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Old Jan 26, 2013, 10:12 PM
jusjak is offline
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Hi guys,

I have Turnigy 1811, kv1500 motor laying around. Do you think it is OK for Kestrel or other ornithopter, if I use one stage reduction of 13.25, which makes maximum of around 14 flaps/sec (no load)? Is there particular reason to go with such high Kv and 2 stage reduction? Vibration, maybe. No experience, this is going to be my first ornithopter. Thanks.
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Old Jan 26, 2013, 10:33 PM
samwei1950 is offline
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Quote:
Originally Posted by Kazu-kaku View Post
SlowHawk2 with Articulated wings Turn system

http://www.youtube.com/watch?v=1hEv6wFSEDo

A conclusion:
Unfortunately, by this system, it is difficult to change direction.
Ornithopter can not turn.
Kakuta-Sensei:
my humble observation & suggestion
this Articulated wings may glide well in the air with current CG,
but extra thrust gained from the Articulated wings changed the CG of the orni when flying.
move forward the CG to cope with thrust line may help to control the direction of the bird
I maybe wrong.....pls kindly try
best regards
Sam
Last edited by samwei1950; Jan 27, 2013 at 05:28 AM.
Old Jan 27, 2013, 12:27 AM
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One more time thank you for everything you do and you are the fastest model builder experimenter I have seen ever . well said Otto AKA seagull


Doctor kazu is a very amazing and generous person in my opinion and one very enthusiastic experimenter and marvelous ornithopter builder regards Brian
Old Jan 27, 2013, 08:39 AM
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Bat 18-3 and Bat 18-4


Bat 18-3 Swing legs: Flight on snow in wind 4-5 meter /second

Bat 18-3 Swing legs: Flight on snow (2 min 19 sec)


Bat 18-4 with articulated wings and swing legs: Flight on snow in wind 4-5 meter /second

Bat 18-4 with articulated wings and swing legs: Flight on snow (1 min 52 sec)
Old Jan 27, 2013, 08:40 AM
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Dsungarypterus 5-8 with Articulated Wings: Very Good Flight on Snow


Dsungarypterus 5-8 with Articulated Wings: Very Good Flight on Snow in wind 4-5 meter /second.

Dsungarypterus 5-8 with Articulated Wings: Very Good Flight on Snow (3 min 49 sec)
Old Jan 27, 2013, 08:42 AM
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Seagull 24iV-4 with Articulated wings: Flight on Snow in wind 6-7 Meter / second.


Seagull 24iV-4 with Articulated wings: Flight on Snow in wind 6-7 Meter / second.

Seagull 24iV-4 with Articulated wings: Flight on Snow (2 min 6 sec)
Old Jan 27, 2013, 08:43 AM
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SlowHawk2 with Articulated wings Turn system test 2 Roll axis


SlowHawk2 with Articulated wings Turn system test 2 Roll axis

SlowHawk2 with Articulated wings Turn system test 2 Roll axis (3 min 2 sec)


A conclusion: By this system, it may be able to be roll.
Ornithopter may turn by Cahnge of Roll axis and Elevater.

The turning is possible by Sean's tail.
Last edited by Kazu-kaku; Jan 27, 2013 at 08:49 AM.
Old Jan 27, 2013, 10:59 AM
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Enjoyed the vids,well done
thanks for sharing
best regards
Sam
Old Jan 27, 2013, 02:30 PM
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Yes. Very educational *
Old Jan 27, 2013, 05:02 PM
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Quote:
Originally Posted by therealthing691 View Post
One more time thank you for everything you do and you are the fastest model builder experimenter I have seen ever . well said Otto AKA seagull


Doctor kazu is a very amazing and generous person in my opinion and one very enthusiastic experimenter and marvelous ornithopter builder regards Brian
Thank you.
Old Jan 27, 2013, 05:05 PM
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Quote:
Originally Posted by samwei1950 View Post
Kakuta-Sensei:
my humble observation & suggestion
this Articulated wings may glide well in the air with current CG,
but extra thrust gained from the Articulated wings changed the CG of the orni when flying.
move forward the CG to cope with thrust line may help to control the direction of the bird
I maybe wrong.....pls kindly try
best regards
Sam
Articulated wings moves CG in the front.
Old Jan 27, 2013, 05:07 PM
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Quote:
Originally Posted by jusjak View Post
Hi guys,

I have Turnigy 1811, kv1500 motor laying around. Do you think it is OK for Kestrel or other ornithopter, if I use one stage reduction of 13.25, which makes maximum of around 14 flaps/sec (no load)? Is there particular reason to go with such high Kv and 2 stage reduction? Vibration, maybe. No experience, this is going to be my first ornithopter. Thanks.
Please Try it.
Old Jan 27, 2013, 05:11 PM
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Quote:
Originally Posted by seagull10 View Post
Hi Doctor,
First thanks for the experiment ,the video and all the efforts!
I have watched the video few times and there is my thoughts:

1. I think that it is evident there is not slight but pretty strong tendency of turning right by some reasons which will analyze later.

2. There is almost no difference with the plate fixed in the center and fixed to the right .

3.When the plate is fixed to the left the system ornithopter - test stand behave strange .First start to turn left and after all the system achieve a good amplitude of shaking, it change the direction of turning to the right again? The last one I think is evident as well.

I think that there is some mechanical reason for such a system's behavior related to the system's shaking and mechanical instability. From what I see on the video only fastening clamp is evidently offset to the left . Probably it act like pendulum and precession force push the test stand to the right .Bigger amplitude on left wing is also possible in result of the shaking and twisting of the stand beam on which the clamp and the ornitopter are fastened.

Probably there are additionally stand leveling issues as well.

So IMO the experiment isn't absolutely pure and it's early to conclude that this new system isn't work.

Mr. Velkov opinion make sense as well and probably in the air without test stand influence the ornithopter will behave different .

I will suggest one more time the same experiment with the clamp mounted backwards.
Also if you still want to experiment it(I don't want to press you in any way) , make this ornithopter to fly first by the articulation system only and after that try this new turning system . This way you will be sure that the ornithopter generate symmetric thrust forces before starting experimenting with the new turning system.

One more time thank you for everything you do and you are the fastest model builder experimenter I have seen ever .
I will really have to fly.
Old Jan 27, 2013, 06:09 PM
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Quote:
Originally Posted by Kazu-kaku View Post
I will really have to fly.
Thanks for the efforts Doctor .
Actually the proper way of turning include roll to the inside of the turn curve so I think the system has to work .Also I am sure there will be asymmetry tn the differential thrust when the articulation angles aren't eqall

Is the right turn of the orni on the video(when it fly) was initiated from you or it turns from it self .or maybe better question is :is it able to fly straight without need of permanent control of the direction?
Old Jan 27, 2013, 11:27 PM
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Quote:
Originally Posted by seagull10 View Post
Thanks for the efforts Doctor .
Actually the proper way of turning include roll to the inside of the turn curve so I think the system has to work .Also I am sure there will be asymmetry tn the differential thrust when the articulation angles aren't eqall

Is the right turn of the orni on the video(when it fly) was initiated from you or it turns from it self .or maybe better question is :is it able to fly straight without need of permanent control of the direction?
SH2 flew straight without doing big maneuvering.
Because it seems to have fly out from a park, I controlled it to the right.
However, it was not able to turn enough and fell.


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