Joystick roll trim shortcut?

[Redglyph]

Hello!

 

Is there a way to trim the joystick with a shortcut command in DCS, on aircraft that don't have an aileron trim feature? For example the Bf109, and I expect the Spitfire to come.

 

With some joysticks like the Hotas Warthog, it's quite hard to maintain a slight angle of the joystick because of the spring, and it's not obvious to have precise movements in that situation, past the central zone. On the aircraft there is no spring, so the best way to emulate that would be the possibility to trim the joystick (a little like the Huey).

 

I have searched a bit but found nothing, maybe I missed this feature?

 

Note: it's possible to set the center in DCS, but it's a permanent and constant settings, so that's not a solution here, since the trim would depend on the torque and air speed/angle of the aircraft.

[Redglyph]

I tried to add the commands to the Joystick/default.lua, but as I was half-expecting, they are ignored:

 

{down = iCommandPlaneTrimRoll, cockpit_device_id  = devices.CONTROL_SYSTEM, value_pressed = -0.1, name = _('Trim Aileron Left'), category = _('Flight Control')},
{down = iCommandPlaneTrimRoll, cockpit_device_id  = devices.CONTROL_SYSTEM, value_pressed = 0.1, name = _('Trim Aileron Right'), category = _('Flight Control')},

 

 

Same for this one,

 

{action = iCommandPlaneTrimRollAbs, name = _("Trim Aileron")},

 

 

But it's not really the aircraft trim (which doesn't exist) that I want to control, it's the joystick calibration.

Edited August 25, 2016 by Redglyph

[Redglyph]

Anyone? Am I the only one finding this stressing on the wrist?

[LeCuvier]

I have come to the conclusion that it would not be useful. In combat the engine power tends to vary a lot, and with every change of throttle input the propeller torque changes. So you would be re-trimming all the time and that's distracting. I tend to use the rudder (pedals input) to give it a bit of bias left or right and that works for me.

[Redglyph]

In combat it wouldn't be necessary. However, it's only a tiny portion of typical missions, where there are long legs for which this would be much appreciated.

[Sporg]

I have tested trim a bit.

 

In cruise, set your propeller RPM manually* to 2000 RPM, and thrust to 1.15 ATA.

You can then control roll with a little bit of rudder input and fly horizontal with not full forward trim.

You will have a speed of approx. 440 km/h.

Stick will be neutral, so good for use on longer stretches. :)

 

I experimented with a little bit left aileron trim in the Special tab in system controls, but while I could make the aircraft fly straight with less use of rudder it had two unwanted side effects:

 

1. The forward trim was no longer enough, so I flew in a slight but constant climb.
   
2. When speed approached 500 km/h and above, the aircraft now had tendency to roll right instead.
   

As I prefer neutral controls at high speed, I prefer to use neutral trim and use rudder at cruise instead.

 

*If you haven't experimented with manual propeller pitch, you really should: It becomes a whole different aircraft, more stable and with lots more possibility of trim.

Edited August 28, 2016 by Sporg

[Redglyph]

I should try that, for now I left it on auto. Thanks for testing it, Sporg :)

 

Yes, I saw the trim in the Special tab, that would be a "ground trim setting" I suppose, I was first hoping it could do the trick and could be controlled by a key but that doesn't seem to be the case. Not that it would be ideal, since cheating and modifying the FM, where I'm merely looking for a way to avoid the joystick spring near neutral where movements are the least precise because of it.

[Sporg]

I should try that, for now I left it on auto. Thanks for testing it, Sporg :)

You're welcome. :)

For more info about auto versus manual propeller pitch, you can look in this thread:

http://forums.eagle.ru/showthread.php?t=149764

 

There's some tips, and people's experience with it.

 

I most often fly manual now.

Yes, I saw the trim in the Special tab, that would be a "ground trim setting" I suppose, I was first hoping it could do the trick and could be controlled by a key but that doesn't seem to be the case. Not that it would be ideal, since cheating and modifying the FM, where I'm merely looking for a way to avoid the joystick spring near neutral where movements are the least precise because of it.

Yes.

These trim tabs were only adjustable on the ground.

And the setting only came after long and winding discussions about in-flight trim. :)

As you might see, the "factory" setting (0 on both of them) seems to be the best compromise after all.

 

About the spring force on the Warthog, I can warmly recommend getting an extension for it.

It makes the spring force much less, and makes your movements more precise.

It just takes a bit of getting used to.

[Redglyph]

Interesting, thanks!

 

It seems the extension or replacing the spring could be a solution, it would also help with the helicopters.

[Solty]

Anyone? Am I the only one finding this stressing on the wrist?

It is intended in the Bf109 to keep the airplane level with your rudder, using your legs.

 

You should not be able to trim the 109's ailerons or rudder during flight. That would be basically a cheat, because it goes outside the intended capability of the airplane.

