Helicopter and Joystick

[ThunderChief]

I read about some people (x-plane forum) removing the centering springs from their joysticks and pedals because real helicopter don't have them.

As I understand it you can use trim so the stick can be at center postion while not manouvering.

 

Does the trim work like in airplanes or can you simply press a button to make current stick position the new center position?

And if so will this go smoothly even if there is great trim diffrence?

[nemises]

wouldn't the stick just list to one side if you let go of it without the centering spring ?...(thinking of an x52 here)

[RedTiger]

And, for whoever answers, could you get a little more basic and explain what trim does in a helicopter. Having never flown a helo sim, I have difficulty visualizing what you're trimming out. Yaw? Forward/backward/sideways movements (nose pitch up/down, helicopter wants to flop to one side or the other)?

[BBQ]

I'm no expert here--but I can tell you that with the Ka-50, how the trim works. In a helicopter, the trim does not work like it does in an airplane. Untrimmed, you are flying along--and then when you hit the trim button, the helo in 3D space is put into memory, and the actual physical stick stays where it was when you initiated the trim. Essentially it holds the stick in place. For non-force feedback sticks it's a little tricky. When you hit the trim button, you have to release the stick and the rudder to their physically neutral positions. The helo will then fly in the new "attitude" with your stick and rudders in their physically neutral position. Not sure if this is the way it is in all helicopters, or not.

[DeCreator]

As I remember, there are some springs inside the stick mechanic, which use about 7Kg of force. So, with angle increasing, more force to your hand. And when you click trim button, this force became to 0. Release button, move stick to another side = forces come back.

It is one trim mechanic. There is also another one - electric. You push semi-directional "hat", and stick became to move that direction itself.

 

Depends on helicopter type.

[Cougar12dk]

The trim should be used to remove any forces that takes the stick away from it's neutral position. It's really taxing to fly for a long time with a stick out of trim. And after a while you start feeling sore in your muscles from straining to keep the stick neutralized.

 

What the trim does, is remove any force that is trying to move the stick away from it neutral position, so you don't have to hold it forward/backward/to the side continuously.

 

I don't remember how it affects the blade's pitch mechanism anymore, as it's been 5 years since I flew, but it's certainly electrical on a Schweizer 269CBi.

[ThunderChief]

For non-force feedback sticks it's a little tricky. When you hit the trim button, you have to release the stick and the rudder to their physically neutral positions. The helo will then fly in the new "attitude" with your stick and rudders in their physically neutral position.

 

That better explains my question. I would like to know if that transition to neutral AFTER trimming will be smoothly.

I mean after trimming the stick will be far of the neutral and the helicopter might react to this before you had enough time to move the stick to center position? (without FF)

 

And if you have a FF Stick will trimming move the "center point" or will it behave like normal stick?

Edited July 22, 2008 by ThunderChief

[VS461]

Helo stick

 

Hey there,

must depend on helo type, I think. On Mi-8, you push the trim button to almost zeroize the artifical "force feedback" (spring load), and by releasing it you set a new zero position for the "force feedback". Pilots "play" with the trim button second by second with smooth stick movements (take-off, land, IFR, for example, not during breakdance above the battlefield); you can hear it in the cargo bay, trim mechanisms are behind the cockpit wall.

On Mi-24s, you can use this trim in the same way but you also have the electric 8-way hat switch to move the stick and the neutral position smoothly. For IFR, maybe this is better, for hard maneuvering, you press the trim button, move the stick rapidly and release the button:joystick:.

Both helos have autopilot to stabilize the attitude around the 3 axes (plus Hinds have an additional fixed-wing-like AP). By pressing the trim button or using the hat switch (or use the pedals with microswitches on them) the AP turns into a "waiting status". I don't know the exact term in English, it waits for the new neutral attitude and will stabilize this new one.

Cheers!

Edited July 22, 2008 by VS461
sth missed

[BBQ]

That better explains my question. I would like to know if that transition to neutral AFTER trimming will be smoothly.

I mean after trimming the stick will be far of the neutral and the helicopter might react to this before you had enough time to move the stick to center position? (without FF)

 

And if you have a FF Stick will trimming move the "center point" or will it behave like normal stick?

 

Good question. You have to do it smoothly--it's a little difficult at first, but you develop a skill after flying for awhile. In other words, the more you practice, the smoother the transition. At first though, it can be frustrating.

 

I'm not sure how FF works--I think it works so the stick stays in the position it is at when you engage trim. Not sure though.

[RedTiger]

So there's a trim button? I just assumed that there was a hat switch like a plane has that adjusts control surfaces on the rotor and fuselage. Is a button the standard thing in helicopters?

