Jump to content

Option choices for BS


sobe

Recommended Posts

In the special section for BS, there are a number of boxes to chose. I am confused as to what they do. I have a WH Hotas with rudder pedals-

 

 

 

Rudder Trim: It would seem like I should check this box?

 

 

Trimmer Mode:

there are 3 choices-

Default-what does that do?

Central position trimmer mode?

Joystick without springs and FFB-since the WH has springs, I assume this is not applicable to me.

Trackir4 using the latest Trackir 5 software, Win10 Pro [Creator Update] updated from Win7Pro Pro 64Bit, Intel® Core™ i5-2500 3.30 GHz 6M Intel Smart Cache LGA115 , GigaByte GA-Z68XP-UD4 Intel Z68 Chipset DDR3 16GB Ram, GTX MSI Gaming 1060 [6 GB] Video Card, Main Monitor 1 on left 1920x1080 Touchscreen Monitor 2 on right 1920x1080 .

Link to comment
Share on other sites

Trimmer Mode:

there are 3 choices-

Default-what does that do?

Central position trimmer mode?

Joystick without springs and FFB-since the WH has springs, I assume this is not applicable to me.

 

Default = For Force Feedback joysticks, you press trim button and the FF does move the centering force to the position where you pressed the trim. So every time you move joystick away from the trimmed position you get the force feedback that tries to get you back to trimmed position, or if you release joystick it will center to the trimmed position.

 

Central Position = every time you trim, you must return the stick to center before its input is reacted again. This is the mode you want to use if you have the centering spring in joystick so you don't need to hold joystick in the position where you trimmed it. It get tiring if you try to keep heavy joystick like Warthog all the time in the various locations where you trimmed it, and you can't return it back to trimmed center if you accidentally moved it away from it.

 

Joystick without springs and FF = This is for joysticks that has either no FF or no other centering force, like how you example can make VKB Gunfighter II to be with dry clutch. It means that if you have joystick that you can move around and when you release the joystick, it will stay in that location where you left it. So every time you press trim, you can take your hand off and joystick stays in place.

 

The similar thing is with the pedals, in real helicopter you would keep the pedals in trimmed position as they are very light. But you have centering spring in the most pedals, so you can set it so that you re-center the pedals after each trim.

 

One thing that makes helicopters to fly difficult is that the cyclic changes the Angle of Attack of the rotor blades. With typical helicopter with counter-torque rotor your pedals is changing its Angle of Attack. And when you move cyclic or pedals to center, you zero the AoA. Meaning you would be in hover or counter-torque wouldn't be pushing either left or right.

 

But as there are internal (Center of Gravity) and external forces (wind) and your own helicopter main rotor rotating (clockwise or counter-clockwise), your helicopter would start to move and rotate at counter direction of the main rotor. So you need to apply some Angle of Attack on both to counter the forces.

 

In Co-Axial helicopter you don't have counter-torque rotor, and as both your main rotors are rotating opposite directions, they will counter each others rotating forces. And that leaves the wind being effective force as your Center of Gravity. And both of those you counter with same controls as typical helicopter (cyclic, collective and pedals) but the pedals are changing the symmetry of the main rotor Angle of Attack. So when you want to turn left, the AoA is increased on the rotor that is rotating to clockwise and counter-clockwise rotor AoA is lowered so your altitude is not changed, but as the clockwise rotor has now higher AoA, it starts to bite to the air and push your helicopter nose to the left.

 

Your helicopter Center of Gravity is constantly moving depending your weight. It typically would exist above your helicopter main rotor, meaning your helicopter is like hanging from a string.

Fig3-1.JPG

But heavier you are, lower the CoG is and more "on tip of the needle" experience you get, as all the mass you have will rotate around the center of the mass. Lighter you are, higher it is.

And your weight changes across the helicopter latitude axis, and the CoG can even exist outside of the helicopter.

 

And when you fly the helicopter, you need to apply controls around that CoG, not where you sit or where you look around. And now you can think it that you are flying an helicopter that is like balancing a forks on edge of the glass:

 

hqdefault.jpg

 

And what does this mean with everything you asked?

 

That is the point of the helicopter controls, you don't ever have "center" of the cyclic, collective or pedals where your helicopter would always hover. It is constantly moving. And your task as pilot is to find that position with your controls so that you can hover. And if you are very heavily loaded (all mass positioned to center) and there is strong external force (wind) you might be required to hold the cyclic at the edge of its movement range. Like if there is heavy wind coming from right, you need to hold the cyclic almost as far right you can so you can hover.

 

Sudden weight change like releasing heavy load weapons or dropping cargo, or sudden strong winds does quickly change the CoG position, so you need to have range of the cyclic to counter it, to balance your new CoG. In overtime the fuel consumption will empty fuel tanks and your weight changes, so you don't even notice that you might be moving cyclic, collective and pedals to counter it as it is so slow change, but it is there.

