Wing Elevon Throw Limits (EPA adjustment)

[jimsky]

Felt I had to post something in the new 'Flying Wings" trial forum.

I've been tearing up the sky with my Scram Blur, just love that little wing. I kind of "forgot" that I has to severly limit the evelon throws via cranking down the EPA settings on my Flash 5X, they are set to about 30%. I'm still a new pilot for the most part.

This past weekend I'm trying to fly my new SuperFly-E, setup with 1.5 inches of elevon throws, as suggested in the manual. Man I'm having problems keeping this thing in the air on Saturday. Finally called it quites and flew the Scram Blur and then the T-IFO when the winds came down.

Sunday I tried the SuperFly again and crash 10 seconds into the 1st flight, popping the front of the airframe in two. :eek: Not the first time, I did this once before and repaired it. No knocks to the SuperFly, I'm flying this like a rookie.

I send David at SuperFly an e-mail and he suggested to limit the evelon throws, mentioning they were HUGE in size. Damn, wish I'd thought about that!

The Scram Blur was downight "unflyable" by me until I cranked down the EPA settings. I'm going to make the repair and add some carbon spars for extra support. Then I'm dialing the EPA's down and can't wait to try it again. EPA limits made a world of difference on the Scram Blur, hopefully it will do the same here.

New wing pilots take note: Learn by my mistake. Limit the maximum elevon deflection initally, then adjust as your skills improve.

I've already ordered the carbon fiber to fix this up "better than new". Where's my GOOP and latex paint?

Jimsky

[BigShark]

I had the same problem on my home brew wings. They were either uncontrollable or wouldn't loop at all. I was using 2" aileron stock on a 52" wing and had huge control throws. I cranked the elevon travel down to 48% and it flew great. It still only needs about half of the stick travel to loop from level flight. More than that and my elevons act like speed brakes. Makes landings easy!

[jimsky]

Just thought I'd share a photo of the SuperFly-E carnage.

"We have the technology to rebuilt it; better, faster... stronger".

Jimsky

[flatfour]

You could also use exponential to achieve the same result. Expo will "soften" the stick sensitivity around the center point, but still give full deflection at full throw.

[jimsky]

I haven't played around the the exponential settings yet. I understand the function and my radio does have them. As a new pilot I guess I still tend to overcorrect. To me it seems restricting the maximum allowable elevon travel is the most straight forward way of reducing "over correction". I will give the expo setting a try.

Jimsky

[BigShark]

Is the Superfly E just a flat plate? Or does it have an airfoil cut into it? I've never really looked at one up close before. Now I'm thinking of building one out of some FFFor some epp I've got laying about.

[jimsky]

It's not a flat plate, it's an airfoil. Looks to be a typical wing profile (flat bottom & bluged top) cut into a triangular Delta wing shape. Thicker in front (narrowest part), tapering down in back (widest part). So it's getting lift from both the airfoil shape and the actual angle of attack.

Jimsky

[Flyin Hawaiian]

Jimsky,
I'm currently using a flash 5 as well, and thought you might be able to answer a quick question: When I tried to limit elevon throw using the EPA feature, I accessed the EPA program, and set CH 1 (ailerons) and CH 2(elevator) to 50% to start.((mixing on). The problem I have is when I pull back on right stick, one elevon goes to half throw, but the other one goes to 100% throw. Same thing happens when I push stick forward (but opposite sides). Side to side stick seems to send elevons in proper direction.......but full throw. It's a new radio, and I'm kinda a noobie.....am I doing something wrong??? I've tried it from the beginning several times and the same thing happens. I did get the throws reduced but had to use dual rates. Is this normal?
Thanks,
Lono :confused:

[wattsup_kz]

With my PCW instead of EPA, I used dual rates on the Flash5 and I just keep the elevator on 50%.

[jimsky]

I had the same problem. The EPA has limits for EACH SIDE of every channel. You need to make 2 adjustments for every channel.

Using a simple rudder example, a rudder moves left and right. You need to set a limit for the right travel excursion and the left travel excursion....two seperate settings. This allows them to be different if you want.

To access the other side of the channel push and hold the stick when making the EPA adjustments. One side comes up as the default, but you have to move & hold the stick to access the other side. When you rock & hold the stick that accesses the "other" side you will know...the EPA will be shown as the default setting...100%. Hold the stick in that postion and reduce the amount like you did before.

So rock that stick when setting the EPA to see and set both adjustment settings of each channel.

Jimsky

[Flyin Hawaiian]

Thanks for the info, Jimsky, I'll give her a try
Lono

[no stick]

Jimsky,
I'm currently using a flash 5 as well, and thought you might be able to answer a quick question: When I tried to limit elevon throw using the EPA feature, I accessed the EPA program, and set CH 1 (ailerons) and CH 2(elevator) to 50% to start.((mixing on). The problem I have is when I pull back on right stick, one elevon goes to half throw, but the other one goes to 100% throw. Same thing happens when I push stick forward (but opposite sides). Side to side stick seems to send elevons in proper direction.......but full throw. It's a new radio, and I'm kinda a noobie.....am I doing something wrong??? I've tried it from the beginning several times and the same thing happens. I did get the throws reduced but had to use dual rates. Is this normal?
Thanks,
Lono :confused:
Lono,

Are you using dual rates as well as EPA on the Flash 5?

Ed

[jimsky]

Aside from the limiting the maxium throws via the EPA settings, I cranked in some negative EXPO. It softens up (de-sensitizing) the stick response around the center position. EXPO settings are just one adjustment for each channel. For my Scram Blur I have EPA set to 35% and the EXPO set to -35% also. Damn am I ever glad I got this computer radio, without these adjustments my Scram Blur would be un-flyable.

Jimsky

[ScYcS]

Huh......i am used to fly my SuperFly(s) with full throws and no expo nor EPA. I tried dialing in some expo and EPA yesterday and couldn't fly the Fly anymore. Back to giant throws. Makes baby jeebus happier.

[jimsky]

I had the same issue with my T-IFO. I learned to fly it with full throws and no EXPO, I'm use to flying it that way. After cranking down my Scram Blur with such good results I tried the same with my T-IFO....and I couldn't fly the thing. I tried adding some limits and EXPO with my Slow Stick, with the similar results. The characteristics of the plane and the skills of the pilot are unique for each situation.

Think of EPA and EXPO as tools to help you tame a plane. They may not always be needed, but nice to know they are there when the need arises.

Jimsky

[ScYcS]

Think of EPA and EXPO as tools to help you tame a plane. They may not always be needed, but nice to know they are there when the need arises.

Jimsky

Agreed.