A while ago I saw a photo of an old metal lathe, looked to be from the 1920's or older, that had a lead screw on the front and the rear of the bed, connected across the tailstock end with a pair of gears. That would have the screws rotating in opposing directions so one would need to be left hand thread. The solution to that would be to use 3 gears.
But two ballscrews in tension with mounts to the bed would counter any bending force. On Monday, December 25, 2023 at 11:37:04 PM MST, Chris Albertson <albertson.ch...@gmail.com> wrote: When it comes to flexing and bending, think about the bed too. If the servo motor and pullies are mounted at the tailstock end, then the bed will carry the reaction forces and see exactly the same tension and “twist” force as the screw. But if the motor is mounted at the headstock end the bed sees no net forces. The twist force on the bad will be the motor’s stall torque times the pulley reduction. Would that be enough to warp a cast iron bad? That depends on the detainees. Also you. want the force of the motor applied to the fixed end near the headstock because none of the mounting points will move as force is applied. In short, think about what bends as force is applied, the motor pushes on the screw one way and the motor mounts in an equal but opposite direction. _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