 

And now when you are flying helicopter, your flight controls are directly linked to the helicopter blades. So the extreme right cyclic will physically tilt the helicopter swash plate.

Ao8JO.jpg

 

And that controls your main rotor Angle of Attack to 90 degree from your cyclic direction.

 

And why this is important in this your question?

 

As I wrote, your cyclic movement range is the same as the movement range of the all AoA you have. So your max cyclic to right is your max main rotor AoA. Your max pedal is max AoA you get.

 

And when you fly the real helicopter, you will find out that what is your CoG all the time depending the position of your controls, it is never in the center, but it is always in the linear scale of the range of your controllability.

So once your cyclic is far right, you can't get from anywhere anymore AoA to your rotors to give you more input.

If your collective is as far up you can get it, you have hit your AoA limit in overall.

 

And that is why you have limitations in flight conditions and weight etc. As you are directly controlling the AoA with everything. If you pull hard your collective up, it means your main rotor all blades AoA is at maximum. Now you don't anymore have any controllability as there is no higher AoA to counter external forces etc. In KA-50 that means you can rotate etc, but it does it so that opposite direction main rotor AoA is lowered so you can turn, but so you can turn, now your total AoA is smaller and you will lose altitude. So after turning with pedal, you need to stop turning so maximum AoA is reached again so you would get back to hover.

 

And now if you think about your physical gaming HOTAS in front of you. You have a spring loaded centering joystick, that you can wave around its maximum input range (like 25 degree to any direction). But in real helicopter you have trimmer that centers your cyclic to the position where you pressed trim. That is done with magnetic lock so it stays there but can be moved with little force. But at any given time does not the trim center the cyclic, pedals or collective. It does just that, initiate magnetic lock to keep it there, so you have more relaxing flight as your controls are very sensitive for small control inputs.

 

The pilot will all the time know the helicopter condition with its own weight etc and external forces by its location of the controls.

But virtual pilot does not who has "Center Trimming" as you always have joystick at the center after trimming.

 

So every time you do control movement and you press trim, you need to bring back the joystick to center where spring does move it. So you have relaxed joystick position. But doing so, you will never know that how much AoA you have left on any direction.

 

And that is why helicopters always has this direct control feedback by not having FBW system where you would trim to new position and then have cyclic at center. There is no "Angle of Turn" mode based your cyclic angle ("If I keep cyclic 15 degree right, helicopter keeps 15 degree roll angle to the right") but it is "Angle of Rate", as the helicopter rotor AoA is changed to fly, and you know constantly how much you can change AoA as how much you have it in reserve.

 

And that makes it very challenging to fly at the mountains where strong wings are blowing at different rates and times, and you need to counter all them at sudden times. And air is thinner, so you are at your AoA limitations easily as thin air requires higher AoA to stay in hover.

 

If you fly with joystick that has no centering spring or you have FF joystick, you will all the time know your AoA possibilities. And you know that what are your flight possibilities just from the position of your HOTAS.

 

And that is what makes flying helicopters so difficult with any centering joystick, as you don't know how you are really flying otherwise than looking out of your window and yet you don't know that how much you have in reserve of AoA for some directions.

 

As for you the joystick is centered after trimming. But for helicopter the virtual cyclic might very well be 90-98% already of its AoA limits, so if you don't notice that cyclic is far edge to one direction or you don't have the Control Input screen (Alt+Enter IIRC) then you don't know it. And you might try to fly in situation where you reach point you are out of control authority and you lose control of helicopter and try to add new inputs that you don't have and you make all just worse and eventually crash.

i7-8700k, 32GB 2666Mhz DDR4, 2x 2080S SLI 8GB, Oculus Rift S.

i7-8700k, 16GB 2666Mhz DDR4, 1080Ti 11GB, 27" 4K, 65" HDR 4K.

Link to comment
Share on other sites

...

Just to add a little too Fri13:s explanation...

Ruder trim: when triming, return them to center if having this checked. Good for centering pedals, but may people (including myself) finds it very confusing and easy to run out of pedal authority.

 

Default: for ForceFeadBack sticks it's like Fri13 described, but for non-FFB sticks the input from it is disabled for a very short time, and you are supposed to center your stick (quickly) during that time. This time can be increased by slightly edit a lua file, but I don't have the details in memory.

 

The other modes are like Fri13 described.

Helicopters and Viggen

DCS 1.5.7 and OpenBeta

Win7 Pro 64bit

i7-3820 3.60GHz

P9X79 Pro

32GB

GTX 670 2GB

VG278H + a Dell

PFT Lynx

TrackIR 5

Link to comment
Share on other sites

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...