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Trim changing for non-FFB joystics


Yo-Yo

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Gentlemen, I'd like to gather your opinions about one more or less important thing regarding trim point changes due to external reasons.

For example, if flaps are lowered, the stabiliser downwash changes and thus elevator neutral hinge moment point changes. It's quite simple and natural for FFB joystics but for non-FFB device it is not so obvious.

In fact, now we have to use a hybrid model for these devices - it is not purely force based, rather position based, but the central joystick position is always a zero force position. Changing the trim with fixed joystick we imitate force changing.

 

Now, imagine that the neutral point of the real stick is changed due to lowered flaps. Generally, in the real plane (or if you have a FFB device) if you want to hold elevator (stick) position you must apply pulling force. But you feel that the stick does not move.

If we decide to implement this feature for non-FFB device it would be necessary to really PULL and MOVE the stick changing its position that does not correspond with a real plane control input...

 

But without it you will never see pitch-down movement...

 

And that is the problem... :)


Edited by Yo-Yo

Ніщо так сильно не ранить мозок, як уламки скла від розбитих рожевих окулярів

There is nothing so hurtful for the brain as splinters of broken rose-coloured spectacles.

Ничто так сильно не ранит мозг, как осколки стекла от разбитых розовых очков (С) Me

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So, if this is implemented, non ffb users would have to either hold the stick forward or back to keep the stick centred?

 

Could we fix this by adding required elevator trim?

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So, if this is implemented, non ffb users would have to either hold the stick forward or back to keep the stick centred?

 

Could we fix this by adding required elevator trim?

 

Yes, but the problem, as far as I can see, is that as you intentionally trim the plane you anticipate the required stick movement, in the case of flaps lowering the effect can be very fast and will require fast reaction with the stick first and only then - with the trim wheel.

Ніщо так сильно не ранить мозок, як уламки скла від розбитих рожевих окулярів

There is nothing so hurtful for the brain as splinters of broken rose-coloured spectacles.

Ничто так сильно не ранит мозг, как осколки стекла от разбитых розовых очков (С) Me

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Yes, but the problem, as far as I can see, is that as you intentionally trim the plane you anticipate the required stick movement, in the case of flaps lowering the effect can be very fast and will require fast reaction with the stick first and only then - with the trim wheel.

I see. I guess at the moment we don't really have a problem as the Mustang, 109, and 190 all have flaps that extend rather slowly so it's easy to adjust. As far as I know the Spitfire's flaps extend rather quickly so the adjustment would have to be abrupt? Is this why you are bringing up this topic?

 

For what it's worth, I have a non FFB stick and I have not had problems with lowering flaps in the Spitfire in CloD. You get used to the effect rather quickly. It is a whole different sim though so of course there could be differences.

 

Flare

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I see. I guess at the moment we don't really have a problem as the Mustang, 109, and 190 all have flaps that extend rather slowly so it's easy to adjust. As far as I know the Spitfire's flaps extend rather quickly so the adjustment would have to be abrupt? Is this why you are bringing up this topic?

 

For what it's worth, I have a non FFB stick and I have not had problems with lowering flaps in the Spitfire in CloD. You get used to the effect rather quickly. It is a whole different sim though so of course there could be differences.

 

Flare

 

I am not sure the CloD Spit had accurate trim like real... And, yes, the reason is that the Spit lowers flaps very fast.

Ніщо так сильно не ранить мозок, як уламки скла від розбитих рожевих окулярів

There is nothing so hurtful for the brain as splinters of broken rose-coloured spectacles.

Ничто так сильно не ранит мозг, как осколки стекла от разбитых розовых очков (С) Me

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I am not sure the CloD Spit had accurate trim like real... And, yes, the reason is that the Spit lowers flaps very fast.

 

Using the elevator trim to land would also be tricky because, according to the Spitfire IX's Pilot's Notes:

 

The elevator and rudder trimming tabs are powerful and sensitive and must always be used with care...

 

there is nothing in the PNs to suggest that the tabs were ever used during landing.

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Using the elevator trim to land would also be tricky because, according to the Spitfire IX's Pilot's Notes:

 

 

 

there is nothing in the PNs to suggest that the tabs were ever used during landing.

