Take a 2x4 scrap and a couple scraps of plywood. Nail a piece of plywood to two sides of the 2x4 to form a corner. Place this in a vice to keep it steady. Place the popper blank in the corner and clamp it. It is now held steady and verticle. Take your dremel and have fun. You can also mount this on a drill press and do the same thing. Also good for holding the blank upright while center drill the thru-wire hole on the drill press. With the money you save, you can buy more plug parts
Jigman