Can you guys explain +expo and -expo and where they may be used.

I believe it depends on the tx. I have both futaba which is -expo and spektrum which is +expo. In a nutshell it allows greater movement on the stick with smaller movement on the control surface. Others will beable to explain it better than I

The proper expotential either + or - for your brand Tx will provide reduced non proportional response near the stick neutral but will provide the total max throw at full stick.

Sometimes this is called soft center. It is benefitial in making smooth control possible on some types of aircraft.

Futaba and Hitec you will want negative expo. Jr you want positive expo and other brands you will have to read your manual. In any case you will never want the 'wrong' expo for your brand radio as this can and will make the airplane possibly even unflyable.

John

Too much of the "correct" expo will leave the radio with a soggy feeling IMO.

its a futaba new 7-cap, whats a good percentage of negitvae expo to use, to soften up the controles a bit, so there not so tuchy?

Usually 20 to 30 percent is a good place to start.

Normally expo would be used on a model with quite control surface deflection to soften response at the mid stick point.

Some caution is needed when using expo for the first time because of the non-linear response, ie the more you move the stick the more responsive it gets. Definitely starting low is a good idea.

Terry

On Futaba, + means that if you move that stick 1/10000000000000 of an inch, that plane is going to react and get out of the way. I usually set mine up initially for-10. I ve flown guys planes with -50 and i am moving the stick over and ov and over to a certain direction and nothing happens until it's darn near to theside. Very sloppy.

sounds good, ill try -10 this weekend, and see how it goes.

Using a 7 CAP on 2 planes with expo set at -40 on both. IMHO smooth as silk! But remember you might also have to lower your throw rate depending on your experience level and type of flying to get a smooth controllable ride.

Just get use to it, Go -10 for a few flights, if it's okay, go further, don't just jump in the lake

I prefer expo over dual rates now. Especially on huge control surface planes.

Actually given that a round servo wheel has a non linear output to begin with, approx -20 to -25 percent actually give you a linear control response.

Thats a good place to start.

It all depends on what you are flying and your flying style.

When you don't understand what expo is in the firstplace why would you want to start off with so much? Hey, not my plane.

I have the Futaba 6XAs radio in an LT-40 trainer. I started with -20% expo on the 3 primary flight controls and fairly low rates. I also had the CG in it's most forward recommended position. Now that I'm comfortable with the plane and doing some mild aerobatics, I've moved the CG ½" aft and bumped up the throws (via dual rates) but left the expo where it was.

The LT-40 when set up for a forward CG and low rates really doesn't need expo. It's a nice feature to have - as long as you're sure you haven't gone the opposite way.