Homemade ATX case idea?

I have this idea for a simple compact ATX case. I think I've
thought of all the issues, but I wonder if there's anything
I've missed. Here is what a cross section looks like, when facing
the motherboard from behind (the ports are facing you).


cardboard wall
|
V intake
____________ __________________
| | | | |
|##### | | | A P |
|##### | \|||/ G C |
|#PSU# | CPU P I |
|##### |=======MOTHERBOARD======= |
|##### ---------------|
|##### [[[HDD]]] | DVD |========] Tray opens to side
|#####______________|_______________|

Airflow enters the case via the top intake directly to the CPU
fan. This air travels over the motherboard to the right, where
it escapes downward over the DVD. This air travels left over the
DVD and around the HDD. Finally, the PSU sucks the air out the
rear. I think airflow will be efficient, because the CPU fan and
the PSU fan work with each other in push-pull tandem.

The PSU and DVD drive rest directly on the base board. The hard
drive rests upside-down, with foam tape spacers at the corners
to isolate vibrations and allow all around airflow.

Not visible in the cross section are two wooden block spacers in
front of and behind the drives. The motherboard rests on top
of these blocks.

Construction is very simple. The two wooden block spacers are
glued to the baseboard, and then the walls are glued to the
basebaord also. The rear wall needs holes for the PSU and ports,
of course. Then, the cardboard internal wall is taped in place
(this wall needs a hole for the power cable to reach the
motherboard). The lid is a separate piece, and it features a
large hole and a cylindrical foam intake. RF shielding is provided
by incorporating an aluminum foil layer in the walls and lid.

I think this case has adequate airflow and will keep all
components cool. If the snaking air path around the drives is
too restrictive, I can punch a hole in the cardboard wall to
allow more flow straight from the CPU area to the PSU.

I think this computer has the potential to be rather quiet, since
it only has two cooperating fans and two major openings. I can
easily modify the lid to incorporate a large muffler and/or
air filter, if necessary. I could also modify the PSU area to
route the exhaust downward through a hole in the baseboard.
That would let me experiment with a large muffler underneath
the baseboard.

I like the simplistic maintainability of this case. There are no
nuts and bolts at all! The various components are simply dropped
into place. Neither the drives nor the PSU obscure the
motherboard from above, so adding/removing memory, CPU, or
expansion cards is a snap. Just remove the lid, and it's all
right there on top.

As a final note, I intend to use this computer "sideways", so that
the DVD tray opens toward me and the ports are to the left.
This minimizes the perceived profile of the computer even if it's
very deep.

So, is there anything I missed?

Thanks!

Isaac Kuo

Isaac Kuo wrote:

I have this idea for a simple compact ATX case. I think I've
thought of all the issues, but I wonder if there's anything
I've missed.

Wooden blocks, cardboard, glue, aluminum foil... Yup. Sounds like
you've got the essentials covered!

-WD

You'd better have a powerful (and noisy) CPU fan, otherwise the warm air
from that heat sink will impair the cooling of other components. A
better idea would be to simply put vent holes in the front of the case
to let the PSU suck air in that hasn't been pre-heated by the CPU heat sink.

--
spammage trappage: replace fishies_ with yahoo

Sooky Grumper wrote:
You'd better have a powerful (and noisy) CPU fan, otherwise the warm air
from that heat sink will impair the cooling of other components. A
better idea would be to simply put vent holes in the front of the case
to let the PSU suck air in that hasn't been pre-heated by the CPU heat
sink.


Some futher thoughts (and I haven't the time to read your entire post):

1. won't that foam beneath the hard drive hold residual static charge
and also be a fire hazard?

2. How are you planning to ground the motherboard? I may be wrong, but I
was under the impression that all motherboards had at least one metal
screw used to ground them to the case (and view the case to the PSU to
the electrical ground).

--
spammage trappage: replace fishies_ with yahoo

"Will Dormann" wrote in message
news
Isaac Kuo wrote:

Wooden blocks, cardboard, glue, aluminum foil... Yup. Sounds like
you've got the essentials covered!

