Need your input on custom case

Adam F · 09-23-2002, 07:19 PM

I'm trying to build a character LCD based mp3 player for my rig. I'm trying to build it as cheap as possible, because my truck has a removable top and somebody could easily just rip the system out and take it with them. I'm going to put the computer behind a plastic panel in the rear to keep it out of site. I have some scrap plastic that I got from work for free. I am attempting to build a case out of it. It's rather thin. A little bigger than the thickness of a CD-Rom. I'm going to build the top, bottom, and sides out of this plastic. I'm not sure how to mount the mobo on this plastic. I'm worried about it possibly melting the plastic.

Now for the questions. How hot does a mobo really get? Should I be worried? Should I mount the mobo directly to the plastic, with some double sided tape to where the holes for the previous mounting points on the old metal case? Or should I maybe use some sort of risers to let some air circulate under the mobo?

I plan on making the case really shallow. Just deep enough to clear the memory sticks. That is the tallest part of the mobo. But I'm also worried about the processor fan being able to properly breathe. It's a 300mhz K6-2 with a good sized heat sink and fan. (see picture) It will only have a few inches above it to move the air around. I'm also going to add a 3" fan somewhere in the case to move the air out. I'd like to mount the fan on the side of the case, not on top. Do you think mounting the fan on the side and having the case very thin would have adequate ventilation? It will just have a 30 gig HD, no floppy, cd, or any PCI cards. Has built in audio. And I plan on mounting the ATX power supply outside of the case. I might even mount the hard drive outside the case as well, only if I can't get it to fit in the case.

What do you guys think? Let me know, good or bad. Here's a pic of the mobo.

bh76 · 09-24-2002, 02:47 AM

Motherboards, especially older Socket 7 boards don't run very hot. The hottest part would be the voltage regulator, and possibly the northbridge/southbridge on newer boards.

Still, the board was meant to be mounted on standoffs. Why bother with sticky-tape when standoffs aren't all that expensive?

How about something like this?
https://www.jameco.com/cgi-bin/ncomm...s=503;537;808;
or
http://rocky.digikey.com/scripts/Pro...US&V=36&M=2210
(or the vendor of your choice)

As for cooling, there's no way to know for sure until you try it. I don't think you'll have any trouble as long as you use a case fan, and make sure that the top of the cpu fan isn't tight against the case.

Dimitris1976 · 09-24-2002, 12:50 PM

I would suggest, unless you want that clear lexan/plexyglass look, to build your case out of plywood. It's much easier to work with than plastic and you can cover it with carpet (same color as the rest of your car's interior) for a stealth installation.
I used 8mm plywood glued together and strengthened with screws.
The mobo should be mounted on brass stand offs- one off them grounded with a piece of wire to the PSU's case.

Filip · 09-24-2002, 09:05 PM

I agree on the plywood part, but perhaps he is using the plastic because of space issues (truck)?

Plywood:
It's easier to work with and can also take an impact better than the plastic. Plus like Dimitris1976 suggested, you can cover it with carpet. Just make sure you cool it well, as carpet will be a good insulator.

Plastic:
You can shape it with a heat gun or really good/hot blowdrier. Otherwise I guess you can use the "crease" method. You might have problems mounting to it because your screws may rip through (if it's that thin).

I would also add spacers either way you go. I don't know how many CFM your 3" fan gets but I think you should be fine, especially keeping the PS outside. Mount it on the side and put a vent on the opposite side. Try using some thin foam or at least speaker grill / screen cloth on the vent to keep out the dust.

I don't know where you're mounting it but consider potential rain/heat when you leave your top off.

Adam F · 09-24-2002, 09:42 PM

Thanks for the input guys. It will be behind a plastic panel, away from view and especially away from the rain. Here is where I plan on mounting it:

Wood might be easier to make a square box out of, but it surely isnt easier to cut. I am using a dremel tool to make the cuts, and wood wouldnt be too much fun to cut with a little dremel. And since it will be out of sight, im not worried about the appearance of the case a whole lot.

I bougth some plastic stand offs today, and they work great. Thanks for the help guys, I'll let you know how it turns out!