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Expos for 3D flying

Old 03-25-2007, 09:53 PM
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mofosheee
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Default Expos for 3D flying

Can anybody suggest a ballpark expos setting for 3D flying................harriers, torque rolls etc.... Thanks ****sheee
Old 03-25-2007, 10:32 PM
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aussiesteve
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Default RE: Expos for 3D flying

Depends a lot on the plane.
I use 60% to 80% for my true 3d'ers.
It also depends on whether or not you are using dual rates. If I am using them, I typically use around 30% expo with very small throws on low rates and 60% to 80% with maximum throws on High rates.

What plane are you using, or intending to use?
Old 03-25-2007, 10:34 PM
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gjeffers
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Default RE: Expos for 3D flying

on my low throws i have my flying around comfortable throws, and on my 3D i have the throws maxed out and have my expo set at 60% on ailerons, 75%on elevator, and 0 expo on rudder.
these are what i use on my ucd 46 and somewhat close to what i use on my other planes but your personal comfort level may differ a little.

good luck!
Old 03-26-2007, 07:42 AM
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exeter_acres
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Default RE: Expos for 3D flying

its all personal preference, but a good starting point is 1/2 of your end point....


meaning if your end point (ATV) is set at 100, set expo at 50
if end point is at 120, set expo at 60
if end point is at 80, set expo at 40.....

These are just starting points.....
Old 03-26-2007, 11:09 AM
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mofosheee
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Default RE: Expos for 3D flying

Thanks for your input! I am flying a; Hanger 9 Showtime, Saito .82 with 100 oz/in. Futaba servos and the Spektrum DX-7 radio. Trying to perfect my rolling harriers. I'm trying to close in on the envelope of radio settings that will work for me. Thank you. Jerry

On Dual rates I currently have 120% with 50ish expo set.
Old 03-26-2007, 02:16 PM
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mtwister
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Default RE: Expos for 3D flying

I do opposite of what these guys list here, I fly on low rates with higher expo, for smooth imac style flying. On 3D I have max deflection with only 20% expo. This way, in harriers, hovers etc... I don't have to move the sticks alot to get instant movement from the plane. When i'm a foot off the ground, I want the surfaces to move as soon as I move the stick.
Old 03-26-2007, 05:31 PM
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FlooredCOBRA
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Default RE: Expos for 3D flying

Wow, 20% is different. Theres no way I could fly like that with the throws I have. I am so used to moving my sticks fast and lots of movement. 20% would get me into trouble.

That reminds me of when I did a maiden flight on my Shrike and had the expo way to low. From the second it left my friends hand it was over correcting over and over again. That was nuts, luckily I managed to bring it back down and adjust more expo.

I usually fly at around 60% expo on ailerons 45 - 50% on elevator and 10% on rudder. This is pretty much what I use on all planes except a Diamond Dust I had. On that one I had 95% expo on elevons but that was a different type plane.

But like everyone said personal preference. What ever stick movement your used to depends on the amount of expo. A little tweaking here and there and you should have a nice set up.
Old 03-27-2007, 10:39 AM
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buildflycrash
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Default RE: Expos for 3D flying


ORIGINAL: mtwister

When i'm a foot off the ground, I want the surfaces to move as soon as I move the stick.
Expo Does Not make your servos move any slower. Why don't you put in positive expo then?
Old 03-27-2007, 02:19 PM
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mtwister
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Default RE: Expos for 3D flying

I never said it made them move slower, I meant more to the point where I didnt have to move faster. That make any sense?
ORIGINAL: buildflycrash


ORIGINAL: mtwister

When i'm a foot off the ground, I want the surfaces to move as soon as I move the stick.
Expo Does Not make your servos move any slower. Why don't you put in positive expo then?
Old 03-28-2007, 01:01 PM
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marc 540
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Default RE: Expos for 3D flying

On low rates I use very little or usually no expo and on hith rates about 20% on elev. and ail. This is on 3D planes with huge throw's (45-55%) I'm used to flying super sensitive!!

