-=i take no responsibility for your actions=-
Step 1: Bottle Cap Saw Blades
-=this blade is designed to cut hard plastic, also when cutting plastic it may create toxic fumes=-
Everything for this comes with the dremel 4000 kit except for a hammer vice and bottle cap.You will also need the following bits: #432 #402 #107 #84922.
First off get a cap (I like to use samuel adams caps) and flatten the edges but make sure they ridges fold outward and not inward, you can use the corner of the vice to do a little bit at a time.
after flattening the cap use bits #407 and #432 to scrape off the rubber junk on the bottom of the cap and smash the cap in the vice to flatten it some more.
Next poke a hole in the center with a small nail (between the top of the "A" and "M" in adams)
Use bit #107 to clean out the hole.
After that you will use the sander once more to sharpen the edges (it will work fine if you dont do this but its recommended). I tilted the dremel at about a 40* angle or so and sharpened all around.
If you want to make teeth use bit #84922 to carve out small ridges on the edges (again this is optional but recommended).
All you gotta do now is attach it to bit #402 and cut some plastic!
Step 2: Nails As Drill Bits
All you gotta do is cut off the head of a nail that can fit in the chuck and you got a drill bit. They would be stronger than regular drill bits as they dont have as many weak spots, also they'll bend instead of breaking under pressure.
There are a few ways of cutting off the head. Of course you could use wire cutters or tin snips but if you want a clean cut you could use the metal cutting saw that comes with the dremel or you could sand down a cut from wire cutters or tin snips.
As nails work well they will create a lot of friction so there will be some smoke. Maybe putting oil on the nail will help.