Automating Aft to Forward Swing Wing in Flight

[L Edge]

After building and flying the Tomcat so the throttle controls the movement of the wing from center to aft, it was there I got the idea to see if I could design a plane that no one has built and flies. The wing would be able to start perpendicular, then either go aft(Tomcat) or go forward(X-29) in flight. By the way, Japan owns the patent and no one yet has built a model and flown.

After I solved the aero and stress problems(see my build) it was up and running. Problems began when club members wanted to take pics and video and asked for low passes. Flipping switches to make the transitions plus trying to fly 25 ft across the deck almost did (The MORPH) in. There had to be a better way.

Just put it together today, thanks to flying helicopters.

Concept:
Set up three modes--
Mode 1) Throttle goes from zero to 100 linearly(Y axis) and you set the wing(called pitch) so the servo is at center(X axis) and stays at zero. This is the flight of a fixed wing. Since I use 2 servos to move the wings, I had to set up 2 channels.



Mode 2) After you switch to mode 2, now comes the part that is different. I know the plane flies nice and stable at 50% throttle so I am now going to leave the throttle speed there and now the throttle stick now becomes the pitch movement which moves the wing either forward or aft. How it is done is in mode 1, you pitch the plane and get it flying. When you are set, move the throttle to 50% and flip your switch to mode 2,

Now the engine speed is constant(like a govenor) and if you want the wing to go aft, lower your throttle down, at zero throttle, the wing is 45 degrees aft. Bring it back to center, the wing is perpendicular, and if you move the throttle to full open, the wing is 33 degrees forward. The position of where you want it depends on the graph of the pitch.

To land or get out of the morphing, you must move the throttle to 50% and then flip the switch to mode 1. This is the only common point to both graphs.
Say you have the throttle at zero in mode 2(full aft) and you flip the switch to mode 1 by accident, your wing jumps to perpendicular position and your engine shuts off!!!!! That can shear your servo or give you perhaps a bad landing when flying low.

Do it right and as you make the pass for video, you can morph the wing either way as long as you go to 50% before you flip the switch. This is the way heli's use the throttle when doing acrobatics.

I am going to set up a 3rd mode and all I am going to do is change the rpm's up to 80% or so after experimentating.

Tommorow, I will explain how to program this and show a video. Then I will set up a video of flying with a pass changing the wing.

If you are going to build a Tomcat or F-111, understand what I am doing, and you can set up a 1 pitch so in mode 2, as you increase your throttle(no throttle curve) the wing goes back so it is 45 degrees at full throttle and you can roll that plane like a drill turns at high speed. I have done enough flight with my Tomcat that I even launch with my wing fully aft.

More tommorow.

 

[L Edge]

I am using a DX9 radio, but other radios you should be able to program the same thing.

The first thing is setting up is the systems requirements. Setting elevons, starting Flight Modes, assigning channels(2 for the servos) for movement of wings is needed. In the system, I also opened up the pitch(it is already programmed to change as the throttle is moved) so it will move as the throttle is changed.

Then I went into the model area and set the plane to fly with the standard rates and expo. The receiver monitor shows the setup. After rudder to the right is 2 wing servos labeled pit. Assign mode 1 to the controlling situation.

Now for MODE 1 -- I said I want to be able to keep the throttle movement from off to full throttle and the wing perpendicular to the fuse at all times. So now you now have a throttle and pitch graph.

Fot throttle stick position, the vertical (y axis) moves from the bottom(motor off) to full open wher the rpm's is the horizontal(x axis) . For mode one, you leave it alone . So half way up is throttle 50%. So do not touch. Under flight mode 1, I assigned these conditions as you see with the black dot under the 1.

Now go to the pitch graph. Goal: want in mode1 to keep the wing perpendicular to fuse. That means no matter where the throttle is, the wing doesn't move!!! Remember Algebra, a flat line means no change in x or y axis. So you move all your points to 50 % so no matter where the throttle moves, it stays fixed.