Marc 540[8D]
Old 03-28-2007, 03:59 PM
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daveopam
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Default RE: Expos for 3D flying

Marc 540 must be a pinch flyer. A thumb flyer normally needs more expo.

David
Old 03-28-2007, 04:03 PM
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Steve
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Default RE: Expos for 3D flying

A high expo on high rates will help out when you leave a 3D manuver. I use 60% on high rate so I can fly the plane normally, even if I stay on high rate for the whole flight. Low rate I use about 20% expo for better slow rolls and such.
Old 03-28-2007, 04:10 PM
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Default RE: Expos for 3D flying

If you are doing rolling harriers, you may find too much expo will throw off your timing. I use little to no expo on rudder, and only a little on elevator.
For other 3D stuff, I run up to 80%. Gotta love flight mode switches!
Old 01-23-2008, 03:42 AM
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mofosheee
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Default RE: Expos for 3D flying

****............ are you still there?
Old 01-23-2008, 06:13 PM
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Default RE: Expos for 3D flying

I have been using 20% expo with 45 degrees on all surfaces....And no right thrust with the motor, centered on the firewall, everything centered on my EXflight Yac 74'' and it fly's awesome....0% on rudder.... Kinda weird because lateral balance is off on the ground but in the air it fly's straighter then any plane I have had before...
Old 01-23-2008, 07:07 PM
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wind junkie
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Default RE: Expos for 3D flying


ORIGINAL: daveopam

Marc 540 must be a pinch flyer. A thumb flyer normally needs more expo.

David
Excellent point. I'm all thumbs and use 50% on both elev and ailerons. 35% on rudder. Throws ~50 degrees on all surfaces unless it's a small fast rolling airplane then the ailerons can have less (35 to 45 degrees).

No dual rates for me (never-ever- friggin crash-o-matic switches). If I want to fly pattern, I use a pattern airplane. My OMP Fusion 90 is so smooth with the above settings, it makes me smile pattern style, but I know I'd never win any pattern contests with it.
Old 01-24-2008, 01:29 AM
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bbagle1
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Default RE: Expos for 3D flying

I usually fly with more expo on my low rates like someone else mentioned earlier. I used to use much higher expo on high rates but since I have changed that feels way too mushy for me. I got the idea of using lower expo from a friend who talked to a pilot who flew a 3d demo at a fly in. The demo pilot explained that for 3d he felt much more locked in using no expo and wanted the plane to do exactly what he told it to. I may not have explained it as well as it was explained to me but you get the idea.
Old 01-24-2008, 06:54 AM
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Default RE: Expos for 3D flying

Granted, I am far from a 3D expert, but I have found that I don't like too much expo. I still use quite a bit, but just enough to make the plane flyable around nuetral. If you crank the expo too high up, it will be extremely difficult to get the control surfaces in every position available. Slowly move the stick and all of a sudden, within very little movement of the stick, the control surface will jump from 50% throw(for example) to nearly full throw. If you need 75% throw, your out of luck. In a hover, too much expo can cause the "chase your tail around the sky" syndrome. At least it did for me. Backing off help alot.

Mike
Old 01-25-2008, 08:08 AM
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Default RE: Expos for 3D flying

Expo"nential" is a curve function that is used to control "how much" a control surface, or whatever is linked to that particluar channel moves in relation to the amount you move the stick at a certain point in the sticks range of movement. Usually Expo will only allow you to make one input, but some mixes have 5 point curves that allow you to manipulate the curve so that the arc varies at different points along the range of movement. Most people just use this on helis and throttle curves, but they are in there.


Expo allows you increase or decrease how much the surface moves relative to the center point at a given point in the sticks movement. With zero expo every increment that you move the stick, rotates the servo shaft the exact same amount. When you start to ajust the expo you create a "curve" in the way the servo responds to your stick movement.

