8' is too long for a ball screw, it can be done but the dia. would be up there at that length to retain rigidity and cure whip etc. and precision ones are very expensive, a proper tension pressured rack & pinion would be the way to go and much cheaper, but due to the large travel/motor rev. some kind of reduction is required, either planetary gearbox or timing belt/pulley.
There are several post in these forums with examples.
Al
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CNC, Mechatronics Integration and Machine Design.
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E. |