 

It requires very small movement... so it would be the first palne I could recommend to use curves :) long stick owners can be happy now :)

Ніщо так сильно не ранить мозок, як уламки скла від розбитих рожевих окулярів

There is nothing so hurtful for the brain as splinters of broken rose-coloured spectacles.

Ничто так сильно не ранит мозг, как осколки стекла от разбитых розовых очков (С) Me

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My opinion is there is no way to know for sure. I'll have to try it out to know . And also personal preference counts.Someone might find it better, more realistic.Others not so much.

Like when driving a motorsport competition car .Some tap the accelerator(bam bam bam) ,some press it smoothly .

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Gentlemen, I'd like to gather your opinions about one more or less important thing regarding trim point changes due to external reasons.

For example, if flaps are lowered, the stabiliser downwash changes and thus elevator neutral hinge moment point changes. It's quite simple and natural for FFB joystics but for non-FFB device it is not so obvious.

In fact, now we have to use a hybrid model for these devices - it is not purely force based, rather position based, but the central joystick position is always a zero force position. Changing the trim with fixed joystick we imitate force changing.

 

Now, imagine that the neutral point of the real stick is changed due to lowered flaps. Generally, in the real plane (or if you have a FFB device) if you want to hold elevator (stick) position you must apply pulling force. But you feel that the stick does not move.

If we decide to implement this feature for non-FFB device it would be necessary to really PULL and MOVE the stick changing its position that does not correspond with a real plane control input...

 

But without it you will never see pitch-down movement...

 

And that is the problem... :)

As a user of a non-FFB joystick, my choice would be for the pull and move solution.

I know it is not ideal, but at least I would get an indication of the changed trim that I would otherwise not have.

 

Maybe a combination with the Kurfürst stick force solution, where you need to move your joystick more, in order to simulate harder pressure on the control surfaces?

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Fly for long time with non FFB joystick and now FFB joystick for some time.

But when you recive in Flight realy neutral point flight condition, allways trim my plane slightly you have to pull or push light force on the joystick control, in the real neutral state plane suffers allways from aerodynamic force and is tend to go up or down.

Dont feel that an issue because allways awaiting with force on stick with open landing gear and flaps center of gravity and forces are moving, feel more realstic then nothing happen because stick is still in neutral point.

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It requires very small movement... so it would be the first palne I could recommend to use curves smile.gif long stick owners can be happy now smile.gif
Proud and happy owner of a long stick :D. I think movement would be fine to simulate the force needed to hold the stick, but hard to tell without giving a try on how it will work, how sudden that pitch change is and how much I'll have to move my long stick so I can't know if it'll be comfortable and manageable or not.

 

S!

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If we decide to implement this feature for non-FFB device it would be necessary to really PULL and MOVE the stick changing its position that does not correspond with a real plane control input...

 

But without it you will never see pitch-down movement...

 

And that is the problem... :)

 

Its a realistic handling feature so I would like to see it implemented.

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This has been an issue that raised discussions in flight sim forums in the past. If I understand correctly, IRL, when flaps lower, the stick moves automatically to the new neutral position, and the aircraft pitches down a bit. Pitching down essentially happens in relation to this forward motion of the stick.

 

In most sims, flap lowering is associated with a pitching up of the plane, and this is the result of the joystick remaining in "virtual neutral" position which is now a "pull back" position in reality, but player has no input of this, correct?

 

If I understand the question : the "joystick's hardware neutral" is modelled in a way that it always corresponds to the "zero-force in reality" neutral position. So, Spit pilot flies trimmed with stick in neutral position, then lowers flaps, real stick moves forward a bit - joystick remains in neutral position but now its neutral corresponds to a forward position in reality, aircraft pitches slightly down and elevator trim is applied to counter for it.

If IRL a pilot chooses to maintain stick in the pre-flap lowering position, he has to apply some force, and this would mean that he is attempting a pitch-up maneuver while lowering the flaps. Such an intention, in the new-simulated center position, should translate to a pull-up motion of the joystick.

 

If the recentering algorithm works well and the input required is not very abrupt, then, yes I would prefer it. It sounds more realistic anyway. IRL, the pilot would be trying to pitch the plane up by holding the stick, so in a joystick we should be pulling back.


Edited by airdoc

The three best things in life are a good landing, a good orgasm, and a good bowel movement. The night carrier landing is one of the few opportunities in life to experience all three at the same time.

