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moss1

What tweak to stop heavy turning tendency in all props?

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Hi everyone,

I want to use Xplane 10 in the worst way, but every add on I have turns way beyond normal, and the amount of adjustments needed are way beyond what I can see as normal. I see this on the dash8, MU2, C208 carenado etc...

Is there a tweak that I could apply to put this to bed once and for all, even if it's not realistic. This is the one and only thing that prevents me from getting any enjoyment from xplane. I have my hardware calibrated. Thanks in advance to any solution. :-)

 

 

Best, Jeff

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Thanks for the link. :-)

Just curious....If the plane doesn't use the SASL plugin, is there a tweak that can be applied in plane maker that fixes this?

 

Best, Jeff

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Even if an aircraft doesn't come with SASL plugins, you simply drag & drop the SASL folder on the aircraft folder and the torque fix sasl script :-) As simple as that :-)

 

I had all of my default X-plane aircraft SASL'ed for the torque tweak :-)

 

In plane maker you can do many different things, but the only one really effective, even if it also compromises other flight dynamics aspects, is to use the Stability Augmentation System.

 

I used it to overcome not only the torque bug but also the overdone effects of crosswind on taxi and takeoff while your wheels are still in contact with the ground ...

 

See here:

 

http://forum.avsim.net/topic/396062-fine-tuning-the-default-aircraft-in-xp10/#entry2562856

 

http://forum.avsim.net/topic/398847-of-course-your-guess-was-right/#entry2587953

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Hi there J.C.,

First, thanks so much for the tips. I did try to fix the issue in two AC so far. The Carenado C208 Caravan and the FlyJSim Dash 8. For some reason, it is still just as bad as before. All I did was add the torque tweak code into the Carenado avionics.lua file as instructed and it remains the same. The Dash 8 I added the the SASL plugin and torque fix, but now the avionics do not work. I am sure in the Dash8 it is because I am not doing it correctly and have to be careful with that product, but the Carenado I am very surprised it did not work at all. Is there a guide anywhere that is available? For example, I watched a video yesterday of X-Aviation's J32 which I do have, and it took off straight as an arrow. I am usually pretty good with working with cfg files and codes, but this has me stumped. I just want to be able to get this issue taken care of so I can use Xplane as much as i do FSX. I must be missing something. Any insight you can give is appreciated beyond words. 

 

Best, Jeff

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Make a backup copy of the DASH8, open in Planemaker and let one engine rotate left and one right. Enjoy your smooth rides.

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The MU2 also takes off straight... - It automatically add's aileron trim when you set the aircraft in the rw ready for takeoff ;-)

 

If you watch a video of a twin / single prop, you can't tell if the pilot dialled in any aileron trim, or if he's moving the yoke / control wheel ...

 

Also, since in X-plane ( just like in MSFS ) setting trim on a mechanical control surface will not make it move when the airflow starts building over it, you will also see no movement starting to happen on the controls in the cockpit :-/

 

Can you send me the lines you added to the Carenado, with that torque fix?

 

Beware that for a twin you need two different variables, one for the left and other for the right props.... and... you have to check if t is CW or CCW. For CCW props the values of the variable have to be negative!

 

P.S.: On what I still consider the best flight dynamics model ever built for a flight simulator, DCS World and for instance it's P51d, correctly shows the effects of seting trim as soon as speed builds up. Even stopped on the floor, if you add significative winds from 12 o'clock, you'll be able to see the control surface starting to move because of the force exerted on it by the trim tab :-)

 

P.P.S: Ralf's suggestion is also very good!  :-)

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Thanks guys. :-)

 

jcomm, I can't thank you enough for all of the insight you take the time to give the community members here. I am at the office right now  :-(  Rainy Monday too....

In any event, I will try this evening to get it to you on here. Thanks again as always!

 

Best, Jeff

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I'll add something of interest.....perhaps..

