What is Expo? | Quick Tip | Motion RC

Exponential (Expo) is something that is sometimes misunderstood but super helpful to any and all RC Pilots
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#RC #expo #rctip

[@friedlhochhaeuser6707]

After so many years in this Hobby, someone finally explained this to me in simple words!!! Thank you James, great explanation as always!

[@MotionRC]

Not a problem!

[@flyboywbl]

People forget the original reason expo exists, to give a linear response to a turning servo arm. With no expo, the first 1/4 travel of the servo arm produces much more throw than the last 1/4 of servo travel. So while yes, it does lower the sensitivity around the center point, It also gives you more of a linear control throw response.

[@IRBry]

that was what i was looking to understand thank you

[@castekracing]

Two years on you're still helping out! Very well explained

[@wallicimo1]

OUSTANDING explanation! Thank you much.

[@peterfranks7619]

Very good video/ explanation of EXPO. 😊 Thanks. Five stars.

[@MotionRC]

No problem, thanks for watching!

[@johnsons74thsquadron74]

Exactly what I need. I will have a whole line of edfs from you guys within a couple years. I have never had a straight definition of expo.

[@MotionRC]

Glad to help. Never hesitate to ask questions either

[@chrispaul7162]

To all, the Radio Link AT1011 radio, negative expo gives you the graph as shown in this video for less sensitivity on the sticks

[@Tickleme3090]

Great explanation, I'll have to learn if I need negative or positive on my Flysky thank you.

[@KevinSebesky]

Great demonstration of an elusive topic. Nicely done, James.👍

[@user-cc3cq7xi6p]

As usual, straight to the point and helpful information!! Thanks!

[@Daniel_SWE]

These videos are awsome! I had so much problem understanding all the different settings when I started. 🙂

[@Airguardian]

Here's some additional considerations: if you set up your aircraft with very neutral CG balance and large throws (typically for better aerobatic capabilities) you kinda want to boost your expo numbers, otherwise planes may be too twitchy and even unflyable. Also certain models (jets in particular) can have extreme sensitivity to roll, more so if you combine ailerons with tailerons and thrust vectoring nozzles, so adding expo may be the only way to retain a decent precision in your aircraft control without sacrificing full deflections that may still be needed for post-stall maneuvers.

[@txkflier]

The servos that came with my first Kraft proportional radio system back in the late 60’s had a single linear rack output instead of a rotating shaft. Since the pushrod moved in a straight line at the servo and in an arc at the control horn, the control surface moved faster as it deflected further from neutral. That’s how expo works. My next radio was a Heathkit that used Kraft KPS-9 and KPS-11 servos which had dual linear racks and a rotary output. I preferred the linear racks due to the built-in expo they created. My next radio was a Futaba FP-T7FG/E which came with rotary output servos. The “/E” meant expo. Futaba also sold the radio as an FP-T7FG/K. The “/K” version had dual rates. They didn’t come with both expo and dual rates because they weren’t computerized; they only had one set of potentiometers. Since I liked expo better than switching rates, I chose the expo version. On my current Spektrum radios, I use a stick position switch on the rudder to put my elevator and ailerons into high rate for spins and snap rolls..

[@ronsrs6151]

Great explanation! Thanks

[@DadsRCHangar]

Great teachings James 👍🏻

[@olsonaviationcrewchief115]

Go explanations thanks James. Keep up the little tips👍

[@ricardomaduro2042]

awesome illustration and explanation of this topic. Lovely ..

[@georgewatts9361]

Great job James

[@AdilErtKaya]

Thank you❤

[@davidmcclain5180]

This is an excellent explanation of Expo especially for me as new flier

[@MasterClassComments]

Another name for expo that some ppl may know is 'dead zone'

[@stigonutube]

cool Thank's for the video thumbs UP, now i understand that function, as beginner the E6 transmitter with E120S heli is super touchy in middle and got me correcting constantly "not fun" as beginner it is already hard enough, hehehe now to try this out at -20 exp tomorrow..

[@JeffsCustomRC]

Great demo and explanation James!! I personally fly with 30% on most planes and find it allows me to fly pretty scale especially with warbirds. Thanks for sharing 👊🏼👊🏼

[@MotionRC]

Thanks Jeff! With Warbirds I tend to do more on the rudder to help on the ground

[@MrRquietstorm05]

Thank you .. very informative..

