[Shotimes] (OT) Marauder

[John Miller]

> Can't that be resolved with a balancing? Or a pre-balanced aluminum
> replacement?

What it really comes down to is that even the best-balanced one piece 
shaft, if it's long enough, is going to tend to whip, particularly if it's 
slung between a typical pair of single-Cardan U-joints.  In that 
configuration, the shaft acts like the center-cage of a CV joint - its 
rotational speed fluctuates during rotation, and the extra 
accelerations/decelerations and higher peak speeds helps promote whip. 
There's a  specific calculation that you can feed in the bending stiffness 
and length of the shaft and it'll spit out the critical rotational speed at 
which the shaft tries to make itself look like a sine wave.

You can use a lighter shaft, or a stiffer shaft, or both (either very large 
diameter aluminum, or carbon-fiber, or carbon-fiber-wrapped aluminum) or 
you can shorten the shaft segments and use a two-piece shaft design (as 
Ford Australia did in the Pursuit Ute.)

John.