RC India

Dear friends,
I am a begginer in RC planes.
Now I am building a RC coro trainer and I would like to share the build Photos.

santhosh where are you in coimbatore..?

I am from Sundarapuram,Coimbatore

The materials used are
Motor
Turnigy 1250kv 500W motor
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=18227
ESC
Turnigy Trust 45A SBEC ESC
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=12191
Battery
Turnigy 3S 2200mAh 20C lipoly
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=8932

Servos
3 x Hobbyking standard servos
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=16269

Control horns ,clevis
From hobbyking
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=8611
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=8639

Control rod,
bicycle spokes

3mm Coroplast
3mm Plywood

Welcome :)  Looking forward to the pictures !

38g servos for trainer?  >:( >:(
so whats the wingspan and length?  :headscratch: :headscratch:

Thanks Mr.Anwar

BTW the wingspan is about 52" with 7 degree dihedral.
I chose the standard servos because the motor is 500W and can provide enough thrust.

The length is 38".

yaar i think these power system will be much heavier for your model.. :headscratch: :headscratch:
what is the AUW you are expecting? ??? ???

AUW is approx . 1.5KG

 :o :o whooo.. thats pretty heavy i think.. my trainer of 50" span weighs 400gms(inc battery).. and your motor has only 1250gms of thrust..
better wait for the seniors to talk about this.. 
this is my trainer
http://www.rcindia.org/electric-planes/home-made-coro-trainer-plane-50'-span/msg117896/#msg117896

Arun, I am relatively new in Electrics,and please correct me if wrong, but I would think that if e.g. you use a 1250 g thrust with a 1250 g model, it will be capable of climbing vertically. In that case, for normal (read trainer) flying, this motor should be capable of handling say a 2 Kg model? Looking forward to some insights from people more knowledgeable than myself.

Arun - I think trainers need only 50 - 75 watts/lb i.e. approx 100 - 150 watts/Kg .Please correct me if I am wrong.Also I am building it as per a plan given by my friend from Sharma models and it stated it needs only 300watts motor.

@sanjay: actually i bought a aeolian 1700kv(c3530) motor first which can lift about 1.2kg and installed in my trainer that was nose heavy, then i added some tail weight and fled which flies good but as i am a beginner it was really hard to control, and crashed...Then i moved to the less kv and less watt motor which can handle 700gms or so, then i felt the difference that flying it is really easier than my first model.
Here it may fly good, but decreasing the weight will reduce the damage while crashes..
This is in my view please forgive me if i am wrong.. :)
 :P :P :P

Arun, you are correct when you say that heavier model crashes create more damage. Heavier (and larger) models I would feel have their own advantages and disadvantages: easier to see in the air, better handling in wind. I have crashed (quite a few times!) a Spadet Corro model, about 2.6~2.8 Kg, but, unlike Balsa, it bounced :)

As the saying goes, crash enough balsa models, and you'll have a tree growing, but you can't plant plastic (although I have tried many times :D

I guess the important thing is AUW should be in proportion to the model size. I am just completing a SPAD with a span of 44", chord 12", length 32". With full Landing Gear and a 3300 mah battery it will weigh 1.3 to 1.4 Kg, or 3 lbs. Let's see how it flies! :headscratch:

Still looking forward to some expert views on thrust vs model weight  :-\

sanjay sir i think i have got more crashing experience  than yours..  :giggle: :giggle:
done about 8-10 crashed till today.. including the one which happend on my birthday..  >:D
the next flying will be this Saturday.. lets see whats gonna to happen.. :)
anyway all the best for your build and waiting to see the pictures..  :thumbsup: :thumbsup: :thumbsup:

Good luck for Saturday, Arun

Santosh: post photos...:)

Sanjay sir here are the photos,
Items ordered from hobby king.
Plan on coroplast.
Fuselage cut out.
Elevator and rudder.

Some more photos.

And some more
Art on horizontal stabliser by my friend Sakthi

Pom horns fixed
Control rod made of bicycle spokes and dowel rod.

servos mounted.
Making of wings from 3mm plywood

Model almost finished with landing gear.

My spektrum 6 channel Rx.
Dihedral cut out from 3mm plywood

awesome build man...  now i know i was wrong.. the power system you choosen will be opt for your plane..  :thumbsup: :thumbsup:
all the best

Its a solid build... :thumbsup:

Thanks mr.swizera

I will post more photos about the wing once I finish it.

