OK, you showed the procedure on setting your tool lengths but you did not explain the tool measure offset read out. So how about explaining how that the tool length measurement does not show the actual Z length from home position to part but shows the difference from your Z0 work offset coordinate, example - your work coordinate Z0 is the locating surface of your part in the vise. (the bottom of your part) I am seeing it that your first tool length is set off your Z0 work offset coordinate, then all your other tool length is measuring the difference between your first tool to all the other tools. That is what that Tool Measure Offset button feature do, am I correct?