CNC Router machine not cutting deep enough Mach 3

Hi All,
I have a problem with my cnc router machine.
It's not cutting to the correct depth.
It's barely scratching the wood regardless to what height wood i use, this is more noticeable when using various text fonts.
I even fit a touch plate to ensure the heights etc were correct and changed the relative info within the script to suite the plate height etc, but still had the same problem.
I'm sure this is a problem within Mach 3, but don't want to start altering settings unnecessarily, as I'm not that familiar with it.
If it helps any, I've noticed when using the touch plate, that after it finished and I click the, GO TO ZERO button, the machine goes to a few mm above the work surface instead of, more or less touching the wood surface.

Any assistance would be really appreciated , Cheers Yarlo

Before going any further you need to check if the machine is moving the distance it's been told to move. If the steps per setting are wrong you'll never cut correctly.

So Zero the Z-axis up in the air and make a mark or measure the distance from the tool to the table, then in the MDI type G1 Z-10 F1000 and measure if it moves down 10mm.

If it moves 10mm as instructed then the most likely cause is the touch plate height in your script is wrong.

The only other possible cause is you have a tool height offset set in the tool table but this would require your code to uses a G43 H# value so it calls a tool height offset. Easily checked by looking at the tool table.

Cheers Dean,
All sorted, for some reason the Z Axis calibration was a mile out, thanks for your support in rectifying my problem.