Nevbie + strange questions

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quietnevbie
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Nevbie + strange questions

Post by quietnevbie » Mon Dec 31, 2007 9:28 am

Hi all, been reading this site for some months.

I have never built a PC myself yet. Now I'm going to, just looking for all possible information from the net & waiting for new GPU architecture from Nvidia & waiting for penryn also.

Never liked the idea of cases that much though, they seem to be obstacles and they seem to involve various fitting/case fan/airflow/heat problems. And they cost alot for being such problems.

So I decided I'll use cardboard material and some cheap tape to create the case. Currently I'm planning to get a big cardboard box, a medium sized cardboard box and a smaller cardboard box. I'll put the 2 smaller boxes inside the big one, and fill the area in between with.. books.

I drew a little plan with Paint:

Image
Plan is to duct GPU/CPU heat out. Or something like that. I'll probably be using aftermarket coolers for GPU & CPU and S-Flex 1200rpm version for all fans except the PSU which might be something like the Corsair VX550 fan.

Some questions:

1. Is cardboard+book layer+cardboard a good dampening material?

2. Does it even matter as I will have air intakes/outtakes, where there clearly are no obstacles between potential noise and outside world?

3. Is it a good idea to just put the motherboard on the cardboard? It won't need airflow near the backside of board, I guess? And the mobo might get less stressed by aftermarket heatsink weight..

4. There are no intakes for the main area in my plan, I'm unsure where to place them. CPU and GPU are clearly the two hottest parts, so their heatsinks will be used in the ducted exits. Will any of the other places (chipsets, capacitators near CPU, RAM) require such cooling, that I should direct an intake fan for them?

5. Negative, positive or even pressure, when there are no other paths for air to go than the planned ones? Or will it matter much?

6. I will probably want at least 2 fans besides the PSU one, for the exits. Does it matter if I put the fans in the ducts, or near the heatsinks, so that they push air via heatsinks to the ducts?

This is just a plan, nothing is bought yet.

colin2
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Post by colin2 » Mon Dec 31, 2007 2:25 pm

How are you going to mount the optical drive, switches, LEDs, and so forth? And will you have to take this thing apart every time you change a cable connection to the mobo? Store-bought cases solve a lot of these problems for you. And you're also going to want to attach stuff so it won't slide around, for which ordinary cardboard will be too flimsy. Masonite or thin plywood would be structurally adequate, but resonant.

That's not to say that making your own case couldn't be lots of fun, and if you search around here you'll find a lot of inspiring DIY cases.

quietnevbie
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Post by quietnevbie » Mon Dec 31, 2007 3:32 pm

colin2 wrote:How are you going to mount the optical drive, switches, LEDs, and so forth? And will you have to take this thing apart every time you change a cable connection to the mobo? Store-bought cases solve a lot of these problems for you. And you're also going to want to attach stuff so it won't slide around, for which ordinary cardboard will be too flimsy.
I'll get a power cable (molex?) & SATA cable outside, so I can insert a backup HDD or CD/DVD drive to the machine during the short periods when I need those.

No LEDs needed I think. Power switch is a good point, but I expect to find some kind of power switch mechanism that is not a part of any case if I seek such from PC stores. Not sure though.

I don't think I'll keep changing cable connections to the mobo during normal use. But yes, I probably have to open the bigger box, take some books out and open the smaller box in order to change SATA etc cables, if ever needed.

Not sure about the sliding? I'll use tape to connect fans.. and I'll put the whole thing on a flat board. I'm not expecting things to run away by themselves, but I guess I'll know more about this in the future! :lol:

colin2
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Post by colin2 » Mon Dec 31, 2007 8:45 pm

Great -- then follow your vision and take pictures and keep us informed! You can always stuff it in a store-bought case later. Do aim for good airflow across anything hot. Monitor temperatures. I assume if you've been reading the forum you know about CPU heatsinks and HD suspensions and you've read the recommended components lists. Starting with quiet and low-heat components is 3/4 of the battle.

jaganath
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Post by jaganath » Mon Dec 31, 2007 10:19 pm

never mind the fact that the case will be a massive fire hazard and provide zero EMI shielding. Just do it, I'm sure it will be better than a case designed by trained engineers.

quietnevbie
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Post by quietnevbie » Tue Jan 01, 2008 11:04 am

jaganath wrote:never mind the fact that the case will be a massive fire hazard and provide zero EMI shielding.
Hmm, which internal components could ignite the cardboard? None in normal operation, but otherwise? PSU area? I could put some legos there. I'm not planning to burn my house, so there should be no external causes.

