Question about pitch and stick throw and elevator movement

[imacken]

I know there was a thread about this a long time ago, but I can't remember the answer.

Pitch and differences between player stick, in-cockpit stick and elevator movement.

Pitch Down - the in-cockpit stick only moves with about 50% player stick throw, i.e. the final 50% of player stick movement doesn't do anything. This is confirmed by looking at the external view where it can be seen that the elevators only move with about 50% stick forward.

Pitch up - the in-cockpit stick follows the full 100% player stick backward movement. However, the elevators do not.  They stop moving around 85% of stick throw, so again, it seems that some of the player stick movement does nothing.

(Best to look in external view while sitting on the ramp.)

If only 50-85% is being used, then why not calibrate that to the full 100% player stick movement?

Is anyone able to explain this to me?

EDITED: 5/10/2022

Edited October 5, 2022 by imacken

[BuzzU]

I never noticed this and had to go check. I get different results from you. I'm using a Warthog HOTAS right now.

Pitch down I get about 60% stick movement when elevator is fully down.

Pitch up I get 90% stick movement when elevator is fully up.

Stick in cockpit is similar.

However, you're right. Our HOTAS doesn't match elevator movement.

[imacken]

I measured mine using JoyTester exactly at the point where the Hornet elevators no longer move with my stick, and it is exactly 50% in both forward and aft, but in the end, the numbers don't matter. The questions are

1) why do the player stick movements not match the actual elevators, 

2) why does the in-cockpit stick match the elevators' movement forward, but not aft, and

3) why are there discrepancies at all?  Surely it could be synced to the full player stick movement.

I've just checked the Viper, and there, I get 40% of my stick movement forward moving the elevator, and 60% aft.  Yep, in-cockpit the stick moves perfectly with my stick.

I'm guessing this has a perfectly rational explanation, and hopefully someone here will tell us!

[BuzzU]

I'm guessing the HOTAS used has something to do with the difference we get.

[imacken]

Maybe, but it's not the differences between us that's important, it's why it happens. See my questions above.

I've just tried various other modules, and some are completely synced with the stick/elevator movement, and some are not. 

[speed-of-heat]

indeed just did the same test, there seem seem to be some flight modes where the travel of the stick and the elevators more closely match in the Hornet 

also spin mode seems to provide a closer match 

this is my current hornet pitch curve :

Edited September 30, 2022 by speed-of-heat

[BuzzU]

36 minutes ago, imacken said:

 See my questions above.

 

I agreed. See my answer above.

[imacken]

2 hours ago, speed-of-heat said:

indeed just did the same test, there seem seem to be some flight modes where the travel of the stick and the elevators more closely match in the Hornet 

also spin mode seems to provide a closer match 

this is my current hornet pitch curve :

 

Thanks Stuart, that didn't work too well for me, but you made me think about saturation values, and if I set Y Saturation to 70% then I get almost perfect match between the elevators and my stick.

So, we can work around this, but my questions 1)-3) 5 posts above are still valid! There must be a legitimate design reason why this is happening as we shouldn't have to mess around with saturation values.

[speed-of-heat]

ah sorry, I was clear the curve was to match the push aspect of the pitch  I will have a play with saturation values as well , good shout

and yes the other question do remain open.. .e.g. why?

[imacken]

Firstly, making the adjustment to the saturation in order to get the elevators respond to the full stick throw makes quite a difference in terms of sensitivity, so I'm glad this issue was raised.

However, we're getting no response here, so I think I'll post this as a bug and see if we can get a response from ED there.

[speed-of-heat]

4 minutes ago, imacken said:

Firstly, making the adjustment to the saturation in order to get the elevators respond to the full stick throw makes quite a difference in terms of sensitivity, so I'm glad this issue was raised.

However, we're getting no response here, so I think I'll post this as a bug and see if we can get a response from ED there.

Improved? Or just different? @BIGNEWYcan we move this to bugs please?

Edited October 1, 2022 by speed-of-heat

[imacken]

Oh definitely improved, as I have the full throw available now for adjustments rather than only about 50% before.

[speed-of-heat]

i will give it a go

 

[speed-of-heat]

Yep so much finer response  and no degradation in performance that i can see... I ended up adapting my old curve to reduce the travel to match the max effective controls and ended up with this:

 

nullwhiich does mean trusting to the centring of your stick and its deadzones rather than ingame deadzones. but gives me 100% of my stick throw to apply . 

