Force Trim

[Mouse]

Helicopter trim has long been a UX issue for DCS. The solution has been acceptable but with the Apache its weakness has been highlighted in a few ways. I know people have touched upon various points I'm about to make, but I haven't seen anyone put it altogether in a single post. So I'll make an attempt and probably choke on it. (Admittedly I'm not going to read all 12 pages of this thread...)

 

1. The traditional DCS trim method has been removed from the Apache. In the Huey, for example, the "Default" trimmer mode would give you a brief window to recenter your controls before the trim kicked in. Last I checked, that timing could be adjusted in the Lua scripts as well. Restoring the "Default" option would probably be enough to resolve most issues people are having. (I personally came to prefer this method because it's less annoying than having my controls get locked out by the alternative option.)

2. Unlike the old "Default" mode, "Central position trimmer mode" allows controls to get stuck if you don't recenter them. Having the helicopter wait for you to recenter your controls is fine until you get task saturated, accidentally lock your controls up, and crash.

 

I know ED says they're going to add a trim reset, but there are some additional, easy improvements to the trim system that can be made for all helicopters:

 

1. Restore the "Default" option for the Apache which gives the player a brief moment to return their stick to center before trim takes effect.

2. Place a timeout on the central position trimmer mode so that controls cannot get locked out for too long. This solves the main problem with this mode.

3. Allow users to edit the trim set time for "Default" and recenter timeout for "Central Position Trimmer Mode" in the settings menu, rather than making them edit Lua files. (This would be nice to have but I'd happily live without it if I got #1 and #2.)

4. Add an option to blend the trim over time, and make that blend rate adjustable in the settings menu (also a nice-to-have). The instantaneous trim that we have now is, in my opinion, the root cause of all the problems with trimming helicopters in DCS. Regardless of which option you pick, if you screw it up, you end up accidentally putting in a sudden, sharp input and unbalancing the aircraft, or your controls stop responding altogether. I admit this is a big ask. Interpolating two positions over time is easy, but I recognize there are additional layers of code and UI that need to support that.

5. Add aircraft-style trim bindings. I can already hear the screeching about this being unrealistic, but I disagree. These bindings don't represent something the aircraft is doing. They represent something that helicopter pilots can do very naturally with their hands. Pressing a button to command the pilot's hand to move the cyclic to a new center position that's slightly to the left is just as realistic as having a button that makes the pilot turn their neck to look slightly to the left. It's not at all unrealistic.

 

As a final note, if you actually put a recenter timeout on the central position trimmer mode, it ends up being really similar to the old Default trimmer mode. The difference is that you gain control immediately upon recentering your control input or after a short time period, whichever comes first. I don't see why this couldn't just replace both the Default and Central Position modes. The only difference would be the delay time, which could be made adjustable by the user.

[kdfw]

if there was an option to set the controls to be more like FBW--deflection of stick in a direction maintains attitude and only gets canceled out by input of opposite deflection.  more like the 2nd option without the constant need to press force trim release and not having to recenter for the stick to get the stick function back. 

[Mausar]

I just fly it like Shark with Flight Director On, simple as that. Problem was in tight turns and slowing down. It feels heavier but nothing to overcome. 

[jparker36]

In case anyone else runs into the issue I had, removing the small (2) deadzone I had put for the collective axis controls eliminated the issue, trim now works correctly.

[tusler]

The real problem I have is when I am returning from a mission and coming in to hover land and the thing get squirmy, I cannot eject LoL

[Jackjack171]

Overkill Simulations just put up a video on Force Trim. 
 

 

[Bewsher]

Just adding this. Make sure your equipment is properly calibrated in control panel then calibrate with 3pd software after.

[Bewsher]

7 minutes ago, ApacheLongbow said:

Sorry, what? 3pd, whats that?

3rd party software used for joysticks,pedals etc. Also control panel is windows control panel to clarify.

Edited March 23, 2022 by Bewsher

[arneh]

In single player there actually is a work around for those that want to reset trim. Switch to CPG cockpit to give George control, as he will reset trim, then take back control. A quick change to CPG and back can be done in a fraction of a second.

