Thank you both, most certainly you, Larry! I get it now. As a machinist I see it! Chuck up some 1/2" alum in a lathe sticking out 6" from the chuck at 2400rpm, life's fine. Do the same with 4' sticking out and it's going to bend and you WILL have a bad day! Watched a guy lose a nearly new Kennedy toolbox pair because he had too much material hanging out the back of the lathe and with the high rpm it "whipped" and landed on his toolbox!
I hadn't factored in the helix! Damn, you are smart!