If it's for tapering the neck from nut to the end of fingerboard, then a calculator, ruler, pencil, clamps, router and a good straight piece of wood does the trick. If it's to achieve the shaping on the back of the neck, then i'm afraid you can't do much other than buying a table router and a LARGE roundover bit, and even then that's just to get you in the ballpark. From thereonin, it's the buttscratcher pictured above!