Graph:

 

[BATTLEAXE]

I am using a DX9 radio, but other radios you should be able to program the same thing.

OpenTx will do all that for you, rather easily too. I do this to set up dynamic rates, throttle trim, etc. How do you plan to accomplish this without the programming?

 

[L Edge]

OpenTx will do all that for you, rather easily too. I do this to set up dynamic rates, throttle trim, etc. How do you plan to accomplish this without the programming?

Back at it after lunch, look above.

 

[speedy7385]

OpenTx will do all that for you, rather easily too. I do this to set up dynamic rates, throttle trim, etc. How do you plan to accomplish this without the programming?

Hi, can you show me how to progam that throttle pitch curve on opentx please. I would like to set that up on my F14. I am using Taranis Qx7s.

 

[L Edge]

Now for mode 2. Flip the switch.
Now what is different. In order to move the wing automatically forward or aft in flight, it works out you need to keep the throttle rpm's constant and so by move your throttle up, the result is the wings go into forward swept motion as you increase the throttle stick, the wings go up further until you hit the end of travel of the throttle.
Now to swing aft, all you do is pull back on the throttle and at 50 %(wing is back to perpendicular) and below 50%, your wing moves aft and at zero or throttle off,the wing is back 45 degrees (like the Tomcat).

How to do it:
Go to the throttle curve and now set up the rpm's. My plane is stable and has plenty of speed at 50% throttle, so I decided to use that position to make the switch back and forth between fixed and wing movement. So throttle curve for mode 2 needs to be fixed at 50% no change, hence no slope so it is flat all the way across so as you change throttle position, the speed is the same. Now assign it flight mode 2, little 2 in square is black and the dot underneath let's you know. On your's, just set the points to the value at which the plane is stable.

Now, for the pitch curve that moves your wing. 50% is the only common point between rpm graph so that is where the throttle position needs to be to make the switch from mode 1 to mode 2. I decided that 50 to 100 throttle will move the swept wing forward and have it go aft from 50 to zero so the wing was 45 degrees back. Limit of forward swept wing is 33 degrees so there are 2 points. So it worked out the -96 was 45 back and +72 is full forward. In your setup, the direction may be the mirror image.

To properly set the center and ends of travel, first set the subtrims to make both wings identical in perpendicular angle and use the ATV to adjust the end travel so the wing is equal and does not hit the fuse or end of servo travel.
Also, I lowered the servo speed to 1 second of end to end travel so it doesn't strip the gears or ruin the servo mechanics.

Since this is a new way of flying, think it thru for what will happen will go like this. You are in mode 2, tooling along at say 85 % throttle with full aft wing (0% throttle) and you stupidly hit the mode1 switch. You will see engine go off, wing slam from full aft to perpendicular position
and I hope your can recover.
No programming master to slave in this program. All done by graphing. not trying to push radios, just see if your system can do the same.

Next I will make a video to show you how it works. Then take to the air for show and tell.

 

[BATTLEAXE]

Hi, can you show me how to progam that throttle pitch curve on opentx please. I would like to set that up on my F14. I am using Taranis Qx7s.

I could, or even better this guy can. I learned all I know about OpenTX from this channel, its also in my QuickTips section of my YT channel linked in my signature below.

Check it out...

This is just one vid. If you have OpenTX then you probably have OpenTX Companion on your computer, and you wil know they look exactly the same. All you gotta do is follow along. Super simple instructions, and if you have any questions about it he is more then willing to answer back on his YT channel. His channel has dozens of vids on the OpenTX. So much info to learn

 

[BATTLEAXE]

Hi, can you show me how to progam that throttle pitch curve on opentx please. I would like to set that up on my F14. I am using Taranis Qx7s.

The other one I learned that was good is the dynamic rates. If your F16 is an edf jet then you might want to check out those on his channel as well

 

[speedy7385]

I could, or even better this guy can. I learned all I know about OpenTX from this channel, its also in my QuickTips section of my YT channel linked in my signature below.

