1.5.7 and "Joysticks without spring and FFB" trim mode

[foxtheancient]

When I saw it in patch notes I was so happy I will be finally able to fly Ka50 and it won't annoy me constantly in the process.

 

However this trim mode seems to be broken. It does nothing for me. Only when "trim rudder" is enabled, rudder trim works. However X and Y axies won't trim. It behaves like you're not hitting the trim button at all. Axis always returs to the center no matter what I do.

 

Anyone having the same issue?

[M1Combat]

I have a feeling it just centers the authority box essentially. I checked what it does even though I don't have a springless non-FFB stick (I have an X65F force sensing stick) and it kinda seemed at first to not work at all... but... With the way that the trim works as a limiter in various modes (like auto hover) I think it offers a new way to center the trim authority box for users who do have springless non-FFB sticks. Seems like it'll work for them just fine :).

[foxtheancient]

Then please explain me how it works. I have such a joystick and it does not work at all for me. I expected it will work in the same way as in the Mi8/Uh-1/Gazelle does. There it is great.

 

It is just in Ka50 such a pain to trim with nonFFB joystick. It seems they realized it so they added option for us. But how the hell it works I do not understand. From my point of view it does exactly nothing.

[foxtheancient]

Thank you for clarification. Is there any way how to force Ka50 trim to work like in other chopper modules for nonFFB joystick?

[foxtheancient]

What happen is, that I level up aircraft (f.e. after slowing down when you need to push the nose upwards), move the stick where I want it to be (where the aircraft's nose is alighned with horizont), press trimmer and what I do expect (and other modules do) is that the nose stays where it is and I can release my stick to center position without messing anything up.

 

When I do it in Ka50 I mess up position of my nose, it continues in direction from where "it came". Like I push the stick towards myself to level up aircraft from dive, set the nose to horizon, hit trimm and release the stick. What Ka50 does is that after this it raises the nose (quite rapidly, easily over 20°). I've tried all trimm modes available yet none is working as expected.

 

There is also a way with holding the trimmer button instead of hiting it. It works in a same way but the problem is not at the "end" but at the "start". You have aircraft in any position trimmed, you hit and hold the trimmer button without moving the stick anywhere from center position and the nose start to dive/climb (related to where it has been trimmed before change).

 

That is pretty annoying you see :(

[foxtheancient]

I see now that it is my misunderstandment of the aircraft's systems. Flight Director's mode indeed works good for me. Thank you very much for learning me that! Only thing I am kind of sad about is that it looks like aircraft ignore other autopilot channels, like heading, thus auto-turn as well. I guess I will need to learn to switch on and off DH mode as needed depending on current situation.

[Holton181]

My understanding about "Joystick without spring and FFB", from when it was introduced in the Mi-8, is that it is for spring- and FFB-less sticks WITH ENOUGH FRICTION FOR IT TO STAY IN PLACE WHEN LETTING GO!

(sorry for "screaming", only want to highlight the main point here)

Some developer at Belsimtek showed in a thread (I can't find again) how they modified a stick, removed the spring and added some extra friction to make it possible to let go of the stick AT THE POSITION WHERE TRIM BUTTON WAS PRESSED, i.e. the physical stick and the virtual one stay in the same position WITHOUT FFB.

 

If you don't have enough friction, you need to hold it in (the exact) place yourself. But if you do, I believe AP will work.

If you have a "heavy" stick the friction need to be so high that it affects the feeling and handling of it in an adverse way. Then you need one of the two original trim modes, i.e. return to center.

 

I have a PFT Lynx and it's a spring- and FFB-less stick but with way to heavy cyclic, so I can't use this.

[M1Combat]

Instead of using FD mode just use the trim like it's meant to be used in the KA-50 :).

 

Hold the trim button in... Fly the aircraft... When you get the aircraft to the attitude/flight path you want it to continue going in then release the trim button and center your controls.

 

Just tapping the trim button doesn't do the right thing. Because it's not designed to be used that way.

 

Look at it more like the button allows you to "grab the trim", then move it by flying the chopper into it's new trajectory, the "let go of the trim at it's new spot".

[rrohde]

Instead of using FD mode just use the trim like it's meant to be used in the KA-50 :).

