cut new hole in door for new 120mm intake fan

[Aharami]

http://pics.bbzzdd.com/users/aharami/IMG_0755.JPG

i wanna put a 120mm fan where the red square is. possible? door is made of steel. How to the hell do I cut thru it? I dont think my dremel can cut it (no pun intended)

I dont care about looks, so it can be a hack job. But I will try to make it as clean as possible.

 

[mjrtoo]

I would use a 4.5" bi-metal hole saw and then mark the fan mounting holes and drill through with the appropriate size bit. The 4.5" hole diameter is nearly the exact diameter of the 120mm fan duct...check out this photograph to see what it could look like.

4.5" hole with fan guard mounted

 

[Zepper]

If you want a proper job, a round hole won't cut it. Go here:
Linkage Look at pic of back of case, see the fan cutout. That's how it's supposed to be done - the better fan companies have mounting template files on their sites that will help laying it out. http://www.jab-tech.com sells a nibbling tool and Radio Schlock does too on their web site (not in stores any more). Dremel can too, but you'll go thru lots of cutting wheels or need to buy a diamond wheel bit. You can see that it is mainly a squared circle with a radius at the corners that may be larger than 4.5" - you can do the entire cut with a nibbler (switch off hands for balanced muscle development ) and clean it up with the Dremel.

Looks like the suggested radius for the corners is about 5 inches. Here's the Sanyo Denki specs PDF

http://sanyodb.colle.co.jp/pro...ail.php?master_id=1143

with the measurements - one is for mounting to the intake side the other is for exhaust side. Specs for other fans may differ but not by much.

.bh.

 

[mjrtoo]

Proper job...I suppose that's based upon purely subjective 'looks' rather than any type of airflow restriction?

Personally I think a radius hole in the side of a case might look stupid, purely subjective of course...

 

[Zepper]

Was editing while you were posting - look again. Not subjective - I wouldn't leave the hole uncovered or treated in some way anyhoo - lots of grills and filters out there.

.bh.

 

[tylerdustin2008]

Using a hole saw is the easiest way to do it if you have a drill. But mind you the 4.5" hole saw is not cheap....

Lowes

I would never attack that thick of steel with regular dremel bits. But with the following I might.

25 Piece Reinforced Cutoff Wheels

Or, this which is a better buy imo.

100 Piece Reinforced Cutoff Wheels

Hope that helps.

Tyler

 

[MadScientist]

Gotta agree with mjrtoo and tyler, a 4.5" bi-metal hole saw is the way to go, but expensive. A cheaper alternative is a jigsaw, if you have one, with a metal cutting blade. I've used this method to cut holes in steel side panels with good results. Here's a guide on cutting a hole with a jigsaw. Tape the bottom of the jigsaw, or the case to prevent scratching the case. Wear safety glasses or goggles.

 

[mjrtoo]

Did you look at the picture I posted? It has a filter/grill on the hole, and actually, it has a perfectly round convex surface that protrudes from the circle just a bit...not bad for about a 15 minute project. And yes, tape the surface of the case, I like the blue painters tape. It comes off very easily with no residue.

Bought the grills here.

 

[Aharami]

Originally posted by: mjrtoo
I would use a 4.5" bi-metal hole saw and then mark the fan mounting holes and drill through with the appropriate size bit. The 4.5" hole diameter is nearly the exact diameter of the 120mm fan duct...check out this photograph to see what it could look like.

4.5" hole with fan guard mounted

i actually like this look. But will a grill like that reduce airflow?

 

[tylerdustin2008]

Yes it will, but not by much. Say you have a 60cfm fan, its going to rob about 10cfm from it. And thats if the grill has small openings.

 

[MadScientist]

i actually like this look. But will a grill like that reduce airflow?

Was about to ask the same question.

For the OP (or anyone else), here's a good guide by Grez on the xoxide forum on how to drill a hole using a holesaw.

 

[ty1er]

Originally posted by: tylerdustin2008
Using a hole saw is the easiest way to do it if you have a drill. But mind you the 4.5" hole saw is not cheap....

Lowes

Yeah using a hole saw would be the path of least resistants.

There is a ~10 dollar cheaper 4.5" hole saw at Home Depot.

I'm going to pick one up to night, since my 120 yate loons were delivered this morning. woot!

 

[mjrtoo]

The holes in that grill are a bit bigger than that link shows...take a look at the picture I posted, you can easily fit the lead of a pencil into the mesh.

 

[mjrtoo]

Originally posted by: ty1er

Originally posted by: tylerdustin2008
Using a hole saw is the easiest way to do it if you have a drill. But mind you the 4.5" hole saw is not cheap....

Lowes

Yeah using a hole saw would be the path of least resistants.

There is a ~10 dollar cheaper 4.5" hole saw at Home Depot.

I'm going to pick one up to night, since my 120 yate loons were delivered this morning. woot!

Whichever you buy, make sure you get one with an arbour, or you'll be hella screwed (80's metal...)