Friends please help me  :help:

how to fix cloth hinges to ailerons and wing.
If possible post a video.

Cut out wing section.
The length was not enough to cover the wing and I had to cut the glued rib from coro  ???

Once again started cutting a new wing .Thank god I had just the required size coro for the wing as leftover.
Wing complete withour ailerons.

Wing complete with aileron,torque tube,torque rod,clevis,servo etc.

Santosh u have build a beutyfull plane......... :thumbsup:

santhosh hope we can see the maiden soon..  good looking trainer man..  :thumbsup: :thumbsup:

One thing I don't understand: why don't you make your hinged surfaces in the normal Spad way? i.e. by cutting the flute on 1 side. One of the main benefits of Spads is the time and hassle saving on hingeing

That said, the model looks good; waiting for the flight report :)

The reason I didn't use hinges in aileron as used in all SPAD is that I wanted the ailerons to more free to control.

The technique for that is

(a) Cut one side flute fully
(b) If you still have sticky controls (which does not happen with me even with 4 mm Corro) then after every 2" cut a 1" solt

Happy New Year friends.... ;D
Let this year be a crash free year.... :giggle:

Same to you Santosh!

very good build , we can also build the wings by using wood spur only ( no ribs). how did you cut the ribs from 3 mm ply ?

To cut the ribs I went to a local Switch board cutter , I drew the things I want to cut on a 3 feet x 1feet 3mm plywood and paid him Rs.150
I got them..But you cannot get it very accurate and straight...
BTW I did not use any balsa on this plane .

superb built santhosh
dude it was really a wonderful plane:hatsoff:

Thanks krishnamoorthy anna...

Made the first flight....a beautiful stall and then a crash...
The Lipo burst into flames and damaged the motor , ESC and the ESC compartment....

damaged plane..

My condolences. May she recover and take to the skies again. All the best.

ohh that was really bad...  :'( :'( :'(
santhosh what happend actually...? short circuit?  :'( :'(

The model was hand launched , flew very well and made a stall and could not recover and nose dived.
since the screws used to fix the motor was protruding from the firewall the battery hit the screws and went into flames.... :banghead:

santhosh next time i will fly your model
dont worry we will do it :thumbsup:

Great build job Santosh. Very innovative and very strong. Looking forward to the flight video.

Finally repaired my plane and got two 3S 20C 2200mAh batteries.
Can I connect two batteries in parallel for increasing my capacity.Also there is a necessity to place two batteries to maintain the CG of the plane at 1/3rd the chord length from leading edge.

Yeah you can use two batteries in parallel but make sure they are at the same voltage before connecting! :)

Looks fine but aren't you pushing the plane to limits !!!

firstly 2200mah battery is way too heavy then 2 of them...... Huge payload on plane.

I would suggest a lighter & power efficient plane .....

You are right rastsaurabh , but without two batteries the C.G. too far behind.The AUW is 1.6Kg and the motor is 500W and wingspan 54"

I would always suggest to rectify the issue..... i remember making a tail with 2 coro sheets .. it was too good and nice but did not use as it was heavy and i  would have landed in situation like yours.

adding a battery is a wise action than adding dead weight though. see if you can reduce the tail a  bit....

such a heavy plane with single coro layer may get exposed to all types of pressures during flight and result in free fall !!!
IF no choice then go for it atleast have a easy & endless flight ..... you can keep flying for >30 min!!!!! with those 2 power houses on your plane.... double check for any screws in your battery compartment this time.

Santhosh I second to rastsaurabh.. That making more load will result in loss of control and free fall when the throttle is reduced under limit while flying.. Is moving the wings possible to change cg?  :(
Any way wait for some advices from  experts.. :)

Arun ,it is not possible to move the wings...:( and also the tail ...  ???
I have turned the screws inside out so that the heads of the screws are inside the compartment.And also I place a foam piece to protect the batteries from  the screws..

Flew my plane with Krishnamoorthy (RC maker).. on 17 FEB 2013.
Krishna set up all the settings required..my plane had a lot of lift so a counter down elevator was required for a stable flight.
I flew for about nearly 15mins...on a single charge....when I was about to hand the Tx to krishna for landing there was a abrupt change in direction of wind and forced my plane down to the ground....The plane broke into three pieces..lost one battery - the 2nd cell showed 0.24V  and overall 7.5V for a 3S..The other one survived..

