MOPED ARMY

Carbide, sometimes called a 'tile cutter'.

After your done using that .. cutter bit..

You will still need files and sandpaper.

It never leaves a perfect finish. The aluminum work hardens, gauls up the bit, and then the extra material in the bit makes little deep grooves that are hard to work out. If you keep it spun up really fast and use light pressure you will have better luck than trying to cut fast with it. As they wear out they don't cut as well and fill up faster leaving more of those annoying grooves. Don't use the square ended one because the sharp edge on the end will also cut grooves into the material. Still looking for better cutting bits.

http://www.dremel.com/en-us/AttachmentsAndAccessories/Pages/AttachmentsDetail.aspx?pid=124

stone for getting through the NiCaSi and then you can use an aluminum cutter

Use a variable speed, and measure 10 times, cut once!

get a flat file to clean your bit every minute or so, otherwise they clog up and dont cut correctly.