MoTheG Show full post »
Argonath
Hopefully that will keep it from snapping in half during flight. Good luck with the next test flight.
D.I.L.L.I.G.A.F.
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ScottLott
For sure good luck, let us know how it turns out!
- Scott Lott
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MoTheG
2. test flight

It flew and didn't bend anymore, I even pulled it out of a dive rapidly.
Conditions: mid-day, calm wind, radio-interference, sunny
setup: nose heavy
It now weights 500g / 17.6oz .
So, two problems are solved but it does not yet fly good.
Sorry I don't have a video, I would love to have one myself, to analyze it.
The roll was erratic, jumpy; I can not describe it any better.
It might have a tendency to lean into the turn after it passes a certain angle, maybe a tip stall but I can not tell.
Authority was there, but it seemed to do a lot on its own.
I never had the feeling it was sliding/yawing.
Noise: The Slot is too loud. It sounds like a glow-engine. I didn't make it very big. I will make it bigger and increase the angle.
If it can not fly with NiMH it is not a plane.
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ScottLott
You know with that whole setup I bet the airplane is flexing in the air quite a bit, which could fo-sho cause those kinds of effects. See if you can reduce the flexing and see how that effects it.
- Scott Lott
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MoTheG
Quote:
flexing in the air quite a bit, which could fo-sho cause those kinds of effects.

you are right before I stiffened it, the flexing did interfere with the roll control very clearly.
It might cause some kind of delay, if the foam gives in at first and then comes back. That would explain the behavior fairly well. I will pay attention to that, the next time.

Right now I'm trying to get the slot bigger, but the stuff I put there is giving me a hard time.

Let's see what happens, when I put a gyro on the roll.
But I will not do that soon, I will report back in two weeks.
If it can not fly with NiMH it is not a plane.
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MoTheG
video

Now I was able to obtain some footage.
There is no audio, to keep the file small.
The video is available in HD.
It looks a bit dark, but it was actually so bright I could not fly anymore.

Sadly the biggest "thing" happened right where my cam-man filmed the ground, to look at it presumably with his own eyes.
Pay special attention to how it likes to roll to full 90°.
Analyze away!
I am blind to my own planes faults.
If it can not fly with NiMH it is not a plane.
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MoTheG
I added two big vertical stabilizers.
the crazy roll is gone now.
Analysis: because of the dihedral the plane turned side slip into roll, not a bad thing in general but it needs dampening by vertical surface.
As the plane would leave a turn it would swing through the horizontal.
also at higher speeds miner side movement would cause quick roll.
The plane has only 10° dihedral total and the string pulls the wing-tips down but that is enough.
I still want more roll response. I think I have to find longer arms for my servos.

It can go fast and slow; there is potential for 3oz of payload; flying is now reasonably easy

Next steps are:
-move the weight further back 3./3 positions
-increase throw
-play with gyro
If it can not fly with NiMH it is not a plane.
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MoTheG
To bad there is so little interest, because this is really great.
I had fun with it today and emptied the battery.
roll is quick and straight now.
high-alpha is fun and it can fly right out of it.(no rocking)
if you manage to stall it, it will simply take its nose down, without doing anything strange. I will have to test a very tail-heavy setup next. I want it to go flat-belly.
there is no flexing anymore I went crazy today and could not see any.
I did miss the rudder somewhat but it was never intended to have one.
All you need is:
receiver 15€
two 9g servos 10€ (maybe bigger would be better)
one 1:1 mixer 0-14€
ESC and 1000 RPM/V motor
9"x6" propeller
120-200g NiMH or LiPo Battery
(Glues of your choice)
and a visit to the hardware store.
I did not use any carbon, mostly:
cardboard from packaging, plywood, bamboo-skewers, packaging tape, natural-fiber string, 8mm x 3mm wood.
much of which might be in your household already.
Here some more pictures:



The ruler is 12".
With the nose and the fins on the bottom it actually looks quite aggressive in the air. It looks like it is carrying turbines or weapons.
.
If it can not fly with NiMH it is not a plane.
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MoTheG
Video



the first flight with the vertical stabilizers.
there is no sound, but it is rather loud. I will change the drive position (pull to push) and make the slot much bigger in the next one.
If it can not fly with NiMH it is not a plane.
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squishy
Good job, it looks like it flies well...I just re-read your post above and the behaviors you noticed, I would have suggested vertical stabs, seems like you nailed it...
"Education is not about filling buckets; it is lighting fires." W.B. Yeats

http://www.youtube.com/user/squishy654
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