 

Hold the trim button in... Fly the aircraft... When you get the aircraft to the attitude/flight path you want it to continue going in then release the trim button and center your controls.

 

Just tapping the trim button doesn't do the right thing. Because it's not designed to be used that way.

 

Look at it more like the button allows you to "grab the trim", then move it by flying the chopper into it's new trajectory, the "let go of the trim at it's new spot".

 

That's good advice. Thanks.

 

I've noticed sometimes with that approach that I eventually run out of ways to change the attitude for some reason, as if I've reached the end of the trimmer range (if that's a thing); once that's the case, the only thing that helps is resetting the trimmer.

[M1Combat]

I've never had that happen...

[foxtheancient]

Instead of using FD mode just use the trim like it's meant to be used in the KA-50 :).

 

There is also a way with holding the trimmer button instead of hiting it. It works in a same way but the problem is not at the "end" but at the "start". You have aircraft in any position trimmed, you hit and hold the trimmer button without moving the stick anywhere from center position and the nose start to dive/climb (related to where it has been trimmed before change).

 

In reality, the second method is not advised or typically used by Ka-50 pilots, because holding down the trimmer button while maneuvering the helicopter can easily lead to oversteering.

https://forums.eagle.ru/showpost.php?p=572028&postcount=34

[Holton181]

@foxtheancient

Did you see my post (#10)?

[M1Combat]

"You may trim in either discreet presses/releases of the button or by holding the button down while you maneuver the helicopter into the desired position. Once the helicopter is stable, you can release the trim button to command the FCS to stabilize the current flight parameters. In reality, the second method is not advised or typically used by Ka-50 pilots, because holding down the trimmer button while maneuvering the helicopter can easily lead to oversteering."

 

Once you learn to fly the "oversteering" isn't an issue. If you fly with the trimmer not held in then you're fighting the trimmer's control authority that originates at it's currently trimmed position.

 

Seriously... I've run the Blackshark for quite a few hours.

 

Hold the button.

[Fri13]

This mode exists for people that are using non-centering sticks. The description makes it sound like force sensing sticks fit in this category but they still "spring" back to center when you let go.

 

It disables the axis trimming while keeping the autopilot trimming. Previously this had to be done by editing the FMOptions.lua

 

It as well works for custom made sticks where you have removed the spring and added few hydraulics that keep the stick position exactly where you move it.

 

It is very nice to fly with such sticks as you always know how the aircraft is going and you don't need to worry about trimming (in aircrafts) at all

[M1Combat]

I'm just not concerned with how the manufacturer intended the aircraft systems be used. I'm concerned with making it all work the best I can to kill as much stuff as possible.

 

If I'm not doing it the way it was designed I couldn't care less. Maybe if the trim in the real Blackshark works like ours then maybe the real pilots should try it my way :). I would pretty much bet they do except in the edge case of slight re-trim where it doesn't matter... But when you're really going aerobatic and dodging missiles and returning short range fire with the gun in HMS mode... Yeah... tapping is bad mojo sir :). You're just constantly fighting against the trim center. If you're one of those "gentle" pilots that only uses vikhr's at 8.5K like a sniper and then you go home to rearm then fine... stick with the tap method :). It works great there.

[Ranma13]

For anyone that's interested, this is a breakdown of the different trim modes when used with non-FFB joysticks:

 

Default - When the trim button is pressed, the center position of the joystick is set to the joystick's current position, and joystick input is disabled for a short moment before it's re-enabled. The intended use is for you to press the trim button, then immediately release the joystick, and the heli will fly as if you are holding it in the position that you pressed the trim button at. Any joystick input afterwards will be treated as inputs in addition to the trimmed position. For example, if you're holding the joystick at a +5 position, then press the trim button and keep the same joystick position, you will now be flying the helicopter at +10. Your joystick movements are relative to the position that it was last trimmed at.

 

Central Position Trimmer Mode - The same as Default, but rather than disabling joystick input for a short moment before re-enabling it, you now have to center the joystick before input is re-enabled. This is useful if you don't want to press the trim button and inadvertently lurch the heli to one side because you didn't center it fast enough, but a lot of people don't like this mode because it feels less responsive than Default.

