Anne Hollerbach

that's a terrific discovery! The only thing I would add would be a suggestion to take a circular file [round wood rasp or chain saw file] and significantly ease the bottom edges of each indentation. You literally create an anticlastic shape in the stake -- the bottom of the slot should fold around the center of the stake and the sides should scoop upward. What you don't want is an indentation with a straight bottom running perpendicular to the length of the stake. This will damage anything you want to form in it.

So use the drill press to shape the X axis, and a round file or rasp to shape the Y axis, and away you go!
Very nifty indeed.