Personally I find George handing over an untrimmed helicopter annoying as I have to fight to regain control of the helicopter each time I take over from him again, but I guess that's what many people want.

Edited March 23, 2022 by arneh

[Eagles787]

6 hours ago, Mouse said:

Helicopter trim has long been a UX issue for DCS. The solution has been acceptable but with the Apache its weakness has been highlighted in a few ways. I know people have touched upon various points I'm about to make, but I haven't seen anyone put it altogether in a single post. So I'll make an attempt and probably choke on it. (Admittedly I'm not going to read all 12 pages of this thread...)

 

1. The traditional DCS trim method has been removed from the Apache. In the Huey, for example, the "Default" trimmer mode would give you a brief window to recenter your controls before the trim kicked in. Last I checked, that timing could be adjusted in the Lua scripts as well. Restoring the "Default" option would probably be enough to resolve most issues people are having. (I personally came to prefer this method because it's less annoying than having my controls get locked out by the alternative option.)

2. Unlike the old "Default" mode, "Central position trimmer mode" allows controls to get stuck if you don't recenter them. Having the helicopter wait for you to recenter your controls is fine until you get task saturated, accidentally lock your controls up, and crash.

 

I know ED says they're going to add a trim reset, but there are some additional, easy improvements to the trim system that can be made for all helicopters:

 

1. Restore the "Default" option for the Apache which gives the player a brief moment to return their stick to center before trim takes effect.

2. Place a timeout on the central position trimmer mode so that controls cannot get locked out for too long. This solves the main problem with this mode.

3. Allow users to edit the trim set time for "Default" and recenter timeout for "Central Position Trimmer Mode" in the settings menu, rather than making them edit Lua files. (This would be nice to have but I'd happily live without it if I got #1 and #2.)

4. Add an option to blend the trim over time, and make that blend rate adjustable in the settings menu (also a nice-to-have). The instantaneous trim that we have now is, in my opinion, the root cause of all the problems with trimming helicopters in DCS. Regardless of which option you pick, if you screw it up, you end up accidentally putting in a sudden, sharp input and unbalancing the aircraft, or your controls stop responding altogether. I admit this is a big ask. Interpolating two positions over time is easy, but I recognize there are additional layers of code and UI that need to support that.

5. Add aircraft-style trim bindings. I can already hear the screeching about this being unrealistic, but I disagree. These bindings don't represent something the aircraft is doing. They represent something that helicopter pilots can do very naturally with their hands. Pressing a button to command the pilot's hand to move the cyclic to a new center position that's slightly to the left is just as realistic as having a button that makes the pilot turn their neck to look slightly to the left. It's not at all unrealistic.

 

As a final note, if you actually put a recenter timeout on the central position trimmer mode, it ends up being really similar to the old Default trimmer mode. The difference is that you gain control immediately upon recentering your control input or after a short time period, whichever comes first. I don't see why this couldn't just replace both the Default and Central Position modes. The only difference would be the delay time, which could be made adjustable by the user.

I suggested the exact same changes for the current trim modes and posted a bug report, but it was closed immediately saying they will add a cheat assignment for trim reset. So it seems all they are getting from this long topic is adding a cheat function instead of seeing what are the fundamental issues with the current trim modes and why people are having problems with it. A trim reset function might be useful for some but is not going to solve that.

[Hiob]

The problem is, that there is no problem. You suggested a delay for the instant trim. Guess what - it has already a delay. The only thing one could now argue about is, what amount of delay you want to have. But that is a matter of taste. Good luck arguing about that.

The recenter issue? Not a problem at all on my end. And before you ask, I use a stick with 20 cm extension and very soft springs. Works as intended. This method is not well suited for pedals though! But you can set the pedals independently from the cyclic.

[Lurker]

I think that a big part of the problem is that users are not used to the central position trimmer mode, but also that the Apache features a flight computer that is specifically set up to keep the Apache stabilized for the last trimmed position. 

