My Z axis calibration is off by a quarter inch or more. If I set the thickness of .75 inches, z axis only carves down .5 inches even though z has been zeroed out. Z axis is lead screw driven. Other axes are correct.
@SD_Fitts Which machine? Which controller ?
I am using a Vevor 4040 S1 CNC and my CAD side is Vectric V-Carve Desktop and G-Sender for the CAM. For a .75 inch board, I have to use .91 inches to go through with a profile cut.
@SD_Fitts Probably first thing I would check is the distance the spindle travels when you manually jog. In other words, move the spindle to its highest point, note down the Z coordinate. Manually jog down by a known distance (using a ruler, dial gauge, or other method). Note the new z coordinate and see if it corresponds to the actual movement.
There is a calibration function in gSender.