Thought I should open this; yesterday I started experiencing some pretty horrendous wing flutter across the whole aircraft. It was a first harmonic, so the fuselage went up, both wingtips wend down (and vice versa), bending I would guess around 200mm!
Apart from the normal stuff, I am carrying 2x 7s 4Ah LiPos (about 0.7kg each) and then a payload of 1-2kg. All up weight of the X8 is around 5kg.
I have fiberglass tape on the underside of the wing, from the root to the tip.
Anyone else experienced such extreme flutter?
I've added some more tape & am about to go for a fly. Hopefully this will reduce this resonance.
I'd add tape to the top of the wing to increase the stiffness as well, so that it can't bend downward as easily.
As mentioned by Christiaan, this problem with the X8 is known. I think I have experienced the same problem flying faster than 100km / h. I am also experimenting with different, fast, cheap and light methods of enhancing the wings strength and by doing so preventing it from getting into a flutter. I am busy creating fibre glass moulds for leading and trailing edge (between wing and elevons) strips that should be easy to fit to the X8. Lets see how that turns out.
Is that fibre glass tape you have got under your wings stiffened with resin?
That is very heavy for a X8, why put in so big batteries do you want it to stay up there for a year :).
Check this video where flitetest reviewed the X8 and you will be amazed what happens to the X8 in the sky.