Pike Giant

[Bobalew]

Any hints on flying the Giant. Camber settings, rudder mix, differential, CG, that kinda stuff. I just can't seem to make mine fly right.

[Keith Kindrick]

What settings do you have now?
Have you started with the Samaba site using their Giant performance settings?

[Wing-span]

The feedback here should be interesting as I am about to set my friends Giant up for him.

I have a few ideas about this wing section MG-06 but I will read what others have got to say first.

[Bobalew]

I started with the set-up Samba recommends. I dont like the way it circles. Others that have this plane love it, so it must be in my set-up.

[Keith Kindrick]

Where is the CG?
What is the expo your using?
What is the Aileron Up and Down in mm's?
When you dive the Giant to the earth what happens?
What radio are you using?

[Bobalew]

CG 108mm i've tried it way forward to way back and everything in between, this is wher I like it the best
No expo
I have tried aileron differential from 0 to 80%
Stylus

[Wing-span]

V tail or X tail?

[Bobalew]

x tail

[nickk]

I started with the set-up Samba recommends. I dont like the way it circles. Others that have this plane love it, so it must be in my set-up.

FWIW, I have been flying my v-tail Pike Giant for over a year now, and I like it a lot. My only other previous experience with the MG06 airfoil was with the Trinity F3F.

Likes/dislikes are generally a function of ones own preferences, flying style, goals etc. etc. Could you say a bit more about what you don't like about how it circles? Is it too slow for you? Does it drop a wing tip? Are you seeing adverse yaw? Is it pitching up on you ?

Keep in mind that I fly mainly on the coast, where the ridge lift is in a narrow band so I am most focused on snap flap settings, ballast and optimal bank angles to stay in lift, but I have had no issues with this ship doing more sedate TD style flying.

Some general comments. Given the size of the flaps I reduced the amount of Ail->Flap mix. I use lots of full span camber (via a slider) whenever I need to climb-out or thermal. I have almost doubled, over time, the amount of snap-flap. I use very little reflex (the airfoil is already highly reflexed).

Hope this helps,
Nick

[Paul Garnett]

it must be your set up,i was in the czech republic a few months ago and was watching an f3j comp, the giant flew very well, turned great and looked a well balanced model, although i have to say that the pike perfect blew everything away!!! it lauched faster, and higher, turned tighter and landed slower than any other model there....soz

[Bobalew]

Maybe thats part of my problem. I have been mostly flying Perfects and now I'm spoiled.

[Keith Kindrick]

The Giant is not for everyone. This is a very versatile sailplane capable working light lift to wind speeds of 9 m/s (20 mph) without ballast. In order to understand the capability of the Giant I personally spent 80 hours setting it up then test flying it. I did have the help of Jo Grini who provided valuable input and guidance making me strive for optimal results.

The CG should be set to reach full potential between 112 and 115mm. It will respond positively back to 117mm in special conditions. A Giant must be flown with an overall incidence level that is neutral. An MG06 will then respond nicely in the turns when this is accomplished. I strongly recommend that you use the actual settings for the ailerons and flaps to aileron mixing with 40% expo. They have this correctly defined.

My radio is the JR 9303 Sailplane version. I use all 5 flight modes with the Giant. You will not be able to use the entire flight envelope without this radio combination. As the wing flies into the conditions one needs to have the capability to rapidly switch the set up to meet them. Using sliders and non preprogrammed parameters will never work as well. Previously I used a Stylus which qualifies me to say the radio is not compatible for the required Giant functionality. As you progress with the design you will not use any elevator trim when while you thermal when it is correct. Instinctively you will learn how to pull elevator at the correct moment as defined by the thermal strength and camber settings. As a rule you will always use camber in this wing while you are flying it for thermal duration. In the wind the MG06 doesn’t require reflex. It will fly normal well into the 9 m/s (20 mph) range without added ballast. When you do use ballast it is far less than the other designs require.

For those who doubt the wind performance over a long duration flight I have attached the plot with wind speeds at 9 m/s (20 mph).

