excellent video.
But why is it slow?

Video is slow because of slow motion feature in my cam -(kept that mode to analyze if something goes wrong )
The plane is slow because it doesnt have propeller -the only force is the push i gave

@Aneesh.p,
Congratulations on successful test launch. 
What was the distance, real time duration, estimated speed?
Regards.

What about solar propulsion?

@k k Iyer sir
   Plane weighs 1330grms
   it flew about 92 feet(28m)
   airborne time is 9 sec

 

@sanjayrai55 sir
I hve used 2 batteries one for rx(1250mah 3s-90grms) and other for motor(2600mah 3s-210grms) so with these included my plane weighs 1330 grms
So instead of 2600mah battery i can use solar cells(230grms) which can give a static thrust  of 500 grms around

Which is more than necessary for leveled flight i guess
but might be a problem when clouded so using extra battery as safe side

From your video it seems it was just a powerful hand launch; no propulsion 

@sanjayrai55 Sir
Yes its just a hand launch
didnt connect the 2600mah 3s to esc but its inside the fuse

Quote from: Aneesh.P on April 16, 2016, 07:26:26 PM
@k k Iyer sir
  Plane weighs 1330grms
  it flew about 92 feet(28m)
  airborne time is 9 sec

3m/s?
Remember your original estimate?
Looks like you didn't mount the solar cells.
So you are probably under 5oz/sqft.
Which is why you were able to save it so easily after the nose high launch,
And why she flies so slow!

Usually on test hand launch, we launch with the nose slightly DOWN, at close to the projected/estimated airspeed.

Would you like to do another test hand launch like this, to get some more data on airspeed and l/d?

https://m.youtube.com/watch?v=ie2thgI193A&feature=youtube_gdata_player

Caution: not a direct comparison. Mine was 48" span, 192 sqin area, 200gms (YES), AG03 at root, AG11 at tip (as accurately as i could carve them  ). 60m from sub2m launch, in 10-12seconds. Ie, 5-6m/s.

All in all, an excellent effort.
Do not stop. Just find a larger field. Chances of success are really good.
Regards.

@K K Iyer Sir
Really glad that you are guiding and correcting me in every step, Thanks for that

I was afraid to include more weight because i dont have any practice in chucking and moreover it doest have propulsion to correct if any (Infact im only used to flying -this is the first time i chucked )

Im not sure about Designed cg so made it a very little nose heavy and to counter that i have included a trim in tail-(thinking of the worse) coz i wont be having my hands on elevator initially
This made it climb hard up while chucking due to the more initial velocity i guess

Im not sure exactly how to know The whole Wing's Max Lift Coefficient correctly
For now i used xflr software and max cl was found to be 3.4(dont know why so high)(Included a -4 degrees washout)
Wing loading for todays flight=5.916oz/sqft
With max cl of 3.4 Stall speed is 10.5kmph=2.91m/s(is it correct?)
Currently working on permission to fly and this will not be the final flight test

Regards
Aneesh

@Aneesh.p,
CL 3.4 eh?

Yes, 1330gms on an 8sqft wing area at 3m/s does need CL of 3.4 for level flight

The test flight profile is clearly not in level flight regime.

I suspect that angle of attack is on an average in excess of perhaps +20deg, i.e., way past the stall.

For an S9000 type airfoil to be at the bottom of its drag bucket, the angle of attack has to be not more than about +5deg at the most. This should give you near level flight at about 6m/s.

I think what happened is probably this:
1. Based on tail volume, you have probably calculated the neutral point correctly, and then placed the CG to give a 10-20% static margin. So far so good.
2. Then, maybe fearing that it is nose heavy, you put in some UP trim in the elevator.
3. The launch was significantly nose high.
4. Launch speed was perhaps too high (Compare pre launch run in your video with mine)
5. Points 2, 3, and 4 together led to a deep stall
6. It didn't crash because you gave corrective down elevator in time, and because you have more than enough TV coeff and static margin.

A few suggestions for your consideration:
1. Check the decalage. More than 1-2deg may not be needed.
2. Hold the model lightly at the CG, in level attitude, i.e., not nose up. Walk/run into wind to get airspeed of around 6m/s. Do not release. See what it wants to do. If it wants to nose up, decalage probably too much. If it tries to lift out of your hand, without nosing up, trim is probably correct.
3. At this stage you try a hand launch. With nose pointing slightly below the horizon. Launch with a push if you are standing still, or walking one or two paces. If you are running, do not push hard, release with a gentle push.
4. Assuming a guess of L/D of 20, the flight path will be about -3deg to the horizon. If the model's attitude is level, the decalage of 1-2deg will give you an AOA of 4-5deg.

Wish I was there to participate in your tests 
Best of luck.

thanks for that sir, I will surely follow those steps 

@Aneesh.P your hard work is really inspirational sir
Iyer sir too

@a3ruz
Thanks for that.  No 'sir' please i'm still studying

A good news and bad news

Good news-
Got permission to fly but on a different field(no grass-only sand and concrete )
included extra 300 grams to compensate for solar cells and circuit-AUW 1610
Initail battery level(2600 3s)-98% and 12.58v
Flew for 290 sec(5min around)
Its kind of windy today
because of the high pitch prop(12x10) my entire flight was in less than half throttle range
throttle range for level flight is one point less than half on my tranmitter(JR XG6)

Bad news
landing would have been good if it would have been a grass fields
there was a sudden change in the wind direction while landing but managed to land the plane due to sand it bounced and slided into stairs of stadium , impact points are right aileron(servo gear damaged) and motor mount came off-every thing else is fine

After flight battery level is found to be 88% and 12.18v
which means only 260mah used(less than 40W)

initial thrust test reading shown a thrust of 350 grms at 40watts will do it again to confirm
Will upload video by tonight its 780mb

Regards
Aneesh

@Aneesh.p,
I presume that your emax 3510 is a 600kv motor,
That goes about 6000rpm on full throttle on 3s lipo, or say 3000rpm on part throttle.
Or 50rps.
So the pitch speed of a 10"/25cm prop is about 12.5m/s at 3000rpm.
Or more than twice your reqmt!