 

Joystick Without Spring and FFB - The joystick position is the absolute position of the cyclic, period. True to its name, this is intended for non-FFB joysticks that have the centering spring removed. Pressing the trim button only programs the auto-pilot, but doesn't affect joystick input behavior.

 

All of these modes are intended to be workarounds for non-FFB joysticks. If you have a FFB joystick with Force Feedback enabled in the options, the selected trim mode is ignored.

 

In the real helicopter, the trim button will reset the centering force to the cyclic's current position, and holding it down will disable the trim force altogether until released. This is why in the real helicopter, pilots (and people with FFB joysticks) do not hold it down but rather press the trim repeatedly. If you hold it down, you can no longer feel the amount of force you're using, making it very easy to oversteer. This doesn't matter for non-FFB joysticks, as the centering force always exists.

 

Also, the trim reset option exists when there's no such thing in the real heli. It's an easy to way to instant re-center the cyclic's position so that you can start your inputs from 0 instead of an offset.

 

This is why you see people giving different advice about how to use the trimmer and Flight Director mode in the Ka-50. For non-FFB joystick users, it's easier to hold down the trim button, move to the position you want to be in, and release. There's not much point in using the Flight Director because the trim button does the same thing.

 

For FFB joystick users though, holding down the trim button removes all force, so it's preferable to press the button instead of holding it down. Flight Director is often used because it allows flying of the heli without having to tap the trim button repeatedly and having the force on the joystick change with every press.

[Meneliki]

Prior to the patch, there was a checkbox in the game options interface, under the 'special' tab called "center trimming mode". This was the solution to the problem you seem to be describing. When you let go of the trim, the aircraft lurches towards where your stick is pointed. The Center Trim mode box made it so that the aircraft doesn't start responding to input after a trim until the joystick is centered again.

 

The problem? This option is missing from the interface in the most recent patch. Any chance we could get it back? Everything was fine with that checked. Now it's a mess trying to control.

Thanks

[Ranma13]

This option is missing from the interface in the most recent patch. Any chance we could get it back?

 

That's what the "Central Positioning Trimmer Mode" is.

[Meneliki]

Not sure I understand your reply.

 

How do I re-enable the functionality of the old "Center Position Trimming" which is both a) apparently disabled by default and b) missing from the interface?

[Ranma13]

How do I re-enable the functionality of the old "Center Position Trimming" which is both a) apparently disabled by default and b) missing from the interface?

1. Go to the options, click on Special tab. Select Ka-50 from the list on the left.

2. Click on the dropdown for Trimmer Mode.

3. Select "Center Position Trimmer Mode".

[Meneliki]

1. Go to the options, click on Special tab. Select Ka-50 from the list on the left.

2. Click on the dropdown for Trimmer Mode.

3. Select "Center Position Trimmer Mode".

 

Ahh, thanks. I was looking for the special tab but didn't see it.

:doh:

[BitMaster]

.......

 

....... There's not much point in using the Flight Director because the trim button does the same thing.

 

.......

 

 

Your statements were correct until you wrote the above. FD mode is not the same as trimming, retrimming or holding the trim button pressed.

 

FD is far more than that and it takes a lot of flying, observation and rethinking why what and how the Ka is operated.

 

FD mode blends the selected AP channels into your "working the controls". Enable/disable Heading or Altitude channel for example and observe how "she" behaves differently. You cannot achieve the same behaviour with Trim button actions...at least not that I figured it out

[Ranma13]

FD mode blends the selected AP channels into your "working the controls". Enable/disable Heading or Altitude channel for example and observe how "she" behaves differently. You cannot achieve the same behaviour with Trim button actions...at least not that I figured it out

 

The AP channels enable two functions: a dampening system which dampens the pilot's controls to minimize pilot-induced oscillations, and a stabilization system that attempts to hold the helicopter at the last trimmed position. Flight Director disables the stabilization system, but leaves the dampening system on. From page 10-24 of the manual (page 360 if you're viewing the PDF version):

 

http://server.3rd-wing.net/public/Manuels%20DCS/DCS%20BS2%20Flight%20Manual%20EN.pdf

 

To disengage the automatic mode and enable director control, it is necessary to press the

“ДИР УПР” (FLT DIR) push-light on the Autopilot panel. By disengaging automatic

control, the automatic angular stabilization is disabled but damping remains for all

channels.