EMI I don't understand, but I guess there should be no differences between some cheap plastic case and this one in that regard.

colin2
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Post by colin2 » Tue Jan 01, 2008 12:20 pm

Why not build the whole case out of lego? I'm sure someone's already done that, but it would certainly make it easier to try out different shapes and configurations.

EMI can cause interference with other gear and in most places it's regulated; but for home use it's not much of a worry. If you have health concerns I recommend a tinfoil codpiece.

colin2
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Post by colin2 » Tue Jan 01, 2008 12:29 pm

... and a quick search shows that there's a ton of impressive lego casework out there, including some people who have really grappled with the technical problems. I say go for that. Less resonant, and way more fun than corrugated cardboard and duct tape.

And consider the possibilities for nonstandard shapes!

scdr
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Post by scdr » Tue Jan 01, 2008 10:55 pm

I would also wonder about how well this design would protect your machine from static electricity. Normally a grounded metal box around your computer provides some protection against such charges. I would be extra careful to touch a grounded part (e.g. the power supply case) or use an anti-static wrist strap when working on this thing.

Also, won't it make it harder to get at your library? ;-)
(Be sure to use an inner box strong enough to support the books when somebody accidentally kicks the thing.)

klankymen
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Post by klankymen » Tue Jan 01, 2008 11:22 pm

I've tried lego cases before.... components are heavier than they look. but with mini-itx lego cases do work.

quietnevbie
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Post by quietnevbie » Wed Jan 02, 2008 8:45 am

To be exact, I have duplos, not legos. First I thought of using them for the case, but soon realised that I probably wouldn't have enough of them. I suspect they wouldn't feel any more customizable than cardboard+tape. (I can't cut legos like I can cut cardboard, for example)
scdr wrote:I would also wonder about how well this design would protect your machine from static electricity. Normally a grounded metal box around your computer provides some protection against such charges. I would be extra careful to touch a grounded part (e.g. the power supply case) or use an anti-static wrist strap when working on this thing.
I'll touch the radiator during building process then. Does the grounding in the metal box have any function during normal use? I think the PSU box is only grounded when the PSU power cable is connected to wall though.
scdr wrote:Also, won't it make it harder to get at your library? ;-)
(Be sure to use an inner box strong enough to support the books when somebody accidentally kicks the thing.)
I'll use the books that no one wants to read. There should be plenty of them.

xen
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Post by xen » Wed Jan 02, 2008 6:51 pm

Sounds like a cool think. I kinda like the idea of having a multi layered box holding all my noisy components. Personally I would put a bit more effort into it and make it out of more sturdy materials, maybe triplex or compressed wood fibre, especially for the inner box. And if you're using multiple boxes anyway, you may want to use the buffer space this creates to create longer noise-blocking air pathways. You could pad all the pathways and the innermost case with thin foam or textile. You'd get something like this:

Image

The mobo sits in its own box with three opening in addition to a hole for the io panel. Surrounding the box are channels with obstacles that make it harder for the sound to escape. If the box and the channels are strong enough, you can cover them with books. A normal cardboard box may cave in under the pressure of lots of books. The inner box and the channels can be covered with a lid, like a plate, and the books make sure that the lid has a firm shut.. Then you can put everything into a bigger box and pad the sides of the channels with books as well.

You could also put the harddisk into the main intake channel, there is plenty of space.

It would be nice to have a usb bracket or something like that sticking out somewhere, though.

Well, just an idea.

Edit:

While eSATA has hot swapping, I don't know if the same would be true of sata and molex connectors.. there is some issue in designing hot swap connectors so that the power is not connected or disconnected in such a way that the partially connected power plug damages the device, during the split second that some pins are connected, but others are not, so it may be dangerous for your optical to just connect it while your system is running.

To answer your questions directly (I'm no expert):

2. I think lots of noise will escape through the exits, your whole book layering effort will be quite in vain without good noise blocking of exits.

3. I don't think it would be wise to put the mainboard flat on cardboard or anything just like that. The backside can get pretty hot.

4. I'd say that if you have normal airflow going from somewhere at the front of the board towards your cpu and gpu, everything else will be cooled sufficiently as well. In my own case, there is no direct airflow path for the cpu at all. Yet when I turn on a front intake fan, the cpu temp lowers by 4 degrees celsius, so there is still turbulence passing the cpu, and I think memory and capacitors will get enough in your case.

