Flightfreak777

Hey everyone!

I just got my new Futaba 6EXAS radio and this thing is sa-weet! It's my first programmable radio an I only have one simple question. What exactly is the Exponential Settings? I know what dual rates are...duh...and I get the End Point Adjustment, but not sure about the Exponential Setting. It says "The same as dual rates, "expos" can be set for both switch positions. (which I know means for dual rate being on and off) but then it says Negative exponential decreases initial servo movement and positive increases initial movement, and the the exponential "curve" can be set between -100% and +100% I;m not sure what that does with my servos....any help?

~Matt

sslayman

My Feedback: (14)

Expo, as it's been shortened to, just means that the movement of the stick will be lowered around center stick, but you will still get full throw at the extremes of the stick movement. This is usually used on helis that are setup extremely sensitive for 3D flying. To be able to hover them with any degree of stability, expo is dialed in so the stick movements around center is very soft (not sensitive) but once you have moved the stick to a certain point the heli will again react quick or very quickly. Expo usage is usually set as personal taste kind of thing. I fly helis, but I don't like expo on my sticks, so I do not set any of my controls to use it. I find it makes the controls to mushy (IMO). Some use it on airplanes so they can land and take off without the need to use dual rates. Landings or take offs can be controlled easily, but once you are into your routine you'll have full throw of the controls. I personally don't know anyone using it on their planes and we have several that are into 3D stuff in our club, with their planes. They like to use dual rates instead. It's all a personal preference.

Later...

Scott!

Flightfreak777

so it's kind of an either or deal between d/r's and expo's?

sslayman

My Feedback: (14)

As far as I know, NO. I think you can set the aircraft up with dual rates with or without expo and vice-versa. Since I don't use it, I can't say for sure. Of course I'm using JR radios so that may have something to do with it, but I doubt it.

Later...

Scott!

carrellh

You can have both. Expo is not controlled by a switch. If you turn it on, it's active if the radio is on. Dual rates are on a switch so you can flip back and forth between low and high anytime you want.

I use expo. I have neurological problems that make it difficult for me to feel the sticks; and I have trouble making very small, fine, movements. Slowing down the movement in the center helps me fly smoother. My brother, who is on the other end of the trainer cord to keep me out of trouble, doesn’t use any expo. He likes maximum sensitivity.

I will be setting up dual rates on the ailerons, and possibly elevator, of my Big Stik. With the throws suggested by GP, the plane is too wild for my current skill level. By cutting it back in my radio, it will fly the way I need and also the way my brother likes.

Expo is something people seem to really like, or really dislike. Experiment with it using a plane you’re already familiar with, so you can really tell what it does. I’d set it at negative 50 percent on one control and do a test flight.

Also, you can set positive expo to ‘increase’ sensitivity in the center. Never tried that, but it is an available option.

If you ever change transmitter brands, and want to set up expo, be sure to check the manual because some brands flip-flop positive and negative compared to Futaba.

hrrcflyer

Flightfreak777,

I agree with what Carrell says about exponential. Please be careful when you set it up in your radio and use a "NEGATIVE" number. As you have learned, you can make the controls more sensative around center. You do this by setting up the expo with a "POSITIVE" number. I made that mistake the first time I set up expo on an airplane and the result was not pretty![:@]. It may also help you see what effect expo has on a servo if you know someone at your field that has a Futaba 9Z or 12Z transmitter (or one of the high end JR radios). These radios have a graph indicating servo movement as it corresponds with stick movement for each channel. The line will be straight if you have no expo set up on that channel. The more negative expo you add, the more the line will bend towards the intersection of the X and Y axis on the graph thereby decreasing the sensativity of the control surface. If you use a positive number for expo, the line will bend away from the intersection of the two axisies increasing the sensativity of the control surface.

If you ask for someones help who has a JR radio, keep in mind that "POSITIVE" and "NEGATIVE" expo inputs have the opposite effect on the channel than Futaba. I hope I have helped you out.

Fly safe and have fun!!
David

rccrazedman

My Feedback: (10)

The best thing is to just play with Expo and find out what it does. Take a plane and set it on your workbench. now turn on your transmitter and add some expo on either your high or low rates side of your switch . for experiementation sake if you have a switch asignability to asign expo to a seperate switch or make your duel rates the same on both sides of the switch and add some expo (more like 80% for experiementation) on the high rate side of your duel rates switch and leave it off on your low rates side of the switch. Now turn your plane on and move the stick back and forth from center to full deflection. now turn your expo on and whach what it does to your control surfaces. just seeing this will much better let you understand what it does and how it helps you.

bgold

Dual rates set the amount of travel you will get at full stick position. Expo is generally used to decrease sensativity at the neutral position of the stick. You can set the amount of expo to different levels for low rates and high rates. I fly mode 1 and elevator and rudder are on the same stick. When I pull evevator my habit is to pull the stick a little sideways also. If I have enough expo in my set up I might not get much if any movement from the rudder even though I moved the stick sideways a little. I know some guys that fly with 80 - 90% expo. Make sure it's a negative setting.