Edited September 1, 2016 by Solty

[Cibit]

I struggled to fly with any sort of precision all of the WWII birds in DCS until I removed the spring and added a 15 CM extension to my warthog. I did this for flying choppers but it has worked wonders with prop driven fighters too.

Also as noted earlier. centering the ball with rudder inputs means a centered stick on the roll axis:)

[Redglyph]

It is intended in the Bf109 to keep the airplane level with your rudder, using your legs.

 

You should not be able to trim the 109's ailerons or rudder during flight. That would be basically a cheat, because it goes outside the intended capability of the airplane.

 

No, the rudder has other effects than countering the torque, it's not its purpose at all, ailerons are there for that :)

 

I think I was very clear that it was not an aileron trim, but a joystick trim. Please read my posts for further details on why it's not a cheat.

[Sporg]

No, the rudder has other effects than countering the torque, it's not its purpose at all, ailerons are there for that :)

 

I think I was very clear that it was not an aileron trim, but a joystick trim. Please read my posts for further details on why it's not a cheat.

Hi Redglyph

 

I understand what you mean, but it's still a cheat. ;)

 

The German pilots could not adjust trim in the air, apart from horizontal stab.

 

And, there are humorous accounts that German 109 pilots "got a longer right leg", because they had to hold the rudder right all the time during flight, to compensate for the torque.

:)

 

So, what you are experiencing, is actually one of the characteristics of the type. :)

Using rudder in order to fly straight was quite normal.

 

With that said, I have never felt big problems holding the 109 steady, neither before or after I got extension on my stick.

Always used the rudder in place of ailerons to keep her from rolling, when flying cruise.

[Whisper]

Always used the rudder in place of ailerons to keep her from rolling, when flying cruise.

 

Isn't that rather fuel inefficient since you are raising drag by not having your ball centered?

[Sporg]

Isn't that rather fuel inefficient since you are raising drag by not having your ball centered?

Probably.

Maybe I should experiment with the rudder trim so it got less. :)

 

But as I said, it seems to be a characteristic of the type, as I understand it.

And experimenting with aileron trim gave me other unwanted side effects as I mentioned.

 

Edit: I didn't seem to get much of a speed increase when having trimmed the plane more for cruise, so don't know how big drag it creates, at least in the sim.

Edited September 2, 2016 by Sporg

[Whisper]

Probably.

Maybe I should experiment with the rudder trim so it got less. :)

 

But as I said, it seems to be a characteristic of the type, as I understand it.

And experimenting with aileron trim gave me other unwanted side effects as I mentioned.

 

Edit: I didn't seem to get much of a speed increase when having trimmed the plane more for cruise, so don't know how big drag it creates, at least in the sim.

 

Well, ever since (recently) reading about how manual pitch control made the plane handle better (and oooh man, it does!), I just follow the simple guidelines (cruising 1.15 ATA @2000 RPM, speed cruising 1.35 ATA @2400 RPM & combat 1.45 ATA @2600 RPM, I know them by heart now :P ), and indeed the bird is far more stable in cruising phases, juste a liiiitle bit off (ie a little bit of pitch trim for nose down, and stick slightly deflected to avoid rolling).

And I naturally do what you explain when I need my hands, ie keep the plane level by applying rudder. But I find the ball really not centered in these cases, to the point of having visible direction slip. I've not checked how much speed I lose by doing so, but for the sake of fuel consumption, I usually just use stick control, I only switch to rudder when needed.

[Redglyph]

Hi Redglyph

 

I understand what you mean, but it's still a cheat. ;)

 

The German pilots could not adjust trim in the air, apart from horizontal stab.

 

It's not a cheat if you consider they had a stick, not a short joystick with a strong spring that makes for very imprecise control around the center zone. When they countered the little torque that is not neutralized by the aircraft (engine offset, ...) by moving the stick a little to the right, for ex. on a Spitfire or a Bf 109, they didn't have that inconvenience.

 

I'm not sure why they'd use big amounts of rudder in flight, except if they had a strong cross-wind, or to compensate some damage. The torque reaction to the engine is mostly around the longitudinal axis, it "wants to make the aircraft rotate" around this axis. Using the rudder turns the aircraft around its vertical axis and changes the incidence of the wings, thus changing their relative up & down pressure, among other things, but I don't think that's the better response to torque. I may be wrong though.

[Sporg]

Well, ever since (recently) reading about how manual pitch control made the plane handle better (and oooh man, it does!), I just follow the simple guidelines (cruising 1.15 ATA @2000 RPM, speed cruising 1.35 ATA @2400 RPM & combat 1.45 ATA @2600 RPM, I know them by heart now :P ), and indeed the bird is far more stable in cruising phases, juste a liiiitle bit off (ie a little bit of pitch trim for nose down, and stick slightly deflected to avoid rolling).

And I naturally do what you explain when I need my hands, ie keep the plane level by applying rudder. But I find the ball really not centered in these cases, to the point of having visible direction slip. I've not checked how much speed I lose by doing so, but for the sake of fuel consumption, I usually just use stick control, I only switch to rudder when needed.