[@reignman0311]

Expo is for ppl that learned with computer controlled radios, us old timers flew without it,but still helpful,lol

[@gregpopp4847]

Great explanation !

[@stainjah]

Oh deadzone. :P last piece of the puzzle. Thanx 👍

[@MotionRC]

No worries!

[@boldlionpro2814]

Thank you thank you 🙏🏼

[@kwcnasa]

Rc model plane tips, very important and useful, about expo (similar to Assetto Corsa gamma settings).

[@markymark3075]

Thanks!

[@DaveItYourselfChannel]

NIIIIIIIIICE tip! 😁👍

[@VIDEOLA1]

Thanks!! 👍🏽

[@georgewatts9361]

Great video James

[@MotionRC]

Thanks George!

[@ChrissiRC]

Great video 👍👍

[@jimnardone32]

very helpful

[@graywoulf]

Thank you for helping me wrap my head around using expo. I will try it out for sure on my simple 3 channel foamies that I crash too often because I am not using expo. Should I use the same expo on both my rudder and elevator?

[@MotionRC]

I do when I start out with a plane and adjust depending on how it flies. Some planes I have more expo in aileron than anywhere else, others are different

[@joeflyer1]

I have three E-Flite models, and all the manuals have recommended expo settings.

[@MotionRC]

I know some do, but it is a weird thing to put in a manual because expo won't affect how the plane flies, just how the pilot who flies it flies.

[@paulballard4243]

I have nerve damage and arthritis in my hands so I am twitchy. I have 50% expo with 100%, 75% and 50% rates. Depending on the plane I will adjust all of that. I’m working my way down in expo slowly

[@PatBALEX]

Nice video James.. I've been flying R/C for 30 years and I never used Expo.. I'm old school..

[@txkflier]

You must still be flying pattern planes from the 1970's and not 3D planes that have elevators and rudders that are more than 30% of the total surface area..

[@MotionRC]

I know a few guys who fly terrific and never use expo. They just have great muscle memory and no shakes (I drink too much coffee ;))

[@txkflier]

@@MotionRC I know guys that fly 3D planes with expo only and no rates. And it looks like it. They couldn’t fly straight if their life depended on it.. ;-)

[@georgewatts9361]

I tend to fly 3D with just expo.

[@txkflier]

On a plane where the control surfaces are fairly small, I set the expo to 1/4th of what the rate is. So for a high rate setting of 100%, I use 25% expo. If the low rate is 60%, I'll set the expo to 15%. On 3D planes with large control surfaces, I set the expo to 1/3rd of what the rate is. So if high rate is 100%, I'll set the expo to 33% and if low rate is 60%, I'll set the expo to 20%. These are my initial settings for the maiden flight. After setting the rates and linkages for what I want the plane to do at full stick deflection, I'll go back and look at the expo settings. If it's too touchy around neutral, I'll increase the expo some and if I'm having to move the stick too much around neutral, I'll decrease the expo some.

[@nutleighgrove3658]

Hey great video ! 👍🏻 Does the the expo setting affect yaw, pitch and roll all in one? 🚁

[@MotionRC]

no, you can set different expo setting for each control surface. some like more on the rudder and less on ailerons etc...

[@joeys5429]

Your supposed to add rudder as well as airalon on a loop to

[@capnhardway]

I'm new and older the old new guy lol, thank you I've just started into rc seriously with spektrum and I'm learning somewhat the hard way how to set the rates and reduced the rates that were in my 3D plane that i was finding it easier to control. Thank you for clarifying somewhat the secret of rc/ expo lol😂

[@colinmacneil3497]

So quick question .I'm new at this and am flying a foam trainer (super cub) on beginner mode...but have a spektrum dx6e, do I need to adjust these or wait till I move to expert mode?

[@MotionRC]

Hard to say really. Expo can vary plane to plane, person to person. Something like an easy trainer cub like you describe is easier to fly without expo as the plane itself won't make sharp movements whereas if you were flying a short coupled wing aircraft, those same movements made on a cub would be devasting in the air. If you can fly the plane well without Expo then try to put some expo in to see if you can feel the difference.

