Ah good point, yes, at those lengths you really don't want ballscrews, they are impossible to support and will warp. But for short distance (up to 8' or so) with a support on either end they are fine.
Yeah, my brain is kinda tuned to those long distances. I also kind of harp on people who say they need really high precision systems, so use servos and spend bookoo bucks on slop-reductive hardware.
Even a cheap encoder, when decoupled from the motor, and directly coupled to the axis it measures, will give better axial positioning than a servo. It boggles my mind why people seem to ignore this in favor of a motor that knows where it is in space, but doesn't know where the axis it is driving is in space.