Would you care to try a prop of 5-6" pitch? (12-15"dia)

Regards.

Edit:
And if you are really flying at ~3m/s, Re is under 60k...

@K K Iyer Sir
I will do a thrust test with 12x6 next time and will surely share the readings

Frankly i dont know much about these propellers
i have gone for 12X10 because i have simulated in Real Flight7.5 software with different props and found that 12x12 and 12x10 takes the least power for a leveled flight

Is it good to go with 12x6 instead ?  Can you explain this part -im confused

@Aneesh.p,
Do not take others views (incl mine) as gospel truth.
Compare with your own experience.

Your first test revealed 3m/s.
I have explained probable reasons why it was so low compared to your original (theoretical) expectation of 6-7m/s (which i feel was a correct estimate)

What's the difficulty in matching the prop's pitch speed with your desired airspeed?
6m/s is about 20fps or 240" per second
If your motor is running about 3000rpm, or 50rps, how much pitch is reqd?
Ans: 5-6"

Right?

Watch at 360p minimum to get clarity

@Aneesh.p,
Just saw your video.
EXCELLENT!

Looks like trim issues are sorted out.

Next you can try 30sec full power, then cut power to zero, and time the glide...

Here's a sample of what can be done with 20-22 seconds of power...

Will attach video in a minute...

Edit:

@ k k iyer Sir i got what u r trying to say

Reasons i got stuck with this configuration is
I have started this design based solar cells followed by motor ,props
So to prove the feasibility of a design i was forced to get motor and propellers even before i started designing(evenbefore knowing my wing dimensions)
and the recomended propellers were out of stock mostly except a  pair of cf1555 multirotor props which costs around 2k(same as my motor(2.5k))
and in the available props i got 12X10,13X6.5,14x7 based on simulator (i already have 12X6)
Didnt use 12x6 because i thought it may not give a static thrust of 1kg(thinking of my plane weight as 2kg -handlaunched)
and then used other 3 props for testing and i hve posted the reading in page 1

and one of the other reason i went for higher pitch is for its climb rate
Initially -one of my method to charge battery is to gain a maximum altitude within minimum time and gliding down to charge battery

But now since i have achieved the limits which i thought was difficult to get ,A better set of electronics can be found but money is a problem 
(in my initial calculations my weight is 1.8 -2kg) all my motor config is arranged for a 2kg plane

Im not a good pilot
Flew first time last feb and have got not more than 2hrs flying experience
The pilot who we used to fly with is in states now(will be coming back after 3months)
and dont know any good pilots nearby

So since i designed it i thought to fly it by myself
Landing damaged my fuse-it slided and hit the pillor  but happy that i got the video to prove my design
Fixing it will take some time and fixing solar cells and testing will take a whole week

My final review is on 11th may
so i will be having a week in between to contact as many faculties and companies out side to fund my project(this is costing me around 30k)

so only time i have is till this sat to do any more flight tests if necessary-My clg wont allow me to fly in good grass fields-and i cant afford any damage to my wings 

So this might be the last flight test unless if its necessary to do so

Quote from: Aneesh.P on April 18, 2016, 11:29:33 PM
Didnt use 12x6 because i thought it may not give a static thrust of 1kg(thinking of my plane weight as 2kg -handlaunched)
Wrong logic. Pl try it now

and one of the other reason i went for higher pitch is for its climb rate
For best climb rate, esp at takeoff, fine (ie, low) pitch is used not high pitch

Initially -one of my method to charge battery is to gain a maximum altitude within minimum time and gliding down to charge battery
Gaining max alt in min time means max use of battery.

But now since i have achieved the limits which i thought was difficult to get
what limits? What difficulty?

A better set of electronics can be found
what is the problem with the present electronics?
but money is a problem 
eh? Where does money come in?
You have everything already for this project. What else do you need?

Looks as if you are going to stop, having achieved your MINIMUM target.
Are you just doing a college project, or attempting something not achieved earlier?

Come on, come on.
So far your attempt is the best combination of theory and practice i've seen on RCI in 3 years.

I will try repairing my fuse and will give the thrust test readings by tomorrow  
and seems like i need to start freshly on props


For best climb rate, esp at takeoff, fine (ie, low) pitch is used not high pitch
--I was initially thinking about maximum dynamic thrust while climbing at cruise speed-(less inclined fast climb)

Gaining max alt in min time means max use of battery
--max amp draw was 14 amps for 12x10 and for highest dynamic pull at least amp i chose 12x10 to gain altitude using minimum amp possible and thought i can charge the battery at 5amps rating while gliding-which can increase flight time-My projects aim

what limits? What difficulty?
I have never designed a plane of this size and a similar sized plane in my clg was weighing around 3kg+, so thought building a whole plane all by myself weighing half as the similar sized one is difficult to achieve
entire designing and manufacturing is done in my room with the help of my teammates
more over i started this project with a max budget of  :Rs:30,000 and to finish it as least as possible

Since there's a lot of work and money kept into it i was afraid to fly it (high chances that i may crash it)

All in all
Hope i should have joined this forum way ahead and will definitely consider on testing new props

Last flight test damage


Done repairing, this time it will be stronger i guess