 

I recently got back into R/C (radio control). So....why not check for "torque"? Afterall, a lot of R/C models actually have higher thrust to weight ratios, than most full size airplanes. Here is what I've tested so far. Hold the planes vertical, with throttle at full, and the fusealage easily wants to rotate opposite of the props direction. That's just as I thought it would.

 

 

 

Rotate off the ground early, and see the left wing dip. Correct with aileron. That's what I'd expect too! For the next test, I trimmed for straight and level flight at half throttle. Then I jammed the throttle full forward, without touching the aileron stick. There was no dip of the wing. No tendency to require aileron correction, and especially aileron trim. That's what I expected too, and have been saying all along. One model actually yawed a bit to the right, because it has some pretty good right offset in the motor mount. All models have some right engine cant. I didn't try the roll on it's back at just above stall speed, because I've done that with models in the past. Some of my smaller models, don't even have ailerons. Just some extra diheadral in the wings, and they turn with rudder. Point is, the lift from the wings, and whatever the spiral slipstream effect is having on the wings and tail surfaces, is enough to easily overcome the effects of motor/propeller torque. What it comes down too, is that I just didn't have to mess with aileron trims at all.........for any power changes. Just like the real planes I've flown.

 

 

 

P.S. I have a big B-25 bomber twin, with an 80" wingspan. Someday, I'll try that one....for torque effects, when I finish it.

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I had all of my default X-plane aircraft SASL'ed for the torque tweak :-)

 

Even the MU-2? Does it work for this plane Jcomm? Cheers Kris P.

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Even the MU-2? Does it work for this plane Jcomm? Cheers Kris P.

 

Nope !  It interferes somehow with it's complex Gizmo plugin. I tried but the results were unexpected... :-/

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Even the MU-2? Does it work for this plane Jcomm? Cheers Kris P.

Edit the Mu in Planemaker, see above. Works great for me.

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Yes, for twins, "Ralf's method" :-) is probably the most efficient one...

 

For singles.... you can add an invisible prop rotating opposite the main one, but that would be rather ... unrealistic :-/

 

... the rest, never mind... :-/

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Also, since in X-plane ( just like in MSFS ) setting trim on a mechanical control surface will not make it move when the airflow starts building over it, you will also see no movement starting to happen on the controls in the cockpit :-/

 

P.S.: On what I still consider the best flight dynamics model ever built for a flight simulator, DCS World and for instance it's P51d, correctly shows the effects of seting trim as soon as speed builds up. Even stopped on the floor, if you add significative winds from 12 o'clock, you'll be able to see the control surface starting to move because of the force exerted on it by the trim tab :-)

 

The  ":-/" emoticon is misplaced. There is not a right (DCS) vs wrong (X-Plane/FSX) modeling of trim behaviour in a pc flight simulator.

 

What we have here is a fundamental limitation, namely the fact that usually a PC flight sim has to be designed for sticks/yokes not capable of force-feedback, nor self-motion. For this reason, the approach used to model trim behaviour in a flight simulator is not univocal.

 

Most flight sims (FSX, X-Plane, etc.) model a "stick fixed" behaviour: the controls will not move unless the user moves the joystick, and the equilibrium position of flight controls is solely determined by trim position, unregardless of the airspeed / AoA.

 

Now, if you think about it, the DCS behaviour is actually not 100% coherent: it considers the effect of airflow on the trim surface, but does not consider the effect of airflow on the complete flight control surface. What I mean is, if the modeling of DCS were 100% coherent, the whole flight surface of e.g. the elevator, would deflect and tend to remain a little deflected in case of a sudden increase in AoA, tending to align with the airflow (this would model the so called "stick free" behaviour).

 

The DCS behaviour, with the trimmed elevator deflecting under the effect of airflow, is, from a practical point of view, not much more than a cosmetic effect. From my experiments, the actual behaviour of flight controls in flight is, in both cases (FSX/X-Plane vs DCS) the "stick fixed" behaviour, that is, the flight surfaces does not react to airflow. Personally, I prefer the FSX/X-Plane approach, that is 100% coherent and where there is a univocal relationship between joystick position and flight controls position.

