This is a combat wing.
It died in mortal single combat.
AKA test flight!
I reduced the size of the elevons, changing them to be rectangular, and some how destabilized the wing in doing so.
Any Ideas teach?
I launched it, and it flew normally, for a second then started to torque roll a little. When I compensated, It rolled sluggishly until it rolled over level.
Then it violently snapped over, and began acting stalled and tail heavy.
I duplicated this twice, then it went into the fence.
I can add more details if you need.
When you say you reduced the size of the elevons, do you mean the width? If so, the first thing I think of is that the reflex was reduced. Flying wings need reflex for pitch stability. But, you seem to be describing a roll issue. Maybe the prop torque overcame the roll authority of the elevons?
Yes I do mean the width, but It wasn't the prop. On Tuesday it flew great, but I had to bring everything down to 50% high rates with 40% expo to tame it down, and even then the roll rate was scary fast.
I was flying it on 100% rates for this flight.
It also behaved like this if I moved the controls too violently at low speeds before trimming, but it was controllable at least.
At 6" back from the nose.
As this is a 3/4 scale copy of the Zagi, I simply scaled it. The Zagi's CG is 8" back from the nose.
EDIT!!!! AIEEE! I just found the flying wing CG Calculator on RC groups. I am flying at the 30% Chord!
I will move it forward and try again.
Thanks for the help Teach, Much appreciated.