Check it out...

This is just one vid. If you have OpenTX then you probably have OpenTX Companion on your computer, and you wil know they look exactly the same. All you gotta do is follow along. Super simple instructions, and if you have any questions about it he is more then willing to answer back on his YT channel. His channel has dozens of vids on the OpenTX. So much info to learn

Cool Thanks! I will check them out.

 

[L Edge]

Here is a demo of how modes and pitch work. Remember in mode 2, the throttle is fixed at one set speed and if the throttle moves upwards from 50%, the wing goes forward and move under 50, it is now starts to go to full aft. Stop it anywhere, it stay fixed.

 

[Tin Man]

Y don’t you just use a three position flap switch for your wing and have full control over throttle at all times?

 

[speedy7385]

Here is a demo of how modes and pitch work. Remember in mode 2, the throttle is fixed at one set speed and if the throttle moves upwards from 50%, the wing goes forward and move under 50, it is now starts to go to full aft. Stop it anywhere, it stay fixed.

Thanks!

 

[speedy7385]

Y don’t you just use a three position flap switch for your wing and have full control over throttle at all times?

That's how I have my setup at the moment. But using throttle to control the sweep seem more realistic.

 

[Tin Man]

That's how I have my setup at the moment. But using throttle to control the sweep seem more realistic.

Ya but I like having full control over throttle at all times. And you can set a timer for how long you want the wing to travers.

 

[L Edge]

Ya but I like having full control over throttle at all times. And you can set a timer for how long you want the wing to travers.

The point of this thread is to understand that using the graph for throttle and wing, you can set up anyway you want. In your case, you don't need a timer for how long, So adjust the graph for the time movement and don't touch the throttle curve. Now you have control of throttle at all times. No other programming is needed.

In my case, I showed that no switching was needed to make a low pass moving the wing from aft to forward in flight. It is the first plane ever to do that in flight. It is a way of showing it off where the group can see it, rather than being way up in the sky. Once you get use to fixed throttle, it allows you to do other things. This is basically the way I can hover inverted with a heli.

 

[Tin Man]

The point of this thread is to understand that using the graph for throttle and wing, you can set up anyway you want. In your case, you don't need a timer for how long, So adjust the graph for the time movement and don't touch the throttle curve. Now you have control of throttle at all times. No other programming is needed.

In my case, I showed that no switching was needed to make a low pass moving the wing from aft to forward in flight. It is the first plane ever to do that in flight. It is a way of showing it off where the group can see it, rather than being way up in the sky. Once you get use to fixed throttle, it allows you to do other things. This is basically the way I can hover inverted with a heli.

Oh ok that makes more sense, but still the idea of fixed throttle on an airplane sound sketchy to me in every scenario except a low fly by. I guess maybe I’m failing to see how this would be useful in commercial use. ( streamer combat ) But hey overall I think it’s a really cool idea.

 

[L Edge]

Oh ok that makes more sense, but still the idea of fixed throttle on an airplane sound sketchy to me in every scenario except a low fly by. I guess maybe I’m failing to see how this would be useful in commercial use. ( streamer combat ) But hey overall I think it’s a really cool idea.

Have your heard about RC 4D flying? Look it up on youtube. When they back the plane up in flight, they are hold the RPM's constant and reversing the prop, like moving the wing forward and backward.

 

[Tin Man]

Have your heard about RC 4D flying? Look it up on youtube. When they back the plane up in flight, they are hold the RPM's constant and reversing the prop, like moving the wing forward and backward.

Yes it’s awesome but in a way they still have throttle control because they control the pitch of the prop. It’s having a fixed airspeed that concerns me. Unless you could have a really over powered system that has almost unlimited vertical at the set throttle, I’m just worried about stalls and tip stalls. I don’t know maybe I’m overthinking it all 😁