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View Full Version : Looking for some modding advice...



A Guy Named Joe
03-29-2005, 10:43 PM
I'm been considering a mod, but not to a case.

I have a computer desk that has a computer compartment and it hides the computer nicely. However, it get's really hot in there. Really hot. I managed to garbage pick some working parts and some parts donated by friends. I got a spare PSU, 2 80 mm fans, a huge 120 mm fan, and wire grill, with some fiber material to keep the dust out.
What I'd like to do is cut a portion of the front door to the cubby hole/computer compartment out and put the two 80 mm fans in the front and the 120 mm fan in the back.

However I want to do a professional job, because one thing keeps me from doing it. My wife. She doesn't want me to do a half @$$ed job and destroy the desk, yet I know I can do a decent job if given the chance and also the help.

I want to use the PSU to power the fans, but yet I need some advice as how I would like to wire it out, and I need advice as to turn on the fans and turn them off. I'm thinking of some type of rocker switch I can flip on and off, but not sure how to go about wiring it.

I need advice!

Frakk
03-29-2005, 11:24 PM
for the powersupply: you can turn on a powersupply without the motherboard and any other components by shorting out the green wire (pin 14) on the 20pin atx header by connecting it to any black wires. if the switch is on, and the pins are shorted, you should hear the fans inside the psu start spinning. now you can connect devices on the power rails

a switch for the fans: this is very easy. the yellow wire is your source of 12V on from the psu, and the two black wires are the ground. you can buy switches from radioshack for fairly cheap, they will have 2 pins, all it does is shorts the two pins/wires. just cut your 12V line, solder the pins to the two ends (doesnt matter which way) and you have a working switch.

Is the comp in a closed area like a box? because if it is, it would be just easier opening the doors or something :) if only the front of the case is open, maybe you should put an intake fan in the front of the case. i wouldnt bother drilling holes on the table and messing with an extra psu if not necessarry :)

Matthew
03-29-2005, 11:24 PM
First off...I wouldn't use a psu for this job...it would just be big and in the way. Get you an old cell phone charger of some sort. Either 5volt or 12 volt for the power supply. Otherwise you would just have a Hugh hunck of metal doing nothing but powering fans and having about 200+ watts wasted. as for the fan's position (And this is only what I would do) I would put them all in the back. Have the two fans at the bottom blowing in, and the 120mm fan at the top blowing out. One as an intake and one as an exhaust. It would keep things nice an cool. Reason I would have them both at the back is it would keep things looking normal and nice on the front, and get the job done almost as well as a blow through would.

Here is a pic of how I would do it. Oh yeah...red is live wire Green is ground.
http://www.optic-illusion.com/fans1.jpg
Here is a Pic on how it will work.
http://www.optic-illusion.com/fans2.jpg

Frakk
03-29-2005, 11:37 PM
power is not wasted, the psu wont draw the current from the outlet unless its needed :) lets say it wont be used up to its full potential :) and the other thing is you cant determin the positions of the fans before you know how the air moves inside the case (thats what matters after all). as I posted before, a front or side intake is necessary for proper airflow and to avoid negative pressure(and dust)
air enters the case from the front, exits in the back through the psu (and rear exhaust), pretty simple. now if the whole thing is in a box, you need to supply the front intake with fresh air and remove the hot air exhausted by the psu so the hot air is not circulated in the box.
If you have the front open, then there is no need for a front fan, only a fan that exhausts the hot air.

A Guy Named Joe
03-29-2005, 11:47 PM
Hmmm, so I wouldn't need all of the extra fans then? I could technically then just put a front grill in the front of the door panel, and then just use one or two of the fans in the back?

Frakk
03-30-2005, 12:05 AM
I'll draw you a picture tomorrow, its too late and i have to wake up tomorrow for school:) if you can take some photos and post it, it would be nice and a lot easier to help, or just give a detailed description of the whole thing because I dont know whats it like:) thanks in advance

A Guy Named Joe
03-30-2005, 09:22 AM
I'll get some picts of the area tonight or tomorrow and post them on here so I can you an idea of what I'm talking about.

Chapel
03-30-2005, 01:53 PM
A tip for the grill, this would cut down your airflow, but you could take the wood cut out and turn that into a grill. It would fit right in the desk and still look nice. Imagine those floor vents for wood floors, the ones that blend into the floor. Something like that would provide enough airflow to get circulation. You got to realize though, that if it gets really hot in there that your probibally not going to be making cooler air go into your case, it will just improve airflow

A Guy Named Joe
03-31-2005, 03:59 PM
Hmmm...like a wood grill? Instead of cutting out one BIG piece and putting a metal wire grill, just make slits for open circulation, put the filter material in place and THEN put the metal mesh grill behind it?
That might sound like a plan.

I think I'm going to have to sit down and draw out some plans of attack before I start work on this. That way I know what I'm doing and can follow a procedure step by step.

A Guy Named Joe
04-04-2005, 10:21 AM
Here are those picts I promised of the area I'll be working with...


