RE: Laddie M's Arrow - 2nd Attempt
When I built it, I weighed all the pieces and it came to 6.4 pounds with the foam core wings, so it's probably a little less than that with the lighter motor. (5 oz difference)
Flew it again yesterday, and ended up moving the battery all the way back to where it was originally, getting the CG about where it is on my glow Arrow when it's full of fuel. (Maybe an inch behind the step.) The 5 oz down thrust and the correct CG are essential for takeoffs from any kind of rough water. Full throttle, full up elevator and after the third bounce, she'll be airborne. With the original 0-0 thrust line, this would always end badly.
I've learned a lot about Delta wing stability with this one. It has the same vertical fin area as the glow one, and the same engine/motor pod box. Evidently, there must be a lot of drag (and thus stability) associated with the glow engine and it's muffler hanging out in the slipstream that you don't get with the little electric motor. I never had dutch roll problems with the glow version, but I couldn't cure this one of it until I increased the size of the rudder. Even now it doesn't have the roll stability of the glow one, and I'll probably increase the size of the upper fin some day.