Trimming the Ka-50

[AlphaOneSix]

I keep wondering if the Kamov aircraft operate similarly to Mil aircraft in this respect. On the Mi-17, the pedalshave microswitches on them so the autopilot knows when your feet are on the pedals. If your feet are on the pedals, all the autopilot does is dampening for the yaw channel, but when you take your feet off of the pedals, you get dampening plus heading hold. I asked AirTito about microswitches on the pedals like this for Kamov aircraft, and he said that they did not have them, so it makes me wonder if the yaw channel of the autopilot is always in heading hold mode unless the trim button is pressed or you're in flight director mode (Mi-17 has nothing like a flight director mode).

[Aser]

If he applies full left rudder and trims, the rudder will be displaced fully to the left with his feet on the floor--so far so good. But that pilot will still be able to apply full right rudder although I'd guess he would experience some resistance as he overrides the trim.

Smokin' Hole

 

I was trying to explain in my post that even with trim held down I can't input full reverse pedal until I release the trim.

Can you confirm if you have the same problem with your pedals??

 

Aser.

[Aser]

On the Mi-17, the pedalshave microswitches on them so the autopilot knows when your feet are on the pedals. If your feet are on the pedals, all the autopilot does is dampening for the yaw channel, but when you take your feet off of the pedals, you get dampening plus heading hold. I asked AirTito about microswitches on the pedals like this for Kamov aircraft, and he said that they did not have them, so it makes me wonder if the yaw channel of the autopilot is always in heading hold mode unless the trim button is pressed or you're in flight director mode (Mi-17 has nothing like a flight director mode).

 

Can you confirm that in Mi-17 you have heading hold with high speed? and not just coordinated turns? just curiosity.

In the AW139 we also have pedal microswitches, but HDG HOLD only works at low speed. In normal flight it provides with coordinated turns.

 

I would ask to ED to implement a key to disable yaw trim, like another reality option ie. external views etc.

 

Regards

Aser

[ericinexile]

I was trying to explain in my post that even with trim held down I can't input full reverse pedal until I release the trim.

Can you confirm if you have the same problem with your pedals??

 

Aser.

 

Yes I do. You may have misunderstood my post in that I was sharing your experience. The part that you quoted was what I imagine should happen in the real world but does not happen in the game. I think that when it comes to flight controls, certain compromises must be made to realism in order to allow for our cheap, plastic input devices. While DCS have for the most part done that, I agree with you that in Yaw they might have to compromise further.

 

Smokin' Hole

[ZaltysZ]

I thought that when you press trim you should have full input in the controls... ??

In western helicopters I've flown at least.

 

I think in real Ka-50 you always have full input in the controls (trim button pressed or not). Trim only changes the position to which controls return after pressure is removed. It is pretty straightforward.

 

Trim works differently in DCS. As there are no pedals with FFB support, there is no way to get real life behaviour. Instead of moving positions to which pedals should stick without pressure, neutral position of axis is moved. This approach has side effect which are very noticeable in situations when controls are trimmed at extreme (like in your described situation).

 

Let's make distinction between real axis of real pedals and axis of virtual pedals.

 

Let's assume that both axis are in range of [-10;10].

 

Without trim both axis have the same neutral position which is at 0.

 

If you move controller to position -5 (half left) then in game pedals are moved to the same -5 - everything is good.

 

Now let's try to use trim. Move controller to position -5, press trim. release trim and neutralize controller. After that controller is in position 0, but in game pedals is at position -5 - so far so good - intended behavior.

 

Now the problem. We have in game pedals at half left position and controller at neutral. Let's try to move in game pedals to true neutral: we move controller half right and in game pedals moves to position 0. What we get? We get ability to move in game axis to the full right in range [0;10], but real controller is already at half right and only can be moved by another half, which will translate to in game position of only 5.

 

So by using trim, we are chopping positions off from other side of axis. How much we chop, depends on how much deflected the control is when we trim.

 

I hope it helps to explain the behaviour you have observed.

Edited January 14, 2009 by ZaltysZ

[Aser]

Thanks Zaltt, now I get the picture!

Any ffb pedals out there ? ;)

 

Regards

Aser

[Belphe]

I'm very sorry if I ask about something that has already been asked about and answered. I'd appreciate if you could just point me towards a thread that describes my problem. Thanks!

Let's imagine this scenario:

I am flying straight and level, course 0, alt 100, trimmed "hands-off", with Bank, Yaw and Pitch Autopilot Assists ON. I decide to alter my course and turn 90 degrees right. I do the following:

- I bank the helo right ~30 degrees

- I apply right rudder as needed and ease on the cyclic to keep the helo in a gentle right turn

- I make minor corrections to maintain altitude

- when nearing the desired course I both gently release the right rudder pedal and slowly move the cyclic to the left to level my bank

However, the Autopilot is set to follow a course of 0 degrees and now I have to counter it's inputs by holding the right pedal slightly pressed and the cyclic pushed a bit to the right to remain levelled on the course of 90 degrees and fly straight.

