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What's Better, Expo or Dual Rates? Both Together?

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What's Better, Expo or Dual Rates? Both Together?

Old 03-30-2018, 03:41 PM
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Default What's Better, Expo or Dual Rates? Both Together?

Frankly, I hate expo. It makes me feel, not connected to my airplane. ESPECIALLY in scale jets. I never use expo and only use dual rates. If my jet feels too twitchy, I'll hit the less is more switch.

There are guys like Ali and Dave Shui, whom you can just hand over a transmitter and they can fly what ever, and in any configuration it seems like, lots of expo, little expo, big rates, low rates, etc....

Is it really all subjective? Kinda like thumbs vs stick grippers? What say you?
Old 03-30-2018, 03:47 PM
Edgar Perez
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I was told once that David Shulman used 90% expo in a Shockwave 😳.
I think expo allow you to do very small corrections, while still having access to bigger throws without needing a switch.
Old 03-30-2018, 04:52 PM
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Niether....flight modes or conditions depending on your brand of radio is the way to go on jets.
Old 03-30-2018, 05:11 PM
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Two completely different things and they can be used independently or together. Expo allows you to adjust the feel around center stick without affecting maximum throws and dual (triple) rates allow you to adjust the maximum throws, which indirectly adjusts feel around center stick. You can even add in flight modes for extra versatility.
Old 03-30-2018, 05:55 PM
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I use both, I tend to run more expo when on higher rates. Expo will change your stick input from linear to more of a curved input. Dual rates actually comtril How much total movement you have on that setting.
I also use flight modes as well, following my flaps usually, except on my 16, no flaps so my flight modes follows my gear switch.
Old 03-30-2018, 06:01 PM
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I never use DR, just start at 20 - 25% expo on everything, and usually this ends up feeling just right ... works when really slow, or stupid fast. I tend to fly a little on the "twitchy" side, and 20% does not mush center out too bad. I really do think it is a preference of personal taste however . I have flown other peoples planes that I know are nimble and quick, but they way they are set up makes them feel like oversized cows. It really is incredible how set up can make for a totally different jet between different settings .

Old 03-30-2018, 06:45 PM
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I don't use either one. I set up dual rates, but I never switch from high rates. Whenever I try to use expo I always crash (yes, I know its me). I don't like the feel of expo.

So now I set up all my planes for dual rates in case I ever need it. But I have yet to use low rates.

The guy who helped me get into jets always use full rates with a lot of expo (so do a lot of other people I know). That way you can have both without having to worry about remembering which switch you put it on.
Old 03-30-2018, 06:54 PM
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I can fly without anything but when it comes to scale a small
amount of expo is nice to keep the flying smooth. I don’t really run gyros so it helps, and high speed servos can be a bit fast for scale or any jets. It’s just a tool to help not required to fly.
Old 03-30-2018, 10:00 PM
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As mentioned above, expo is to keep the flying smooth, I use both, around 25% on low rates and about 35% expo on high, on my Boomer I fly high rates on the elevator with 35% expo, on the final flare I keep ballooning a bit so, I will increase the expo to 40% to make the elevator a bit softer, on the ailerons I use low rates with 25% expo.

I had a gas airplane that I was flying on high rates on elev and aile with about 40% expo, I was comfortable flying it like that.

I made a conscious decision some time ago to only fly high rates with expo because it is simpler to fly that way, so far I'm half way there making the switch.
Old 03-30-2018, 10:04 PM
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Yup, sounds like the weathering thread: we all have our preferences!
Old 03-30-2018, 11:11 PM
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No right or wrong, but guys with expo are usually smoother to watch, I guess it’s how your brain is wired and if you are a nervous ‘twitchy’ hand person, a little expo stops the tiny movements you would see in flight. BVM seemed to have designed aircraft that were soft around the center, so expo was not required for some people. The CARF Ultra Flash is very sharp around center stick, so smoother with expo. Now so many models use gyros, that acts like expo.

i set my models up with as much movement as required for every flight manoeuvre and expo to balance the feel between the two main controls on my mode 2 stick set up. Then I just have gear and a flap switch to drive during a normal flight.
Old 03-30-2018, 11:31 PM
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+1 (except I am mode 1)
Old 03-31-2018, 04:08 AM
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I always start with the settings the manufacturer recommends in the airplane manual. As I fly over time I adjust each surface for what feels better to me - almost uniformly a reduction in expo. I always have three levels of dual rates and eventually adjust them so the mid level is for my basic flying. If I need more or less for some reason (something happens to the plane, conditions change suddenly) I have options. Airplanes with very large flight surfaces generally need more expo as in 3D propeller planes.

I even use negative expo often in the elevator for inverted flight when pushing the stick. You can program positive expo when pulling the elevator and at the same time negative expo for pushing it in Spektrum transmitters.

Gyros add expo. If my craft has a gyro I usually have no expo in the mid rate setting where I normally fly. But I have expo added in at the low and high rate settings in case I want to turn off the gyro.

Old 03-31-2018, 01:38 PM
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To me the two key words here are - human error. I've seen quite a few models crashed with the pilot's excuse
being 'I forgot to switch to (insert high or low) rates'. Expo for me, lots on rudder.

I was once told by a well known pattern flyer that with rotary servo outputs you actually need about 20% expo to
defeat the negative expo that the linkage geometry creates & bring control response back to linear. Think about it ......
Old 03-31-2018, 04:55 PM
Doug Cronkhite
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I use both.. The problem with using only expo is when you have to use a lot of it to tame something down.. There is a point where a 'knee' develops in the curve, and the control throw increases at a rate MUCH too high to control reasonably.. Except for 3D rates on an aerobatic airplane, I never really get above about 20% on any surface.
Old 03-31-2018, 10:39 PM
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I used to use dual rates but as my jets got faster and faster and me feeling more comfortable with high speeds, I started to use Expo, and conditions/flight modes. For landing I like to use 10% or less expo so i have more linear feel of the elevator. All this is subjective and learned.
Old 04-01-2018, 04:17 AM
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I use 25% expo There is a lengthy technical explanation why, but the important thing is that It feels better to me.

Dual rates: I only use them in maiden flights.. 2 or 3 chances to get the right amount of response on the first flight. After this, I disable the dual rate function, and fine tune the single setting per axis.

Some gyros have some built in expo, gain settings etc that changes the response of the model. Then I suit the tx setting to match the 25% expo feel . Most times is getting very low values in the tx.

Servo speed response: Its extremely important! some times even more than expo and dual rates, but as said in english, is another can of worms. :-)

Happy easter to all, Enrique.

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