This means that unlike helicopters like the Huey, which do not feature any kind of SAS at all, or the Mi24 which has a SAS channels which work in a very different way (and which most people don't even use properly) this leads to some very obvious user error. 

I find it very telling that people like Casmo, and other SMEs have no trouble with the trim options in the DCS Apache, despite not really using any kind of special hardware to fly it. I think a lot of people are making an elephant out of fly, simply because of their previous experiences in other DCS helicopters. Fly it like you are supposed to fly it (trim often, trim for pedal movements, trim, trim trim). 

Maybe I'm just talking out of my behind, I don't have the module yet, but I don't think the module is at fault in this case. 

[Hiob]

12 minutes ago, Lurker said:

I think that a big part of the problem is that users are not used to the central position trimmer mode, but also that the Apache features a flight computer that is specifically set up to keep the Apache stabilized for the last trimmed position. 

This means that unlike helicopters like the Huey, which do not feature any kind of SAS at all, or the Mi24 which has a SAS channels which work in a very different way (and which most people don't even use properly) this leads to some very obvious user error.

Sorry, but that is not true. The Trimm in the Apache works exactly the same as in all other Helicopters (Huey e.g.), at least so far as it is implemented yet. All the "flight computer" does is, dampening PIO (same as in the Hip). But that has no effect on what happens when you trim and let go of the controls.

As of now it has the EXACT same effect as in the Huey. The only difference is, that you can set the different trimmer modes, individually for pedals and cyclic.

 

13 minutes ago, Lurker said:

I find it very telling that people like Casmo, and other SMEs have no trouble with the trim options in the DCS Apache, despite not really using any kind of special hardware to fly it. I think a lot of people are making an elephant out of fly, simply because of their previous experiences in other DCS helicopters. Fly it like you are supposed to fly it (trim often, trim for pedal movements, trim, trim trim). 

 

 

I think it's more of a problem for people who have no or little prior experience to DCS Helicopters. Because if they did - they would know, that trimming has always worked this way and that it is no different in the Apache. The Apache feels differen of course, in its Flight Model, but the practice of trimming is the same.

Edited March 23, 2022 by Hiob

[Lurker]

4 minutes ago, Hiob said:

Sorry, but that is not true. The Trimm in the Apache works exactly the same as in all other Helicopters (Huey e.g.), at least so far as it is implemented yet. All the "flight computer" does is, dampening PIO (same as in the Hip). But that has no effect on what happens when you trim and let go of the controls.

 

That's not what it does, according to people I spoke with the flight computer in the Apache is set up to keep the aircraft stable for the last known trimmed position. If the controls are moved (or aeordynamic conditons change enough) past the SAS limits then it will disengage completely until the trim button is pressed again. 

This is how it's supposed to work in the real Apache, and from what I've seen (it's extremely stable) this is how it works in the DCS Apache too. When flown correctly. 

Edited March 23, 2022 by Lurker

[Hiob]

9 minutes ago, Lurker said:

That's not what it does, according to people I spoke with the flight computer in the Apache is set up to keep the aircraft stable for the last known trimmed position. If the controls are moved (or aeordynamic conditons change enough) past the SAS limits then it will disengage completely until the trim button is pressed again. 

 

You should really fly the Apache first.

See, what trimming does is, it holds the cyclic in it's position when trimmed (more precise - it reliefs the forces for the trimmed position). The result is, what you described. The Helicopter will hold its current attitude (given it was stabilized when trimmed). In the Huey this is a completely analog and none - augmented process, in the Apache there may be more going on in the background (kind of like in a fly-by-wire aircraft) - BUT the result and the "User Experience" is the same.

As far as trimming is implemented in DCS Helos, for all intents and purposes, it works the same in all Helicopters (*maybe not for KA-50, don't know). You move your cyclic to a position, you press and release the trim button and the cyclic will stay in this position AS IF you would still holding it there. And the aircraft acts accordingly. Absolutely the same thing in the Apache.

