Z cut issues

I am having an issue with the Z axis not cutting deep enough. I have an openbuilds lead screw 1010 machine. I’m using 1/2 MDF, on the through cut it only cut to about .380" on the other cut set to .071 it cuts maybe .025. The Z axis is adjusted to with in .002" of zero. I’ve set the MDF thickness to various depths (.500 to .550) still has the same issue. This has been happening in previous cuts, so it’s not new… Here’s the link, this was design in Easel. …Any ideas as to the issue.

Have you calibrated your steps per millimeter? I set my material .03 thicker than what it actually reads with calipers to ensure a complete cut