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Author Topic: CNC "rackmount" pizza box server plans for MiniITX mobo, PSU and dual 3.5" HD  (Read 10475 times)

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From the included readme1st
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Bare bones "rackmount" format computer case.

This is 99% of everything you need to build a basic "rackmount" format or "pizza box" format computer case, based upon the excellent Via Epia MiniITX format boards.

This design allows for the MiniITX mobo, MiniITX PSU, and two 3.5" hard disks all to be mounted in a robust case with EXCELLENT noise cancellation properties and EXCELLENT airflow through the case.

In the drawings the mobo, PSU and 80mm fans are all represented by simple boxes outlining their maximum dimensions, so within this framework you can for example rotate the 170 x 170 mm mobo 90 degrees, or decide if this is the front or the back of the finished case, as you choose. I would recommend against rearrangement of the component positions though.

Design notes.

1/
All construction is from 10 mm thick acrylic, you decide if you want clear, coloured, smoked, whatever.
Building this case from acrylic should cost no more than £25 (UK pounds) in materials.
Acrylic is strong, a good electrical insulator, a good sound insulator, and unfortunately for a computer case also a good thermal insulator.

2/
The air flow through the case is managed by two cheap generic 80mm case fans (though I would STRONGLY recomment you buy two decent 80mm fans from http://www.dorothybradbury.co.uk/, I suggest two NMB-MAT RB-80-L at £8.45 each) with flow in series between the two should one fail, the air flow path is in by the motherboard, across the motherboard, where it is directed by the air dam into the first hard disk caddy.

In this caddy air flow over BOTH important surfaces of the hard disk, before going around and then cooling both surfaces of the second hard disk in its caddy.

From here the air passes through the PSU, through the fans and out the case.
Despite the lower power consumption of Epia boards, you could fit a more powerful MiniITX board, as this design addresses one of the biggest weaknesses of the ATX design, in that every single major component has forced and channeled positive air flow.

The design of the channels and the order in which flow happens is optimised to dissipate any mechanical noise inside the case, and not to carry it out through the vents. Fan noise will be minimal.

3/
Cabling and wiring.

I've left basic parts of the canvas blank, such as the square cut out for the motherboard I/O panel, the air entry, the air exhaust, and the PSU mains plug.

I have left these blank because this way you can make slight alterations to suit yourself, if it was me I would for example strip the casing off the PSU and run it naked (quite safe in an acrylic box) for better air flow, and solder in a IEC socket mounted directly on the rear panel, I'd also recess the mobo 10mm and fit a front air entry filter next to the I/O panel cut out, and I would direct the exhaust air out the rear, this way I'd have a "pizza box" with the mains cable at the rear and all the I/O and air filter at the front.

Pay particular attention to passing the hard disk data and power cables for the second hard disk through the internal air dam, you want enough room to pass the cables but not a big void to short circuit the air flow, the first hard disk is easy, but watch cables don't block air flow, use rounded IDE or SATA, you do not need the second hard disk.

Also pay attention to the ATX power cables through the air dam to the mobo, you also want a snug fit that doesn't cost you air flow.

4/
General construction and assembly.

Mobo mounts can be drilled and tapped straight into the base. Ditto PSU

Fan carriers are dead simple, just two sheets with angled recesses to hold the fans snug, make it a nice push fit for the fans, if you buy Dorothy Bradbury quality cans fit then and then glue the fan assembly into place permanently, make sure the two fans both work together, not against each other.

Hard disk carriers are slightly different between disk 1 and disk 2, disk 1 carrier has an extra bit of air dam. Hard disks go centrally to allow air flow over both sides of the disk, just drill and tap for hard disk mounting screws, AFTER you make sure you have the hard disks the right way around for the data and power cables, eg data and power cable ends pointing towards the PSU.

Recess hard disk mounting screws into sides of carriers, You can secure hard disks + caddies from below with recessed screws.

Even if you only fit one hard disk, make both caddies, they also serve as air ducts.

I'd make the base and four sides, and leave the lid as a separate item screwed on with recessed screws.

The nice thing about this is you can see in, so you can see if cruft had made it past the air filter and is clogging, or you can see status LED's etc etc etc.

In theory, apart from the fan carrier recesses, the mobo I/O, the air entry and exhaust, and the IEC socket, you could make this entire thing with no CNC machning at all, just cut the acrylic to size (or buy it cut to size) and drill and tap or glue where needed.

However, there is a lot of scope for some nice CNC work to make this a really, really nice piece of kit.

5/
Notes

As it stands this design is 444 mm wide, 350 mm deep and 75 mm high, it is only the 10mm thickness of the construction material that stops it being 1U, but nevertheless is is a pleasing dimension, and due to the internal structures such as the air dams, fan carriers and hard disk caddies it is literally strong enough to stand on.

THINK THRICE, MEASURE TWICE, CUT ONCE is very much the motto here, if you end up with problems or things not fitting or working out extremely neatly and effectively then you simply were not careful enough, or you decided to alter something for no good reason.

Glue the four box sides and base together.

Glue the hard disk caddies together.

Glue the air dam together.

If you buy Dorothy Bradbury fans and check orientation glue the fan carrier in place

DO NOT GLUE ANYTHING ELSE, use countersunk fasteners, and do not glue these things until you have offered up and done any required machining, eg front and rear panels require air vents and I/O, air dam requires cable notches.

6/
Finally, this design. like all my stuff, is released under the GPL V2.0


7/
Zip file contains Rhino .3dm files, autocad .dxf (CAM metric) and images, everything you need.



25th June 2009

Online Tweakie.CNC

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Well presented project - must have taken you a lot of time to compile.
Can't help thinking that you have some shares in an acrylic company though.  ;D

Tweakie
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.
Took about 2 hours, but then I have built them in the past which made it easy.

As for the acrylic, no, I buy mine from my local supplier (Plastexe) but it is a vastly under-rated material IMHO, incredibly versatile...







Online Tweakie.CNC

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Wow !

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.
That's *NOTHING*

By the cubic foot acrylic isn't that cheap, but, you can do some really impressive things with it, my (final) conversion to digital photography came about because I made a very impressive coffee table for someone to their design, basically a stack of different shaped pieces in a very pretty very light green glass coloured acrylic all bonded together into one lump, doesn't sound like much but then neither does Bryce Canyon when you describe it as a bunch of different shaped slices of stone stacked on one another.

Anyway, being quite proud of it I took a whole reel of pictures of it once it was delivered and in situ in a nice modern setting.

Got home and discovered there was no bloody film in the camera.

Trouble is "we" generally only see the material used in cheapo cafe menus and things so we tend not to appreciate its various qualities.

You can cut / drill / mill / tap / bend / bond / polish it, only your imagination limits you.

I grew up playing with wooden blocks, my boy plays with flame polished offcuts, he isn't interested in cruddy wooden blocks when he can experiment with acrylic in various wired shapes and colours, all with kid safe edges, all hygienic, all unique.

Toys r Us got nothing on daddy's scrap bin... lol
sorry, don't understand what you're trying to ask/say.