It is probably the right thing to do, I'm just lazy. ;) :D

 

And thanks for confirming my findings about manual pitch. :)

 

Should probably just use the ailerons too, especially since I have stick extension anyway.

[Sporg]

It's not a cheat if you consider they had a stick, not a short joystick with a strong spring that makes for very imprecise control around the center zone. When they countered the little torque that is not neutralized by the aircraft (engine offset, ...) by moving the stick a little to the right, for ex. on a Spitfire or a Bf 109, they didn't have that inconvenience.

 

I'm not sure why they'd use big amounts of rudder in flight, except if they had a strong cross-wind, or to compensate some damage. The torque reaction to the engine is mostly around the longitudinal axis, it "wants to make the aircraft rotate" around this axis. Using the rudder turns the aircraft around its vertical axis and changes the incidence of the wings, thus changing their relative up & down pressure, among other things, but I don't think that's the better response to torque. I may be wrong though.

Apparently it is a disputed issue, and maybe only happened in badly trimmed airframes.

You can read more about it (and loads of other interesting stuff) here:

http://www.virtualpilots.fi/feature/articles/109myths/

 

About the stiffness of the Warthog stick, you are right it is more stiff around the centre than the real thing would be.

But that doesn't change the fact that you could not change aileron trim on the 109.

So the correct solution IMO is the remove the big spring, and/or get a good extension. So you can easier correct with ailerons.

 

With that said, I didn't feel it was a big problem for me even when I flew without extension.

And I never removed the big spring either.

But, as mentioned above, maybe because I just corrected with rudder, which admittedly might be wrong of me, when I read closer :)

Edited September 4, 2016 by Sporg

[Redglyph]

Interesting read, thanks for the link!

The rudder bit seems this is to compensate an airframe problem on some G models, and not related to the torque though. Those pilots were courageous indeed! :worthy:

 

But that doesn't change the fact that you could not change aileron trim on the 109.

Again... not what I proposed, which is trimming the joystick to get rid of the off feedback force.

[Whisper]

It is probably the right thing to do, I'm just lazy. ;) :D

 

And thanks for confirming my findings about manual pitch. :)

 

Should probably just use the ailerons too, especially since I have stick extension anyway.

 

Just an update, I discovered yesterday I had a full right aileron trim set up on the special tab for the 109 (ie full right set up by the ground crew, probably remnants of previous tests), which explains the rather big rudder input I had to make to keep the plane straight. Once zeroed, the plane is indeed really not far from stability and the rudder required for level flight is minimal.

[Redglyph]

Just an update, I discovered yesterday I had a full right aileron trim set up on the special tab for the 109 (ie full right set up by the ground crew, probably remnants of previous tests), which explains the rather big rudder input I had to make to keep the plane straight. Once zeroed, the plane is indeed really not far from stability and the rudder required for level flight is minimal.

 

Rudder? Do you mean the -K is modelled with some kind of aerodynamic fault, like the -G mentioned above?

Edited September 10, 2016 by Redglyph

[Sporg]

Just an update, I discovered yesterday I had a full right aileron trim set up on the special tab for the 109 (ie full right set up by the ground crew, probably remnants of previous tests), which explains the rather big rudder input I had to make to keep the plane straight. Once zeroed, the plane is indeed really not far from stability and the rudder required for level flight is minimal.

Ah, that explains it. :)

 

I don't have fully centered ball, but not much off either when I use rudder to fly level.

[Sporg]

Interesting read, thanks for the link!

The rudder bit seems this is to compensate an airframe problem on some G models, and not related to the torque though. Those pilots were courageous indeed! :worthy:

You're welcome. :)

But that doesn't change the fact that you could not change aileron trim on the 109.

Again... not what I proposed, which is trimming the joystick to get rid of the off feedback force.

I think I understand what you mean, but still think it's not representative of the real aircraft.

For me, part of the beauty of this simulation is that we experience also the compromises and imperfections of the real aircraft.

And this is one of them. :)

 

About the Warthog, I stumbled over this comment from Yo-Yo, ED's FM designer:

I hate the type of loading Warthog has - strongly pre-tensioned spring and almost no force gradient as you deflect the joystick. Extremely non-informative and exhausting feeling... and way far from the real plane feeling. So, I can imagine how irritating is to hold it 1 mm forward applying almost full force.

 

And this a conflict between accurate modelling and game controllers design.

I think it says a lot. ;)

 

I have been happy for my Warthog stick, but also beginning to feel it's deficiencies.

 

I would love for someone creating a replacement gimbal using cams instead.

(But probably wouldn't be able to afford it.. :D :D )

Edited September 4, 2016 by Sporg

[amazingme]

I switched from a spring based joystick (Saitek X55) to a FF stick (MSFF2) (one week ago), and I immediately felt the difference in the inputs. So much better now... I will never go back to a non-FF joystick and let's hope ED also fixes the minor FF bugs. Only now I understand what Yo-Yo meant in those posts :)