Tip for cutting in a case fan

[Spartan]

I have been wanting to add a fan to the top of my case for awhile but was dreading taking out all of the components to keep the metal shavings from getting in them. Here is an idea that I came up with to be able to cut the hole while leaving the components in place.

I cut 6 pieces of cardboard small enough to fit inside the case and taped them together. Then I taped them to the top of my case on the inside. The six layers were thicker then the blade I was using on my dremel. After I marked the hole I just cut through the case and cardboard and it trapped all of the bits of metal. When I finished cutting I removed the metal piece and vaccuumed it. I them took the tape off the cardboard and lowered it about 1/4 inch and vaccuumed again to be safe. It worked great and no metal fell inside the case. Now I'm figuring other ways I can use the same mehod to spruce up my case.

-Spartan