[Bobalew]

Keith
"A Giant must be flown with an overall incidence level that is neutral".
So my CG should come back? and the plane needs to be flown with alot of camber. How about aileron differential?

[Keith Kindrick]

Your CG needs to be moved rearward. You will adjust the stab to compensate for this change. You will use 0 differential. Set the Ail Up 16mm and Ail Down 8mm. Mechancally it is what it is.

[Tuomo]

Stupid question: How CG relates to airfoil efficiency? Why MG06 needs rearward CG?

I thought CG position is mainly about stability and elevator feel :confused:

[Regnar Petersen]

Hi Tuomo

I have CG on my Giant at 115 mm and the tail is neutral at 88,5 mm (see Samba HP). At this setting the plane becomes very agile, without you losing control over it. Dialing in some exponential will be necessary.

Keith:
You will use 0 differential. Set the Ail Up 16mm and Ail Down 8mm. Mechancally it is what it is.What is the difference off setting differential up mechanicly, and dialing it in using the transmitter?

Regnar

[Jurgen]

I was wondering about that difference in differential too, it doesn't make any difference, unless he means that for first 8 mm both run same at half stick, then the lower stops dropping while the upper runs further up till 16mm at full stick. In normal differential both reach end point simultaneously at stick end. Curious if that is what he means.

About aft CG, what is aft CG? Is a neutral diving plane (straight line) already "aft" for some people? There aren't laws for description, communication is limited and misunderstandings likely. Still glad RCgroups is around.
Jurgen.

[uzim]

I recently sold my new E-Tragi 705 (MH-32), because in my opinion, the glider is limited in it's end speed and after a speed dive, the recovery isn't very good either. I know, my expectations are on the higher side. Building quality of the Tragi is excellent and the glider does look very well either. My colleague is very happy with the glider. Now I want an E-glider with the same thermalling capabilities but with better speed qualities. Therefore I decided to go for the Pike Giant. After reading this thread, however, I'm a little bit unsure, if I'm able to get the best out of this bird. I'm flying actually a Viking, that I like a lot. I've sold lately a FS-16 and a Big Sting.

Regards
Urs

[Bobalew]

I after flying the Giant today with some help from someone who knows the plane well, I am finally making friends with it. He had me put a ton of camber in it for thermal circling, and that made a big difference. Also, elevator to flap mix helps it turn true. What I was not used too was the speed in which it must be flown. I was getting it too slow and chocking it in a turn. Now that I am comfortable with the higher speed, it seems to lock in. This model really moves around well even in wind, without ballast.
This is now my F3J wind airplane.
Thanks for the help

[uzim]

So, I can read between the lines, that flying in narrow thermals will get difficult with this plane despite the high camber? I always thought, that this plane can be flown like a normal F3J? I want the E-version, and therefore the plane will get even havier and therefore faster. I doubt, if this is the plane I want.

Urs

[Keith Kindrick]

I have never seen a reason to use the snap flap with the Giant. You must have been using very minimal flap deflection in this mixing. A properly setup machine will react poorly to added drag induced by this function while flown in light to medium thermal duration conditions. If the air density is high (lots of humidity) you can possibly do worse flying this way. This is not true when you add weight and fly in stronger conditions. The one hint I can give you is to use rudder for turning. Let the camber remain fixed as long as possible so the wing is pulling its max C/L as long as possible.

In lighter lift the farther back CG location makes using massive camber 5mm a pilots call. If you find the speed and turn radius too hard to hold on a consistent basis dump the camber. A 3mm value is far more than adequate for most conditions. An MG06 wing needs to have camber in the wing most of the time ~ just a question of how much and when.

[timmig]

I flew my Giant in F3F with a CG setting at 114! I found it would not get on "step" as well nor turn as hard until I got the CG back far enough to have it really "turn and burn" Forward of this--the place flew nicely--but didn't "pop" out of turns and definitely was slower at light wingloadings!
FWIW
Tim
PS-- I also used "snap flap" in the turns-- not as much as with my Trinities--but probably 1/4 to 3/8" of droop. It turned much harder with this--especially above 16oz wing loadings.