Myself with Krishnamoorthy(holding the Radio)

good atleast you have 15 min of flying..... ( did you practice on Simulator?).....
but loosing 2 batteries on 2 sorties is a bad part.... next time plan a lighter plane and it should last long!!!!

for me its different i dont know flying and loose models due to crash.... but others fly them gracefully.!!!

santhosh-r  dear friend, I :salute: to your smile, this is the second time your plane has crashed burnt/broken in such a short time and you have taken this hit like a man. Plain and simple :hatsoff:

For next time pls do consider the advice some seniors have pointed out

ya, santhosh was correct.
but the plane was too stable in heavy wind also {:)}
anyway im very much happy to fly your model :salute: :bow: :hatsoff:
next time we will rectify our mistake :thumbsup:

flying brick....now I will once again start building the plane rectifying all the errors or mistakes made in the crashed plane.... 8-)

my best wishes to you !

My flight video...
http://youtu.be/8R-P3Apr0Lw

hey hey still under process... (:|~ (:|~ (:|~ (:|~

now ready...arun

Are you saying that you already have a new plane ready for test flight ?  {:)} {:)} would you mind postings pics of your plane here with all the new details for us to see ?

Yeh santhosh looks like it was windy as you said.. It always trying to go up..
Any way nice flight...  {:)} {:)} {:)}
Rebuild it as soon as you can..
@Flying brick Yaar actually we were talking about the video
The video was under processing when he posted the video url.. Got it?  >:D >:D >:D

now I came to know that my rudder servo was also damaged during the last crash....
the gears on the output shaft had some teeth missing...
check out my youtube video...
http://www.youtube.com/watch?feature=player_detailpage&v=oASqebLfdFs

Got it Arun!  :P looking at the pace of Santhosh's last builds I must be excused for assuming that he was ready with a new one 8-) :giggle:
It was the first though that came to me !!

Once again started making  a nearly new plane...
Savaged the wings , horizontal stab , and vertical stab from my broken coro plane...
Got some E shaped aluminium rods at my home...here are some pics of the build...

Not yet fixed the stablisers...planning to fix it using cable ties to the stick (aluminium rod)...
A 24gm hextronix motor,, 20A hobbyking ESC... 2 x HXT900 servos ...

Santhosh is that blue wonder enough for this?
What is the auw?
Looking very neat.. and it will fly cool...  :thumbsup: :thumbsup:
By the way did you guys flyed today? with dileepettan?  >:D >:D

That motor sitting only on a cable tie looks scary  :-\ :-\

Can't get you " blue wonder" ...

BTW it was too windy and cold today in the morning ,we went to the site and were just talking for about  2hrs and came back ...

sanjay sir..the motor is not just held by the cable ties...there are three screws firmly holding the motor to the bar...I used the cable ties just because I could not align the four screw and the hole...

 :thumbsup: :thumbsup:

Santhosh is that 24gm motor produce enough thrust?
The wings looks heavy :(

You are right ..arun but the  motor is specified as 400g thrust with a 8 x 4 prop...
Keeping my fingers crossed for the test...
I will update about AUW ....
I thought that the wing will act like as that in a glider...
If this motor will not work...I will replace it with my 3536 1250kV 500W motor..

That is fine another option is make another wing and use a smaller lipo with same motor...

all the best for your new plane, waiting for video  :thumbsup: :thumbsup: :thumbsup:

Ok Arun,, Let me try all the combos .. 2s / 3s , 24gm motor./ 500w motor , new wing /old wing....and find out the correct combo..

BTW thanks everyone  :salute:

Santosh, why don't you try the old formula - 75~100 Watts per pound of weight, and see where it gets you? Decide the prop, and then on the basis of these 2 figures, select a motor

sanjay sir , I am expecting  a AUW of 700gm with a 2S 1000mAh and 800gm with 3S 2200mAh....
As I have seen this wing producing a lot of lift for my 1.5Kg previous coro model ,I thought that eventhough the motor is underpowered  for this plane the wing may produce some decent lift..is it correct?

BTW the power of this motor is 85watts...you are right ,I need to get a new motor / reduce the weight of the plane right?

What is your motor KV & what prop are you planning

AUW of 800 gms => 85 W is OK

Lift will also depend on the angle of incidence

I am planning to use  a 8 x 4 prop and the motor is 1300kV
motor http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=2069

I think it will be underpowered. Thrust is not enough, and with 2S, you have max wattage of about 50 W, in actual running about 30~35 W, with 3 S about 80 W max, actual running about 50 W