"H. Adam Stevens" wrote in message ...
Excellent post.
Don't forget those of us with three bladed props. Or four; whatever.
Your point illuminates elegance in thinking.

Actually, the number of blades doesn't really matter if you can get within
the ballpark with the tach, stopping the apparrent motion will let you fine
tune it.

The real fun is that my tach reads 120/77 times what the prop is turning.