James Louis wrote: > John, > Welcome to EMC2! I can't answer all of your questions, but I will share my > homing experience: a CNC mill homes every axis from the standpoint of the > tool and all movement during homing is positive. This means the table moves > to the left and toward you, and the spindle moves up. Now your tool is at > the right, rear, and top of your work envelope. This is Machine Zero. > Every move from this location is negative. Enjoy Well, there is no reason it has to be this way. Full up for the spindle is a good choice, and G-code defines that as the positive direction. But, on my Bridgeport, the X home is near the center of table travel. The machine coordinate system really is of no use except for defining limits of table travel, and possibly for safe positions for tool change, etc. So, the machine coords are of use to internals of EMC, but the user never needs to know about that coordinate system. What the user needs are the workpiece coordinate systems, and when you position to a place relative to the part and take measurements with gauges, edge finders, coax indicators or whatever, then you set the work coordinate systems, generally with the touch off feature in Axis. EMC takes care of figuring out the mathematical offset between the machine coords and the selected workpiece coordinates.
Jon ------------------------------------------------------------------------------ BlackBerry® DevCon Americas, Oct. 18-20, San Francisco, CA http://p.sf.net/sfu/rim-devcon-copy2 _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