[Steel Jaw]

On 9/30/2022 at 6:32 AM, BuzzU said:

I never noticed this and had to go check. I get different results from you. I'm using a Warthog HOTAS right now.

Pitch down I get about 60% stick movement when elevator is fully down.

Pitch up I get 90% stick movement when elevator is fully up.

Stick in cockpit is similar.

However, you're right. Our HOTAS doesn't match elevator movement.

Same for me with my Warthog HOATS.

[imacken]

OK, so after checking all my modules - about 15 - it is only the Hornet, Viper and F-5E that are affected by this issue.

In all cases, setting Y saturation to 60% fixed it for me, giving full deflection which in turn gives me more control as I can now use the full stick throw for actual elevator movement in those 3 modules.

(I'll post on the bug section on this later.)

[TimRobertsen]

Were you thinking of this thread?

 

 

[imacken]

Yes, that was the one!  Thanks for that.

However, it doesn't explain some of what we are discussing here now.  I'm doing more investigation so I (we) can understand the relationships between stick throw, elevator movement and in cockpit stick view.

[rossmum]

The aircraft has a fly-by-wire system whose entire purpose is to interpret your inputs to figure out what you want it to do, then manipulate the controls accordingly. There is no direct linkage (except in mech reversion mode which is an emergency backup), there is always a computer between your stick input and the control surfaces. You are not flying the plane, you are telling the computer what you want the plane to do and it is flying the plane for you.

You will also find that even many older aircraft without fly-by-wire will not necessarily give 100% stabiliser deflection with 100% stick deflection, because many of them have pitch-gearing systems which serve to stop you breaking the plane at high speed and do so by adjusting the ratio between stick and tail movement. MiG-19, MiG-21, Mirage F1, and from memory the Viggen are all examples of this.

[speed-of-heat]

@rossmumthanks for that, and that makes sense, though with the Hornet their is a physical  limitation in pitch of the stick as well, it will only travel forward about 1/3 of the distance it will travel back)

That said with the F5E it limits roll after the wheels are raised, do you need full roll authority on the ground ? 

[imacken]

9 hours ago, rossmum said:

The aircraft has a fly-by-wire system whose entire purpose is to interpret your inputs to figure out what you want it to do, then manipulate the controls accordingly. There is no direct linkage (except in mech reversion mode which is an emergency backup), there is always a computer between your stick input and the control surfaces. You are not flying the plane, you are telling the computer what you want the plane to do and it is flying the plane for you.

You will also find that even many older aircraft without fly-by-wire will not necessarily give 100% stabiliser deflection with 100% stick deflection, because many of them have pitch-gearing systems which serve to stop you breaking the plane at high speed and do so by adjusting the ratio between stick and tail movement. MiG-19, MiG-21, Mirage F1, and from memory the Viggen are all examples of this.

Good point, but I'm not sure that is answering the questions here.  This only affects Hornet, Viper and F-5E in the 15 or so modules I own.

I just cannot see why stick movements are restricted in terms of their authority control.  I have tested in a lot of different circumstances, e.g. take off, landing, combat, etc., and although the elevator responses can be different, I have not seen a circumstance where the aft movement on the stick ever commands full authority at default settings. (I think forward movement is a different issue - see linked thread above.)

So, for me, I have set the Y saturation on the Hornet and Viper pitch axis to 80%, and I'm happy with that.  (The F-5E is more complex!)

[BuzzU]

All you've done by decreasing the saturation is limit the movement the elevator will have with your stick movement. It still moves the same amount. You could have accomplished the same thing by being more sensitive to your stick movement. An extension on the stick would do the same thing.

[imacken]

I think you may be missing the point. By changing the saturation, you get more stick movement for the same elevator movement, hence adding sensitivity by nature of the longer throw. 
Btw, I do have an extension on my stick. 

[SMN]

It's a similar situation with the roll.
Full aileron roll deviation occurs when the stick  is not fully deflected
When changing the roll saturation Y to 85% stick corresponds to aileron

[imacken]

Yep, roll can be adjusted as well in the 3 modules mentioned.