 

The fact that DCS has more refined flight model is another story and not linked to this trim issue...

 

Marco

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Well .. I used to be a firm believer in the "Torque is modeled correctly" school of thought, but now I'm not so sure .. in fact now I'm trending the other way, with the caveat that (as jcomm's pointed out elsewhere) it's not necessarily torque itself that's modelled incorrectly, but some other limitation in the FM that sets up the torque modelling to have an exaggerated effect on the aircraft's handling.

As I don't have a scientific perspective (not even basic maths and physics .. ;)), I rely a lot on those boffins who do in order to form my opinions, and also on people with real world perspectives to draw upon. It's not real understanding .. it's more of a faith thing lol!

I'm hopeful that this issue will be addressed sooner, because like JComm has said .. this is a flight simulator, and like JComm I sometimes experience an existential meltdown when I consider that the sim I'm flying is a inadequate representation of reality. So .. @ the moment I have 4 sims on my PC ... X-Plane, FSX, P3D and DCS ... and I drift between each as my dissatisfaction with any one set of issues becomes too great to bear.

P.S.

I have completed the following fixes .. and they work to my satisfaction ..

1. JS32 - CW/CCW fix
2. AN-24 - I think was already CW/CWW on my release ..
3. the default C90B - the Torque fix applied to both engines work like a charm .. so does the CW/CCW fix (obviously not both at the same time!)

4. FJSim Dash 8 - CW/CCW

 

** The MU-2 - doesn't matter which tweak I use .. this plane behaves erratically so I'll keep flying it the way I used to .. but my new perspective has spoiled the experience for me!

.. and then for a break I also fly a lot in my brand new Flight1 KingAir B200! Now REALLY I wish they would do some of their magic in X-Plane .. once the torque stuff is sorted .. or design it specifically to behave as it should. Cheers, Kris P.

 

P.S.. We should ask en masse @ Frooglesim's Youtube channel for him to push the question to Austin and Ben .. hopefully he has more traction?

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As I don't have a scientific perspective (not even basic maths and physics .. ;)), I rely a lot on those boffins who do in order to form my opinions, and also on people with real world perspectives to draw upon. It's not real understanding .. it's more of a faith thing lol!

 

 

I put out my thoughts, because I never observed it, in RW flight...........except for the situations as already mentioned; slow airspeed and high power, or pushing the left gear down on the takeoff roll, during a touch and go. And since there are many aircraft I haven't flown in real life, I started asking other pilots, as well as digging up a lot of pilot reports on the internet, in addition to many videos. I've found nothing to imply, that there is a continual force, which needs to be trimmed out, as a normal phase of flight. As airspeed doubles, lift squares. That means that the force of lift is easily overcoming the torque produced by the engine and prop.

 

When I was finally able to ask a friend about his piloting experience with the 2800 HP single engine Skyraider.........and he said that it was "yaw" to worry about on the takeoff roll, and not roll.....my level of being convinced, increased by a larger margin. The Skyraider is included in a group of planes, that could easily roll sideways off the deck of a aircraft carrier, if the pilot punched the throttle after missing the wire. Once again, that's a case of high power combined with low airspeed. In the normal course of takeoff, enough lift is provided to overcome the roll tendencies, once the plane has enough speed to sustain a normal takeoff. Lift is quickly multiplying from that point onward.

 

As to the MU2. I have not talked to a rated MU2 pilot. I've only read articles on the internet and in magazines.

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Thanks LA .. you were actually the catalyst for my developing perspective .. way back when .. and I believe we all got a little hot under the collar .. I owe you an apology! Friends?
 

 

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@Murmur: 

"but does not consider the effect of airflow on the complete flight control surface. " - not true :-) - observe what happens to your other control surfaces as you deflect your rudder wildly... 

