Flaperons [IDEAS]

[captainmib]

Flaperons are a combination of flaps and ailerons, found on various airplanes.

https://en.wikipedia.org/wiki/Flaperon

Thanks to @MinusAndy and @Jeroen Ottens for sparking this topic.

I've had the following idea for ages, but it can use some perfection. (I think I've borrowed this idea somewhere)

Red - Input for flaps

Yellow + Turntable - Input for ailerons

Combined - Flaperons

 

Please post your ideas, suggestions, or questions in this topic.

[MinusAndy]

I’ve put the aileron input through the middle of a diff in each wing. The diff casing is moved by the flaps and transfers the resting point of the ailerons down. The aileron runs from the other side of the diff.

I have spoilers flaps and flaperons on this but it’s requiring a lot of work to stop the backlash.

Edited November 17, 2020 by MinusAndy

[captainmib]

Ah, I understand your solution.

The old diff's are great for this.

But you mentioned a lot of backlash, right?

 

Edited November 17, 2020 by captainmib

[MinusAndy]

Yeah because of limited input from the joystick so much of the overall movement is soaked up by the linkage. I’m currently adding Knobs of God to the back of the fuselage so it directly drives the two diffs and the joystick and rudder pedals follow.

[2GodBDGlory]

Cool! I didn't know that such a mechanism existed!

[dhc6twinotter]

Here's a variation of a control mixer I used for the drooping ailerons on my Piper Super Cub.  The overall movement is somewhat limited, but for the purpose of drooping ailerons or flaperons, it works well.  The yellow axle is the input from the control stick, and the red axles are the outputs to each flaperon (or drooping ailerons).  The black balls would be connected to the flap mechanism and move up/down as needed.   It's a bit difficult to tell in the picture, but the grey part in the center is a CV joint.

There are also ways to just use control mixers using levers and no gears, much like many of the Technic helicopters use.

 

Edited November 18, 2020 by dhc6twinotter

[dhc6twinotter]

7 hours ago, captainmib said:

Flaperons are a combination of flaps and ailerons, found on various airplanes.

https://en.wikipedia.org/wiki/Flaperon

Thanks to @MinusAndy and @Jeroen Ottens for sparking this topic.

I've had the following idea for ages, but it can use some perfection. (I think I've borrowed this idea somewhere)

Red - Input for flaps

Yellow + Turntable - Input for ailerons

Combined - Flaperons

 

Please post your ideas, suggestions, or questions in this topic.

Sorry for the double post, but I did want to say that is a really creative solution.  I like that a lot! 

[MinusAndy]

4 hours ago, dhc6twinotter said:

Here's a variation of a control mixer I used for the drooping ailerons on my Piper Super Cub.  The overall movement is somewhat limited, but for the purpose of drooping ailerons or flaperons, it works well.  The yellow axle is the input from the control stick, and the red axles are the outputs to each flaperon (or drooping ailerons).  The black balls would be connected to the flap mechanism and move up/down as needed.   It's a bit difficult to tell in the picture, but the grey part in the center is a CV joint.

There are also ways to just use control mixers using levers and no gears, much like many of the Technic helicopters use.

 

I really like this solution. I think I’ve had a result last night with my backlash issue but if it doesn’t work then a variation on this is a great compact solution. B be wing able to centrally mount this means I would use at least half the amount of gear connections and that will hugely help the backlash issue.

What are people using as a joystick mechanism? 

[Void_S]

12 hours ago, captainmib said:

I've had the following idea for ages, but it can use some perfection. (I think I've borrowed this idea somewhere)

Amazing idea!

I see one more (may weird enough) use of this thing - a suspension. Imagine that "flaperons" shafts now a the wishbone shafts (they must be turned at 90 degrees).

• Red output will act as "both wheels together" suspension and may be used for the ground clearance adjustment
• Turntable will act as "left-right" suspension.

As an option, the turntable may have a harder spring and red output softer. This assembly will work with a suspension with a kind of anti roll-bar.

[steph77]

Here are some interesting linkages that may interest you:

 

 

 

Edited November 18, 2020 by steph77

[MinusAndy]

Those are fascinating! 
I’m in a fortunate position as a good friend of mine has an old helicopter which I have access to and all the linkages are on the outside. It’s fascinating! I particularly like the tail rotor which is wire controlled using a worm screw type thing with wire wrapped around it. I will make a scale one at some point using cord and a Lego worm screw.

 

[2GodBDGlory]

10 hours ago, Void_S said:

Amazing idea!

I see one more (may weird enough) use of this thing - a suspension. Imagine that "flaperons" shafts now a the wishbone shafts (they must be turned at 90 degrees).

• Red output will act as "both wheels together" suspension and may be used for the ground clearance adjustment
• Turntable will act as "left-right" suspension.