[jcosta]

Stupid question: How CG relates to airfoil efficiency? Why MG06 needs rearward CG?

I thought CG position is mainly about stability and elevator feel :confused:

Tuomo,


The CG changes depending on the incidence of the tail. The correct tail incidence for the X-tail Giant is obtained when the plane flies neutrally with a CG between 115 and 117mm.
For the V-tail nose cone fuse it is very different, the CG should be between 105 and 107mm. That is because the incidence is fixed on the V-tail version.

For the general thread:

The MG 06 has been designed to use an enormous amount of camber (10mm). It also needs at least 7-8mm snapflap.

[Tuomo]

Tuomo,


The CG changes depending on the incidence of the tail. The correct tail incidence for the X-tail Giant is obtained when the plane flies neutrally with a CG between 115 and 117mm.
For the V-tail nose cone fuse it is very different, the CG should be between 105 and 107mm. That is because the incidence is fixed on the V-tail version.


Yeah, I know.

I was pointing to the fact that regardless of CG, the only important thing is to fly the wing at ideal lift coefficient. CG is about stability, control and "feel". If we forhet the extremes, CG has very little to do with performance.

Basically, you have to find a CG that feels good. Then concentrate on flying well, and you plane will perform well.

[Keith Kindrick]

Tuomo ~ Do you own a Giant?
CG for this plane is just part of the setup. You will have to fly one to understand how all the other parameters play a role with the MG06 section.

[Tuomo]

I have not flown Giant but I have concidered it as a possible F3J windy weather plane. That is also why I started reading this paticular dicussion...

What I said about CG was about theory and concepts. People seem to talk about CG as a thing having massive effect on performance. Plane getting on step etc... Actually CG has very little do with actual performance. A forward CG and high incidence certaily somewhat increses drag, but 99% of performance differences are totally wing and airfoil related.

CG and incidence has certainly very much to do with stability and control feel of a plane. With a well handling plane, you have much better chances to fly the wing better -- and achieve better performance levels. Ideal stability and feel are different for each task and pilot, but principle is allways the same: you have to have good and easy control on plane in order to make it perform well in all phases of flight. Trust me and you will be much happier :)

I observe that everyone talks how much extra camber (and also snap flap) Giant needs to perform well in thermal flying. Typical to MG06 section, said... Now the question is, how does this affect the trimming procedure? Increasing camber increases also incidence and stability -> you can move CG rearward and still have the original stability.

Or to say it differently, if you do most of your flying with trailing edge dropped 5-10mm, then you should perhaps start concidering thermal camber as the starting point of trimming? Do all the dive tests etc. with actual flying camber? (Slopers certainly think it differently.)

BTW This is the opposite of what I have learned about Corado/Zenith. Is has so much camber that the actual "neutral setup" of airfoil is with some reflex.

So when talking about performace I would not be so worried about CG. Someone in internet says that 114mm is good, another report argues for 110mm... But there are only starting points for you own decision. Relax and trim the plane to feel good for you - it will then also perform better.

What looks like a much hotter question, is to what camber MG06 is optimized??? It certaily likes camber in thermal flying - but does 10mm extra camber mean that you flying the plane outside its optimum performance envelope. Maybe you would be better off with wing (plane) that has more camber and can be flown trailing edge neutral (or close to it) for the most of the time???

Sorry for the long post ;)

[jcosta]

What looks like a much hotter question, is to what camber MG06 is optimized??? It certaily likes camber in thermal flying - but does 10mm extra camber mean that you flying the plane outside its optimum performance envelope. Maybe you would be better off with wing (plane) that has more camber and can be flown trailing edge neutral (or close to it) for the most of the time???




Precisely, the MG06 is optimized for camber changing! AFAIK it was designed for slope 4-axis flying. There was a great study on it by Alain Zutter, the link is in Pierre Rondel's site, I think.