[hot427cobra]

When you say "10lb sledge hammer is destroying the 2 x 4" are you placing the 2x4 in a horizontal position or vertical position?

I have the 2x4 vertical as if I am driving a stake into the ground; the spinner ear is playing the part of the ground. In the vertical position the 2x4 transfers all the hammer energy straight down. If you have the 2x4 in a horizontal position, then only a portion of the energy is transferred to moving the spinner ear, unless the hammer is striking the wood immediately above the ear. However I would find this difficult to do without the hammer accidentally striking the fender on the down stroke, ouch.