Twin ball screw drive on X - configuration question

[Smiler]

Maybe someone out there has had experience trying this already but I am currently pondering what is the best way to run 2 x 16mm ballscrews to move my flying gantry on my machine, still at the design stage so any modifications needed would be much easier at this stage.

What would work best out of the 3 configurations below and what would not work and why...!

Option 1 - 2 x 23 Steppers running each screw independently off of the same driver card

Option 2 - 2 x 23 Steppers running each screw as above but also a toothed belt linking the two together to prevent misalignment

Option 3 - 1 x 23 Stepper (or maybe larger) running on one screw with the two screws linked with a belt.

If linking them with a belt then how do you go about getting the right length belt or do I adjust my design to suit a standard belt??

Option 3 for me no question.

Using option 1 or 2, if one motor stalls, the other may continue to drive and you couldl get a bit more than racking. Slaving axes or driving from the same driver won't stop this happening unless you are introducing some sort of closed loop monitoring. Can't beat doing your alignment in hardware IMO.

Single drive with belts or rack and pinion would be how I would do it or as John suggests, drive the gantry from the centre underneath the table.

Just my opinion of course
Regards, Jeff.

[Gary]

Personally i would connect one motor to each ball screw and drive with its own driver, or use a belt and pulley to connect both ball screws and run from a larger motor.

Dont bother running two motors from one driver, this will cause you problems.