[JesseK]

Great post John; it should add a bit for knowledge to many varying levels of experience.

For our lift, I've done some math. We too will be using some surgical tubing to aid in the lift. We're using a 5/8" thick 2"/turn threaded rod at 50% of its critical speed -- we can increase that if we decrease its load. The hope is that we can use only 1 RS-775 to power it, yet we may still add a second one just to be on the safe side if we have weight to spare.

The surgical tubing serves a second purpose too, however. At the top and the bottom of the rod's range of movement, we've lathed off the threads in order to prevent the nut from getting ripped apart should the programmer's 3 safety pieces fail. At the bottom the tubing will combine with springs to lift it out of the bottom dead zone, thereby enabling us to continue scoring even sensors/code fail.

(Yea I know, threaded rod is heavy -- but we 'got a guy' who knows what he's doing with it, so I'd rather error on the heavy-but-quality side than try our multiple failed winch ideas again...)