Not sure how to work these.

I have been trying to make my Mining Turtle in Tekkit mine a 3x3 square all the way down to bedrock, Excavate 3 works, but not always, and not all the way to Bedrock.
What exactly do the numbers at the end of the Excavate command represent, and how can I make this work?

Ask a Pro.
I have personally never used excavate, sorry.

Anybody?

basically you say excavate 3 and it digs out a 3x3 area until it reaches bedrock or until its inventory is full, then it returns to where it came from

EDIT: it also keeps giving output on how much it has mined etc as it goes, it is a small enough code but written very well