What that does practically is change how the plane responds to what you are doing with the sticks. Most thumbs flyer that want to be really smooth add a little expo, like -25 (which is +25 if you fly JR stuff) to soften up the center so that in the range of the stick where you want to be really smooth you do not jerk the plane around with tiny movements.
So to adjust expo for low rates you fly the airplane and see where the plane is jerky and seems too touchy and you add expo until the plane responds smoothly, but not sluggishly to subtle control inputs. Part of getting this right is to set your low rate throw so that you just barely have enough throw to execute the most demadind manuever you do on low rates and no more.

Then for High or 3D rates typically what I try to do is adjust the Expo so that when I am on high rates the plane "Feels" like it is on low rates when I am making small changes but when I want big movement the plane still moves. An easy way to do this is to actually look at the curve on the Dual Rate screen and flip your rate switch back and forth, you will see the curve change as you flip back and forth between low and high rates. Just adjust the high rate expo so that the center of the curve out to about 20% of the range of movement are the same. OF course they will seperate as you move out further on the curve because the end points are different on low rates and high rates.

Once you do that you should just about be able to make an entire flight on high rates and never notice it on takeoff or landing. Before I figured this out there was no way I would ever accidentally land on high rates because the plane would be too twitchy. Now I do it all the time because high and low rates feel so much alike around center stick.


Generally, I use about 25-30% expo on low rates for everything but Rudder which is about 35-50%.
On high rates I am about 75% on rudder and everything else is about 40-50%.
Old 01-25-2008, 08:36 AM
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Default RE: Expos for 3D flying

I found that is is very plane dependent. 40% or -40% expo is way too much on some planes or control surfaces while others need up to 60% for 3D. It is very easy to tell when you have too much expo. You will end up "chasing" the controls. It is easy to over do it on the rudder. With 60% + of expo the first 1/2 inch of rudder stick movement will give you like an inch or two of rudder movement. The next 1/2 in of rudder stick movement will give you 4-6 inches of rudder movement. You end up either giving too little or too much rudder and then trying to correct causing you to chase the controls. This is particularly evident when hovering.
Old 01-26-2008, 11:56 PM
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Stick40
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Default RE: Expos for 3D flying

Im a pincher and i run 0% expo on all the surfaces on my u can do 3d. At first i ran lots of expo but i flew a plane of my buddys that was super sensitive and it grew on me.

Stick 40
Old 09-15-2021, 10:18 AM
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Default Absolutely agree fast response means low expo.

Originally Posted by mtwister View Post
I do opposite of what these guys list here, I fly on low rates with higher expo, for smooth imac style flying. On 3D I have max deflection with only 20% expo. This way, in harriers, hovers etc... I don't have to move the sticks alot to get instant movement from the plane. When i'm a foot off the ground, I want the surfaces to move as soon as I move the stick.
Yes I have 20% on Ailerons for quick response to alternating rolling harriers and 30% on elevator and rudder.

But it's more about STICK time that counts different expo settings can be accommodated with the relevant skill it just makes it a bit more comfortable. NO SUBSTITUTE FOR AIR AND SIM TIME. SIM time for the relevant first steps and hours on sticks and Air time to perfect your model and make it real especially with some wind thrown in the mix. 85 percent of my maneuvers are learnt on the SIM beforehand its an absolute must IMHO
Old 10-03-2021, 08:36 AM
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Default

this could be a pop-corn thread... but it ain't... yet
Some very good comments on expo above, so I won't add any. Dual rate: I'm using a 3 position switch on my DS-24, for all the aircraft I own, including sailplanes. For all of 'em top position of the switch is Takeoff, mid is Flight, bottom Land. For the 3D stuff I use lo (usually 25-35% travel) deflections on the Takeoff and Land positions. Some of the 3D aircraft are quite pitch sensitive, and I end to over control for a landing, the more so if the whole gang is watching Using reduced deflections for landings helps me regain my posture

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