Here is my build log for my Crow T Robot replica from MST3k
Crow Eye Mechanism
1. Mark a 3/8" wood dowel .5" and 1" from the top.
3. Make a .5"x1.5"x.4" plastic piece as shown, a piece of old gift card will work fine. (Note that a 1" long piece is shown, i extended it later)
2. Drill marked areas .161" dia (#20 Bit) and make a 1.5" cut down the center of the dowel.
4. Install plastic piece to dowel as shown using a 6-32x1/2" screw and #6 nut.