5. I think if you create negative pressure you won't be needing any intake fan. I would only use an intake fan if you want to blow at a specific part, such as your memory banks.

6. I think that if you have a duct in a certain position, then it doesn't matter whether there is a fan blowing into the duct or sucking air out of the duct, the airflow should be the same, as long as the duct is the only possible airpath for the fan in question. But a push fan may be able to better target the heatsink, if the duct offers room for the air to move around the heatsink instead of through it.

kittle
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Post by kittle » Thu Jan 03, 2008 11:04 am

Very cool idea here :)

For the record - cardboard is NOT flimsy or weak when used properly. If you take a single walled box you get from the grocery store, or a moving company -- yes it will be thin and not very strong.

But with some enginueity, planning and the right amount of glue - the stuff can be quite strong. I have built things out of cardboard as a hobby for many years so i know whats possible. I have a cardboard speaker box, that sounds pretty good. I have a CD holder for about 200CDs -- its quite sturdy. And I used to have a stand for my 40lb home stereo receiver that i could sit on. All made from cardboard and glue (with some tape to hold it together while the glue dries).

some other suggestions:

go with what xen said about the foam, but get some styofoam blocks and build a barrier between the outer and inner boxes. This adds a lot of strength as well as sound dampening.

A small piece of masonite or 1/4 inch fiberboard would be a great place to mount the power and reset switches as well as any status lights you want.

The only thing im wondering is how you will keep the expansion cards standing upright.

and now you'v got me wanting to try simmilar things.

quietnevbie
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Post by quietnevbie » Fri Jan 04, 2008 7:58 am

xen wrote:Personally I would put a bit more effort into it
I'm not exactly a craftsman, quite the opposite, so I'll try to keep it relatively simple. :)
xen wrote:you may want to use the buffer space this creates to create longer noise-blocking air pathways.
Perhaps a 90 degree curve in each pathway? I'd imagine a complex pathway maze would make air less.. willing to move, but I have no idea how air really behaves in these kind of situations.
xen wrote:You could pad all the pathways and the innermost case with thin foam or textile.
What kind of difference would foam/textile padding make, when compared to simply using cardboard? I think padding like that is out of my skill level, haha!
xen wrote:If the box and the channels are strong enough, you can cover them with books. A normal cardboard box may cave in under the pressure of lots of books.
Valid point. I'll do this even without the books on the top, though. I plan to invest 0€ for this case, so I guess I can put some other junk on the top. Hopefully the various components I buy will have exotic packaging materials that I can reuse in the case.
xen wrote:You could also put the harddisk into the main intake channel, there is plenty of space.
Yes I could, but the PSU box will have extra space anyway, for the cables.. and routing the power there is easy. PSU airpath would be quite lonely with the PSU only.
xen wrote:While eSATA has hot swapping, I don't know if the same would be true of sata and molex connectors.. there is some issue in designing hot swap connectors so that the power is not connected or disconnected in such a way that the partially connected power plug damages the device, during the split second that some pins are connected, but others are not, so it may be dangerous for your optical to just connect it while your system is running.
Luckily that isn't a problem, as nothing prevents me shutting down the system while I plug the cables to backup HDD/optical drive. :)
xen wrote:I don't think it would be wise to put the mainboard flat on cardboard or anything just like that. The backside can get pretty hot.
This doesn't sound like a very realistic threat to me, but then again, I don't know myself. I imagine the cardboard could heat up to 100C with no problems? My mobo would be dead before that. :)
xen wrote:I'd say that if you have normal airflow going from somewhere at the front of the board towards your cpu and gpu, everything else will be cooled sufficiently as well. In my own case, there is no direct airflow path for the cpu at all. Yet when I turn on a front intake fan, the cpu temp lowers by 4 degrees celsius, so there is still turbulence passing the cpu, and I think memory and capacitors will get enough in your case.
Thanks for the answer. I originally estimated that I'd use 4 fans + PSU, which seemed alot when compared to many of the systems around here. Now I suppose I'd start by using a fan both at CPU and GPU ducts, and no intake fans at all. Though it is said about tower coolers that the components near CPU won't get as much airflow as designed..

