This one's a total copy-paste of Vaibhav's plane with respect to dimensions.
http://www.rcindia.org/self-designed-diy-and-college-projects/first-flight/
Only differences are:
1) It's made of 4 mm coro + high density thermo,
2) Wing is flat-bottom aerofoil instead of flat,
3) It has a 160 W motor + 9*4.7 prop instead of a 120 W + 8*6 (in Vaibhav's setup).
This bird is certainly heavier than Vaibhav's but i hope the power setup will compensate for that.
Couldn't maiden it as it was raining/ windy all day, will try in the morning.
Questions:
1) The aerofoil has 1 in thickness at 1/3 chord. Will it make any significant difference as compared with flat-wing? (I've read in a post by Sai sir that aerofoils don't give much advantage over flat-wings for small models)
2)The servos are placed close to the elevons. How much will the position of CM have to be changed?
Many thanks to naatumach (Vaibhav Sharma) for the detailed plan. :thumbsup:
Hope mine flies as well! :)
1.I have also read that airfoils dont make much difference in models.
But that is not entirely true. Try building one fuselage and two sets of identical wings, one with airfoil and one without. The airfoil makes the glide longer and sturdier.
And I believe that especially in my model which i has a less than one thrust to weight ratio, i feel that airfoil makes a difference.
2. Where ever you place the servos, just find the CG of the aircraft and place the 1/3rd line about an inch behind the CG. If the a/c nosedives reduce the distance, if it flares up increase the distance.
The closer you keep the Servo and the battery the better it will fly. The reason is that
There are three heavy components, 1.Motor 2.Battery 3.Servo.
Motor's is fixed. Battery is near the 1/3rd line, so its fixed too. So now you are left with the servos and the plane is balance. Now if the servos are of 10gm and is 1cm from 1/3rd line the torque induced is 10gm.cm and if its 10gm and placed 10cm away it'll cause a torque of 100gm.cm which will cause too much instability, so i recommend the servos be kept close to the 1/3line.
Regards
Wow that is one wierd looking plane. UFO :) Post vids too. Plan on giving it colour for visibility? since its more of a square.
It is actually a very common design.
If you taper the planform it will resemble a mirage, but its planform is designed for high speed.
To make it adapted for our purpose we make the have a low aspect ratio and viola you get the pizza box.
Quote from: Swapnil on June 20, 2011, 09:53:47 PM
It has a 160 W motor + 9*4.7 prop instead of a 120 W + 8*6 (in Vaibhav's setup).
How does one find out the Wattage of the motor?
Well, it's generally specified in the motor manual.
Also, Wattage = (max. voltage) x (max. current) .....
Quote from: rajathv8 on June 20, 2011, 10:55:13 PM
... Plan on giving it colour for visibility? since its more of a square.
Yup. How about all black? Or maybe black+silver?
It'd look more like a UFO then. ;)
Could also try adding a tractor-beam to kidnap pizzas! ;D
So my max voltage is 11.1V (3cell) and max current is 18A (ESC) ? so that makes it 199.8W?
Is this correct?
Oh no, you got it wrong!
It's the max. current of the motor you need to consider not that of the ESC (as we are calculating the motor's wattage).
Did some test throws. I don't know if one can use the term 'glide' for a plane with such dimensions, but it did go straight without dipping forward or backward.
I think you're good to go. Yes one really cant use the term glide for it :P
The rain gods hate me! :(
All I could do with it indoors was paint and name it.
Now it's called 'The BugHunter' ! 8)
Pics follow...
Top view...
Upside down..
some more...
and this...
is that paint or printed paper or textured paper?
Poster colours+paint+varnish+permanent markers...
I assure you, no 'printed paper or textured paper' was harmed during the paint job. ;) :P ;D
I know it looks like a 6-year-old's work, but that's all I can do with colours! ;) :)
Quote from: rajathv8 on June 20, 2011, 10:55:13 PM
Wow that is one wierd looking plane. UFO :) ...
Well, I initially thought of naming it 'The Pizza-kidnapper from Pluto' or 'The JungleBoy'...but now it's 'The BugHunter'. :D
it looks good. shouldn't u hv flown it before you try to decorate it?
im getting too anxious to see it fly
Quote from: Swapnil on June 23, 2011, 10:20:51 AM
The rain gods hate me! :(
All I could do with it indoors was paint and name it.
Rains man!
I 'decorated' it so that even if it doesn't fly, it'll make my wall look impressive! :)
thats optimistic :)
Increased vertical stabilizer area as suggested by Vivek (Jatayu)....
Took it out this morning.
Broke my first prop! :D :D :D
WooHooooooo!
My BugHunter FLIES! ;D ;D ;D
Just did the maiden.
1) Went straght up at 30o
2) then 3 rolls
3) 1 loop
4) then hovered for like 3s
5) then a bad landing (bent prop adaptor base)
It was Super-Awesome! ;D ;D ;D
(Anwar sir, can't we get a dancing smiley? ;D)
A million thanks to Vaibhav (naatumach) and Vivek (Jatayu) for all their technical and non-technical help and for supporting me throughout. Really grateful to you guys! :) :hatsoff: :bow: {:)}
And sorry guys, no video. Will do another sortie this afternoon on a paddy farm and record it.
PS: This was with a 10*5 prop and launched at 50 % throttle.
{:)} {:)} Congrats on ur flight !
Try getting a prop-saver adaptor and lot of O-rings those give a second chance for those thin flimsy SF props... try posting the videos of ur second sortie.
Happy Landings! ;D
Thanks! Will get a prop saver and loads of props from RCD today!
My dad's really impressed!
Ah, this is really gonna compensate for my bad grades! ;D
Congrats! :)
I use rcdamaka's Rs57 props they dont break easily. I have crashed nose first twice in a row and they havent even chipped.
The a/c is indeed fun.. Just waiting for the video :)
I tried Electric and SlowFly props and personally i think SF are easier to manage in flight
Gonna reapair it and post video ASAP! :)
Did you fly it again?
No, it's being modified...
And rains...
Great art work, Please post a video. ;D
Really sorry, I won't be able to post a video soon as I'm busy with another project.
This bird flies great. Couldn't record the maiden flight but I have some great memories flying it with my dad! Right now we are 'flying' in our new i10! ;D ;D ;D
congrats :)