Here's the front view of the door. I'll need to cut a hole to work with the grill area somewhere on the door.
http://www.geocities.com/agnjoe1/cab1.jpg
Here's the area with the door open...
http://www.geocities.com/agnjoe1/cab2.jpg
And here's a side view of the area with a open area for cables...
http://www.geocities.com/agnjoe1/sidecab.jpg
Now here are the measurements for the area....
19 1/2 inches...
http://www.geocities.com/agnjoe1/cab3.jpg
by 11 inches...
http://www.geocities.com/agnjoe1/cab4.jpg
by 20 inches deep.
http://www.geocities.com/agnjoe1/cab5.jpg

fishies
04-04-2005, 10:37 AM
Are you leaving the case in the desk or are you making that desk cupboard the case?

A Guy Named Joe
04-04-2005, 01:53 PM
The midtower case will stay in the cupboard. I'd like to possibly cut out the front portion of the door, put some type of grill in the woodwork for the front door panel, and possibly wire the front panel area with the 2 80 mm fans. It also might be possible for me to cut a portion in the inside of the desk where the open rectangle space (see the side cabinet view) and possibly put the fans there instead as to not cut out the front door panel so as to leave the astetics or the look of the desk intact.
Then I'd like to cut a portion of the back out, and put the 120 mm fan in the back of the desk and use it to shunt out and expel the hot air via the back.
I'll also take some picts of the equipment I have gathered so far tonight or tomorrow if I have some time.

Matthew
04-04-2005, 02:03 PM
Have you considered using that precut side hole? It may save you some cutting.

fishies
04-04-2005, 02:04 PM
coolio.

i'll pm you some ideas for the front, if you want.

A Guy Named Joe
04-07-2005, 09:37 AM
Man, I was REALLY hoping to win that Dremel.

Oh well, that'll make my project that much more harder without the proper tools.

Anyway, The more I think about it, the more I just might use the precut side hole instead of the front. I'm still torn at this point as what to use and what would be best.

fishies
04-07-2005, 09:40 AM
Drill and a jigsaw, dude.

Matthew
04-07-2005, 10:33 AM
Yeah...jigsaws are QUITE handy, and fit perfectly in this job. In fact, I like it better for cutting than a dremel. Its easier to control, and make a *perfect* cut.

A Guy Named Joe
04-08-2005, 12:08 PM
Yeah, I think that'll have to be the tools to use.

And I think I've decided on using the precut side hole. Sure it would be nice to get a direct front to back route, but I think the side vent will do just nicely.
Ok folks. I'm going to start drawing out the plans and making my attack on this soon.
And I'll be taking pictures of the whole thing to document it.

Matthew
04-08-2005, 02:46 PM
Well man I wish you the best of luck and keep us posted on how it turns out.

Zuke
04-08-2005, 03:24 PM
So, have you decided against the additional fans and PSU? If not, you're best bet would be to wire a 12v relay to pins 14 & 15 of the slave PSU and wire the 12v leads to the computer. That way the fans kick on when your computer does.

As for the desk/tower idea, I can understand why your wife wouldn't want you to ruin that desk. You're best bet would be not only to put a vent on the inside panel, but to also get a case with better airflow to start with.

X child
04-21-2005, 01:48 AM
I friend of mine has his computer in a desk like that and had some overheating problems. All he did was take his side panel off the computer case and open the door of the desk. So maybe you could cut a bigger hole where the precut hole is and add one or two fans. But I think most importantly for you is to take the side panel off of the case. Or another thought may be to cut a hole in the back panel of the desk so your powersupply and any other fans you have sucking air out of your computer goes directly out of the desk.

OldY
04-21-2005, 06:31 AM
SNAP
I have exactly the same case that i am using for my doom 3 case mod :p :p
Rock on!!!

A Guy Named Joe
04-21-2005, 02:28 PM
Ok, here's an update on the desk mod I'm doing. Sorry it's been a while. I had problems logging in to update this thread.
First off, I decided AGAINST putting the 2 80 mm fans into the front door panel with a vent in the front. I figured since there was an existing pre-cut hole area in the side, it would be best to use that instead, and then cut out a hole in the back to vent out the hot air through the back. Since this is now the plan I began work.
I first cut the hole in the back with a hole saw bit. I didn't realize how deep the wood actually went, but let me tell you, NEVER cut a hole with a 12 volt battery drill! It took me an hour to cut through 3/4" inch of some solid maple oak wood. But I was finally through.
Next was reorganizing cable placement. I found another round hole WAY up near the top of the desk, so I rerouted almost all of my cables through that hole. That way, I can manage the mess underneath my desk. By adding a couple of cable clips for the wires, it's amazing how nicer it looked and functioned.
That's where I've left off so far. I'm planning to get the smaller fans and the large fan installed and wired, so I can begin testing on the spare PSU. I'll need to get a SinglePost, Singlethrow switch so I can turn the fan units on and off with a flick of the switch. But the work is progressing.