Board Thread:Questions and Answers/@comment-68.248.233.182-20130301141000/@comment-6024139-20130304170825

Well I've looked at it briefly. It seems all you do is write "excavate X" where X is replaced with lenght of one side of the square it will excavate. It will just continue down until it runs into some obstacle, run out of energy or fills the inventory.

Before doing that you just put any fuel in the first slot and type "refuel". Maybe there's a more complicated way of doing it, but I don't see the point.

You may be better off with a quarry.