No problem! I'll just hit the trim for a millisecond (as I have achieved a fairly stabilised flight in a fixed direction) and the helo should be again "hands-off" straight and levelled!

NO!!! :(

As I quickly press and depress the trim button, and immediately release the controls (both rudder pedals and the cyclic) the new autopilot settings interpret their position as their new "0,0"! My helo yaws even more to the right (as I have kept the right rudder pedal pressed when trimming) and tries to bank to the right for the same reason (cyclic held a bit to the right while trimming)...

:cry:

What do I do now? I mean, to fly straight and level on my new course of 90 degrees I would AGAIN have to counter the autopilot's new settings with Left rudder pedal and cyclic movement and when levelled press and release the trim again... Only this would "save" the controls shifted to the left now and the whole process would repeat... :huh:

This can all be perfectly seen when we enable the R_Ctrl+Enter helper window...

So, after flying the first leg... is my Shark never to fly straight again???:(:cry::helpsmilie:

Please, explain how all this could be omitted. I mean, there has to be a way... right? Right??

[ZaltysZ]

Probably you should have to make your turn with pressed trim button and release it only when you are perfectly aligned with your new course. If you make your turn without trim button pressed, you will have to fight autopilot. The amount required to negate corrections of autopilot will contribute to over trim.

 

To summarize: you should make corrections only when trim button is held pressed; making corrections and only then pressing trim gives problems.

 

P.S.: of course you can make a turn without trim pressed, just after that make any final corrections while trim is held pressed.

[Belphe]

I'm cool with that. It's just that I read so much here and on other sites that in real life pilots very often only "tap" the trim, not hold it and maneouver... This method was discouraged by many here in this very post... That's what confused me.

 

I'm all right now... :thumbup:

[IvanK]

Try punching out HDG hold before you turn ... do your turn then rengage it, blip the trimmer. This will synch HDG hold to your new heading. Also if you are not navigating per see put the DT/DH switch in the centre position., that way you can see the HDG hold diamond on the HUD and will automatically Synch HDG hold to your new heading.

[Reticuli]

I don't think the autopilot cares how much extra control was required for that particular orientation when trim and the hold channels were still on. It seems to use the orientation for the new AP attitude hold. Now, the trim part is different, but the AP will compensate, I think, when the hold channels are all on. I could be wrong, but I would guess your problem is usually having yaw input when hitting trim rather than the pitch and bank being too much. When pitch and bank *are* a problem, it's usually because you're changing collective at the same time or handling the controls too quickly and your orientation hasn't settled sufficiently. Aircraft do not respond immediately and there's always some delay. And if you're changing collective, the pitch & bank will need to be altered slightly. Ivan's recommendation will also help if you can't release pedal/twist habitually.

Edited January 16, 2009 by Reticuli

[docehrenhoefer]

So, after doing a lot of research in SimHQ and eagle.ru forums and trying a little bit: the best method to bypass the trimming problem is to engage flight director when you use a self-centering non-FFB-joystick. Esp. when flying NOE or in the attack phase.

It´s not exactly fly-by-wire/autotrim, you still have to trim, but much less and you don´t have to fight the autopilot (I still can´t believe it´s just 20%... for me it seems like it is much more).

You don´t have any problems with rudder trim far off-center and with wrong trimmings that made my helo rotate fast or crash tumbling into the ground (very embarrassing when that happens 3km off your targets - can you imagine those grinning mudrats??)

 

So: fd off and route mode/dth on while in transit, when carefully closing in to the battle area fd on with a careful trimming (trimmed on a 40km/h pitch lets you gain and lose speed very fast), when establishing hover fd off and autohover on. That worked like a dream for me.

You can even take the right hand of the joystick, doing slight heading changes using rudder and keeping altitude (collective brake and heading hold mapped on throttle, FD, auto-hover and trim mapped on joystick (X52)).

 

Trimming while in full battle is much more difficult than keeping flight attitude....

 

Greetings.

[Reticuli]

Yes, that's essentially what I do myself, except with the autotrimming GlovePIE script and it set to the FD mode by double tapping and cycling to it. No manual trimming necessary ever. The only time I have FD off is when I need the autopilot to hover for me, but usually I do that by myself. I like to bank left and not have to hit trim in order for it to hold the bank. What surprises me is how weak the rate-dampening is in FD mode. There's still a lot of drift. Certainly an improvement over the channels being off, though.

[docehrenhoefer]

Yes, that's essentially what I do myself, except with the autotrimming GlovePIE script and it set to the FD mode by double tapping and cycling to it. No manual trimming necessary ever. The only time I have FD off is when I need the autopilot to hover for me, but usually I do that by myself. I like to bank left and not have to hit trim in order for it to hold the bank. What surprises me is how weak the rate-dampening is in FD mode. There's still a lot of drift. Certainly an improvement over the channels being off, though.

