Circles with Dremel?

[Isolate]

In my forever long quest to drop the temp in my case I have done a million crazy things. I finally decided to plunk down and purchase a dremel in order to create a hole on the side of the case to mount a fan. My original intentions were to cut out a square smaller than my 80mm fan but after viewing some pics of the rigs of forum members, it appears all the holes were circular. How would I be able to make a circle with my dremel? Any advice would help, this is my first case mod and I don't wish to ruin it, Thank you!

[VHockey86]

Id suggest a hole saw for a normal power drill, would make a much much nicer looking hole then you could do free hand with a dremel. They have em at any local hardware store for around 10-15 dollars, handy tool to have around the house

[Telexen]

Very, VERY carefully! You'll probably end up with some jaged edges. Just get a template for a fan of your size and go on that.

I think it's best to use a holesaw for holes like that...very clean cuts.

[Urban_Squrill]

Ya i added my blow hole on top of my case. Using a dremel to make the first hole and then a jigsaw. I would suggest to use one of those really big round bits.

[cracked]

a holesaw would work great but i never used one and all my holes came out great. what i did was i drew a circle on the case where i wanted the fan. then i drew a circle about 3mm less in diameter than the original and drew it inside the original. then i used the dremel with a cutting wheel to cut out the smaller circle and that way i didnt cut outside of the larger circle and didnt have to worry about jagged edges and stuff. then i took a grinding bit and ground down the edges to where the hole was the diameter of the larger circle. and thats it. works great.

drew

[jerrygarcia]

If you know a commercial electrician, use their knock-out cutters. They go up to 4" + and have a perfect hole with no jagged edges. I do have a access to a hydraulic punch set that I have used.

I also had an HVAC guy cut a hole for me with a circle cutter. It is some kind of drill bit that cuts on the side of the bit. You clamp down your drill in a compass like contraption and using a small center hole, cut out the hole with the drill/compass.

http://www.tools-plus.com/malhc1.html

[Idigguns]

Knockouts are great, but they can sometimes warp the metal around the hole. IMO, the best thing to use is a hole-saw. Next best, a dremmel working slowly and carefully. Finish it off with a file to clean it up.

[MrPurple]

I was always under the impression of using a hole saw and then using the dremmel to clean the edges off.
I would put a block of wood underneat the area you are going to drill tho, so as to not bend the metteal or cause too many jagged edges (makes your filing alot simpler and faster).

[Idigguns]

I've used hole-saw's many times, and have never had to clean up the cut afterwards. I've never had a problem with the metal warping either.

[cube42]

http://www.mnpctech.com/DremelCircle.html