Tony,
Just wanted to let you know you have a winner. This program is just what most Hobby level CNC users needs.
A few quick suggestions about the tutorial. In your tutorials you refer to the airfoil as a wing spar. In the U.S. we call those "ribs". Also when you cut out the interior of the ribs you used a pocket command. This results in unnecessary machining time. A profile cut to the inside would have been a better, quicker choice.
You guys are very fast programmers!!! Wow.
Bill