FSXA FDE for ships

#1
Hi,
I would like to learn about FDE for ships.
I know I will have to edit the cfg. and air. files, but it is hard to get a simple tutorial for beginners.
I understand most of what the SDK says, but linking it to the reality of a ship is not easy. Is there anyone who could give me suggestions on how to tackle this?
Thx.
Marcel
 
#2
Hi,

It depends on what kind of ship you are speaking about. A living world one (with a sim.cfg), an AI one (with an aircraft.cfg and an air file) or a 'sailable' one. And what type of ship is it (length, weight, etc.)
If a Living world one: just use the sim.cfg of one of the others in the simobjects folder and perhaps adapt the contact points depending on what the reference point (the center of the model) is compared to the ground/water;
If an AI one: the air file is not important, just use one of an aircraft (Cessna for a small boat or B747 for a big ship). Same thing for the aircraft.cfg but there you have to make some more changes. I do not think this is the right way for FSX because FSX has the Living World sim.cfg option.
If a pilotable one: the same goes as for the AI one. I suggest you take a look at the .air file and aircraft.cfg of one of the pilotable models on www.FS-shipyards.com. They are for FS2004 but nothing has changed compared to FSX but for the fact that FSX is not so dependent on the .air file and more on the aircraft.cfg.
Good luck and 'les boules'.
 
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#3
Hi Roby
Thanks for the quick reply.
What I actually would like to learn is improve the FDE of ships so that they can become really pilotable like a good aircraft.
There are lots of very nice ships available (both AI and pilotable), but it is very rare to find one that has the capabilities that I would like to see:
- a well tracking Autopilot, that is following the plotted course without oscillating all the time.
- a good reverse thrust so that you can manoeuvre decently when docking or mooring the ship.
- a good braking system (maybe a short version of the reverse thrust?)
- a good ankering system so that the boat is not moved away by the current or the wind.
- maybe a good kind of push back system?
I have found a very good "auto pilot" gauge system and when you install it on a ship you can immediately see whether it is obeying to the AP or not.
I also have been looking at the cfg. files and seen that there is reverse thrust possible, but it does not seem to work on ships being created on the basis of the cessna cfg file.
Just to indicate you, that I have been spending already a lot of hours on the subject, but I feel that without some one to teach and guide me, I am coming not much further.
All help is welcome.
Marcel
 
#4
I am afraid that is all the help I can give. The rest is trial and error, a bit of understanding, a bit of intuition and a bit of experimenting.
 
#5
Hi,
The last three weeks I have been concentrating on creating a reverse thrust for ships with a piston engine. There are many very nice freeware pilotable ships available for FSX, but they nearly all lack a reverse thrust. I had several conversations with Michel Paquet who has published on these forums his quest to create his own ship from scratch. I am very grateful to him that he shared very openly his experiences with me. This + all other things I've been reading through, lead me to the conclusion that Flight dynamics editing is often done on a trial and error base.
So i wanted to find out if, for the reverse thrust, there was'nt a universal method that could be applied.
Therefore first a small theoretical framework, but as simple as possible (my excuses to people who know much more about this and who'll say that I am oversimplifying):
A piston engine in FSX delivers forces that make a shaft turn in 1 direction only (clockwise). That movement can not be reversed (i.e. anti clockwise). So reverse thrust does not come from the engine.
On the shaft sits the propellor.
There are 2 kinds of propellors.
A fixed gear propellor that can not create a reverse thrust,
and a constant speed propellor that can.
Why? Because it can feather. This is what happens when you feather a propellor:
So it can create a reverse thrust, because it can change the angle of attack of the blades in the air or in the water.
Back to FSX:
It is actually rather simple to create a reverse thrust for a ship.
You go to the aircraft CFG file, look for the propeller section and see that you set the following parameters:
propeller_type= 0
beta_max= 65
beta_min= 15
min_gov_rpm= 500
prop_feathering_available= 1
prop_auto_feathering_available= 1
min_rpm_for_feather= 500
beta_feather= -65
prop_reverse_available= 1
minimum_on_ground_beta= 1
minimum_reverse_beta= -14
The rpm values may somewhat vary and the beta values (feather angles) are not absolute either. But I am pretty sure that the reverse beta must be a negative value.
And maybe a propeller with 4 blades works better for a boat, but I don't know for sure.
How do you make this work when piloting?
Pushing first F1 and then F2 will not work.
There is a command Cntr+F2, that is often misunderstood. In most literature it says that it reduces the RPM. But in Microsoft literature I found that it actually decreases the propellor beta (angle of attack of the blades), which means that it is the feathering command.
So if you are piloting a ship and want to reverse:
Push F1 first, keep Cntr+F2 down for some seconds, give throttle again and you'll be in reverse.
To return to normal thrust: again push F1, then Cntr+F4 for some seconds and give throttle again.
Voilà, problem #1 of the pilotable shipping solved.
Up to the next one: improving the autopilot tracking...
Cheers
Marcel
 
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