 

@pryoski:

 

Just like you I also have a few sims: FSX, DCS, ELITE, X-Plane.

 

My only grip with DCS is that the concept/purpose of that sim is far from what I really like in a sim. I use it solely to be able to profit from what I consider the most advanced flight dynamics model available for a PC sim. There are limitations in that sim though, such as poor modelling of navaids ( can't do a nice IFR flight unless I pick the fancy A10c, ka50 and program their FMSs...).

 

In ELITE I have a rather old-fashioned ( fs4/fs5-like ) world representation, but a tremendously accurate engine and in some aspects also light dynamics model, provided you fly your aircraft inside of the regular IFR envelope. In terms of instruments, and easy reading of them all in the 2D instrument panel, ELITE is also superb! and a great tool to practise IFR, allowing for RWW injection as well...

 

X-Plane 10 is, for me, put on hold again. I'm really becoming tired of some limitations / innacuracies ( some very basic ) in it's flight dynamics / systems / engines modelling and even in terms of how it renders the World around you, models navaids, etc... It has potential, but as far as I am concerned, it is frozen, waiting for Austin to melt it...

 

I gave up on P3D simply because I wanted to have FSX to be able to use aircraft that are not available for the Lockheed platform. Having both would be... a mess for me... FSX is, after all these years and since I started using it, then quited using any sim around 2007, and came back with MS FLIGHT, after all - I'm going to be fulminated by writing this, but I couldn't be more honest... - the most advanced, embracing, complete, civil flight simulator still available ( yes, I have an eye on each new Flight Gear release, I still remember Fly! and Propilot, Flight Unlimited, MS FLIGHT, and a couple of others less known to the public...).

 

So... I would classify mostly as a VERY SATISFIED FSX user, a DCS lover, an ELITE loyal admirer, an X-Plane 10 "hoper" (the word does not exist in english, I believe...)

 

Guys... don't measure flightsims by the number of bits in the address space.... Classify them by how their vehicles behave on the simulated air / space / World as a whole... how accurate, detailled, overwhelming some add-ons can be, the number of available choices of add-ons of quality to suit your needs, and of course their intrinsic potential... 

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Classify them by how their vehicles behave on the simulated air / space / World as a whole...

 

But ..? You've already mentioned that FSX doesn't do multi with engine failure ... even the mighty PMDG 777!

 

I do recognise what you're saying though. I too experience a flight simming induced existentialist melt-down on occasion! :lol:

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Yes, of course FSX has lot's of limitations when we get outside of the "normal" flight envelope (and so does X-Plane 10 ) and has poor engine out effects ( that can be fine tuned and are nonetheless very acceptable on some aircraft ). 

 

:-)

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** The MU-2 - doesn't matter which tweak I use .. this plane behaves erratically so I'll keep flying it the way I used to .. but my new perspective has spoiled the experience for me!

 

In the MU-2 the editing through P-Maker, choosing a combination of CW and CCW also works. Just make sure that when you select the aircraft for flying, and while standing on the rw, you reset the aileron trim to neutral ( I have a joystick button programmed for aileron and rudder trim rest to neutral ), because Tom automatically added flaps and aileron trim for takeoff, to counter the excessive roll due to torque.

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@Murmur:

 

"but does not consider the effect of airflow on the complete flight control surface. " - not true :-) - observe what happens to your other control surfaces as you deflect your rudder wildly...

 

Correction!   Murmur is RIGHT !!!  :blush:

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Regarding the MU-2 .. thanks anyway JComm and Ralf ... unfortunately it appears to be the only plane I have that refuses to cooperate. Your tips did work JComm, to a point. Once I'm climbing or cruiing there is still a small tendency to roll to the left ... but it is a continuous inexorable movement that eventually has me spiralling down to the left if I leave it uncorrected. In other words I'm still unable to fly 'hands off' even after the tweaks! The JS32 and the AN-24 are NOW a dream to fly though! (post tweak):)

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