Physics for true-to-life performace; a Tutorial

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Flaperons

FlaperonsPage 1/3​

Flaperons are quite simply a control surface that can be used in a way that mimics the Flap Function (IE Increase lift of both wings together) and also Mimics the Aileron Function (IE Increase lift of just one wing, while the other may actually go the opposite and reduce lift) <There are also spoilerons, they are similar to setup, but they work on spoiling the lift of one wing thus dropping that wing> there are other combinations but lets try to keep it simple.

We will look at just the Flap surface (Flaps) and riging them to work as a Partial Aileron. In this example We will make the flaps work in just the + lift set, as most flap systems do not have an up (-AoA) range. (in this Example, if flaps are lowered then one flap will go up while the other may go down even further. (There is a way in G3 to set a maximum down range <A little to complicated to tackle at this time, but this will cause only one flap to go up if the other is fully down as a Flap function>.

Lets pick an aircraft that has both flaps and Ailerons and Create a working Flaperon system from the flaps.

Save As
See Pic “Save As.jpg”
I chose the Cessna 182 as it is simple and brings up a few other topics (It is also an Aircraft that anyone with G3/3.5 has). Make sure you “Save as” a New name so the edit will take place on a G3 stock plane. Also good to "Save as" for a Downloaded one so you can keep the original. Left click "File" and select "Save as" from the drop down menu.

OK we have a copy of the Aircraft and we now know it is safe to edit without fear of Ruining an original, (Some thing to come back to if all goes funny ;) )

Identify the Servo for the Control surface
See Pic "Flap Flaperons (01).jpg"
Lets first have a look at what servo/s are moving the flaps in its Stock Condition.
Go to the Flap in the AIRFRAME section of the Editor and you will see that Our Cessna has a Servo called "Flaps Servo".

This will not do for our need, we need two separate Servos to work the flaps independently, We will get to that later. but just now, Lets see what The ELECTRONICS section of the Editor has to say about the Flaps Servo.

Identify the Servos Input Channel
See pic "Flap Flaperons (02).jpg"
Left click on the ELECTRONICS section of the editor and You should see a list of all the Servos Etc. Now left click on the "Flaps Servo" and you should see its details. if you click on "Input for this Servo" you should get a drop down Menu that shows all the options for what is telling the servo to move. it can be a servo or a mixer or a Channel, In our case it is a channel. Receiver Channel 5.

Setting Up a New Channel Part 1, Editing existing Flap channel setup
See Pic "Flap Flaperons (03).Jpg"
Left click on the SOFTWARE RADIO + sign to list all the output channels, select Channel 5 and left click the + sign next to it. this will display the input for this output channel and some other params. At this time, I like to rename the input to keep things easy to work around. so left click the input for channel 5 and then left click again, this should allow you to now type in a new name. (See pic "Flap Flaperons (05).jpg" for the name set). Back to Pic 3. Now.
You will notice that On the left there is a Input Channel for and some other details. Currently The input is (The knob) take note of the Other details as we will need to mimic these for the other channel.

Adding a New Complex or Simple Input Feed
See Pic "Flap Flaperons (04).jpg"
First we will add the Aileron Input to "Output Channel 5". (This will need to be a Complex Input Feed, where as the Knob input is just a "Simple Input Feed") So right click on "output channel 5" and select "Add Complex Input feed" this will now give you a new Input (Rename it to Aileron) and have a quick look at the Options On the Right. See pic "Flap Flaperons (05).jpg"
 
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Flaperons

Flaperons Page 2/3​


Adding Physical Servo To ELECTRONICS
See Pic "Flap Flaperons (06).jpg"
So we have channel 5 set up with input from knob and have Added new Input for Aileron (Not yet Programmed) so now lets Add a New Servo. We will need to operate the Flaps Independently.
Just Right Click on Electronics and Select "Add Physical Servo"
Again here you can rename the Servo for Easy Identification. Some thing like "Flap Servo L" and "Flap Servo R". make sure that Both servos have the same settings IE Servo speed etc , But the "Input for this Servo" option needs to be a different channel. Which Brings Us to the next part. (Chose a channel that is not being used or created yet) In our case Receiver Channel 6 is free so I chose that. and Now to set up "Output Channel 6".

Setting Up a New Channel Part 2, creating/selecting new Channel.
See Pic "Flap Flaperon (07).jpg"
First We need to add the Flap Input (Make sure you chose a Channel that is empty of any inputs or can be emptied, <In this case "Output Channel 6" was Empty>) So, to add the Flaps input (Input from the Knob) we right click on the "Output Channel 6" and select "Add Simple Input Feed" Now rename it to Flap. Select The Knob as the "input channel" and make sure the settings are the same as the Flaps input for "Output Channel 5".
We will also need to add a Complex input feed for the Ailerons. So right click again and this time select "Add Complex input feed". Rename it to "Aileron".

