How can you check the incidence on a V-Tial glider

[ToniGe23]

Hi, I have an all moulded f3j glider I have had problems trimming it for straight flight it seems to be flying with its nose up when I do a dive test it pulls out sharply and loops! I have moved the CG back but that does not work it stalls in on thermal turns, so I think I have a incidence problem if I purchased a Great Planes laser incidence meter can I check a V-Tail with it.
Or should I be checking something else.

Tony.

[Ollie]

Use the elevator trim tab (down for slightly higher air speed trim) or adjust tail linkages. Don't worry about controls set at neurtal position or incidence measure.

[F3X]

Hi, I have an all moulded f3j glider I have had problems trimming it for straight flight it seems to be flying with its nose up when I do a dive test it pulls out sharply and loops! I have moved the CG back but that does not work it stalls in on thermal turns, so I think I have a incidence problem if I purchased a Great Planes laser incidence meter can I check a V-Tail with it.
Or should I be checking something else.

Tony.

What model is it? It might answer some questions.

[ToniGe23]

Hello Ollie, yes it flys a treat with some down trim but I do not like flying the plane like that as I fly with different trim phases,
Hi F3x the model is the Latest STARLIGHT 3000 this is not just my problem 2 other pilots who purchased the planes at the same time have noticed it
I also have a new Starlight 3000 cruciform tail and the CG is the same with no problems it gets around the sky where ever I want it
not so with the V-Tail it does not penetrate and when pushed with some down elevater as soon as its taken out the plane balloons up
The recommended CG for the V-Tail is 100mm to105 mine is at 102mm I am a very experienced pilot but when the CG is at 105mm its very nautral and sometimes stalls in a thermal turn into a violant spin
any thoughts

[Ollie]

"Hello Ollie, yes it flys a treat with some down trim but I do not like flying the plane like that--"

Why don't you like flying the plane like that? Function? Looks? In your head?
Up to about 5 to 7 degrees, the tail drag coeffecient is not changed very much or at all.

[ToniGe23]

It is a good 3mm down trim suggesting something is not right, but I would still like to check the incidence from the wing to the V-tail can a great planes laser incidence meter check a v-tail or will it only check a convensional tailplane.

[Ollie]

"It is a good 3mm down trim suggesting something is not right--"

It looks bad but, it's not so bad from its functional point view. Try it not to be looking at the tail close up. After a time, it will look almost normal. Change your view if you want to. Think function rather than looks.

[Brian Wa]

Buy a Graupner Incedence meter, these check both Vee Tail and a Conventionl taiplane.
Very accurate and simple to use.

Check out the Graupner website:

http://www.shop.graupner.de/webapp/commerce/command/ExecMacro/Graupner/macros/main.d2w/report?lang=en&show_cat=5480

Click on the PDF link in the bottom corner of the page to get the operating instructions.

Brian

[Dolphinman]

It is a good 3mm down trim suggesting something is not right, but I would still like to check the incidence from the wing to the V-tail can a great planes laser incidence meter check a v-tail or will it only check a convensional tailplane.

Why do you care to measure the incidence? It is not going to change the behavior of your airframe. You obviously have an incidence problem that you are correcting with down trim.

Sounds to me like you should either leave it as is, or go ahead and reduce the decalage by either lowering the trailing edges of your v-tails or raising the trailing edges of your wings, if that is possible with this model. FWIW.

Scott

[ToniGe23]

Yes, your right scott my friend who has the same problem raised the trailing edge of the wing by about 3mm and it started to cure it but as we two man tow these gliders the wing should be bolted directly onto the seat.

I suppose I will have to bite the bullet and move the v-tails its just they are a 2 piece V that plug into the rear end so may give me problems.

[ToniGe23]

Brian, Just been on the Graupner web site and thats the tool I have been looking for I did`nt know they made these I wonder if Gliders in Newark might have one or i will get one direct from Graupner. cheers mate.

tonyg

[Dolphinman]

Yes, your right scott my friend who has the same problem raised the trailing edge of the wing by about 3mm and it started to cure it but as we two man tow these gliders the wing should be bolted directly onto the seat.

I suppose I will have to bite the bullet and move the v-tails its just they are a 2 piece V that plug into the rear end so may give me problems.
Tony,

Yeah, the plug in v-tails are problematic with respect to adjusting incidence. I am surprised that it takes as much as 3mm at the trailing edge of the wing to "start to cure" the decalage problem with your friend's ship.

I checked out Starlight the 3000 via a web search, as I was not familiar with it. It looks like a very high quality ship. I am surprised you and your friend are having this kind of problem with them.

Hope you find a satisfactory solution to the problem.

Scott

[ToniGe23]

Scott, Its odd because my friend also has one of the first starlight 3000s but he has never had a problem with that so maybe its a new fusalage mould

I`m going to purchase a graupner meter and see if the problem can be sorted

I know the maker of these but don`t want to complain yet incase i`m wrong

These Starlights are the current model to fly in europe other than Pike Superiors
they are top quility.

tonyg

[solo6796]

Sounds like maybe two things going on. Your dive test and trim for level flight suggests it's nose heavy, to me. Radio programming for the V-tail may need some differential, so that when turning left, the stab on the right deflects more than the left one. If they are deflecting the same amounts, the left one may be acting like a horizontal stab, dropping the nose, and looking like a stall in turns.

That worked for me on my Yardbird and Super-V.

AJ

[psoff3x]

Hi Tony

Just keep stalling in those thermals mate, gives the rest of us a chance :D

Pete S

[ToniGe23]

Hi Tony

Just keep stalling in those thermals mate, gives the rest of us a chance :D

Pete S
Oi, next time keep an eye on your model !

Ordered a graupner incidence meter today from Gliders that will sort it.

tg

[ToniGe23]

Recieved the Graupner Meter this morning when I opend the box one of the meters missing and also the english/french instructions.

not very happy!

tg

[Ollie]

The placebo works on your mind just like a incidence meter for a V-tail.

[ToniGe23]

Hi,
Its been a few weeks I have had the incidence meter from Graupner and the V-tail was out by 2 degrees.

I have adjusted the tail and took the Starlight 3000 out today to see if there was any differece.

On the first launch I noticed the marked difference in the penetration into wind

I got into lift and made considerable height then done the dive test.

The model went perfect no tucking under no pulling out .

perfect

The rest of the day was great thermal after thermal the model was totally a different machine.

I think this does go to show that all moulded models are not perfect.

tg

[Emanuele]

Hi,

I have the same problem with V tails (I hate V tails :mad: ). Unfortunately before hating them I already purchased three kits.

I tried the link in the previous post but it does not work anymore, so I was wondering if this is the device you are using:
http://shop.graupner.de/webuerp/servlet/AI?ARTN=64

...by the way, how much did it costs ?

Thanks a lot for your help.
Emanuele