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This has been an issue that raised discussions in flight sim forums in the past. If I understand correctly, IRL, when flaps lower, the stick moves automatically to the new neutral position, and the aircraft pitches down a bit. Pitching down essentially happens because of this forward motion of the stick.
If I understand what Yo-yo explained, it isn't that IRL stick moves "automatically", it's that stick keep its position but you feel the pressure and have to hold it to keep that position. In a simulation the pressure can only be simulated in FFB, but without FFB the only way is to really "move" your stick to look like a pressure even though that movement isn't real. The question is if we would like to see that fake movement to simulate the real pressure, or the stick keeping it's position but lacking the RL pressure modelling.

 

In most sims, flap lowering is associated with a pitching up of the plane, and this is the result of the joystick remaining in "virtual neutral" position which is now a "pull back" position in reality, but player has no input of this, correct?
In most sims flaps lowering is associated to a pitch up due to a principles of flight misunderstanding, they think "flaps rise lift so nose has to rise also" while IRL flaps rise the lift so you need less AoA thus nose goes down… that's the difference between a simulator and amateur arcadish games :music_whistling:.

 

 

S!


Edited by Ala13_ManOWar

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In most sims flaps lowering is associated to a pitch up due to a principles of flight misunderstanding, they think "flaps rise lift so nose has to rise also" while IRL flaps rise the lift so you need less AoA thus nose goes down… that's the difference between a simulator and amateur arcadish games :music_whistling:.

S!

 

You may find interesting an experiment comparing the behavior of a Yak-52 to a simulated WW2 airplane. The pilot was asked to forcefully keep the stick at the same position after lowering flaps in order to check the airplane behavior (this is exactly what Yo-Yo is referring to in his question). The result was a pitching up of the airplane -something that is seen in most ww2 sims. This is essentially what happens because of our non-force feedback joysticks, as they are maintained in the hardware neutral position. In reality, the stick automatically moves forward because of flow downwash, which changes the pressure on the elevator, felt at the pilot's hand. Pilots do not oppose it, and the aircraft pitches down as a result. Maybe there are some differences among planes.

 

There is a whole discussion in another forum about it; i ll just post the link to the video here because it maybe of help.

 

[ame]

[/ame]
Edited by airdoc

The three best things in life are a good landing, a good orgasm, and a good bowel movement. The night carrier landing is one of the few opportunities in life to experience all three at the same time.

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You may find interesting an experiment comparing the behavior of a Yak-52 to a simulated WW2 airplane. The pilot was asked to forcefully keep the stick at the same position after lowering flaps in order to check the airplane behavior (this is exactly what Yo-Yo is referring to in his question). The result was a pitching up of the airplane -something that is seen in most ww2 sims. This is essentially what happens because of our non-force feedback joysticks, as they are maintained in the hardware neutral position. In reality, the stick automatically moves forward because of flow downwash, which changes the pressure on the elevator, felt at the pilot's hand. Pilots do not oppose it, and the aircraft pitches down as a result. Maybe there are some differences among planes.
Mate, I know the vid, I know BoS is wrong, and I know how it works.

 

Of course there is an initial nose lift, but that's only minimal and happens for a few seconds, the later and definitive state is a nose down pitch and never ever the few seconds pitch up while flaps are moving and aircraft slowing down, the moment at what you feel a pressure in the controls you have to counter to keep it steady (or gently back the throttle to revert when it's over). I have played with that myself many times in the Cessna as it helps you enhance the runway line of sight but full flaps makes you flare almost horizontally what rises the prop strike chances and you have to carefully watch it out for the aircraft owner's sake if you like your balls in place. So yeah I'm really aware of how it works :lol:,

 

665488_4594816700936_1437815280_o.jpg

 

 

 

And no, Yo-yo isn't asking anything related to this. Just, would you like a fake controls movement to simulate the pressure or the real non moving controls but without feeling the real pressure?

 

S!


Edited by Ala13_ManOWar

"I went into the British Army believing that if you want peace you must prepare for war. I believe now that if you prepare for war, you get war."

-- Major-General Frederick B. Maurice

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And no, Yo-yo isn't asking anything related to this. Just, would you like a fake controls movement to simulate the pressure or the real non moving controls but without feeling the real pressure?

 

S!

