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        Discussion rc ornithopter homebuilt

#1 arun.sreelakam Dec 31, 2012 12:15 AM

rc ornithopter homebuilt
 
SO its time to upload my dream build now... started my rc hobby just few months before but.. more than anything ornithopters are my favorate and i didnt go for buying one..:) instead i decided to make one..:D
gone through all the website as possible.. didnt find any build log..
finaly decided to build my own so that i can make a build log later.. :p:p
selected kinkade's slowhawk as my model and started to download as many pictures of that.. using my ideas and stuffs available locally and started my build few monts back..:mad:
the main problem was the gear assembly.. and searching for proper gears.. i dont want to spent more by getting gears online..
got some help from kazuhiko Kakuta(rcgroups) and models previously submitted in RCIndia as well..:o:o
now the wing action is almost good in my calculation getting enough trust..
see my video of wings test... and please give your valuable suggestions...
:popcorn::popcorn:

http://www.youtube.com/watch?feature...&v=JGTNA9Vc5r4

#2 arun.sreelakam Dec 31, 2012 12:19 AM

2 Attachment(s)
some pics of main body and tail assembly.. :)
will upload the vid later :mad:

#3 KOROBELNIK Dec 31, 2012 03:32 AM

The two front wheels must rotate clockwise

#4 arun.sreelakam Dec 31, 2012 03:51 AM

Quote:

Originally Posted by KOROBELNIK (Post 23667324)
The two front wheels must rotate clockwise

why so?
what changes it will make..?

#5 arun.sreelakam Dec 31, 2012 03:54 AM

ornithopter tail completed
 
here comes the entire orni tail assembly also done..
please give me your suggestions friends...

rc ornithopter homebuilt testing (1 min 48 sec)

#6 KOROBELNIK Dec 31, 2012 05:58 AM

http://ovirc.free.fr/GLDAB_JAPAN.php

#7 arun.sreelakam Dec 31, 2012 07:48 AM

Quote:

Originally Posted by KOROBELNIK (Post 23667687)

but sir i didnt get you.. :confused:
the gears must round clockwise only if i am using GLDAB system right?:confused::confused:
please explain the thing.. i am really new to this.. this is my first build..:mad:

#8 seagull10 Dec 31, 2012 08:47 AM

Quote:

Originally Posted by arun.sreelakam (Post 23668186)
but sir i didnt get you.. :confused:
the gears must round clockwise only if i am using GLDAB system right?:confused::confused:
please explain the thing.. i am really new to this.. this is my first build..:mad:

For the GLDAB doesn't matter in which direction gears rotate but for the ratchet ( the wings glide position locking device) does. The orientation of the ratchet determine the direction of the gears rotation. If you don't have ratchet mounted don't worry about the direction of gears rotation. If you have it then the gears must rotate in the direction which allow their free turning when the motor is on and locking when the motor is off.

#9 seagull10 Dec 31, 2012 09:12 AM

Quote:

Originally Posted by arun.sreelakam (Post 23666672)
SO its time to upload my dream build now... started my rc hobby just few months before but.. more than anything ornithopters are my favorate and i didnt go for buying one..:) instead i decided to make one..:D
gone through all the website as possible.. didnt find any build log..
finaly decided to build my own so that i can make a build log later.. :p:p
selected kinkade's slowhawk as my model and started to download as many pictures of that.. using my ideas and stuffs available locally and started my build few monts back..:mad:
the main problem was the gear assembly.. and searching for proper gears.. i dont want to spent more by getting gears online..
got some help from kazuhiko Kakuta(rcgroups) and models previously submitted in RCIndia as well..:o:o
now the wing action is almost good in my calculation getting enough trust..
see my video of wings test... and please give your valuable suggestions...
:popcorn::popcorn:

http://www.youtube.com/watch?feature...&v=JGTNA9Vc5r4

Bravo Arun , Good job !

I suppose it will fly as it is, just find some flying field with taller grass for minimizing ground strikes impact . Also some play with center of gravity will be probably necessary too.

If it doesn't fly then increase the flapping angle.Your one look like 30 degree ,most common is between 45-60 degree .This will lower the necessary flapping frequency as well.
Also if it is not stable enough make flapping angle asymmetric regarding the horizontal neutral line or for example if your total flapping angle is 50 degree make it flap 40 degree over that imaginary horizontal line and 10 degree down.

I wish you success and Happy New Year !

#10 arun.sreelakam Dec 31, 2012 11:14 AM

@seagull
 
thanks a lot for your critiques sir... will try it...
:)
the flapping angle is 30 up and ~15 down...
if the thrust is not enough will try to increase the angle...
and sure will upload the results..:):):)

#11 n553302 Dec 31, 2012 12:01 PM

Looks like a flying machine arun.sreelakam.
When balancing the bird for it's first flight nose heavy will be to your advantage especially if the wind speed is very high. Also you mentioned this build is fabricated based on a SK Slowhawk. From the Slowhawk setup manual Sean suggest the neutral pitch angle of the tail should be about 20-25 degrees from the horizontal, my Slowhawk is set at this amount and fly's well. Yours is somewhat less that this I believe. Sometimes if one of these birds will not turn as quickly as you wish extra 'up elevator' is required to help push the tail in the desired direction. His manuals are available free online if you look around.
Have luck, looks great so far
Rick

#12 arun.sreelakam Dec 31, 2012 08:54 PM

@rick
 
thanks rick, and i noticed that yesterday from some site(http://sgdrone.com/Content/Images/uploaded/Assemble.pdf)....

i can change the angle when ever i want so now its been set to about 20 degree.. but i am confused, if i make it to 30 degree or so will the down elevator work?
i mean will a 10 degree of elevator change takes the birdie down?:confused::confused::confused:

#13 n553302 Dec 31, 2012 09:24 PM

Down is easy, very little down elevator is required.
During forward level flight you will probability holding the elevator stick slightly forward and the tail will be more or less level with the wing. If you are using a computer radio you may want to set the control movements to their max, no such thing as to much throw.

#14 arun.sreelakam Dec 31, 2012 10:37 PM

@rick
 
anyway i had lifted the tail part to 25~30 degree up.. and going for a maiden soon...
thinking upon to cover the body using foam.. to prevent damage in case of crash.. :)
will update the result dude.. thanks a ton for your help... :o:o

#15 n553302 Jan 01, 2013 01:47 AM

As mentioned a few post ago, deep soft grass,weeds make for a good landing zone.
I've seen pictures of a length of rubber or silicon hose slit and mounted as a skid plate.


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