Edited March 23, 2022 by Hiob

[Lurker]

38 minutes ago, Hiob said:

You should really fly the Apache first.

See, what trimming does is, it holds the cyclic in it's position when trimmed (more precise - it reliefs the forces for the trimmed position). The result is, what you described. The Helicopter will hold its current attitude (given it was stabilized when trimmed). In the Huey this is a completely analog and none - augmented process, in the Apache there may be more going on in the background (kind of like in a fly-by-wire aircraft) - BUT the result and the "User Experience" is the same.

As far as trimming is implemented in DCS Helos, for all intents and purposes, it works the same in all Helicopters (*maybe not for KA-50, don't know). You move your cyclic to a position, you press and release the trim button and the cyclic will stay in this position AS IF you would still holding it there. And the aircraft acts accordingly. Absolutely the same thing in the Apache.

 

Yes I understand how trimming works in real and in DCS helicopters. My point was that unlike other helicopters you have SAS systems trying to keep it stable on it's last known trim, until SAS authority is reached.

I'm not sure what point you are trying to make here? Is it supposed to be different in the Apache for some reason? Why is trim reset something that is desireable in the Apache? 

@Hiob check out this thread. 

 

Even something as simple as taking off is very different in the Apache, compared to the Huey or the Hip, if you follow procedures correctly. 

Edited March 23, 2022 by Lurker

[bradmick]

Moved to:
https://forum.dcs.world/topic/296437-ah-64d-takeoff-track-files/?do=findComment&comment=4924709

Edited March 23, 2022 by bradmick

[Hiob]

@Lurker There is really no point in arguing with someone who hasn't even tried it yet. I'm done with it.

 

The Heading hold thread covers a completely different topic, which you would know - if you have actually tried it.

[Lurker]

2 minutes ago, Hiob said:

@Lurker There is really no point in arguing with someone who hasn't even tried it yet. I'm done with it.

 

The Heading hold thread covers a completely different topic, which you would know - if you have actually tried it.

I will try it when it's available in the trial. I was not arguing with you, I'm genuinely curious about your opinions. But you are incredibly rude. So I'm done with you too. 

Edited March 23, 2022 by Lurker

[Hiob]

5 minutes ago, Lurker said:

I'm genuinely curious about your opinions.

That wasn't my impression at all.

[markturner1960]

On 3/21/2022 at 3:17 AM, SkateZilla said:

 

Thanks, thats very useful, I have a quick question - when you are talking about the need to re centre the stick before you can use it again after changing the settings in special, ( around minute 13 - 14) I dont see the white diamond moving back to centre when you are presumably doing this....why is that ? 

43 minutes ago, bradmick said:

I’m a big fan of the central position trimmer. It mirrors actual force trim procedures with one caveat: you don’t recenter the stick in the aircraft. But the procedure is the same.

1. Press and hold the force trim interrupt

2. Move the flight control to the desired position

3. Let go of the force trim interrupt while simultaneously letting go of the stick to center the joystick.

 

Alternatively:

 

1. Move the flight control to the desired position

2. Perform a short press and release of the force trim button then immediately let go of the flight controls to center the stick

 

The other thing to work on is making “millimeter movements” on the flight controls. You’ll want to make large movements to set the initial fight control positions, and then use “pressure/counter-pressure” with your fingertips to maintain position. If you’re finding yourself fighting the trim. Then perform a short press of the force trim release button to adjust the flight control reference point. 
 

the other thing to remember with the central position trimmer is that it WILL lock out the axis trimmed until you recenter, so if you keep pressing the pedal or holding the cyclic in position, you won’t be able to fly at all until you center the controls. 
 

In summary, the mantra:

Interrupt (the the force trim), set (the flight control in the desired position), release (the force trim and flight control to center)

 

interrupt, set, release.

 

Hope it helps! New pilots to the Apache struggle hard with this too, so don’t feel bad.

 

This is tricky if the force trim button is on your cyclic, as you cant let go and still operate teh button. maybe best in this situation to have the force trim button bound to a hat on the collective? 

