Aileron/elvator or elevon/taileron?

[stevem1928]

My next project is to build an F-35 JSF. I am wondering what will give better control on 2 servos. aileraon/elvator, or elvon, taileron? Here is a 3 view of the plane.

For the elvon/taileron configuration, one sevro will control an elvon and a taileron on the same side.

[BMatthews]

Someone on RC Groups tried a taileron setup on a short coupled Bipe indoor foam flyer. It didn't work worth beans. The JSF is a bit stubbier than his bipe but not by much. I'd stick with the ailerons and elevator if I were you.

Do a search to find his attempt. I think it was in Foamies or Parkflyers.

[omega blood]

Tailarons should work fine. It's not much different from the wattage F-22 wich uses the same thing.

[stevem1928]

I have used full flying tailerons (no aileron or rudder) on an F-18. The plane kind of skidded through the turns. It did not bank or roll well. I am hoping to avoid the skidding turn.

Here is picture of the plane.

[feathermerchant]

My wattage F-22 flies great with elevons. I use a lot of travel but they seem effective at all speeds. Make sure to match your travels as I found that one servo travels a different distance than the other.

[vintage1]

Looking at the plane I would say that yoiu definitley want working elevators. Not try and use the ailerons for pitch control.

As to whether roll should be done on the tail, or the wing, its a moot point. Both will work, my guess is that most eyeball snatching rollrate would be using ailerons, but personally I think I'd use elevon mixing on the tail surfaces.

Its going to be fast, so it won't need a lot anyway.

[raptor22]

I'd use the aileron/elevator setup for a better roll rate.

--Alex

[stevem1928]

Should I make the ailerons the same size as the ones on the 3 view picture above? Or, should I make the larger? I am going to split the elevator surface 2/3 of the way back, and make just part of the surface move. I made a quick flat plate fan-fold model. I got the the CG right, on the first toss.

[raptor22]

They're fine for high speeds. Bigger is always better in my opinion, but I'm a freak as far as that's concerned. Most people would try to conserve the scale look.

--Alex

[stevem1928]

I have decided to go with elevons and tailerons. Due to the large split between the elevator halves. It will be much easier to run run a carbon rod down each side of the fuse. The tailerons will be connected to the elevon torque rod on each side.

I have attached a picture of how it will be set up.

Raptor22, Let me know if there is an easy way to set this up with an elevator. Keep in mind that the posterior half of the fuse will be occupied by the fan

[raptor22]

Very cool; how 'bout this: put the the servo's in the wing, as if you were building a flying wing w/ elevons. Have the control rods connected in the center of the elevons. Inboard of the elevons put another control horn that is linked to the elevators like it was a servo control horn. Bypasses the fuse completely and is very simple to set up.

--Alex

[stevem1928]

Raptor,

I think what you are describing, is what I have shown. One servo controls an elevon and a taileron on one side. The control rod runs from the servo, to a conrtol horn which is connected to the elevon. That same control horn then has another control rod which goes back to the ipsilateral taileron (same side). By raising and lowering the connections at the control horns, I can make the elevons or the tailerons more responsive. Make the elevons more responsive for better roll, or vice-versa for better pitch.


I am not sure of a good way to make this an aileron/elevator without some type of bifurcated elevator control rod.

[raptor22]

I will send a picture when I can; you need zero special equipment.

--Alex

[raptor22]

Here it is. As you can see, the "Elevons" (actually thay are flaperons; elevons in this case would be useless; they would act as spoilerons and dump lift with an "up" command) are connected to the tailerons. I really like this idea, as it is a way to couple the scale features of the jsf w/ no cpu; the full scale model actually uses computer controlled flaperons and tailerons as well as the traditional controls to achieve max maneuverability.

Good luck, and keep us posted.

--Alex

[raptor22]

If the pic is too tiny, send me you email so I can send one that does not have such tight file restrictions (102kb? cmon.)

--Alex

[glowpwer flyer]

i belive it should be taileron and elvon it work much better and it be fine. Because there right on top of each other and it be great working.

Kevin