Fan hole cutting

[mw521]

I was gonna post this because some people are "mechanically challenged" when it comes to cutting holes in your case etc. On the up side, I have seen some guys work in here that I envy. Anyway, if you have a problem cutting a fan hole, try a knockout punch. You just drill a small hole and tighten this thing down and instant hole. Used by electricians and such to punch holes in electrical cabinets. The bad side is these things are expensive. Unless you are punching a load of holes and charging for each one forget it. BUT, maybe if you know an electrician friend of a friend, you could borrow one to poke that hole or two. Here's a link.
http://www.greenlee.textron.com/products/holemaking.html

[nikhsub1]

I use bi-metal hole saws and a drill. Next best thing to laser or cnc cutting! 3 inch for 80mm and 4.25 inch for 120. The only bad thing is they are kind of $$$ - but once you have one...

[The Overclocker]

my good old fake dremal is my trusted weapon, but i dont use it much cus i keep bearking disks

[lennytiger]

my dremel multi is cool the disks wear down too fast though

[klosters64a]

Greenlee punches are great. The catch is that ones for large holes are quite expensive.

[DodgeViper]

You can buy just the die, and bolt rather cheap. You do not need the hydraulic pump and ram. I have the entire set up to 3 inch and have used a rachet or box end wrench.