Panel cutting

Is it supposed to be very hard to cut through the metal side panels with a dremel? I'm using a rotary tool with those flat circular disks to try and cut the case but it doesn't seem to have enough power to cut through. It's a rotary tool with 10,000-30,000 RPM with setting 1 as the slowest and setting 6 as the fastest. I checked the manual and it said that when using the disks to cut through steel I should have it on the slowest setting (1) but when I try to cut the case it just skims the surface taking off paint and when I apply more pressure it slows to a stop. What speed should I have it on and are there any special methods I should use to cut it. Thanks.

I do most of my cutting with a dremel but jigsaws work better for big, open stuff- IF you have one (I don't.)

It will take a while to do big areas with a dremel, and go through a few wheels.....!

But the trick is to hold it steady and apply just enough pressure to get it to START slowing down, barely. I mean literally almost no difference between no pressure and the most pressure you should use: dremels work on the theory that extremely high rpm, and almost no pressure will give you a nice neat cut...and it can, but it is slow.
I wrecked two dremels getting used to just how lightly I had to bear down on them: I used to weld for a living and we used similar tools that were much more expensive- and durable.

Would have been cheaper if I had just bough a jigsaw! (and faster too)

Use either a reinforced fiberglass cutting wheel or a diamond blade (hard to find and expensive). Like the other guy said, jigsaws are great.

You want to keep the rpms at around 20-25,000.

Nibblers work but give you hand cramps and if it is a big hole, you will likely throw the damn thing at a wall.

There is always air nibblers or plasma cutters.

I normally run about 5-6 when cutting case sides or tops. 1 os way too slow. Once you are through originally, take your time and let the wheel do the work. Most of the time, it just takes a little practice.
As rogerduggans said, be prepared to go through a number of wheels if doing a large area.

Setting 5 seems to be working really well. I've already gone through 3 disks doing a 6 inch cut....I guess the 8 that came with it aren't gonna be enough. Looks like i'll be going to the local hardware store and picking up some steel-reinforced ones.

if it took you 3 wheels to do 6 inches then you are doing something wrong.

Using 2 re enforced wheels I cut 3 80mm fan holes

I would seriously recomend getting a jigsaw even one of the cheaper $30 jig saws will do the job. Dremels are great for intricate stuff and cleaning up cuts but for a big job a jigsaw is way more convienient especially with a blade that's 20-30 TPI cuts like friggin butter (if butter was metal and your knife was a jigsaw)

I cut out a ~2" x 18" section of metal out of my car door (rusted ) using two FG reinforced wheels and a Black & Decker RTX (LOT more power than a dremel)

Works a lot better than my old dremel. Dremels don't have enough torque and slow down too much. I wish I had the RTX when I started modding.

But if you're doing larger cuts, go with a jigsaw like said above.