View Full Version : Install Top Exhaust Fan Through Metal?

08-15-2002, 03:23 AM
My brother just got a new tower, and wants to install an exhaust fan at the top of the case. How does he cut a circular hole through the metal? Thanks

08-15-2002, 08:01 AM
I used a lathe type bit in a drill press, you could also use a jigsaw or dremal

08-15-2002, 08:34 AM
I use a jigsaw. Just mask the top of the case with masking tape, markout the cut and holes, drill your mounting holes and a starter hole for the jigsaw then just carve the piece of steel out. Finish off the edges with a file then peel off the masking tape and give it a cleanup. ;)

08-15-2002, 09:53 AM
Wiggo Do you use a template when marking the holes to drill?

08-15-2002, 10:02 AM
Just go off the fan, mesure the inside of the fan and use something to draw that size circle (compas, lid, etc.) and your away :thumb:

08-15-2002, 10:08 AM
I use the 3" drill bit and use the fan as a template. I then draw two a diagnol lines to make a cross one like this "/" and another one like this "\" on top of it. That will give the actual center of the fan and the starting point for my drill.

08-15-2002, 10:51 AM
I just measure where I want the center of the fan and markout the hole with a compass (3" dia for 80mm, 3.6" for 92mm and 4.7" for 120mm). Then I line up the fan with the marked hole and drill the pilot holes for the screws (these are then drilled to full size (5-6mm) once the fan is taken away. Then I drill a 3/8" hole just a few mm's inside the cut line then with the jigsaw (using at least a 32pt metal cutting blade) cut almost to the marked line (try just to stay just to the inside of the line) till the hole is cut. Smooth and finish the hole off with a curved back file. :smokin:

08-15-2002, 11:08 AM
These may work. Depending on the situation when he's ready to start cutting we will be able to do it. Thank god for my wind tunnel plus :lips:

08-15-2002, 11:45 AM
I'm lucky, we have a machine shop at work :D
I can have as much "fun" as possible, during off-hours that is...

08-15-2002, 11:53 AM
ya so it must be easy for you.

Mr. C
08-15-2002, 12:06 PM
If you are mounting the blower externally, the opening won't really have to be very tidy - the fan hides a lot.

08-15-2002, 12:29 PM
ya but making the hole hidden would be hidden by a fan which is not something you really want to look at. as its not really professional at all. However this is not the case if you decide to mod your case with a monster and have the air from the fan come in through the monsters mouth.

Mr. C
08-15-2002, 12:37 PM
Yes, it's a matter of taste.
Personally I don't mind the fan extending 1 1/4" above the case. That way it is drawing the uppermost air out of the case, which should be the warmest air inside. Instead of allowing a deadspace at the top of the case interior.

But it does look cleaner if the fan is mounted internally.

08-15-2002, 12:46 PM
I didn't even think of that. That would help manners some won't it? Speaking of. I have two cd-rom drives at the top two bays of my computer and well I have a rounded ata cable set up on those drives and the drives get so close together that the rubber coating on the rounded cable ends up breaking because of it. Not really breaking but you know how plastic will start to turn a little whitish when it weakens? Well its starting to look like that. Besides that its blocking air flow of half the fan.

Mr. C
08-15-2002, 01:00 PM
Be scientific, mount the fan internal and get some good readings on your temperature. Being as you will already have all the hole and hardware you can switch it to external and see if it does make a significant difference.

I've just always had mine external because of physics I guess?
I'd really have to do some cosmetic work on the hole in my case before I could try an internal mount.
But actually, like I said I really don't mind the fan sticking up - kinda like the blower on the hood of a street rod. LOL

08-15-2002, 01:16 PM
hehehe ya that's true. I can make my computer look even more hooked up. I think I might do that just for that affect. I'll stick a baseball card in the fan to make it make a loud sound like kids used to do to there bicycles to make them sound like motorcycles.

Mr. C
08-15-2002, 01:21 PM
LOL Own it man:thumb:

08-15-2002, 02:39 PM
uh oh..........this was a real brief thought I didn't put much thought into it but something I just thought of was.....how exactly do you get the power cable with the molex connector into the case?

08-15-2002, 03:00 PM
i drilled a hole where the cables come though, then cut through from the main hole to there, just be carefull not to slice the sheilding.

Mr. C
08-15-2002, 06:56 PM
I cut off the molex connector as I'm running the blower from my fanbus. I did double up the heatshrink tubing at the point the wire comes through the hole, in case there is a burr there - better safe than sorry.

08-15-2002, 10:24 PM
this is getting more diffucult then I thought. Its just not as easy as it seemed yesterday.

08-15-2002, 11:27 PM
What's the best way to "finish" an external fan? Are there any shrouds available?

08-16-2002, 09:43 AM
It wouldn't be too hard to shape something up for the job. ;)
:beer: :beer: :beer:

08-16-2002, 09:47 AM
:D I guess you could cut some plexi for the sides & if you used a fan with an led ... now you've got me thinking. How do you average over 45 posts a day?

