Wing Flutter

Posted by Simon Howroyd on July 26, 2013 at 4:54am

Hi All,

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.

Si

You need to be a member of diydrones to add comments!

Join diydrones

Email me when people reply –
Follow

Replies

  • james sowell July 29, 2013 at 9:20am

    http://www.rcgroups.com/forums/showthread.php?t=1555543&highlig...

  • Jay Bryon July 26, 2013 at 2:16pm

    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.  

  • Wolfgang Luck July 26, 2013 at 5:56am

    Hi Simon

    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?

    Greetings Wolfgang

  • Christiaan van Vollenstee July 26, 2013 at 4:59am

    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.

     

    https://www.youtube.com/watch?v=PoJLgAlkABE

     

     

     

This reply was deleted.