I should add - rotational inertia becomes a detractor with big ballscrews, too. An 8ft ballscrew weighs a lot, and that can make positional overshoot a problem

I should add - rotational inertia becomes a detractor with big ballscrews, too. An 8ft ballscrew weighs a lot, and that can make positional overshoot a problem with steppers or servos. Also, most ballscrews that hobbyists buy are rolled screws, and I've never encountered one of those that was super straight. it doesn't matter much for accuracy if they are a bit warped if the bearing support is done right, but it sure can make the whip a problem.