Hello to all! I'm building a CNC router for wood machining for a friend of mine and the best way I found to drive the Y joint for this particular design, given the size of the machine, is the following:
One rack and pinion on each side of the longitudinal axis of the machine and each pinion conected to a servo motor using two steps of reduction with synchronous belts to achieve a 10 to 1 ratio. I've found several topics on the forum talking about the homing of an axis arranged like this. I guess to have screw regulated home switches for each Y joint is almost a must (in case you don't use linear scales). But I was wondering if it's possible to use ,in conjunction with that, the index pulse of an encoder coupled to directly to the pinion. My idea is to offset the index pulse on each encoder via HAL to make both sides of the Y joint trip the index pulse together and stay squared during homing. Is this a good practice? About how to drive both Y joints as one axis: I've read that there's a way of simply adding two Y joints for the Y axis in the 2.8 master branch but I don't know if there's documentation available already. But I was thinking about slaving one of the motors (using them as pulse and direction at the beginning to make things easier) and use the encoder on the pinion only for following error and homing. I don't like the open loop approach a lot, but I don't know if it's that easy to use them as servos in position mode without having too much trouble. Any thoughts? Thank you as always! Leonardo _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
