Exponential

[Fly Boy 3]

Hi all, just wondered if fliers who use exp. on ailerons, also use it on elevator ?  Thanks

[PeterF]

I use it on rudder, elevator and ailerons.

[Jon H]

I rarely use it on anything. I do have 10% on 1 channel each on 2 models as it was just the cherry on top when it came to the setup, but its 2 out of 36 primary flight channels in my fleet. 

 

I would always recommend you start with none, get the rates right (most models are flown with very excessive rates which makes them twitchy) and then add some expo at the end should you need it. When it comes to setting the rates the ailerons are easy as you just keep lowering them until you get the maximum roll rate you want at full stick deflection. Similar story with the elevator, just keep decreasing it until you feel you are running out with the stick hard back, then add a little back in until its comfortable. 

 

I have flown loads of models where you never move the stick in a circle bigger than a 5p piece as the rates are so high. Its not a nice way to fly so drop them down and use the full stick travel instead of expo. 

[Phil Green]

I dont use it on anything. Just move the stick less 🙂

[Philip Lewis 3]

35 minutes ago, Jon - Laser Engines said:

I would always recommend you start with none, get the rates right (most models are flown with very excessive rates which makes them twitchy) and then add some expo at the end should you need it. When it comes to setting the rates the ailerons are easy as you just keep lowering them until you get the maximum roll rate you want at full stick deflection. Similar story with the elevator, just keep decreasing it until you feel you are running out with the stick hard back, then add a little back in until its comfortable. 

 

I have flown loads of models where you never move the stick in a circle bigger than a 5p piece as the rates are so high. Its not a nice way to fly so drop them down and use the full stick travel instead of expo. 

 

I agree 100% with what Jon says above and we both come from pretty much opposite ends of the spectrum, but I do use a lot of expo, but that's in a very specialist type of flying (pattern flying) where I really do want the controls very soft around centre.

 

Same experience as Jon, most club type pilots fly with far too greater control movements making models very twitchy and difficult to keep on a straight line, the other advantage of setting the full aileron by the roll rate you want is that it's easier to exit rolls on point if the roll rate is consistent.  

[GrumpyGnome]

Horses for courses - most of my models now have none, but a few have some, on the control surfaces that need it...... not necessarily all surfaces, not necessarily same amounts on each surface....

[Brian Cooper]

There isn’t an answer that is set in stone. All models fly differently and all pilots have their own style. 

 

Some pilots like to use exponential, and some don't. 

It won't do any harm to experiment with it. 

[Phil Green]

Try flying an aerobat on Reeds!

[Wookman]

Try flying anything on reeds!

[Jon H]

1 hour ago, GrumpyGnome said:

on the control surfaces that need it

 

Agreed. This is the key point though, need. If they need it then by all means go ahead. I have on mine, and its fair enough. My beef is using 30% straight out of the gate while flying around with twice the rates the model needs. This is not helped by donkey recommendations from many kit manufacturers when it comes to both c/g (too nose heavy) and rates. 

 

My order of operation when setting up a model would be c/g, rates, test fly, rates adjust, fly, rates adjust, fly, c/g adjust, fly, rates, c/g, rates etc...with those two set, then expo is the clincher if you need it. 

[Brian Cooper]

8 hours ago, Phil Green said:

Try flying an aerobat on Reeds!

Yeah, done that.... but it was about 60 years ago. 

It was a natural progression from single channel. . . it just needed a delicate touch on the switches to get the best from a model. 

 

Happy days - and I am glad I was there - but digital proportional radios are better. 🤣

[GaryW]

Personally I found exponential rates cause more issue than they solve and I've found over the years dual rates to be way more beneficial when & if needed to be honest therefore I never use exponential rates specially when teaching people to fly in the same way I wud never use a mixer to mix a liitle rudder with ailerons with scale models as I tend to do that manually on the sticks

Edited February 28 by GaryW

[Paul De Tourtoulon]

I did use it in the 1980's when I started flying helicopters but not at all anywhere now, it can be dangerous on the elevator when landing, especially in windy conditions, so NO thanks,,,

[leccyflyer]

I routinely use 35% expo on ailerons and elevator, arrived at by experimentation, as I like the soft feel of the sticks around the centre of their action. That is coupled with tending to set my low rates quite a bit less that the manufacturer's recommendation, as I don't use huge control movement, especially on elevator. Nearly all of my models are set up with High, Mid and Low rates on the same switches on each transmitter and high rates on elevator is mostly used for take off. Most of my flying is done on the low rates, as that is how I like it. I don't set different expo for those different rates.

[GrumpyGnome]

Many many ways to skin this particular cat - definitely no right or wrong! 

