With that model and it's thrust to weight ratio, it is pointless and risky to give a conventional hand launch. Hold in your left hand pointing at 60 degrees up, give 70% throttle, and release

I am reminded of an old saying:
"If all else fails, read the instructions"
So I did.
With due respect to all participants on this thread, i'm quoting what the manual says:
The first flight.
Do not attempt to hand glide this model.
The Funjet is designed for hand launching only. Always launch directly into wind.
The model should be launched at 1/2 to 3/4 throttle,
With the wings level and the nose angled up at an angle of 20-30 degrees.
Don't launch the model "downhill" like a glider.

The manual also says "the Funjet Ultra rolls slightly to the left on full throttle"
Regards.

That's one interesting thread to contribute after a long time

Quote from: dhruvafreak on December 11, 2015, 07:51:49 PM
Since I'm Pursuing my Aerospace Engineering and i have come across Adverse Yaw condition which acts because of Spiral propwash generated by single engine prop planes.
It causes yaw when they are flown at high power and low speed (takeoff and climbout, for example.) The prop doesn't blow the air straight back, but gives it a bit of a twirl which causes yaw.

Dhruva you are right, BUT not for a pusher like Funjet Ultra. it is for an aeroplane with nose mounted props and where the slip stream modifies the airflow pattern over empennage. See image and co-relate with what your Aerospace Eng professor's taught you



Shobit sir

I had written about chuck take off earlier in my thread 4 years ago, it is not 50% 75% or 100%. Thumb rule is just enough so that it slips out of your hand, that's why the pilot needs to hold it and determine how much throttle, later some one else may chuck it.

i understand, it is against the very method we learnt in real flying, believe me, as Nandan said, that's how it work in these Funjet kinds (Having owned and flown quite a few funjets & ultras i can tell you this)

Quote from: rcpilotacro on April 14, 2011, 06:27:11 PM

13. If launching SkySurfer or a easy star kinda aeroplane, DO NOT make the mistake of chucking with full power, ... THE KEY is open power only so much that she is tending to slightly sliding out of your hand. chuck it from a higher to lower ground if possible and available, if not it is fine. During Chuck ensure wings are level and chuck it like a javelin. after chuck slowly open power and climb away GENTLY.

Shannon is spot on

At high power Low speeds even fighter aeroplanes get into torque roll, sometimes it is uncontrollable and crashes. Pilots have lost lives because of this

Read page 92  of this document, worth keeping a copy of this document for all supersonic aerodynamics students

http://www.pixel-architecture.com/web/forum/massilia/MIG-21/DCS%20MiG-21bis%20EN.pdf


KEEP IT COMING

Yes Sir, Agreed.
I meant that only for front mounted single engine prop planes. I did mention it in reply #17  

Thank you for the Pdf sir. Very informative 

Quote from: dhruvafreak on December 13, 2015, 11:26:23 PM
Thank you for the Pdf sir. Very informative  

Believe you me, couple of decades ago, Mossad or CIA would have given their right hand for that document. a lot of it mentioned in that document was enigma for  most western aerodynamicists. In fact One Iraqi pilot defected a MiG 21 to Israel and that's is the firsts time US & ISrael got to see the MiG 21 up close. Legendary & my hero Danny Shapira flew it and landed dead stick

Full account here (nothing short of a Hollywood movie)
http://theaviationist.com/2014/04/28/israeli-mig-21-007/

Good to see The Boss back!
Dhruva said:
Since I'm Pursuing my Aerospace Engineering and i have come across Adverse Yaw condition which acts because of Spiral propwash generated by single engine prop planes.
It causes yaw when they are flown at high power and low speed (takeoff and climbout, for example.) The prop doesn't blow the air straight back, but gives it a bit of a twirl which causes yaw.

Dhruva, the propwash spiral on the fin produces yaw, but what is adverse about it?

Adverse yaw is when the down going aileron produces more drag than the up going one, producing yaw due to drag opposite to the direction of roll...

See 90 degree roll to the RIGHT in the initial pics?
Reason?

Like I said, without the Fluid Dynamics; just release, don't chuck. Use adequate amount of power and point the nose up so just by releasing your grip the model takes off

KK Iyer Sir , Yes the adverse yaw is only because of the Aileron Drag.

What i wanted to say is in general when a single prop front mounted rc aircraft is hand launched, the prop induced roll and yaw because of the propwash when added to the adverse yaw induced for countering that torque roll gives a huge unwanted yaw which is disastrous.

