Curt, everybody.

An imbalance 1"-1.5" from center (as in a spinner) causes much less vibration than the same imbalance 5" out, like on a prop blade.

If a spinner has a bad imbalanced, it can cause the fillings to fall from your teeth... But if you modify the blade holes with a Dremel type tool, in a plastic spinner and you are no too far off, you will hardly feel it.