I wonder if the intake channels should have equal (combined) area (at the tighest point) as the outtake channels. Otherwise the air would have to flow faster at the tight spot, or at least watching a.. river makes me to think so. And I imagine it would be equal to restricting the airflow. :)
If so, then I'm not sure if I should even try with one intake fan (in addition).
xen wrote:I think if you create negative pressure you won't be needing any intake fan. I would only use an intake fan if you want to blow at a specific part, such as your memory banks.
Exactly. Not sure if I need to blow at a specific part (RAM, chipsets with heatsinks, CPU caps?).
xen wrote:I think that if you have a duct in a certain position, then it doesn't matter whether there is a fan blowing into the duct or sucking air out of the duct
Yeah. I guess the only differences would be possible noise character variations.
kittle wrote:For the record - cardboard is NOT flimsy or weak when used properly. If you take a single walled box you get from the grocery store, or a moving company -- yes it will be thin and not very strong.

But with some enginueity, planning and the right amount of glue - the stuff can be quite strong.
Thanks for the hope. :) I'll probably use it improperly though. I think I'll have to try minimize the weight it supports, and mainly use it for directing the air and reducing the noise slightly.
kittle wrote:styofoam blocks
These at top might work, instead of books. If I find this interesting material anywhere for free, that is. :)
kittle wrote:The only thing im wondering is how you will keep the expansion cards standing upright.
Sounds bad. Will the expansion cards really have problems behaving, if only connected to the PCI/PCI-E slots, and not supported by the case at the rear?
kittle wrote:and now you'v got me wanting to try simmilar things.
I'm honored. :)

xen
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Post by xen » Fri Jan 04, 2008 1:14 pm

quietnevbie wrote:Perhaps a 90 degree curve in each pathway? I'd imagine a complex pathway maze would make air less.. willing to move, but I have no idea how air really behaves in these kind of situations.
Well I'm not sure... but note that mounting a 120mm fan PSU inside a Antec P180 forces the air to move in a 90 deg angle so it seems like quite an accepted thing to do. I've seen the kind of case build I described before, and if you want your case to be silent I think there is really no escape in creating some angles in your airflow because you need the noise to bounce back instead of going straight out, if you want your book-buffer to be of any advantage to overall noise (I think).
What kind of difference would foam/textile padding make, when compared to simply using cardboard? I think padding like that is out of my skill level, haha!
Well, I'm not talking about noise blocking but more about the noise reflecting quality. I think pure smooth cardboard can still reflect noise quite well.
xen wrote:You could also put the harddisk into the main intake channel, there is plenty of space.
Yes I could, but the PSU box will have extra space anyway, for the cables.. and routing the power there is easy. PSU airpath would be quite lonely with the PSU only.
Hehe, yeah I only mentioned it for the case that you would want to eliminate harddisk noise to a greater extent without creating TWO complex air pathways instead of one. The PSU alone wouldn't make much noise I'd say.
xen wrote:The backside can get pretty hot.
This doesn't sound like a very realistic threat to me, but then again, I don't know myself. I imagine the cardboard could heat up to 100C with no problems? My mobo would be dead before that. :)
Well... the issue is that normally there is still some convection cooling at the back of the case making sure there is at least some heat being transferred through that channel... I don't know what the effect would be if you take away that channel. It's also a bit of an emotional thing on my side: I just don't like the idea ;).
Though it is said about tower coolers that the components near CPU won't get as much airflow as designed..
Right... you mean tower coolers that have fans on the side, as opposed to regular coolers than blow down onto the cpu, which creates lots of turbulence around the cpu, right? Well, can't help you there, it could be important. I guess you'll have to experiment with that.
I wonder if the intake channels should have equal (combined) area (at the tighest point) as the outtake channels. Otherwise the air would have to flow faster at the tight spot, or at least watching a.. river makes me to think so. And I imagine it would be equal to restricting the airflow. :)
If so, then I'm not sure if I should even try with one intake fan (in addition).
Yes, tigher spots mean the air has to travel faster, but if your exhaust fans can handle it there should be no problem. If you exhaust cannot inhale as much air as it wants to exhale, then you are in trouble, but I would think even one open 6x12mm intake should be enough for two 120mm exhaust running at 5V to perform at an optimal level. But I'm not experienced with this, so you better not take me at my word ;). If your intake opening starts to make noise of itself because of the fast airflow, you should consider redesigning it ;).
kittle wrote:For the record - cardboard is NOT flimsy or weak when used properly. If you take a single walled box you get from the grocery store, or a moving company -- yes it will be thin and not very strong.
Naturally :). I was speaking of my experiences with normal boxes stacked upon each other, when they don't exactly match in size.
kittle wrote:styofoam blocks
These at top might work, instead of books. If I find this interesting material anywhere for free, that is. :)
We dutch call it "squeekfoam" ;). I've never seen it for sale anywhere though, it only arrives as a packing material for other stuff... maybe you can shop around electronics stores and the like ;).
Sounds bad. Will the expansion cards really have problems behaving, if only connected to the PCI/PCI-E slots, and not supported by the case at the rear?
Depends on whether you plan to attach heavy things to your cards ;).