 

The trim button will do the same thing while it's held down, but will additionally disable force trim as well. From page 6-6 in the manual (PDF page 80):

 

“ТРИММЕР” (Trimmer) button – Cancels all force on cyclic with the trimming

mechanisms. When released, the autopilot will stabilize current angles of pitch,

bank and yaw

 

and page 13-30 (PDF page 480):

 

Pressing the “ТРИММЕР” (TRIM) button on the cyclic stick cancels the autopilot’s

position signals for bank (K), pitch (T) and yaw (H) and releasing it places the angular

position of the helicopter in 3D space in memory.

 

Without force feedback, force trim doesn't do anything, so the trim button and Flight Director end up doing the same thing: disabling the bank/pitch/heading hold, but leaving the dampening system on. As long as the AP channels are on, the dampening system will always be on (barring a system failure). If you turn on Flight Director and turn off the AP channels, the helicopter's behavior will change because you've disabled the dampening system.

Edited July 18, 2017 by Ranma13

[Holton181]

So, back to the original subject, "Joystick without spring and FFB"...:music_whistling:

 

I have now done some testing myself, with both trim techniques.

"Joystick without spring and FFB" do work the way I described here, actually the same as Ranma13 described it here but with different words and perspective. I have been forced to hold the stick as steady as possible in the trim position since I do not have friction enough to let go.

 

It does appear to be bugged though! :joystick:

 

I will elaborate soon but first some important things to remember, some has already been mentioned already, just repeating it here:

1) The actual trimming is occurring when RELEASING the button, no mater

trim technique.

2) When trimming (i.e. releasing button) it's crucial to have stabilized before trimming. When trimming the autopilot uses the helicopter orientation in 3D space as reference, not cyclic position. If you move the stick and trim before the helicopter has settled in the corresponding attitude, you'll get in trouble!

3) Both trim techniques are supposed to work, shall only be personal preferences.

 

 

 

Test with technique "Attitude-Click"

"Attitude-Click" is when you first change the attitude of your helicopter and when stabilized press-n-release the trim button. Trim shall be done frequently!

It is important to trim at a stable hover before liftoff. Gets a little bit jumpy otherwise, but possible to correct.

My experience is that it does work as intended, It appears it does nothing, but it actually do "program" the AP. That can most easily be seen when having next way-point at either side of you and activating "Automatic Flight Mode". The helicopter makes a turn towards it and then return to the same attitude as when last trimming, all without moving the stick.

But I can see some issues:

When releasing trim button the nose do a small jump but quickly returns to trimmed position. It doesn't seem to matter if I constantly click the button while changing attitude or fulfill the attitude change and click ones.

I successfully flew a mission using this technique though.

 

Test with technique "Press-Attitude-Release"

"Press-Attitude-Release" is when you start by press and hold the trim, then change attitude, when stabilized you release the button. This is my preferred technique, the one I have been using for many years now (with return to center). Unfortunately the trim appears to be bugged some strange way making "Attitude-Click" work but "Press-Attitude-Release" not.

What happens (to me, and as I understand it to OP as well) is this:

I press the button and change attitude, when releasing my nose makes a rather big jump, similar to how foxtheancient (OP) describes it, and does not return to trim attitude!

Trying to counteract it with cyclic input with trim makes it jump again.

If I then counteract it with cyclic input without trim and stabilize as intended, I can activate "Automatic Flight Mode" and it fly as planed. But deactivating "Automatic Flight Mode" then press and hold the trim, my nose makes another jump similar as the one before but opposite direction.

I relay can not use "Press-Attitude-Release" when having "Joystick without spring and FFB" enabled.:(

 

 

I believe it's a bug making "Press-Attitude-Release" not usable with "Joystick without spring and FFB" enabled, but if someone has a confirmed way to make it work I'm eager to listen.

[Ranma13]

Is it possible for you to make a video showing the behavior you're seeing with the trim, and with the input viewer displayed (press Right Ctrl + Enter)?