-WD

Actually he doesn't!
Where's the popsicle sticks and rubber bands?

Hank

Sound like a great project. The only thing that comes to mind is
cooling the video card. Maybe some inlet vents above the DVD
that will allow cool air to the video card. If it's onboard video,
it should be no problem.. But a GF4 runs about 12 watts.

These are great fans to run at 7v or even 5v for low noise cooling

http://www.casecooler.com/pan80hydwavb.html

On second thought, I didn't see the cardboard wall.

If the hard drive overheats, maybe remove the
cardboard wall and add inlet vents on the front near the DVD.

Try Dtemp for monitoring hard drive temps.
http://private.peterlink.ru/tochinov/

Great idea

On 26 Jan 2004 11:00:35 -0800, (Isaac Kuo) wrote:

I have this idea for a simple compact ATX case. I think I've
thought of all the issues, but I wonder if there's anything
I've missed. Here is what a cross section looks like, when facing
the motherboard from behind (the ports are facing you).


cardboard wall
|
V intake
____________ __________________
| | | | |
|##### | | | A P |
|##### | \|||/ G C |
|#PSU# | CPU P I |
|##### |=======MOTHERBOARD======= |
|##### ---------------|
|##### [[[HDD]]] | DVD |========] Tray opens to side
|#####______________|_______________|


So, is there anything I missed?

Thanks!

Isaac Kuo

Where does the stuff plug in?

Will Dormann wrote:

I have this idea for a simple compact ATX case. I think I've
thought of all the issues, but I wonder if there's anything
I've missed.

Wooden blocks, cardboard, glue, aluminum foil... Yup. Sounds like
you've got the essentials covered!

What? No duct tape? BAH!

Sooky Grumper wrote in message ...
Sooky Grumper wrote:
You'd better have a powerful (and noisy) CPU fan, otherwise the warm air
from that heat sink will impair the cooling of other components.

I figure that the other components don't need as much cooling.
In particular, the location of the DVD and HDD drives in most
tower cases seems to get so little airflow that I think I'll
be fine. The air may be warmer but the amount of flow will be
large and fast (note that the air path is "bottlenecked" around
the drives).

A better idea would be to simply put vent holes in the front of the case
to let the PSU suck air in that hasn't been pre-heated by the CPU heat
sink.

I'm concerned that this will let too much sound out, and it will
reduce the amount of airflow through the CPU. As it is, the
PSU fan will give the CPU airflow a small boost because the only
major intake is above the CPU.

However, I'm not going to go through all of the trouble of
sealing things airtight for a "negative pressure" case. The air
intake will NOT be completely sealed against the CPU fan, so
extra air can leak in bypassing the CPU heat sink. Also, the
rear side needs holes for the various ports (VGA, audio out,
ethernet, keyboard, mouse). I'm not going to bother making those
holes airtight, so extra air can enter from there.

Some futher thoughts (and I haven't the time to read your entire post):

1. won't that foam beneath the hard drive hold residual static charge
and also be a fire hazard?

I am talking about 4 small pieces of double sided foam mounting
tape in the corners. I don't think there's any chance of static
or fire. Also, using plain old packing foam has been done. On
silentpcreview.com there are examples of hard drive "mountings"
using nothing but cut up packing foam to isolate their vibrations.

2. How are you planning to ground the motherboard? I may be wrong, but I
was under the impression that all motherboards had at least one metal
screw used to ground them to the case (and view the case to the PSU to
the electrical ground).

I hadn't really put much thought into grounding. The more I
think about it, the more I just can't see that it's necessary.
Certainly, it's not needed for the drives--I've seen plenty of
examples of drive "suspensions" where obviously the only grounding
is via the power and IDE cables. Similarly, the motherboard is
surely grounded to the PSU via the ATX connector. Also, some
computer cases isolate the PSU from the case via rubber grommits
to isolate vibration (reducing noise).

The only thing I can think of is that grounding to the case may
assist in RF shielding.

In any case, thanks for the feedback! I really hadn't thought
about the grounding issue. Perhaps there are other important
issues I hadn't really thought of yet.

Isaac Kuo