xen
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Post by xen » Mon Jan 07, 2008 8:04 pm

Btw, just so you know: if you put any expansion cards in your motherboard, you will have to lift the mobo about a centimeter above ground level, because the expansion card front plate reaches below your motherboard level.

quietnevbie
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Post by quietnevbie » Thu Jan 10, 2008 9:14 am

xen wrote:
Sounds bad. Will the expansion cards really have problems behaving, if only connected to the PCI/PCI-E slots, and not supported by the case at the rear?
Depends on whether you plan to attach heavy things to your cards ;).
Well, some popular aftermarket cooler probably, as I don't have much trust for the retail solutions. Doesn't get much heavier than that, I guess. :?
xen wrote:Btw, just so you know: if you put any expansion cards in your motherboard, you will have to lift the mobo about a centimeter above ground level, because the expansion card front plate reaches below your motherboard level.
Thanks for the note. This means that I'll use lego bricks or something under the mobo. And this also means that the backside of the mobo will get some airflow.

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Post by xen » Thu Jan 10, 2008 11:48 am

After seeing that I have enough components lying around to build a new (old) computer myself, I've decided to try my hand at this myself :). I'm planning to build a cardboard inner box lined with 12mm foam, which sits inside an outer box with the space between filled with 30mm styrofoam. I want it to be small and lightweight. The mobo is full atx. The atx power supply and the harddisk+optical sit in front. Looked at in a tower orientation, the bottom 'wall' contains the intake pathway and the top 'wall' contains the output pathway. I hope 2x12cm (24 square cm) air paths will be enough for the airflow generated by one 12cm@low voltage and one 8cm fan (PSU) that act as exhaust fans. The 120mm fan will be mounted in the side panel of the inner box (which is the top panel in desktop orientation) and it sits next to (hovers above) the cpu, northbridge and vga card, drawing air through the only available intake path, which passes the harddisk. I'd make a drawing if not for this operation system (os x 10.3) for which there does not seem to be a single simple paint application available, apart from xfig, but oh, the horror. But the idea is that there are air pathways inside the styrofoam walls. I just hope I will be able to salvage power switch and leds from an old Dell optiplex case I stil have lying around. Shorting the two power switch pins with a screwdriver doesn't seem like a good way to start the system once the case is finished ;). The electronics store we have in town doesn't even sell resistors, I doubt it caan help me with leds and switches.

I also doubt whether this case will do anything to stop the sound of the whining harddisk I will be putting in it, from reaching my ears... but we'll see.

scdr
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Post by scdr » Thu Jan 10, 2008 1:42 pm

What is the styrofoam for?
Not much good as sound insulation - want something denser than that.
For isolation (vibrations) probably want something less rigid (e.g. sorbothane or gel).

Also bad news if it gets really hot (releases nasty gasses).

xen
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Post by xen » Thu Jan 10, 2008 2:12 pm

Hm I was thinking that maybe the styrofoam would serve to reflect some of the noise back into the case. I guess I'm wrong about that then? 1cm of styrofoam holds only about 5 cells, very little mass. Is the only way to create a noise-block the use of high density materials? I'm not worried so much about vibrations because the cardboard doesn't seem to me to be a good medium for transmitting vibrations.

But if it gets really hot.. the styrofoam is treated with fire-slowing-down-chemicals as is the inner foam. Maybe that won't be of much help when the rest is cardboard ;) :P.

So what would you propose? There is this special material from www.ichbinleise.de which is just high density layer of 2mm, but very costly, and I'm already planning to use one layer of it (it's part of the 12mm foam). The only alternative seems to be a think layer of paper or a wood (MDF) enclosure, but now we're talking about one heavy case ;).

Would it be better to just replace the styrofoam with more layers of cardboard? I doubt that will have much effect, really... are generic sorbothane sheets available on the end-user market?

In any case, or at least in this case, I'm using the styrofoam also just as an easy-to shape product for making the air pathways, so even if it doesn't do much, it still serves some purpose.

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