Elevon programming
 

This is cross posted from the "Radios" section as I'm coming down to the wire on time. This section seems to get more traffic than the radio section.

I did a search, but couldn't find exactly what I was looking for.

I'm getting my first ever plane that has elevons and I was wondering how hard the programming is for it. I looked through my manual (Futaba 7C), and it seems pretty simple. I just have no idea what values I need to use and what exactly they mean. Is there a resource (other than trial and error) that explains this?

I'm guessing that the percentages for aileron and elevator control how far the control surface moves as compared to each other (or each other's inputs). I have no idea what "differential" is referring to.
Any help would be appreciated...

RE: Elevon programming
 

I'm not familiar with futaba radios, but a 7C ought to have a built in mix for elevons. usually one servo is plugged into the elevator channel and the other into the aileron channel. Then you set the throws according to the model's instructions. "Differential" typically refers to the difference between the distance a control surface moves in opposite directions. In the case of ailerons it refers to the difference between the amount of up and down travel. Differential is most frequently needed on non-symetrical airfoils (Clark Y etc), but is often useful on biplanes. It compensates for the difference in aerodynamic drag between upward and downward deflection. I also use differential elevator throw if a model requires a lot of down elevator for inverted flight.
Hope this helps a little.
Walt

RE: Elevon programming
 

It does have mixing for elevons, I'm just not sure on how it should be set up.
Basically, you turn on the mixing.
Then you set up percentages for elevator, aileron, and differential.
And you're done. Assuming you know what these numbers should be, that is.

Here is the manual to the 7C (elevon info on page 45).
http://www.futaba-rc.com/manuals/7c-manual.pdf

Here is the manual for the plane I'm getting (in 3 languages, even).
http://www.ikarus-modellbau.de/Anleitungen/su27.pdf

The elevon section in the manual is fairly short and shows how to change the values. There is no info on what those values refer to.
The plane manual only goes into building the plane, not setting up what servo plugs into what channel and whatnot.
I'm gueesing it's going to be fairly easy via trial and error, but I'd like to know as much as possible before I fly it and find out the hard way.

RE: Elevon programming
 

I couldn't tell in the model instructions what the control throws were supposed to be. That said, the diffrential for my deltas has only been a issue when I wanted to do repeated rolls and stay in a straight line. Other wise after the third or so roll it starts to kinda do a barrel roll and not on the axis of the model. Normally I don't worry about diff. The biggest thing I would thing about when progaming the Tx is how much throw for each action wether ail or ele and then dial in some expo (I like 30%) to make things a little softer at the center of the stick.

RE: Elevon programming
 

It depends on how you want to fly. Do you want max throws? Medium? It is also very nice to have more up then down when giving roll input (the surface that moves up moves further than the surface that moves down). Do you want your plane to have a wicked roll rate (high aileron diff) and a calm elevator (low) or visa versa? It depends on your flying style. Set up the mixing as per the manual of the plane and if you don't like it like that, you can change it up.

RE: Elevon programming
 

FA451, didn't look at his links did you [&o]

DC are you going with the advanced set-up?

RE: Elevon programming
 

I'm going from an aileron trainer to this, so I'll probably start with the basic setting and make the necessary changes to the plane when I'm ready to 'upgrade' to the advanced setup.

I would ask the guys at the LHS, but they went out of business. At least the LHS where anybody actually knows anything about the products, that is. I thought I would have the plane last night, but it didn't show up. Priority mail from 2 states away and today is day 3 from shipping notice.

If I only knew what each value actually did, I wouldn't have any problems with this. I'm hoping that it's easy to figure out and that I'm just making much ado about nothing...