Hi guys im in the middle of building my machine but i would like to know your thoughts on what thickness ballscrew i should be looking at to span over 1829mm ( 6ft ) without none to much "whip" and another thing is the pitch as on zapps website they do a 5 or 20mm pitch in the 20mmOD screw, the machine im building is for precision work mainly but with it being a 6x4 bed i was thinking that a 5mm pitch would take all day get to the other end? :confused: