This is my first ever attempt to build an Rc plane.
I used ice-cream sticks or Popsicle sticks to build the main structure.
hope you like it...:)
That's quite inventive to use ice scream sticks. Every time some one tries to push the envelope that's amazing
nice model archer :hatsoff: and where do you fly in Manipal ??
Very nice any details
Very innovative one... absolutely different material from those which are conventional...Is this capable enough to survive in air.
this wont fly, your proportions aren't right, will be extremely tail heavy
Not just tail-heavy, it looks too heavy overall. And fragile.
@archer
You joined over a year back and this is your first post?
Welcome anyway.
May i suggest that you preserve this model as a first attempt at construction, and not use it as a first attempt at learning to fly?
Believe me you'll find this to be good advice.
Best of luck.
;D ;D :giggle: :giggle: ;) ;)
@K K Iyer:sorry did not post anything over here probably as I am kinda new to this...
anyways thanks for the feedback people..
actually I'm bad at flying and well already flew and crashed the plane...:P
it was a nose dive from a good height (those from MIT would know close to double the height of hockey ground from cricket ground) and well model did take damage....
part of the nose along with motor was dug in the ground and one of my friends had to pull it out...
anyways being an inexperienced pilot I flew it for close to 3 minutes before I had to give in to the winds and model fell to its fate...:(
the advantage for this is that it is a truss type structure....
so i could simply replace the individual struts which get damaged and voila its ready to fly again...:D
@rcpilotacro: the plane was not tail heavy, infact the CG lies very close to 1/3rd of the chord of the wing...:)
its because of the geometry...
the total weight of the plane including the electronics was 824 grams...:)
yeah I could agree the control surfaces are probably too big and kinda do provide excessive control but well I personally liked it...:)
I had a total of 3 flights, first one for close to three minutes and well ended up in a bad crash, call me being dumb and well sort of helpless... but could not record the video of the first flight.... :'(
that had an impact on the front of my fuselage and damaged 6 struts...
just replaced them and flew again....:)
I have posted the Images after my first crash....
The second flight was short lived and lasted only 10 seconds guess the heavy winds during the flight added up to my bad piloting skills...:P
it was done in MIT hockey ground. This broke my wing joint.
here is a video link to it if anyone would like to see....
http://www.youtube.com/watch?v=UsRghBj-at8#ws (http://www.youtube.com/watch?v=UsRghBj-at8#ws)
and well a slow motion link to what really happened...
http://www.youtube.com/watch?v=pk4s97b2QFw#ws (http://www.youtube.com/watch?v=pk4s97b2QFw#ws)
the third one was a simple glide after a small power up and well suddenly motor kinda stopped responding.
was guessing it might be an ESC issue...
@rcrcnitesh: I have a some pics taken during construction, will post them soon...:)
that might give the idea about construction...
given here are the pics after the first crash...
well here are the construction pics starting from airfoil to wing to the plane without rudder and then finally the complete skeleton with dihedral in the wing and rudder roughly arranged....:)
the covering was of butter paper....:)
Used two 5g servos for aileron and a 9g servo for elevator.
the whole horizontal tail was the elevator...:)
here are the pics:
rest of the pics...
No words sir
Simply superb
What may be the weight?
if your cg is okay, give it a shot at flight
R u a engineering student?
@iwincar:yup I'm pursuing my BE in aeronautical engg. in MIT Manipal.
@sanjayrai55: I did fly it have a look at the videos...:)
this was second flight and a really short one.(I'm not really a pilot and it was the first plane I ever flew...:P)
@vinayb1984:the model weight is 824 grams.
it is hollow and you can have a look at the skeleton in the pics posted above.
If you Observe carefully, you can see that even the motor mount in the first design was made up of ice cream sticks.
I changed it to ply wood after the first crash....
Both were sturdy but the plywood mount due to lesser thickness was lighter....:)
@swapnil: Forgot to mention earlier I had literally drop tested my fuselage from the third floor of my building to see weather it breaks or not.
results were promising as there was no damage....:).
here are the pics of my second model:
@archer
Did you know that tissue paper and butter paper can be shrunk tight by spraying lightly with water using a Colin bottle or a toothbrush dipped in water?
Is there a section of bottom longeron missing?
Have more comments but battery down.
Regards
@k k Iyer: wow didn't know that... :o :o
thanks for the tip...:)
that will definitely help me as I'm kind of rebuilding the plane not the whole skeleton but the covering....
there is no longeron missing in the fuselage...
that section was originally designed to snap i.e. it was supposed to act as a weak point and break preventing much damage to other part of the plane.
But well since there was no weight behind it so it would be useless (as a proposed weak point) in case of a crash condition in which the nose hits first.
In case of tail hitting the ground first it might work (hopefully as the technique using which the corner joints were made ended up giving me extremely strong and sturdy joints, stronger than the material itself. Can post a picture and description about it if anyone would like to know..:).)
would be waiting for your further comments....:)
@archer
The first thing to decide is the objective. Do you want to build
1. Something with ice cream sticks
2. Or an airplane that can survive test flights without crashing and enable you to learn to fly RC models
I notice that you have other material like (3mm?) biofoam.....
Anyway, here goes. Two old time aeromodelling thumb rules.
1. Add lightness
2. Throw it (the material) in the air. If it falls to the ground, it's too heavy!
Wing loading
The single most important thing for a trainer model is wing loading. Very broadly 6oz/sqft for 3 ft span, 6-9 for 4 ft span, 9-15 for 5 ft span, 12-20 for 6 ft span etc (these are just ballpark figures to give you an idea, not hard and fast rules) (multiply by 3 to get approx gms/sqdm)
Send me your model's span and chord size.
Seems to be 36x5 or maybe 40x7. Say 1.25 to 2 sqft. At 864 gms or 30 oz, the wing loading must be in 15-25oz/sqft range. Far too high. Wing loading has implications for stall speed as well as structural strength. Your wings have to be able to take at least 2 or 3 g, ie, 1.5-2.5 kg.
Also send me whatever details you have about the motor(name & number), the battery, Esc and prop.
If still interested after the above lecture, let me know for future messages on power loading, structural strength and integrity, performance requirements, design parameters etc.
Will be out of touch from 29th Jan to 10th Feb (son's wedding)
Agree with Iyer Sir.
Congrats sir for your son's wedding...
@archer: You should spend a couple of hours now on serious studying of various topics such as aerodynamics, power systems, etc. Also, study a bit more on how to design aircrafts, building an aircraft, do's and dont's etc...
thanks for the info Iyer sir...:)
and congratulations for your son's wedding...:)
I wanted to experiment with different materials and Ice-cream sticks were one of the alternatives...
being extremely cheap, I was able to make the whole structure in less than :Rs:300, which includes the glue cost.(the ice-cream sticks used had a total cost close to :Rs:150...;)..)
the wing loading is roughly 4.74kg/m^2 or 15.55oz/ft^2.
I intended the plane to be an acrobatic plane rather than a trainer... ;)
that is why I have huge control surfaces... :)
the motor, prop combo allows me to have a maximum static thrust close to 1.7kg.
the battery I am using is a turnigy 2200mah 20/30C lipo; the motor is turnigy D3542, 1000kv, 665W; the propeller is a 12X6 propeller bought from aeroengineeringworks, Chennai.
the setup has a 50 amp red brick ESC.
the stall speed is close to 11.6m/s for cl value of 0.6...
I know the combination seems overpowered...
but I wanted the plane to fly fast and be able to hover and also do vertical climbs.. ;D ;D ;D
again thanks for the info...
would love to know anything and everything which could improve my plane's performance and my knowledge about designing them...:)
@utkarshg13:
i guess i have some info on those...;)
but doesn't hurt to improve the knowledge...:)..;)
anyways from a design perspective the design is a basic high wing forward swept design with dihedral as is seen in the pics.
the airfoil used is a wb135/35 with the basic chord length of 11cm.
The fuselage has a fishtail design, in order to minimize drag.
since I couldn't make a round section with sticks so I went with a triangular design....
has a lesser C/S area...
the plane statically stable as the CG lied ahead of AC...
hope this info gives a clue about the plane and its designing....:)
would love to share any other info if required regarding the plane... ;D ;D
How are you building the wing without Spar,a solid enforcement ?
@iwincar:
good question... :)
the leading spar consists of arrangements of ice-cream sticks placed with the broadside parallel to leading edge...
the trailing edge has a simple arrangement of sticks as can be seen...
along with this arrangement, to improve on the stiffness, I used hollow tubes near the trailing edge and a flat CF spar close to 2/3rd of the wing and another thin rod in the leading edge...
this arrangement proved to be fine...:)
and that particular spar used was the most expensive part in the structure (costing around :Rs: 60) which I did not mention earlier...:P
the tubes were being thrown away from my college workshop, so I picked it up and used them...:)
@archer
With all due respect, i think you have too many objectives, some of which may contradict each other.
May i suggest that you don't try to meet all your requirements in a single model?
Spread them over 2 or 3. Say one cheap, one trainer, one aerobatic etc.
It is of course possible to meet all these requirements in one model. For example:
1. Under Rs 500 for material
2. Fully aerobatic
3. Unlimited vertical performance.
Here is an example i built last year. Spitfire.
36" span, 330gms AUW, 660gms thrust. 160w. 3s 1000mah, 4-5 minute endurance. Fully aerobatic (even without huge control surfaces or large throws). Speed range 20-110kmph. Hand launch. Can be caught by hand on landing.
(And by the way, it's a flat plate airfoil, no NACA, Eppler or Wortmann....) Edit: especially not a sailplane airfoil!
Best wishes for your efforts.
That slo-mo video was great. It shows the need for the structure to be able to resist torsional loads, the launch to be not so hard, the controls not to be so powerful etc.
Edit:
As my comments could look like criticism to you, (though only well intentioned) i will refrain from further comments, except to respond to specific queries if any. Regards.
KK has valid points. Looking at the Slo Mo footage few take away on flaws-
-the aircraft is starving for power,too heavy
-off course flying skills
-structure and design count major one
@K K Iyer:
not at all sir...:)
In fact its great to know I'm getting to learn so much regarding building planes....
Reading about is different and of course building and flying requires a different skill as well....
I am working on another plane...
these points help me incorporate changes to my model at the same time... ;D
Sorry if any of my comments did offend you, it was not at all my intention...
its just that I have lot of excitement that's why I wish to explain more and more about how I went around designing it... :) ;)
@iwincar:
Agree with you....
yes the craft was starving for power, though really couldn't understand why... ???
Do you think is the motor underpowered for the weight or is it a design issue...???
@k k Iyer:
also the plane seems brilliant...:)
do you have the video of the flight...?
Archer: in fact your design is quite different reminds me like the one saw with sketches of Leonardo Vinci (certainly not comparing you) but visual feel to it quite radical ...
Since u r an techi there is distinct ratio to weight:dimension: motor:battery: prop size
Da vinci...???
whoa didn't know that.. :o :o
do you have a link or any other info regarding that...?
would love to see it...:)
(I hope he did not patent his design...:P :P)
would agree to you on your second statement... :thumbsup:
Wow Great Plane Sir :)
Chk da Vinci flying machine designs
Quote from: aman1256 on January 30, 2014, 06:21:16 AM
Wow Great Plane Sir :)
Thanks aman1256... :)
Quote from: iwincar on January 29, 2014, 11:24:57 AM
Archer: in fact your design is quite different reminds me like the one saw with sketches of Leonardo Vinci (certainly not comparing you) but visual feel to it quite radical ...
Since u r an techi there is distinct ratio to weight:dimension: motor:battery: prop size
Quote from: iwincar on January 30, 2014, 10:56:23 AM
Chk da Vinci flying machine designs
yup the design does seem radical guess he tried his best to mimic the birds in his ornithopter design....
I really wonder what if it flew....?
@archer
Quote from: archer on January 28, 2014, 01:13:58 PM
@k k Iyer:
also the plane seems brilliant...:)
do you have the video of the flight...?
Not brilliant. Just nice. Here's a 35sec clip...
http://www.youtube.com/watch?v=zXoPSLAQ9Fk#ws (http://www.youtube.com/watch?v=zXoPSLAQ9Fk#ws)
nice flight and it is brilliant... ;) {:)} {:)} :bow:
Hope I fly my next plane properly...
also manage to get a little more air time.... :P :P
I know adding landing gear would mean extra weight but it will help save the prop, most of the time
Good job on the overall plane very innovative :-)
Thanks Hellyflyer.... :)
and will definitely take your advice.... ;)
I should have added them in the first place.... :banghead: :P :P
The whole thread is a breath of fresh air :thumbsup:
Archer, this is a very interesting and commendable effort. As an engineer myself (IIT-B, Class of '79) I appreciate and commend the thought and effort you have put into the very original and well planned design and build.
After going through the comments by others, I can assure you they have not really understood what you are doing here. Therefore go on tinkering; you are almost there!
All the best :goodjob:
thanks a lot sir... :)
I'll do my best and will continue to experiment..... ;)