 

[Zepper]

That Milwaukee holesaw doesn't say it is good for metal - looks like it is for wood and/or sheet rock.

.bh.

 

[ty1er]

Originally posted by: Zepper
That Milwaukee holesaw doesn't say it is good for metal - looks like it is for wood and/or sheet rock.

.bh.

Here is a copy/clip from the product info:

Milwaukee's 4/6 Hole Saws feature a multiple tooth design with varying tooth sets and gullet depths. These are constructed with a minimum 3/16 In. thick steel back resulting in a more durable, longer lasting. Made of Bi-Metal, the high speed steel teeth are electron beam welded to the high alloy steel body. Containing cobalt, the teeth are ideal for both wood and metal applications. Hole Saws provide up to 6 In. holes for the general construction, plumbing, electrical, maintenance and remodeling industries.

O, I just relized that this is online only, not avalible in store.

 

[ty1er]

Originally posted by: mjrtoo
Whichever you buy, make sure you get one with an arbour, or you'll be hella screwed (80's metal...)

Good call. hella screwed.... lol

 

[Aharami]

i was gonna get the grill mjrtoo linked at frozencpu, but it would have been close to $12 with shipping. Then I remembered that I had some old speaker grills lying around.
Made my own fan grill
As straight as I could make it. Good enough for me. Yea, the protruded one from frozencpu would look better, but it came down to $12 vs $0. As I said, I dont really care for looks, just functionality.

I'm not sure if Im gonna go out and buy a hole saw just for this project. It's pretty expensive and most likely I never use it again. I have some reinforced cutting bits for my dremel and do the best I can with those.

Oh btw, my input fan is gonna be a Scythe SFF21E 49CFM 20.1dBA

 

[Aharami]

Originally posted by: MadScientist

i actually like this look. But will a grill like that reduce airflow?

Was about to ask the same question.

For the OP (or anyone else), here's a good guide by Grez on the xoxide forum on how to drill a hole using a holesaw.

anyone know where I can buy "c-channels" mentioned in above guide? asked around in lowes and home depot. Got blank stares back.

pic of what Im talking about
http://www.pccasegear.com/images/fanholesm.jpg

description on guide

This is essentially a long strip of rubber or plastic that has a hollow pit in it, so that when you look at it in cross section, it resembles the letter ?C?. It can easily be cut to length, so you can just wind it around your fan hole, and where it meets itself, cut it with a sharp knife or scissors, and you magically have a professional-looking fan hole.

 

[herm0016]

look at automotive places. its kinda like the stuff they put on the edge of a door to protect the paint.
I did a 120 hole in the top of my enlight rackmout case with a dremel and the fiberglass reinforced cutting disks. i only used about 2 of them to do it. then i used a grinding attachement to finnish up th edge nice. it worked very well.

 

[Aharami]

Originally posted by: herm0016
look at automotive places. its kinda like the stuff they put on the edge of a door to protect the paint.
I did a 120 hole in the top of my enlight rackmout case with a dremel and the fiberglass reinforced cutting disks. i only used about 2 of them to do it. then i used a grinding attachement to finnish up th edge nice. it worked very well.

thanks. was it a PITA to make a round hole with a dremel?

 

[BonzaiDuck]

The "C- " or "U-"channel rubber grommet can be found priced by the foot-length at www.mnpctech.com.

A hole-saw can make a perfectly round hole -- provided it has an arbor and you drill the center-hole precisely to start it. I'd think it would also make a lot of racket and noise.

I use fiber-glass-reinforced Dremel cutoff wheels to cut fan-holes 92mm and larger. A nibbler tool only lasts so long -- unless it's the $45 motorized kind sold at Harbor-Freight -- and the manual nibbler tool will really leave you with sore -- even pinched and bleeding hands -- if there is much work to do.

The trick to using the dremel:

Score the circle as precisely as humanly possible. I'd use an etching or scratching tool, like the diamond-tipped pen you can get to etch your identity on metal possessions, but a sturdy nail with a sharp point will also work.

Same principle for cutting straight lines with a Dremel applies: you want to make several passes that leave a groove in the metal -- making it easier to make additional passes. Don't bear down on the blade -- you'll eventually wear out the brushes of the drill -- so you make your cuts by touching the blade to the metal in repeated passes.

The groove you cut should have a shade smaller radius than the scored circle, because you're using a circular blade to cut a circular hole, which is going to make the groove wider than for a straight cut.

Once the saw is beginning to cut through the metal, or there are only a few places where the metal is still joined with the outer surface, you can wiggle the nearly-severed disc free.

You can then use the same blade at right angles to the cut to shave irregularities from the edge of the hole until the original score mark defines the holes perimeter.

It takes a steady hand and practice, and it may take more time, but I've been more inclined to cut 120mm holes this way. there's also another reason: you add to the stability of the case panel if you leave a brace in the shape of a cross that's maybe a quarter inch wide for the spokes and just shy of eclipsing the fan's hub. The dremel allows you to cut the hole in "quarter-round pie-slices" to leave the reinforcement intact.