[bradmick]

2 minutes ago, markturner1960 said:

This is tricky if the force trim button is on your cyclic, as you cant let go and still operate teh button. maybe best in this situation to have the force trim button bound to a hat on the collective? 

On my warthog I gave it bound to my CMS switch, my thumb naturally rests there. CMS forward is trim release, left attitude hold, right altitude hold and back holds disengage. I map all my trimmers there because of how my setup is….setup, lol

[dburne]

5 hours ago, Bewsher said:

Just adding this. Make sure your equipment is properly calibrated in control panel then calibrate with 3pd software after.

I would never calibrate in control panel, I have a VKB stick and Virpil throttle, I only calibrate in their software.

[cfrag]

15 hours ago, Hiob said:

BUT NOTHING HAS CHANGED IN THE BASIC WAY THE DIFFERENT TRIMMER MODES WORK

Thank you for the (at least for me) very helpful hints on how the various modes in the Special menu affect how trims are set up. It helped to resolved one nagging Issue I had (after adding a small dead zone, the joystick returned control to me after trimming).

It seems to me, many here (me included) are baffled by one option that seemingly is missing, or that I can't get to work. In simple terms (for me), trimming simply sets constant values for dx and dy offset that are added to your x and y cyclic inputs. In the Huey, Hind, Gazelle, Shark and Hip, I can press a 'trim reset' button that simply resets that dx/dy to 0/0 (usually buffered, within 0.5 seconds). The controls return to 'true stick' values, no offset, so to speak. I can't find that on my Apache, or can't get it  to work that way. I assumed that the 'Force Trim / Hold Mode D- Down' (which the Manual seems to indicate a "Reset") does not, in fact do what the reset button does on the Huey et al. I guess that is what is throwing off so many of us, and that is what many (me included) would like to have. Then again, it may be just me, and I'm (again) overlooking the obvious. 

So I guess, the question is: how would I, without looking at my control indicator effectively zero the offset, or which setting in special would give me that functionality when used with "Mode D - down'? That would help me a lot - thank you for any hints.

 

[bradmick]

2 minutes ago, cfrag said:

Thank you for the (at least for me) very helpful hints on how the various modes in the Special menu affect how trims are set up. It helped to resolved one nagging Issue I had (after adding a small dead zone, the joystick returned control to me after trimming).

It seems to me, many here (me included) are baffled by one option that seemingly is missing, or that I can't get to work. In simple terms (for me), trimming simply sets constant values for dx and dy offset that are added to your x and y cyclic inputs. In the Huey, Hind, Gazelle, Shark and Hip, I can press a 'trim reset' button that simply resets that dx/dy to 0/0 (usually buffered, within 0.5 seconds). The controls return to 'true stick' values, no offset, so to speak. I can't find that on my Apache, or can't get it  to work that way. I assumed that the 'Force Trim / Hold Mode D- Down' (which the Manual seems to indicate a "Reset") does not, in fact do what the reset button does on the Huey et al. I guess that is what is throwing off so many of us, and that is what many (me included) would like to have. Then again, it may be just me, and I'm (again) overlooking the obvious. 

So I guess, the question is: how would I, without looking at my control indicator effectively zero the offset, or which setting in special would give me that functionality when used with "Mode D - down'? That would help me a lot - thank you for any hints.

 

The D - Disengage, disengages the Attitude and Altitude hold modes after they've been turned on. That's all it does. It doesn't reset or release the force trim. In fact, force trim doesn't  auto center at all on it's own, you have to move the flight controls (because it's a magnetic brake that holds the flight control in position). There is no 'trim reset' in any helicopter that i've flown that magically centers the flight controls, this would be a terrible idea in a real helicopter. The real Huey does't have it, the Lakota doesn't have it, the Apache doesn't have it and neither did the TH-67. The trim reset won't help, understanding the theory behind how the trim in the sim works and what it's trying to replicate in the age of non forcefeedback sticks is what'll help.