[@davidcarroll2035]

Thanks, I’m just beginning and all I’ve done up to yet is spend. Lol, I haven’t even flown yet in truth, I’ve got a local club lined up and I’ve done the uk’s online multiple answers test and paid my registration fee, I’ve bought 3 planes up to yet that I’m praying will serve me. First I bought the hobby zone Sports Cub S V2 micro, then I’ve bought the Arrows Bigfoot 1.2 and the E flight Crescendo Evolution, and also because I’m Apple when it comes to computers I’ve had to buy a PC Laptop to go with the RealFlight 9.5s kit including the controller. I forgot to mention the second hand DX8 transmitter to put them all on. You may wonder why all this and no flying yet? Good and fair question, and the answer is my health, I’m disabled and any trip out causes me severe pain, I cannot stand unaided but I could sit in a chair for an hour on a good day. All my old hobbies have been taken away from me and I so wanted an hobby I could share with my Grandson so this is it. Sorry for all the background but just saying thanks without explaining why your video is so helpful to me wouldn’t be enough. I’m hoping an Autumn and winter on realflight will be enough to start flying next spring, God Willing of course. I’m about skint now and my wife has moaned about what I’ve accumulated up to yet but I’m thinking one more purchase… and that’s the Eflite Aero Scout. What is your opinion on this? Dave

[@meticulous_al]

Hi James, you left out the real and main reason why Expo was created. Expo was created because a servos travel is not linear and travels in a rotary "ARC". At the the beginning of the servo travel there is more control surface movement and less control surface movement as the servo reaches the end of its travel. It is a geometry thing. Expo was created to decrease the travel at the beginning to match the travel and the end, so you have the same control surface travel through out the linear stick movement.

[@txkflier]

The pushrod hole in the control horn also moves in an almost identical arc (depending on the length of the servo arm and control horn). If the two are equal in length, 40° of servo rotation will cause 40° of control surface deflection and 20° of servo rotation will cause 20° of control surface deflection. So, without expo, the travel is linear. The purpose of expo really is to introduce non-linearity that makes your plane less touchy around neutral.

[@RARenfield]

There ya go.

[@tonydeaton1967]

Some warbirds are almost unflyable without expo.

[@unknowninvictus2520]

I have a question, how does expo interact with rates. Does the expo get applied on the new rates or do the rates get applied to the already existing expo curve? Edit: it would be logical that the rates shrimp the expo curves and do not get recalculated as that gives the same thing. But nevertheless those can come in handy since rates basically increase or decrease total elektronic resolution of the controller.

[@MotionRC]

Expo will not inhibit the rates, it will only dead the movement around the middle of the stick for whatever rate you apply it too. On most transmitters, you will be able to set an expo for any given rate. So, for example, you may have an aerobatic high-wing cub with high rates (for stunts) and low rates (for relaxed flying). You could set more expo for the high rate setting so the sticks aren't too sensitive during high rates, and a low expo on your lower rate as the control surface deflection will be smaller anyway. It's all about a feeling and experimenting with it to suit your flying style and what the aircraft can accomplish for you

[@JB73691]

Dual rates please/.

[@spencer-rowe8743]

What expo would you suggest for jets?

[@txkflier]

I use 1/4th to 1/3rd of whatever the rate is. So, if the rate is 100%, divide it by 4 or 3 and use 25% or 33%. See how it feels and adjust as desired. Expo comes down to feel and everyone is different..

[@v.e.7236]

Couldn't you mitigate the excess throw by adjusting the rates, thereby by-passing the EXPOs altogether?

[@MotionRC]

Its not about the overall throw, its about the movement in the middle of the sticks. I use the same expo whether my rates are 100% or 50%. That won't change the curve, just how far the surface moves at the max end of my stick movement

[@v.e.7236]

@@MotionRC Thanks for the explanation. A little smarter every day.

[@Ozzy50]

Is this the same as saying "high rate and low rate?"

[@Ozzy50]

I continued watching the video. You kinda answered my question. So it ain't the same. Rate is the amount of throw at full stick. Can someone confirm that? Lol thanks. I'm new to the hobby

[@f1matt]

@@Ozzy50 yes

[@MotionRC]

Next week's video is about rates! Expo and Rates are definitely different. Rates will lower your level of deflection of a given servo movement, expo doesn't change the full movement of a servo, just how "fast" you get from end to end

[@ignaciovera8107]

Me seeing the youtube image front page of theis video: S T O N K S

[@MotionRC]

Subliminal messaging...(I wish my stock charts looked like these)