 

I really would like to try your GlovePIE script, Reticuli, but I own a Vista 32Bit Machine and PPJoy does not want to work on it...

In the meantime I have fussed a little bit with my computer chair and modified it, so that a have an approx. Huey-Like HOTAS and Collective Config. (...ever seen that darn grinning face of your wife :D telling you she thinks you are just an over-sized child???? :gun_rifle:) Now flying the beast is just a dream...

[Ramstein]

....... my solution to DCS Blackshark's trim. You can download it at the lower link to AVSim Online.

 

.......

 

 

Could those tha thave tried Reticuli's Solution andscripts let me/us know if it is an improvement and if so how much? I still have not yet tried it.. kinda scared of messing something up..

 

Thanx,

:joystick:

[Ramstein]

These helo happenings have me baffled.. I will have everything set great, flying along,, and don't even need any pressure on the stick and will either be flying really slow, less than 50 kph, or even at a hover very close to zero kph.. and all of a sudden the nose will point straight up! Then it will dive down, looking like it is trying to recover from this huge glitch!

 

WTH?? Why is it doing this? :cry:

 

Thanx..

:joystick:

[Guest gurami]

center the ball

 

I can more or less maintain a heading, turn to a new heading and maintain the new one, but i can't keep the ball centered even in straight and level flight. The settings i use are dh/dt sw in the center position, 3 ap channels on, trim after turn with neutral stick. What i find is that the BS flies straight and level with 0 bank (I need some cyclic to the left to achieve that) and the ball about halfway to the right.

[Reticuli]

Could those tha thave tried Reticuli's Solution andscripts let me/us know if it is an improvement and if so how much? I still have not yet tried it.. kinda scared of messing something up..

 

Thanx,

:joystick:

 

Really nothing to get messed up. Nothing in it changes your sim installation or permanantly will damage your computer. The LUAs are just internal Blackshark stick PPJoy and X52 profiles, which you save and load within the sim. GlovePIE does not install and is only active when you hit "run", communicating directly with PPJoy. It's just a little background utility. You just run it wherever. Only PPJoy installs, and that's a totally benign piece of software that I've never heard of anyone having problems with it corrupting their computer. The Vista compatibility is something I've just heard about. Maybe the original creator could be convinced to fix it a little. I heard he got miffed about people not appreciating his work, or something. We love you, dude! Come back! This should take you less than 10 minutes to get up and running to at least try, after you've read my wordy instructions. I recommend you always cycle through the modes when you first get in to the helo. Have the control panel red thing up so you can see where you're at in the trim state. And unless you are using the Route flying or need the autopilot to hover for you, use flight director. Oh, and never turn the hold channels off when in FD. Occasionally you may need to look over to make sure they're still on if things get squirly.

Edited January 23, 2009 by Reticuli

[auricom]

OK.. I have read every page, and checked every youtube video.. I am getting the hang of using the trim , however there is still some behaviour that seems bugged..

 

To test, I put the Ka-50 on the ground and spun the engines down to idle and started messing with the trim and noting stick position (for the record, I do not have a FFB stick -- maybe that's my problem) .. I am using a Saitek AV8R ..

 

Anyways, my experiment was simple.. I left the stick centered, and pressed the trim button, held it and released.. I noticed the stick moved back slightly, so I repeated the process.. center the stick (hands off) and pressed the trim key (t on my keyboard -- wanted to make sure i was not committing any stick input)

 

again, the stick moved back slightly in the cockpit.. repeat with 6 or 7 more presses of the trim key, and the stick will eventually be cuddled up in your lap..

 

So here's my question: if the trim is supposed to neutralize the stick at current position, why is the stick *moving* on it's own when i press and release the trim key?

 

Can anyone shed some light on this behaviour, or try to reproduce it? Maybe it's a bug with my stick drivers if nobody else can..

[Fakum]

I wish I could help you, but I am not expieriencing that with my Cougar?

[sonic]

Did you try defining deadzone for the X and Y axis on your stick?

[auricom]

Hmm no but it's worth a shot I'll give that a try .. But it's strange that the stick actually moves slightly *after* I release the button, doesn't seem like a deadzone issue to me..

 

Is there somewhere in DCS to define a dead zone or do I need to do that w/ my joystick software?

[MBot]

Sounds like a problem with the stick, perhaps the electronical center of your stick is slightly aft of the physical center. So even if you think your stick is physically centered, for the computer it is pointing slightly aft. This would explain the build up of aft cyclic every time you trim in Black Shark. Perhaps re-calibrating your stick will remove the problem.

[sonic]

You can define deadzones inside DCS

[auricom]

Thanks guys.. Defining a small dead-zone has indeed resolved this issue, and a couple other wierd little glitches I was having.. appreciate the suggestion :)

 

tonight I move onto figuring out the weapon systems on this bird :)