Building a Case

[MotF Bane]

I have never built a case before; this will be only the second case I have ever owned.
My basement contains more screws than you could imagine, as well as various screwdrivers, ratchets, a table saw, a band saw, a saw-zawl, a jigsaw, a dremel, a wizzer, and an air compressor.

The case will be 18x18x18 (inches, thus a cube), obviously inspired by the Mountain Mods cases. However, I do LAN parties, and am concerned about the strength of the 1.5 - 3.0 mm aluminum they use. Also, the 400 dollar price tag is rather restrictive.

Therefore. I intend to build the cube out of steel panels. The corner points will be reinforced by steel brackets. The motherboard will be a horizontal mount in a top compartment; said top compartment will also be able to contain a 3x120 radiator. The lower compartment (which will be taller) will contain the external bays and several more fan intakes. At the back of the lower compartment will be mounting holes for another 3x120 radiator. There will be space for two power supplies, at the back just below the top compartment's floor. The hard drives, pump(s), and reservoirs will all sit in the lower compartment. The top of the case will have an acrylic diamond shaped window, with an 80mm fan in each corner. The sides of the case will have acrylic square windows. The entire unit will sit on top of four wheels. The back where the motherboard sticks out will be an aluminum panel that can be removed to be replaced with ease.

Does anybody have some thoughts or opinions, or perhaps tell me what I need to use? Also, I want this thing to have massive CFM and low sound. I do overclock, and am planning to give this case a single PA120.3 radiator with a Laing pump with Petra's DDCT-01 top. I won't bother naming my current rig, as this case is intended to service my computers for several years. Perhaps a mix of quiet fans except where the radiators will be mounted?

 

[Zepper]

Why don't you use a Lian Li mobo drawer for mounting your mobo - save you a heck of a lot of time and you can get them as replacement parts on several sites for around $25.00? You'll just have to figure out a way to retain a solid ground path while avoiding galvanic corrosion by isolating the aluminum drawer from your steel chassis. Or check out the Yeong Yang cube server case and just buy and mod it. There used to be a link in this section to the "Borg Cube" that someone did from it.

YY at Directron: http://www.directron.com/yeongyang.html

Mfr's page: http://www.yycase.com/workstation.htm

"Borg Cube": http://www.thewarfields.com/ExoticPC.htm

.bh.

 

[WoodButcher]

I did the slide out mobo tray. I used steel and alum not thinking about corrosion,,, helluva-thing considering I spent almost ten years doing copperwork. No prob yet though,
I cut out the tray behind the CPU to facillitate easy heatsink changes.

my rig

top down

back

alum & steel owwwww!

Scavenge a steel mobo tray, I liked the raw steel look so I wire wheeled everything and applied coat of car wax. In the house that will prevent rust for many moons.

 

[MotF Bane]

...alright, can somebody cover briefly this whole thing about galvanic corrosion? I'm a high school AP Chemistry student with a C average, so I have a minimal idea of what goes on... but the metals are just touching each other, they aren't being used to do anything more than hold parts, right? So how can they corrode without something affecting them?

 

[sc0rpi0]

Originally posted by: Zepper
... You'll just have to figure out a way to retain a solid ground path ...

Computers are grounded through the power supply. No extra grounding of the case is required.

 

[Zepper]

The mobo drawer has to be grounded to the case. . There will be a small leakage current running from the mobo drawer to the case itself as part of the ground path. So if you isolate the aluminum drawer to prevent corrosion, you will have to rig a ground strap to the frame.

MotF,
There there can be corrosion due to the dissimilar metals. It's the same principle used in thermocouples.

.bh.

 

[WoodButcher]

Thinking about it more I can't recall ever seeing personally a prob with steel and alum. Minor corrosion with roof nails and alum but that was galvanized nail, ie- zinc coated, or plain old rust because of water added to the mix.
Zepper, does that alum mobo use steel screws? Seems to me the screw threads would be a nasty place to corrode, also in an alum case what would you use for a power supply? do casemakers use grounding straps everywhere? Wiki did mention using grease to isolate the metals. When I have a chance there is a shop near me I'm gonna go case-diving.
MotF Bane, don't sweat it, as a high school AP Chemistry student with a C average your a few steps up on me. 30 years later and I wish I went to HS. Cute girls! I went to wiki and looked up galvanic corrosion and still hate tech papers. They never seem to end for those of us that wish to learn. Look up one item and then I get into the properties of metals and then the elements and on and on and on.
Simply speaking disimilar metals work like a battery, Ions discharge and the lesser metal will corrode or break down. read the wiki. good explaination.

 

[Zepper]

I'm not sure what kind of screws Lian Li uses with their cases. I had their EX-34 HDD cage here and it had swaged in stainless steel threaded bushings for the screw mountings. And the custom, shouldered HDD screws are isolated with rubber bushings. I rigged ground straps like in the olden days of the IBM AT case (first to isolate the drives from the case on plastic rails) to ground the drives to the case even though I probably didn't need to. You can get aluminum M3 size thumbscrews for use with Lian Li cases (anodized in different colors too if you want). If the Al parts are anodized, that's an insulator so probably no corrosion. Caig Labs (http://www.caig.com - great stuff but not cheap) contact cleaners and protectants will prevent corrosion between dissimilar metals too.

.bh.