Strange flight Behaviour ( Any ideas )

[sumone]

I scratch build a lot of flying wings.
Small , Medium and large wings and in general they fly fine .
Mostly the behave fairly predictable .
My favorite wings to fly at the moment are quite small at about 600mm wide .
They are quite fast and fun to ramp up and dance around the sky.

Now recently i have noticed some strange behaviour (Not on every flight because yesterday i flew all day and it didn't happen at all).
But when it starts it seems to last that whole session.

What happens is when i punch the throttle it wants to bank left and dive (I don't believe it to be engine torque as i know what this feels like . This feels more like a servo thing . I Have tried the following.

* Re-centered the servos and pushrods. (re-trimmed)
* Checked that there is no play in control surfaces
* Motor mount isn't loose.

I'm stumped .
Anyone else had this problem or have a solution ?.

 

[Hai-Lee]

I would check which way the servos "twitch" when the battery is connected! To me it is the same effect you get if you have a poor battery connection which causes the Rx and Servos to brown out and then when the voltage returns to twitch before resuming their proper operation.

Just a guess!

Have fun!

 

[sumone]

I would check which way the servos "twitch" when the battery is connected! To me it is the same effect you get if you have a poor battery connection which causes the Rx and Servos to brown out and then when the voltage returns to twitch before resuming their proper operation.

Just a guess!

Have fun!

I think your on to it Hai-Lee.
Need to test it at home with the wing stationary (Clamped to the bench)
and see if i can replicate the problem.
This is Gunna be loud.
So I'm telling the wife you told me to do it

 

[Hai-Lee]

I think your on to it Hai-Lee.
Need to test it at home with the wing stationary (Clamped to the bench)
and see if i can replicate the problem.
This is Gunna be loud.
So I'm telling the wife you told me to do it

That's OK I am always in trouble with my wife so adding your wife as well to the list will be only a little extra!

I hope you can nail it because intermittents can be a pain to tack down. I had an intermittent motor that took almost 6 months to properly identify!

have fun!

 

[Merv]

Check for flexing in the airframe & motor mount.