo chair That PSU is old I think, I remember to see this plugs on P1 and P2 Computers. No use for it now days only for old mobos. They used it as the 4/8 Pins we have now on new mobos

 

Yep, Computer King is right. I took apart an old 1995 pc and it had 2 of those connectors. They are like the 20+4pin cables that are used today in modern pc's, just they're meant for much older computers.

 

You sir have an AT power supply connector right there, It was the motherboard connector standard before the Pentium 2 was released, at which time the computer industry saved up its pennies and bought the letter X to slap on the back of AT and bame the ATX standard was born, just wish they could decide bitween metric and imperal dimensions!

 

Interesting... if only I had an old Pentium to power?

Anyway, project is on hold now because I'm moving house, starting a new job, and have no money (not a good combo), but I'm thinking over the cooling solution - might use 120mm fans, or cut some holes for mesh. Styling is the only real concern (because it has none!).

For now, I can't do much until l I either get hold of a dremmel or jigsaw to cut the exhaust for the PSU and CD drives. Then I can cut the cooling fans as well.

Still need to resolve my "structural" solution. At the moment, the bolts just run through the nuts, so there's no way to get it un-done if you were to close the whole case... which you can't. I want a way of fixing the nuts to the brackets (superglue doesnt work). Would solder the nuts on do the job? Or maybe something like Loctite?

The nuts would also have to be in the exact place, because as I've mentioned, I've had to turn some of the holes in the brackets into ovals so you can line-up all the panels correctly (really, down to ~0.25mm)... which won't be easy. I'm also still thinking about a threaded insert and perspex cube combo (ala Phinix Cube) although I haven't been able to find anywhere that sells either. Using the original holes in the perspex sheets, I could clamp the corner together then drill through those holes into the cubes so there should be no errors.

Much to think about, but it's just brainwaves untill my first payday...

 

This is looking really good. I love that HDD rack.

 

Some months later...

Hello folks.

I've actually got round to resuming the project after putting it on hold in August. I got a dremel for christmas, which replaces my hacksaw as my tool of choice, opening up a whole world of perspex cutting possibilities.

Having looked out the old box and disassembled it, I made a list of what else needs done:
1. Cut a hole for the PSU in the rear.
2. Cut holes for the DVD and CD-RW drawers
3. Cut holes for the 120mm fans in either end.
4. Fix down the HDDs cage and DVD drives
5. Somehow get a power switch, and possibly a couple of sata ports in the front.
6. Work out a way to close the box - considering the nuts and bolts.


So, first job, cutting the PSU. I drew up a template, drilling holes in the corner. Then I dremelled some of the shorter cuts, and hacksawed the longer cuts - the dremel is pretty rough.





Not bad, except my PSU has one screw in the wrong place, which I didn't notice when I drew up the template. Obviously ATX spec isn't good enough for my PSU. I drilled another hole after this.


I've been a bit less aspirational about the build than I was in the summer, and decided some plastic L bracket would be good enough to fix things down. The DVD drives and HDD rack are bolted down. The PSU screws into the back panel.

I also decided to turn round the DVD drives to face the front, as I'm now planning to use it as a media pc and that would obviously be more handy.





Good good.

I got the holes for the DVD drives cut in the same way... though this time the template didn't work very well. The top drawer couldn't even open.



Following this I filed plenty off and tidied things up, I plan to add blanking plates on the end of the DVD drawers, stealth mod style, which will look a lot neater.

Cutting holes for the cooling fans had always been a blocker, untill I got my dremel. I did some practice on a spare bit of perspex first.



The results were't bad. The dremel cuts pretty rough, and you can't get a perfect circle, but with a bit of filing, sanding and polishing it looks fine - plus, the grill is in the way so you can't really see the errors.



With that done, I moved onto cutting the ends. The fans are mounted in the centre of the panel - thus, half the airlfow is directed to the lower level to cool the PSU and HDDs. The rest flows along top over the motherboard, although the top level is a bit less restrictive to the flow.

The plan:


Some innovative vice mounting:


Zee results!


I don't have a flexi-shaft for the dremel, so I can only cut at an angle into the plastic. This has created a cone shaped cut-out; which I actually quite like.

The finished product:



Having got this far I put the whole thing back together... which takes ages. Getting to some of the corners to turn the nuts is nearly impossible. I really need to think how I can just have a screw-in solution.

The bottom deck - I needed a longer IDE cable, this stylish yellow number was cheap. The whole thing is a cable-tidiness freak's nightmare.


The top deck is a bit more organised. Bow before the mighty Geforce 4 MX!






The whole thing works, which is super, considering what it's been through. The 32GB hard drive sounds like it might die soon, so I might re-install windows on the newer 160GB, hopefully it will be a bit faster too.

So, still do be done: power switch, front bay covers, and final touches.