Ask any woodworker if he can drill a square hole, and he'd say that of course ... with a hollow square mortise chisel & bit. But that's kind of cheating: it's basically drilling a round hole and chiseling the rest to make the square hole.
But did you know that there is a way to actually drill a square hole? With a Harry Watts square drill bit (named after its inventor, who patented it back in 1917). Here it is in action:
Confused? Here's a neat animation that shows what exactly is happening (hint: the bit is shaped like a Reuleaux triangle):
Pretty nifty, huh?
It was more a matter of a technical observation, and I certainly welcome comments from any craftsman with more experience in such things than I have.
Will L certainly added much more information, even though he didn't address the point that I had raised. Although his comment may appear negative, he is simply adding more detailed and technical information - information that I found instructive.
Since you didn't appreciate either comment, I'll oblige you: Wow, that's an awesome drill. Square holes! Cool! WTF. LMAO. Square holes FTW!
Better?
I'd reach for the plasma cutter every time, but then I don't have to do small holes.
[ed:]-SIMILAR!!! , SIMILAR, DAMMIT!!!
IT'S NOT GODDAMNED SIMPLE AT ALL IT'S FREAKING SORCERY!!!
::rant over::
You can also see the shank oscillating viz the cutting-bit center.
On a normal drill, the shank is obviously perfectly on-center.
Then your rotating-triangle can just notch out the corners.
-Still, -VERY similar to what a woodworker's bit does.
And quite simple to a Rotary Engine in a Mazda RX-8