I came to know about this clearly when me and my team were preparing  for SAE-VIT Payload competition and during final testing one of the aircraft was chucked with full throttle and it just had unwanted yaw and crashed. The Aircraft didn't roll throughout  the flight and the torque compensation was done by the aileron.
So both unwanted yaw made the aircraft yaw and dive.

Sir, the initial pictures are from the maiden flight. I have given 100% throttle to make sure i have a good climb but turned out that I received more than 90 degree Left roll sir.


And then in second flight, tried 50% on throttle with more alfa and this time the torque roll was reduced a lot.


Sanjai Rai sir is just right. I can just leave it vertically and it will just go. But sir I'm worried what if it just starts rolling just after leaving from hand and prop could hit the chucker. I have never tried vertical takeoff.

Since i grew up in free flight days, i used to launch RC models holding them by the fuselage below the wings just aft of the CG.
Then with my electric Spitfire and 60% Curare learnt to hold them above the wing, at knee height, and give a gentle underhand toss at a shallow upward angle with 50-60% power.
Will probably work for you too! (No prop bite danger either)
Similar to what Rai saheb said, except he didn't mention the underhad toss!

(I'm known locally as the 'low throttle guy' who won't use full throttle even for takeoff!
Probably comes from my glider flying background, where one is always alert for a linebreak on tow!
Most of us don't have Gusty sir's exposure.
That MIG he posted climbs 750ft per second..
Hard for me to even imagine, as 5ft/sec was the best i encountered..)

But launching apart, try to find a way to log the actual speed (out of the 300 kmph potential)
One of Gusty sir's friends (in Mumbai?) went over 450kmph some months back...

Tried New Light Wieght Setup which is ultra cheap:
Motor : NTM 1700Kv 6s (Pulling 68A peak with old 1300mah Nano-tech 35C) (15$)
ESC : 80A Blue Esc from Hobbyking (37$)
Prop : 6x6 Apc
Still gotta track the speed but i believe it is 150-200 kmph around.

Check that Low pass at 00:55
www.youtube.com/watch?v=H-5ewKC_qNM

Too good

Very nice 

Thank You Saurabh sir and Sanjay sir 

that was fast n furious 

Thanks Vishal Sir. You shall see it once

Hey Dhruv, i'm buying the ultra soon, decided on my power system for now, just stuck on the servos, how are your turnigy metal gear servos holding up after all the speed flights ? Is it necessary to invest in one of those Hitec expensive servos as the company recommends?

Thanks and the speed you got from the above set up is sickkk.

Hi , Yes the MG90s are still going great. I have logged around 47 Flights. They have less then a mm slope after all.
They still are going strong and i can ensure you that they wont disappoint you.
I have done full power loops with these absolutely fine.
Not about the money but one cant wish for any better on this jet.
At last just the peace of mind shall be there while flying  

@dhruvafreak,
Saw your video again today.
You are able to talk while flying this at full throttle!
Wow!
I couldn't even see it.
Had to depend on the sound to anticipate where she'll be next in the video...
Great stuff. Great field.
Regards

Woah!
That is some crazy speed!
Good thing is there are no speeding fines for flying too fast

@K K Iyer Sir,
Thank You sir   
Regular flying the aircraft has reduced the fear i had or maybe the helicopters did   


@Topalle
Thank you buddy. About the fines, we never know 


Posting a video (Something crazy)
Tried strapping a camera with 200mw Vtx and have a look.
Although it was not a 100% fpv flight but can say 70%ish it was. My friend recorded via his phone though a 7 inch screen. I was flying visually and using separate screen combined to bailout incase  .

www.youtube.com/watch?v=DbBjT0OIciI

@dhruvafreak,
Excellent experiment!
We need Gusty sir's input on why it looks much faster from the ground, than in the onboard view

@K K Iyer sir Thank you.
I guess the explanation will include lot of maths with angle and curves

Gusty sir's input will be great 

Quote from: dhruvafreak on January 28, 2017, 01:54:23 PM
@K K Iyer Sir,
Thank You sir   
Regular flying the aircraft has reduced the fear i had or maybe the helicopters did   


@Topalle
Thank you buddy. About the fines, we never know 


Posting a video (Something crazy)
Tried strapping a camera with 200mw Vtx and have a look.
Although it was not a 100% fpv flight but can say 70%ish it was. My friend recorded via his phone though a 7 inch screen. I was flying visually and using separate screen combined to bailout incase  .

www.youtube.com/watch?v=DbBjT0OIciI

Awesome!!!