 

I 'm not sure it is that simple. The way I understand it is that without the "joystick-hardware-null-position-always-corresponds-to-zero-force-position-IRL" novel algorithm, we would always see a pitching up with flap lowering, and perhaps it is this that Yo-Yo refers to as "never see aircraft pitching down". With the algorithm, we would see pitching down, but we would have to apply back pressure on the joystick, which IRL would not correspond to stick movement.

 

As far as I can tell, the question is "would you rather have unrealistic joystick movement or unrealistic aircraft behavior with flap lowering?" For this I 'd choose the first, because as I said, a pilot applying force to the stick to keep it centered, is essentially trying to pitch the plane up when lowering flaps. It sounds more intuitive to have to do this if you intend to pitch up, instead of always getting a pitch-up attitude when lowering flaps while you rest your hand on the neutral stick position. Perhaps I 'm wrong though, please correct me.

 

As for the video comment, it's a long story, I won't get into it, because it can easily derail the thread to another aerodynamics discussion.

The three best things in life are a good landing, a good orgasm, and a good bowel movement. The night carrier landing is one of the few opportunities in life to experience all three at the same time.

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I 'm not sure it is that simple.
What I'm sure is Yo-yo's question was that simple :smilewink:.

 

 

The way I understand it is that without the "joystick-hardware-null-position-always-corresponds-to-zero-force-position-IRL" novel algorithm, …
What I'm not sure is DCS works like that any more.

 

 

 

 

As far as I can tell, the question is "would you rather have unrealistic joystick movement or unrealistic aircraft behavior with flap lowering?" For this I 'd choose the first, because as I said, a pilot applying force to the stick to keep it centered, is essentially trying to pitch the plane up when lowering flaps. It sounds more intuitive to have to do this if you intend to pitch up, instead of always getting a pitch-up attitude when lowering flaps while you rest your hand on the neutral stick position. Perhaps I 'm wrong though, please correct me.
No, Yo-yo never said aircraft would perform unrealistically, he's just asking the users' opinion on the way you'll feel that behaviour in your controls, faking a controls movement that isn't there IRL or eliminating the real pressure you can't feel without FFB.

 

 

Mine is Joystick movement is a minor issue but we should feel that pressure one way or another without FFB although hard to tell without giving a try. That's all.

 

 

S!

"I went into the British Army believing that if you want peace you must prepare for war. I believe now that if you prepare for war, you get war."

-- Major-General Frederick B. Maurice

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If I was to choose I would make it as every other DCS model for sake of standardisation. Also, I am fairly certain that in DCS p51 flaps dropped mean it is harder to pull full deflection, especially noticeable when curves are applied.

I would rather go for feeling the change than nothing at all.

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Sorry for being late to the party but my vote is that lowering flaps should affect the elevator hinge moment meaning I think the virtual stick should move to a new position as governed by the altered downwash due to the new flap position. I think this would make sense since this is what happens already if you trim a virtual aircraft that has trim tabs on the elevator (like the DCS P-51): Even though you don’t move the position of your controller, the virtual stick moves due to the trim tab deflection. So I think if the elevator hinge moment is changed, be this due to a trim tab deflection or flap deflection, the result should be the same. :)

 

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If we decide to implement this feature for non-FFB device it would be necessary to really PULL and MOVE the stick changing its position that does not correspond with a real plane control input...

 

 

In CloD - after TF fixes - is in that way, lower flaps make nose heavy and affect trim, need move a non FFB stick/adjust the trim.

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My feeling would be to have the sim act the real thing in regard to FFB and the virtual (in cockpit) stick and the RL forces which affect...

 

Hopefully stick makers could include FFB in the future for higher end HOTAS' as standard (cheap sticks with ffb, are really bad, for what the user really wants to achieve), alleviating the non-ffb sticks' at center for neutral force after trimming. Compensating is rather easy, even if it doesn't "look" right

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Hopefully stick makers could include FFB in the future for higher end HOTAS' as standard ...

 

Highly improbable that some joystick brand will venture in Force Feedback joystick for flight games after Logitech failure/debacle, due licenses involved:

 

https://en.wikipedia.org/wiki/Immersion_v._Sony

 

High cost and little market does not match...


Edited by Sokol1_br
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Gotta love it when technology patents end the market for a product that consumers desire.

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