08-16-2002, 10:40 AM
It use to be much worst. :eek:
<img src="http://forums.tweaktown.com/attachment.php?s=&postid=2935">

08-16-2002, 11:00 AM
40 is big enough but 175!?!?!? :eek:

I have like 2.15? :rolleyes2

08-16-2002, 11:04 AM
Well after the "great burn of '01" we sorta went into overdrive when the forums came back online but sadly with the loss of years of content. :smokin:

08-16-2002, 11:14 AM
ya I heard about the burn but I wasn't a member of the forums at that time. I think it was at tweak3d.net that I heard about the servers going up in flames. Cause from my understanding they are both run on the same servers.

Mr. C
08-16-2002, 11:27 AM
this is getting more diffucult then I thought. Its just not as easy as it seemed yesterday.

Oh come on now - you had a fine idea, go with it.
We're just throwing suggestions and experiences in the air for you to see. You go for it any ol' way your heart desires.

For me it was a progression, first the blower hooked to a toggle.
Then along came an LED indicator -- yeah, like I couldn't hear the fan running:laugh:
Then as another fan & lights came about a baybus was just a neccesity to clean up the mess inside the case.

Of course, a good plan that is well thought out is hard to beat but there is always a way to incorporate future growth. Hec, a tweaker is never gonna' be 100% satisfied - it just comes with the territory I guess.

08-16-2002, 11:47 AM
never satisfied? I guess that will include me casue I never know how I want the inside of my comp to be all cleaned up. I constnatly redress my cables and I'll take it all apart and put it all back together the way it was when I first started. How much is a bay bus again? That may clean things up a bit.

Mr. C
08-16-2002, 12:05 PM
Mine cost me about $3 to build.
I used a genuine Martha Stewart pillbox from KMart for $0.79 and some 3M wire connectors for just over $2 for a 3 pack.
I already had the wire and spare molex around + the other neccesary parts - like I said, mine was a progression.

To the best of my limited knowledge I have the only PC on the planet with an integrated Martha Stewart brand-name component inside:cackle: : peace: :p

08-16-2002, 12:33 PM
Can you take a picture or maybe type out some instuctions? I already have my power cables dressed up in spiral wrap. A fan bus will just make things better? But my power supply is only a 300 watt. Can one molex connector power all the fans in my case?

Mr. C
08-16-2002, 01:25 PM
Fans don't take much juice. You can run 3 or 4 off 1 molex with no problem -- I honestly don't know what the maximum number would be.
I used the squeeze type connectors to split the wires.
You can always split the wires again, make 2 into 3 etc. etc.

Additionally I used the insulated spade type connectors to hook everything up. that way if I ever need to change a fan, switch or LED I won't have to drag everything out of the case to solder it. Just put a spade on the new component with a pair of pliers and plug it in. Though soldered connections do look nicer, they aren't quite as handy sometimes.

There are some excellent fanbus tutorials on the web, virtualhideout.net & 7volts.com for instance have some.

Here's a simple drawing in paint of the basic schematics involved.
Trust me, it's a lot clearer than my cheesy camera's pictures.

08-16-2002, 01:35 PM
ok I"m gonna put some definite considerations into making a fan bay bus. Its definitly gonna be my next case mod. The fact that its so cheap I can probably do it before the next lan party. Which is in a few days I think. For a few bucks I got some stuff at home and with my dads expierience with the sodder tool (forget it I ain't touching it) I'm definitly gonna have some fun doing it.

Mr. C
08-16-2002, 01:38 PM
do a Google search for fanbus, get some ideas then apply your ideas to them and see what you can come up with.
No rush, and yeah, I'm thinking you'll have fun:thumb:

08-16-2002, 01:46 PM
yup I hope so. One more question though (definitly not the last one) where in your case do you have the fan bus located? I mean like I said I have my power cables dressed up with spiral wrap. Its a bit stiff.

08-16-2002, 01:50 PM
Here's a good set of wiring diagrams for fan buses, http://www.fanbus.com/thelab/Schematics/baybus_schematics.htm ;)
I usually put them into a spare 5.25" drive bay. :D

08-16-2002, 02:13 PM
This is all good stuff. Looks like I am gonna have to build on myself cause 15 dollars for a cliff forgotlastname fanbus is 15 bucks. With the amount of fans that I gotta I would need to buy like 3 of them. Kinda sucks how it only supports 4 fans. I have 5 case fans. I also have dual 30MM hard drive cooling fans. Also my 6-MM delta that I would like to wire up in it.

08-16-2002, 05:19 PM
The Dremel is also quite handy if you can borrow one. I suggest using the heavy-duty cut-off wheels instead of the standard cut-off wheels since they last longer.

Mr. C
08-16-2002, 06:50 PM
Correction Notification
In the horrid graphic I posted earlier the hot wire for the LED is depicted as going to the wire leading to the switch from the 12V wire.
This is in error, in actuality it is wired to the hot wire located between the switch and the fan. If wired as shown in the above diagram you would actually be creating a closed circuit and would result in bypassing the switch altogether allowing the fan and light to operate at all times, independant of the switch being in the on or off position.

08-16-2002, 08:04 PM
:cool: Thanks for the update. :cool:

Mr. C
08-17-2002, 10:06 AM
I guess I got caught up in the artistic process and lost the whole technical aspect:laugh:

08-17-2002, 01:52 PM
:cool: Looking good counts too. :cool: