Originally posted by shupack
from an engineer's standpoint i think that's wrong. the heavier prop will act to absorb engine vibrations, not amplify them. a lighter prop won't amplify them either, but will absorb less.
How will a heavier prop "absorb" vibrations?
I am by no means an engineer but I like to think about things so this is how I see things:
A heavy prop is harder to accelerate, therefore, during the combustion stroke, the reaction on the torque generated by the engine is that the engine (thus also the airframe) will try to move in the opposite direction more than it would with a light prop.
Have you ever mounted an engine on swing rubbers? All mine are, and I can clearly see the difference in engine movement between a light and a heavy prop. Particularly at and just above idle rpm's you see the difference. Also the resonance frequency of the entire system changes with the use of lighter or heavier props.