As an option, the turntable may have a harder spring and red output softer. This assembly will work with a suspension with a kind of anti roll-bar.

That could be very interesting!

[steph77]

Back to flaperons...

I search for a while a compact way to reproduce the F-14 flaperon system.

When the wings are deployed, the flight surface is similar to regular planes but when retracted, the plane becomes a Delta wing using flaperons.

My search stopped at this point wher the mixing unit had to progressively transfer the movement from flaperons to regular ailerons

[MinusAndy]

You could possibly do that using a diff in each wing that progressively dropped them as the wing swept back but I’m not sure you would be able to accurately make it progressively mix in terms of being able to deploy the flap at varying degrees when it’s influenced by both wing angle and pilot input. I think it would lend itself to hydraulic control pretty easily but treebling that with axles and levers with the limited input of a Lego joystick would be pretty tricky

[MinusAndy]

Actually, on the f14 are we not dealing with elevons on the rear control surfaces? That would be even harder to build as a progressive mix. 
there’s a dude called Gabor on Flickr who builds some insanely complex rotor heads etc, but they tend to be enormous. A compact version would be really tricky.

Im not sure even crash cramers f14 does this and that’s pretty much the benchmark for me in terms of Lego aircraft.

[dhc6twinotter]

12 hours ago, MinusAndy said:

Actually, on the f14 are we not dealing with elevons on the rear control surfaces? That would be even harder to build as a progressive mix. 
there’s a dude called Gabor on Flickr who builds some insanely complex rotor heads etc, but they tend to be enormous. A compact version would be really tricky.

Im not sure even crash cramers f14 does this and that’s pretty much the benchmark for me in terms of Lego aircraft.

Yes, I think you are correct.  F-14 has elevons.  I don't think building elevons would be any different than flaperons, and I tend to think it would be pretty much the same type of mechanism.   I think Steph77 may be referring to the spoiler setup on the F-14.  The spoilers on the F-14 are also used to augment roll, so one side may pop up to assist the elevons during a roll.  It looks like this only happens when the wings are swept forward, and the spoilers are deactivated in swept back configuration.  I don't know that the F-14 has traditional ailerons; I think it just uses flaps the whole length of the wing.  Pretty fascinating aircraft.

[steph77]

1 hour ago, dhc6twinotter said:

Yes, I think you are correct.  F-14 has elevons.  I don't think building elevons would be any different than flaperons, and I tend to think it would be pretty much the same type of mechanism.   I think Steph77 may be referring to the spoiler setup on the F-14.  The spoilers on the F-14 are also used to augment roll, so one side may pop up to assist the elevons during a roll.  It looks like this only happens when the wings are swept forward, and the spoilers are deactivated in swept back configuration.  I don't know that the F-14 has traditional ailerons; I think it just uses flaps the whole length of the wing.  Pretty fascinating aircraft.

True. I try for a while to reproduce méchanically this: (And this is really harder than building an whole helicopter system)

EDIT: interresting section from 0:42

 

EDIT 2: To complete:

Spoilers

The spoilers located on the upper surfaces of the wings are used to control roll as detailed above under Flight Control System, for braking on the ground as part of the Antiskid system and as a part of the DLC system (see next header).

The spoilers are only used forwards of 62° wing-sweep as further aft these conflict with the fuselage.

 

Source:

http://www.heatblur.se/F-14Manual/general.html#flight-control-system

 

 

Edited November 20, 2020 by steph77

[Rudivdk]

1 hour ago, steph77 said:

The spoilers are only used forwards of 62° wing-sweep as further aft these conflict with the fuselage.

What pops to mind is some lever connected to the wings and activated by the sweep-motion that engages/disengages  the spoiler control system at around 62°. Set 8052 has a mechanism which might be a useful starting point. But I think it will be really difficult to do that with acceptable (minimal) backlash...

@captainmib: I really like your solution, because it is very easy to incorporate in any build. It is easy to change the black rods for longer 9l ones or even custom ones to increase the length between cockpit and wing inputs, and by changing the length of the red or yellow connectors you can even amplify or de-amplify (is that even a word...?) the movement from the control stick. Very nice

@Void_S that suspension idea is also a very interesting concept, would love to tinker around with that some day...

Edited November 20, 2020 by Rudivdk

[captainmib]

@Rudivdk Thanks. Hope it helps. I'm not taking credit though, I think I borrowed this somewhere, but can't remember where or what it was.

It's true that it has various options.

You could even leave the turntable out I think, replace it with a liftarm, and do the steering (yellow) through a liftarm as well.

[aeh5040]

Some very interesting ideas here. The concept has a fair bit in common with a mechanical joystick remote, of which there are several designs out there, e.g. https://brickshelf.com/cgi-bin/gallery.cgi?f=301922