The gcode output from Fusion360’s CAM processor uses G28 (rapid move to machine home) commands both before a job runs and and it is complete.
As far as I can tell, the G28 command quickly moves tool to the machine’s absolute (MPOS = 0,0,0) position, which is where the Shapeoko homes exactly at the point the limit switches engage. Since it moves quickly, the G28 command often trips the hard limit alert and halts all operation.
My current work-around is to just remove all the G28 commands (1 before the job and 2 after), but it seems to me that there must be a better way since they seem to be commonly used with other CNC systems.
What’s the correct way to handle G28 without tripping the limits? I suspect G28 really wants to go to “near home” which would be 0.5cm before the limit switch in each direction, but not sure how to change the functionality of that command without altering grbl on the control board.
Can the machine’s home position (MPOS) actually be zeroed 0.5cm off of the limits so that G28 stops before them under normal operation?
Loving my Shapeoko XXL so far; just working through the details to make it fast, smooth, and reliable. Thanks!