Proper use of exponential servo control for sequence flying
 

I'm starting to play with expo on my new radio/airplane and I don't think I like it. It has also made me aware that I use rudder and aileron similarly buy elevator much differently. With rudder and aileron, I'm either making small adjustments for track and heading or pushing the stick all the way over for manevers. In this case, expo seems to help smooth the track and heading part. On the elevator, I use the full range for all aspects of flying the sequence. In this case, expo gives me the feeling of vagueness in the middle, and over sensitivity at full stick. Kind of like my '67 Plymouth.

I guess my preference on expo is about 40% rudder, 20% aileron, 0% elevator.

Am I crazy?

RE: Proper use of exponential servo control for sequence flying
 

If it feels good and you have the control you need and want, You Ain't Crazy.


Good flyin

Dale

RE: Proper use of exponential servo control for sequence flying
 

Most newcomers to expo feel the same way. In reality a servo with a rotary output moves more around center than it does near the ends in a linear fashion. As the servo reaches the end of travel it moves more side to side than it does in the direction of the control surface. Still you aren't crazy. It probably does feel "good" as that is what you have become accustomed to. Small inputs are needed more around neutral for precise control. I have had many students say the same thing only to come back the next season and say they now enjoy and use expo. Give it a try as you will most likely become accostomed to the new found tool.

EXCAP232

RE: Proper use of exponential servo control for sequence flying
 

I'm easily confused by the barrage of so called advise. You gotta do this and you gotta do that otherwise your flying will suffer. I started using expo because of advise. Getting used to it doesn't make much sense to me unless it will eventually lead to improved scores.

Maybe I'll cut back and work up slowly.

RE: Proper use of exponential servo control for sequence flying
 

Yep, takes some getting used to.I use -80 expo on everything except trottle.I use a 9CAP.Flying sequences much easier now.Not as jumpy.

RE: Proper use of exponential servo control for sequence flying
 

Hey Ilike,

Don't get too disheartened with all the advice. It's your plane and you can set it up however you like it. You can talk to every winner at competitions and their set up will be different..........no two the same. And guess what? They are all great sticks!

In Air Force pilot training I watched a lot of good pilots wash out because they were assigned to weak instructors. A weak instructor only learned one way of doing a maneuver, and they rarely acknowledge there are other techniques out there that also work. As soon as someone tells you "you've gotta do it this way".......politely nod and move on........

The flip side of the coin is, to become a better pilot, don't be afraid to try a new technique. It sounds like that's what you are doing here, and that's good!

Now, how about that expo...........

If you are having trouble keeping your straight and level.......well...... straight, then a little negative expo will help. If you are having trouble overcontrolling and your maneuvers are not smooth, it will also help there. If your straight and level is not causing trouble and all is smooth, then don't worry about expo. There are a lot of variables and reasons why some planes fly better with expo, and others fly fine with none. I'll go into them if you are interested, but I think this post is long enough for now.

CJ

RE: Proper use of exponential servo control for sequence flying
 

Don't forget, JR radios are positive expo to soften around center, opposite of Futaba (negative to soften center, as mentioned above).

Baron

RE: Proper use of exponential servo control for sequence flying
 

Yeah, I forgot that once and nearly buried a brand new P-51 on its 2nd flight! The elevator was really sensitive on the maiden so I dialed in some expo. I put +60% instead of -60% expo on my 9c[X(]. I had the hardest time landing, must of went around 5 times!

RE: Proper use of exponential servo control for sequence flying
 

One thing to look into is the use of dual rates. I have 3 independent rate switches for the 3 controls. I use mostly high rate aileron, and use low for 1 or 2 roll circles. I use low rate elevator for most of my flying, using high (30 degrees) for tail-slides and some spin entries. I use low rate rudder for most flying also, using high rate for tail-slides, rollers and the occasional stall turn.
I have an entirely separate 3D program with 45 degrees on high rate everything with -60 to -80% expo. Low rates are the same as my sequence set-up with -20% on ail/rud, with +15% on elevator (10 degrees of throw). Futaba flyer.

RE: Proper use of exponential servo control for sequence flying
 

ok , negative expo (futaba) softens the response of the servo around the cente but can anyone tell me what positive expo is used for , I cant think of any manouvers that could benefit from positive expo, plane becomes totally uncontrollable

RE: Proper use of exponential servo control for sequence flying
 

The servo throw is not linear due to the circular motion... TRUE!! ... but assuming the horn is a similiar length to the servo arm, the ratio of Servo Deflection-to-Control surface deflection will still be (nearly) linear. I am currently flying planes utilizing plus/minus 45 degrees of control throw... so the ratio is very nearly 1-to-1... as the arm gets shorter, and/or the horn gets longer, the linearity dissappears.

RE: Proper use of exponential servo control for sequence flying
 

CJ,

Sounds like you were an IP. Where at? I was a Tweet IP for three years at Willie before moving on to the electric jet.

RE: Proper use of exponential servo control for sequence flying
 

Class 8306 plus seven years T-38's at Columbus. You had to be near my generation if you worked at Willie......What are you doing these days?

By the way guys, the Talon had a roll rate of 720 degrees per second.......pretty brain scrambling........and used expo to tame the ailerons near center. That was 1950's technology. We ought to be using a pressure sensitive stick on our transmitters by now, like your electric jet. We'd have more precise control and not have to worry about expo at all........Just pull harder when you need it. Even that is 1970"s technology. The radio companies are holding out on us!

The latest technology is the Raptor.......when you pull hard enough, the stick passes a detent and gives you "MONGO MODE".....instant wall or water fall. You get ultra high rates with no need to flip switches, and it's very controllable. Pressure is the secret......not the amount of stick movement.......which is simply a throw back to the old cable and pulley controls planes used to use.

What kind of roll rate could you get with the 16?

CJ

RE: Proper use of exponential servo control for sequence flying
 

I always test the expo while I'm progeraming it. I test everything I program. It's too easy to get confused or make a mistake. I seem to make lots of those when I don't check everything. I can't imagine programing something without the RX on and then taking off without checking it.

To test expo while programing hold the stick between center and full(not centered, but not full throw) while changing the expo amount. The surface that you're controling should move closer to the center of the throw the more you add. If you're doing it backwards the surface will move away from center.

RE: Proper use of exponential servo control for sequence flying
 

Ilikeplanes:
My preferences are: low throws: Ail -25, ele 0. rud 0; High throws Ail -35, rud 0, ele -15
as you can see I love extreme Rudder and my confort level on aileron begs for expo.-

so you are not crazy o.k.

I alway do what Audiomixer sugguest, good procedure!!

RE: Proper use of exponential servo control for sequence flying
 

Hey CJ, My brother is Capt Peter Allen Selkey jr.. he was an Tweet IP in Hell Rio, Tx approx 2000-2003... Now flies the Strike Eagle an Seymour Johnson... Know him by chance??