[Cuban8]

I don't use expo and don't use rates once I've set the model up to my liking. I've only gone down the expo and rates usage route when I dabbled with some mental funfly models with huge control surfaces.

Edited February 29 by Cuban8

[Brian Cooper]

This is a thread which has been done to death, eh... 🤷‍♂️

 

Personally, I use rates and I use expo. . Both of these useful features are freely available and I make full use of them.

There is no "set" amount to use for an entire fleet of models. ... it depends on the model, the pilot and the style of flying. . Each is different. 

 

There are no wrong answers. 

Use whatever is in your comfort zone. 

[SIMON CRAGG]

On 28/02/2024 at 08:37, leccyflyer said:

I routinely use 35% expo on ailerons and elevator, arrived at by experimentation, as I like the soft feel of the sticks around the centre of their action. That is coupled with tending to set my low rates quite a bit less that the manufacturer's recommendation, as I don't use huge control movement, especially on elevator. Nearly all of my models are set up with High, Mid and Low rates on the same switches on each transmitter and high rates on elevator is mostly used for take off. Most of my flying is done on the low rates, as that is how I like it. I don't set different expo for those different rates.

Pretty much the same here.

 

Its a good facility to have, so I have always used it since it started to appear on Futaba gear many years ago.

[Jon H]

1 hour ago, Brian Cooper said:

his is a thread which has been done to death, eh... 🤷‍♂️

 

Poor Flyboy didnt know that 😉 

 

9 hours ago, Cuban8 said:

I don't use expo and don't use rates once I've set the model up to my liking. I've only gone down the expo and rates usage route when I dabbled with some mental funfly models with huge control surfaces.

 

I use rates alot on the warbird stuff. I normally need more elevator authority for takeoff/landing and have a higher aileron rate to help me out when landing in choppy conditions. The high rate is also there to help me if an aileron servo decides to die as the increased authority will be helpful if i am down to one, and vital if the servo fails when it is not in the neutral position. If it failed at full deflection on low rate, i need a higher travel from the remaining one to stand a chance of over powering it. Sure its a very unlikely scenario, but its not impossible and its just another line of defence against a loss of control. 

[Fly Boy 3]

Correct Jon. My apologies, did not know that this thread was on at a previous time.    Cheers

[Jon H]

Its been done about a million times, usually causes a disturbance in the force once we all get going 😉 

[ron evans]

At the risk of flogging a dead horse, here are a few of my thoughts.

I have a few small e models which are quite quick, but they will fly slowly and land nose high--great fun.

To achieve this I have lots of elevator movement, but this makes the model pitch sensitive at speed so I tried some expo.

This did work fairly well at speed, but I didn't like it at lower speeds, and definitely not to land.

I could have switched it in and out during the flight, but at my age I'm trying to ease the workload on the sticks.

What might work is a variable rate linked to the models airspeed, giving full throw at low speeds, gradually reducing as speed increases.

Don't think I've ever seen such a gizmo, and probably overkill for my simple models, but perhaps the jet boys use something similar, they also have a wide speed range to deal with.

Ron

 

 

 

[Wookman]

If you are using open tx or one of its variants I don't imagine it would be hard to take the throttle setting as a master and mix it to the aileron and elevator throw.

Not sure how but somebody out there will.

[PDB]

1 hour ago, Wookman said:

If you are using open tx or one of its variants I don't imagine it would be hard to take the throttle setting as a master and mix it to the aileron and elevator throw.

Not sure how but somebody out there will.

Yes you can automatically change rates based on other conditions such as throttle position, the telemetry from an airspeed sensor, etc.

 

 

[Jon H]

12 hours ago, ron evans said:

I could have switched it in and out during the flight, but at my age I'm trying to ease the workload on the sticks.

 

Obviously i cannot speak for you but there should be very little workload associated with having a flying rate and a landing rate. Assuming you use the landing rate for takeoff as well its only two switch flips per flight. 

 

Admittedly i am very used to flipping switches as most of my models need me to flip gear up, elevator rates low and timer start all within the first 4 or 5 seconds of the flight. Landing is similar with switch flips needed for gear down, flaps half, elevator rate high, aileron rates as required, flaps full. I make my life easier though by flying a proper landing circuit with points of reference on the downwind for each action. This means each is spaced a few seconds apart giving ample time to keep up with proceedings. in either case, i have a practiced procedure stuck in my head and i never deviate from it. Its 2nd nature and i do not even think about it, i just flip 'em. 

 

While i can understand the desire to keep things simple you can degrade the performance of the model with this approach as the setup is a compromise. Having two sets of rates, or a flight mode for different phases of flight gives you enhanced controllability and hopefully, more enjoyment of the model. My Warbirds would be so difficult to fly/land without having the setup i do and i wonder if this is why so many folk struggle with warbirds. Its not the model, its the setup.