These are dremels:
http://www.dremel.com/en-us/Tools/Pa....aspx?catid=13
There are knock-offs too that probably work just as well and are cheaper.
To cut the grrove, you'd use a cutting wheel like these:
http://www.dremel.com/en-us/Attachme...Cut-Off+Wheels
Dremels or the like are absurdly useful for this hobby. You can all kinds of bits to grind, cut, and even rudimentary "machining". No self-respecting hobbyist would be caught dead not owning one, so drop everything and go get one!