[ThunderChief]

What i forgot to say was that I am interrested how it works in DCS, because a gameing joystick is diffrent to a real one and DCS is so realistic that I thought the transition could cause some trouble.

Maybe it would help to know how fast the helicopter would respond to stick input.

[BBQ]

Gaming sticks work fine in DCS--no worries. I would imagine it responds to stick input just as it does in the real thing. Instant.

[Yellonet]

I'm looking to buy a FF stick to go with BS, does anyone have the Saitek Cyborg Evo Force and could give me their view on it?

[-sulan-]

I'm looking to buy a FF stick to go with BS, does anyone have the Saitek Cyborg Evo Force and could give me their view on it?

 

I'd also be interested to know since my MS forcefeedback 2 is getting a little worn down.. :)

 

Interesting discussion..

[AlphaOneSix]

So there's a trim button? I just assumed that there was a hat switch like a plane has that adjusts control surfaces on the rotor and fuselage. Is a button the standard thing in helicopters?

 

That kind of trim does not exist in a helicopter. In a helicopter (well, most helicopters), you have magnetic brakes and springs attached to the flight controls. When the force trim button (and that's what it is called, "force trim" specifically, not just "trim") is NOT pressed, the magnetic brakes are energized, and any movement of the controls is against the springs. So you could just let go of the stick and it won't move (same with pedals and collective, if they use the same system) since the springs will hold the controls in place. Pressing the force trim button deenergizes the magnetic brakes, so that moving the controls gives no feedback. When you are done moving the controls, you release the force trim button, reenergizing the magnetic brakes, and you have spring tension again in the new control position. During maneuvering, the force trim is constantly being pressed and released, or sometimes even just held down for extended periods. During straight and level flight, you can go for quite a while without hitting the force trim button.

[ThunderChief]

So how will force trim work in DCS as I have no magnetic brakes in my stick as far as i know ;)

[RedTiger]

So how will force trim work in DCS as I have no magnetic brakes in my stick as far as i know ;)

 

I would guess that when you have the force trim button depressed, you can waggle the stick around but your Ka-50 will not react. On screen you'll probably see the virtual stick move around. Let go of the button and now moving the stick moves the helicopter and you'll see the virtual stick now moving from the new position.

 

This is just a guess though. ;)

[Yellonet]

But that wouldn't work like in the real chopper then.. as I understand it the stick can not be disengaged from controlling the aircraft, just from the forces put upon it.

[AlphaOneSix]

Moving the stick always moves the helicopter, regardless of whether or not the force trim button is presed.

 

In game, when you move the controls around, you would press the force trim, do your control inputs, then let go of the button. When you let go of the button, also let go of the stick, or at least just let it return to center. Now your joystick is centered, but as far as the game is concerned, it is still where you left it. If you release the trim button, but don't let your joystick return to center, it will still make the new center where you released the trim button, then start adding more control input because you are now pushing the joystick away from that center...I know that may not make much sense, I am just not very good at explaining how it works in the game. All I can say is that it feels fairly realistic to me (I am not a pilot but I have worked on helos for many years and I have recently flown an Mi-17 for about an hour). Obviously the most realistic thing woulod be to have a FF joystick where the stick has spring tension when the force trim is not pressed, and is just floppy without tension when it is pressed. Also, when you release the button, it shold stay put in that spot under spring tension (but still be able to move and control the aircraft, just with a new center).

[Duke49th]

Sorry for Offtopic, but did any of you know what is happen to this site: http://leftside-limited.com/index.html ?

 

I'd like to build a collecitve like the one shown there, but there is no Video....only a Video for the Stick.

[Yellonet]

Moving the stick always moves the helicopter, regardless of whether or not the force trim button is presed.

 

In game, when you move the controls around, you would press the force trim, do your control inputs, then let go of the button. When you let go of the button, also let go of the stick, or at least just let it return to center. Now your joystick is centered, but as far as the game is concerned, it is still where you left it. If you release the trim button, but don't let your joystick return to center, it will still make the new center where you released the trim button, then start adding more control input because you are now pushing the joystick away from that center...I know that may not make much sense, I am just not very good at explaining how it works in the game. All I can say is that it feels fairly realistic to me (I am not a pilot but I have worked on helos for many years and I have recently flown an Mi-17 for about an hour). Obviously the most realistic thing woulod be to have a FF joystick where the stick has spring tension when the force trim is not pressed, and is just floppy without tension when it is pressed. Also, when you release the button, it shold stay put in that spot under spring tension (but still be able to move and control the aircraft, just with a new center).

Indeed, there should be an option for FF stick or not, and when you enable FF you get the effect that you spoke of. Maybe in a future module :)

[Yellonet]

So, no one here has a Saitek Cyborg Evo Force?