Brief Description: Prop Spinner 2 - Opposite Sides of Spinner
After coming up with the shape of the prop... I tackled how to find the exact opposite side of the spinner for the other cutout. (I tested the pattern on both sides of the prop and it was exactly the same.)
After much pondering, I came up with drawing the circle shape of the spinner and using it to find the center of the circle. Using it, I was able to find the exact other side of the spinner.