Adam - I was concerned that yard-sticks might snap during a pull-out from a dive. Instead, I used Coroplast on edge, several layers (4 in the center, tapering in layers towards the tips). If the stress gets to much, the spar can flex somewhat. To further reduce the chance of "snap" manouvers, I used the slow 100oz-in GWS servos (0.33s transit for 60º) for everything but the throttle.

What's your opinion - will it fly? Is a 25cc Poulan enough?

P.S. I added some specs to my earlier post with the pics.