mshay

My Feedback: (3)

what is it, whats it do, and where is it.. i have read about people building kits and say im going to remove it. i realize its got something to do with the wing but exactly what? thats the question?

davidgeorge212

diheadral is the angle in the center of the main wing on your plane. If you look at most planes the main wing will be in a slight "V" shape. The dihedral in an airplane wing will sort of act as a "self righter" kind of like the bottom of a boat hull. If you put the airplane in a turn, the dihedral will help you come back out of it. If you take out the dihedral like in "sport" type planes with straight wings, it generally makes the plane more sensitive on the controls and allows the plane to roll faster.

mshay

My Feedback: (3)

do you have a picture of this? all i see in my wings are tear drop shaped, doesnt exactly look like theres a "v" shape in there. but then again i may not have any planes with this either.

noveldoc

My Feedback: (2)

Enough dihedral makes your plane self righting.

When you turn, the low wing is more flat so presents more area to airflow and generates more lift. The high wing is angled and presents less area, losing lift.

As a result the low wing eventually lifts back up to stable position.

Tom

ByLoudDesign

HERE YOU GO!!!

ByLoudDesign

Here you go!

Lnewqban

http://en.wikipedia.org/wiki/Dihedral_(aircraft)

mshay

My Feedback: (3)

excellent. pictures are worth alot of words, got it totaly different then what i was thinking or previously told. thanks

Lnewqban

The negative dihedral is also known as anhedral.

This is used for airplanes that are so stable in roll, that need some help from a wing with anhedral (opposite to dihedral).

tail strike

My Feedback: (1)

Don't let them guys kid you diheadral is what you get when you eat green apples

mikegordon10

I'm not sure anyone has answered the OP's question "What is dipheral?" Don't ask me I have no clue. I even looked it up but alas I failed to find it.

NM2K

My Feedback: (14)

Erm, I think he misspelled dihedral - don't you?

Dihedral is not your enemy!!!

I love it when a new person comes to the field to learn to fly. All of those fellows that just learned how to fly well enough to solo greet the new guy and begin to download all of their new found knowledge into the poor fellow's brain. A good bit of which is wrong from the git-go. Fortunately, said newbie won't remember much of what he was told. The dihedral thing is one of the first things the newbie will hear. Unfortunately, that one usually sticks. So, model number two arrives at the field with no or negative dihedral as a result. The new modeler's enjoyment of the hobby usually takes a dip at this point. After all, he's been flying long enough to have an airplane he HE/SHE modified from stock, with his newly gained superior knowledge. Many folks continue making this same mistake (altering the stock proscribed dihedral) for the rest of their modelling careers and never flying a really good flying model.

I have had newbies approach me after seeing my model's dihedral and telling me that a flight instructor would be along shortly. (smile)


Ed Cregger

ser00

Hi everybody,

The amount of dihedral that I build into a wing, for me, depends on the type of model and wing the kit has. If I was building a plane with a constant chord wing, then I would build the plane with the suggested amount of dihedral (such as a four star 40, for instance). If I am building a double tapered wing, then I will build the wing upside down, with the root ribs glued at 90°. This causes the top of the whole wing to be flat, but the dihedral is built into the wing from the bottom. This happens because each rib from the root to the tip, gets smaller in both dimensions. A good example of this is the Ultra Sport wing. I build my Ultra Sport wings this way and it comes out with just a little less than the recommended dihedral. Why do it this way? It makes it alot easier to join the wings halves together. Just my 2 cents.

Happy flying and soft landings!

SER00

50+AirYears

Dihedral is a friend. It is what allows free flight models to stay airborn in stable flight for extended flight times without any control input of any kind during the flight. It helps trainer aircraft train newbies. Back in the days when I first started in RC (1962, years after I had been flying free flight and control line) most of us flew with rudder only, or sometimes with rudder and throttle. No elevator, no ailerons. Without dihedral, or without adequate dihdral, smooth turns were essentially impossible. In fact, without dihedral, the plane would eventually fall out of the air. With dihedral, rudder only or rudder throttle equipped planes had a number of possible pattern manuvers, including consecutive loops and rolls. When aileron control became practical, the need for dihedral became reduced.

Even now, if one were to loose aileron control in a plane with some dihedral, the plane possibly could possibly still be steered for possibly a safe landing with rudder. Without dihedral, loss of aileron could end up in a rekitting. Had both happened to me, BTW.

Top_Gunn

My Feedback: (6)

Just a word of warning. Dihedral may be "your friend," but only up to a point. Too much dihedral and aileron turns become difficult or impossible because the adverse yaw makes the plane turn the wrong way. Lanier used to make a plane called the "Super Trainer 40." A guy in my club won one in a raffle and gave it to the club to use as a club trainer. I thought it had way too much dihedral, but built it per the plans on the assumption that Lanier had tested it and knew what they were doing. Mistake. If you didn't coordinate turns it would turn the wrong way. This is not what you want in a trainer. So I built another wing, with a lot less dihedral. Plane still sucked (much too fast for a trainer, for one thing), but at least you could turn it with ailerons.

mikegordon10

Being a Pylon Racer I always thought the ailerons banked the model and then the elevator turned it. Silly me.

NM2K

My Feedback: (14)

It wasn't the dihedral that was causing the adverse roll problem that the Lanier Super Trainer 40 was experiencing. The problem is known as adverse roll and its cause is improper aileron differential. You can have the same problem without any dihedral at all.

Too much dihedral in a wing makes the model less fun to fly than when it has the proper amount of dihedral, which is seldom zero.

Dihedral's job is to keep the wings level. This takes a lot of work off of the pilot and lets the pilot relax a bit and steer the model mostly with rudder. Ailerons are for adding the proper amount of bank when using the rudder to turn the aircraft.


Ed Cregger

Top_Gunn

My Feedback: (6)

No, it was the dihedral. My first attempt to deal with the problem was to put in a huge amount of aileron differential. Didn't help much. It's true that improper differential can cause the same problem, but that wasn't what happened in this case: I know how to set up aileron differential.

The reason too much dihedral can make a plane turn the wrong way is the same reason you can turn a plane with the rudder. The adverse yaw from the ailerons, or the yaw induced by the rudder, makes the plane yaw, so that the bottom of one wing is now facing partly forward. The air striking the bottom of this half of the wing makes the plane roll, and then the lift from the wing (not the elevator, or at least not just the elevator) turns the plane in the direction of the roll.
To correct this problem on a plane with lots of dihedral by using aileron differential alone, you'd have to have so much differential that you didn't get any adverse yaw at all. Short of having no downward movement at all on the down side of the aileron, which would mean you had spoilerons rater than ailerons, I don't think you could get there with the Lanier Super Trainer 40.

The moral of this story is basically that a plane using ailerons needs less dihedral than an equivalent rudder-only plane, so if build1ng a plane designed for rudder only, it's usually good to reduce the dihedral. There are exceptions. I know a guy who added ailerons to a Sig Kadet Senior, leaving the dihedral as it was, and it flew OK.

The rudder doesn't turn the airplane. The rudder just makes the airplane yaw (rudder-only planes) or cancels out the adverse yaw from using the ailerons (4-channel plane). On a three-channel plane, the yaw induces roll, as explained above, and the lift from the wing, with help from up elevator, turns the plane. On most small 4-channel planes, you turn just by rolling the plane with the ailerons, and the lift then turns the plane. That's why you can turn a plane with ailerons without using any rudder at all.