Adjusting Complex Input feed. Actualy, Go to page three and hook up the servos etc. then come back to this part.
See Pic "Flap Flaperons. (08).jpg"
To adjust the Complex input feed (The curve) you just need to click on the line where it says <<Graph Points>> this will make a small box on that line appear off to the Right.
Click on that small box with the 3 dots [...] and a graph will appear. See pic "Flap Flaperons (09).jpg"
Adjusting the graph takes some practice and understanding of the Values. but you will get the hang of it. Essentially we want the two Output channels to be opposite to each other. See pic "Flap Flaperons (10).jpg" and compare to Pic "Flap Flaperons (09).jpg"
 
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Flaperons

Flaperons Page 3/3​

At this stage Or just before this stage it is a good Idea to hook up the servos to the "SOFTWARE RADIO" "Output Channel" and then the servos "Flap Servo L' and "Flap servo R" to the left and Right Flaps. This is probably better to do just before you do the "Adjusting Complex Input Feed" part, This way it will give you a chance to see what your changes there in the <<Graph Points>> will make. trial and error will be a bit easier ;)

Hooking up the Servo to the SOFTWARE RADIO" "Output Channel"
See Pic Flap "Flaperons (11).jpg"
In My Case "Flap Servo R" was the new one, so it is the only one that is not already hooked up. so Lets select it and then click on the Drop down Menu for "Input for this Servo". You will see the New Channel Now Called "Receiver Channel" and in our case "Receiver Channel 6"

Hooking up the Servo to the flaps
See Pic "Flap Flaperons (12).jpg"
Go to the Airframe and select the flaps. you will see that there are Two servo options One left and one right, select the drop down menu for the servo side we just created (In our case it was the right side) and select the "Flap Servo R" Servo for that side.

OK, Now they should be hooked up and moving, do check that they are moving in the correct directions. and Make sure that they work that way in all switch settings.

Checking your Switch settings "Input Feed When"
See Pic "Flap Flaperons (13).jpg"
Go back to the "SOFTWARE RADIO" and select "Output Channel 6" and click the + sign next to the Flap and Aileron Input, this will revile the options of selecting when the particular input will be active called "Input Feed When", make sure they are the same as the other Channel, (IE Channel 5's Flaps are the Same as Channel 6's Flap. and Channel 5's Ailerons Are the Same As Channel 6's Ailerons, In my case here, I have made sure that they are all "Always". When Always is selected, no other params need to be the same in the "Input Feed When" Options).
 
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Thanks for the effort, appreciate it

Outstanding tutorial dhk79, and it took a long time and a lot of effort to write it all down. Thanks a lot,

Mike
 
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dhk79 said:
We've had tutorials on modeling, texture mapping, importing to RF, and doing colorschemes. This one is going to focus on setting up the model's physics, such that it flies just like a real RC model would fly or "true-to-life". There are a few people who like to adjust the physics so that a biplane can do 400+ MPH. Well that is simply ludicrous, and we're not going to go there.

There is a further refinement known as "scale" performance, where the aircraft is supposed to fly exactly like a miniature version of the full sized aircraft. Some minor adjustments have to be made to achieve true "scale" performance. This is because while you can scale down the aircraft, you can't scale down the air in which the scaled plane flies. The airflow across the model's airfoils, therefore, will not separate and become delaminar at the same point along the surface. We may touch on some of these adjustments, but the primary focus will be to just get your model to correctly fly like a RC plane.

For those that would like to follow along as the steps in creating the physics model unfold, here is a freshly imported copy of the plane that we're going to work on. No changes have been made to the physics, this is how it shows up when first imported to RealFlight.
Click to expand...

Can't open the Tutorial_EA.3GX file.
 
We've had tutorials on modeling, texture mapping, importing to RF, and doing colorschemes. This one is going to focus on setting up the model's physics, such that it flies just like a real RC model would fly or "true-to-life". best tactical reviews There are a few people who like to adjust the physics so that a biplane can do 400+ MPH. Well that is simply ludicrous, and we're not going to go there.

There is a further refinement known as "scale" high performing light , where the aircraft is supposed to fly exactly like a miniature version of the full sized aircraft. Some minor adjustments have to be made to achieve true "scale" performance. This is because while you can scale down the aircraft, you can't scale down the air in which the scaled plane flies. The airflow across the model's airfoils, therefore, will not separate and become delaminar at the same point along the surface. We may touch on some of these adjustments, but the primary best folding knife focus will be to just get your model to correctly fly like a RC plane.

For those that would like to follow along as the steps in creating the physics model unfold, here is a freshly imported copy of the plane that we're going to work on. No changes have been made to the physics, this is how it shows up when first imported to Real light.
Click to expand...

I just signup here to say you thank you. Just awesome information you have added in this thread. Actually, I was looking for clear physic explaination.
 
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If you really want true to life performace, there are three things you need to know about your plane.

center of gravity,
lift to weight,
Thrust to weight.
 
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