strange behaviour of my new bird

[Theo coenen]

After I crashed my Kestrel e few weeks ago I have build a new bird. I made some minor changes, but these are not that big that it would have anything to do with it. I just simplyfied the crankshaft and its parts and I canged the hinges a little.
I also wanted to go back to 3 mm carbon rods as leading edge, but with this it will not fly, as soon as a switched to 4 mm rods it is flying again.

Is it possible that the course off this is the total length off the conrods, or has the flapdistance or flaprate anything to do with it?

In the beginning with the Kestrel I had the same problems, after I changed to the 4 mm leading edges the problem was solved.

I am slightly confused now about this. Can somebody explane this to me please?

[eekflyer]

Hi Theo, Could the issue be one of leading edge flexing, or, lack of ridigity ?

EEK

[Chronister]

If you want to use 3 mm rods, you might be able to compensate for their excessive flexibility by increasing the flapping angle of the mechanism. I think the stiffer 4 mm rods will always be more efficient though.

[Theo coenen]

Nathan Thanks for youre help, changed it and it works. changed somthing else and it does not fly.

now what did I do different.
I changed the conrod lenght and old style hinge with 4 mm leading edge, and it worked perfect.

changed the Hinge to a different style and it does not work. Everything else is the same.

tommorow I will get a new carbon rod so I can repair the old style hinge and try this again.

And I will see if I can pick up the digicam so I can make pictures off this "new" model.

[eekflyer]

Would like to see it !

[Thomas Sk]

Hi Theo,
How does the "strange behaviour" of your bird exactly look like when "it will not fly"?
Does it simply not take off because the wings don't produce enough lift?
I'm wondering whether this may be due to the same technical reasons as with the problem I still have (see "REM Eagle turns nose down", thread=423710). So I'm very interested on every news you can post here...

[Theo coenen]

Thomas it looks the same. It takes off and then it pitches nose down with a left turn. I will do some more testing today, and report it here. i just picked up a new 4 mm carbon rod so I can repair my old style winghinges.

[Theo coenen]

The old style wing hinges are back in place and it wants to fly again. It still has no power to climbout. The next thing I will try is to go back to the conrod lenght I had before. I made them 2 turns shorter so I cam on the original lenght for the Kestrel.