FSX-MS Inherent flaw of FSX to give too much ground friction?

[abax2000 1]

Can you do some tests and report back ?

Ok

[Johan_Dees 84]

Right now we know it's bad, it changes the Takeoff Run Distance PMDG must have tweaked for months to achieve realistic values.

 

You only know its different Alec, so what should the real NG do ? Otherwise its only assumptions.

 

We already know we need too much thrust for taxi, and not in NGX only.

So friction was too high, its been lowered to realistic values what gives taxi a much improved behaviour.

Now the runway thrust is too high, cause we have lower friction, and yes it needs adjustment if you want your old behavior back.

(Aired, table 1506 can change this)

 

So in short, its a take it or leave it deal. And is free, but might need some work on the airplane to get in sync.

And thats the result of MS setting it too high in the beginning, putting all of us on the wrong path.

We can adapt, will need some work, but in the end the realism is better, and worth it.

 

One isnt pushed in using this, its a free choice. But one needs to understand some side effects on high fidelity planes, but can be overcome.

I of course will do it for my favorite planes myself, knowing a bit of air file edit helps, the rest is community effort.

 

EDIT: Oh, you can have a middle way, use Pete's solution, and just change the sliding friction, the rakeoff roll stays the same, but non ice runways behave like they should do.. prevent you from sliding all over the place.

[Alec 370]

Is that possible? That would be already excellent! This way we will have our Distances unmodified but with much more realistic feeling during Taxi Turns and landing in Crosswind.

[flying_bob 38]

Ok guys help the less technical.

I downloaded 4859j, added it to FSX modules folder (overwriting old version)

I downloaded the latest LUA files. added the "friction.lua" file to the modules folder.

I opened the FSUIP4.ini file with notepad.

 

-under [General] section added the entry

PatchSIM1friction=Yes

 

-under [LuaFiles] section I added entry for friction

20=Frictions ** note 20 is my next available number

 

anything else that need to be done or should I be good to go, anything else to do inside FSUIP4 menu of FSX

 

Appreciate

Thanks

[willywonka 36]

NGX's taxi power is too high? All I need is about 27% to break away and 22-24% to maintain. TO weight is about 140000-150000 lb. I see some people saying they use 40%?

 

Side friction is terrible though.

[doorstep 46]

Well I used it (A big thank you Johann) and to my mind it is realistic now with the NGX. Take-off roll included. Well done to Johann and Peter.

[Pete Dowson 558]

-under [General] section added the entry

PatchSIM1friction=Yes

 

If you want to use the "frictions.lua" file, then there's really no need to use that parameter -- it's for unregistered users, to simply apply Johan's last posted changes. Those are the ones included in the suppied example Lua in any case.

 

-under [LuaFiles] section I added entry for friction

20=Frictions ** note 20 is my next available number

 

FSUIPC maintains the [LuaFiles] section automaticly. There's never any need to edit that section.

 

anything else that need to be done or should I be good to go, anything else to do inside FSUIP4 menu of FSX

 

You can load any specific frictions plug-in by assigning it to a button or key combination, so you can experiment, or, once decided which is best for each aircraft profile simply add sections to load the relevant Lua plug-in, i.e. by adding to the INI file:

 

[Auto.<name of profile>]

1=lua <name of Lua frictions file for this profile>

 

for each profile.

 

Then each time you load an aircraft, the correct (hopefully! <G>) frictions will be loaded.

 

Unless you wanted all non-profiled aircraft to use Johan's values, you should delete your

 

PatchSIM1friction=Yes

 

line. Best to test things with default FSX settings first, don't you think?

 

Rgards

Pete

[Maxthrust 0]

You only know its different Alec, so what should the real NG do ? Otherwise its only assumptions.

 

We already know we need too much thrust for taxi, and not in NGX only.

So friction was too high, its been lowered to realistic values what gives taxi a much improved behaviour.

Now the runway thrust is too high, cause we have lower friction, and yes it needs adjustment if you want your old behavior back.

(Aired, table 1506 can change this)

 

So in short, its a take it or leave it deal. And is free, but might need some work on the airplane to get in sync.

And thats the result of MS setting it too high in the beginning, putting all of us on the wrong path.

We can adapt, will need some work, but in the end the realism is better, and worth it.

 

One isnt pushed in using this, its a free choice. But one needs to understand some side effects on high fidelity planes, but can be overcome.

I of course will do it for my favorite planes myself, knowing a bit of air file edit helps, the rest is community effort.

 

EDIT: Oh, you can have a middle way, use Pete's solution, and just change the sliding friction, the rakeoff roll stays the same, but non ice runways behave like they should do.. prevent you from sliding all over the place.

 

First of all, GOOD JOB JOHAN!! I've been waiting for the equivalent of the fs9 sim1.dll mod for a very long time. :yahoo:

 

Now the hard part is done, I don't mind adjusting 1506 values for my jets..

 

Now the trust for lower altitudes ( say < 5000ft ) must be reduced by the same amount with the rwy drag, that would eliminate any excessive takeoff performance issues for the majority of the airports but wouldn't effect climb/cruise performance. I think it's worth a try. :Thinking:

 

To bad I have my exams for the next two weeks, otherwise I would like to help you out with the testing, etc. :p0304:

 

Keep up the good job sir :drinks:

[FSMP 95]

With the introduction of Peter Dowson latest version of FSUIPC, the USER is now in direct control of what planes they choose to modify the Friction on.

 

ie,

If PMDG have tweaked their plane to handle as published by Boeing, then you may not have to add a Lua Correction file for the PMDG 737NGX.

 

If you don't like the taxi performance of the Microsoft C172, then you can change it to whatever you want, using FSUIPC.

 

Maybe someone in the FS Community will even put up a website, with Developer and User contributed Friction Lua files for a selection of popular FSX aircraft.

 

------

What Peter Dowson has done is truly an exciting breakthrough.

How it is starting to become possible to alter the Internal working of FSX, in real time, with simple Lua scripting.

Yet another way to put new life into FSX !!

 

Possibilities are endless. Just for the ability to be able to change the Friction in real time.

(1) Brake Pad wear simulation.

(2) Tyre wear simulation.

(3) Brake failure simulation.

(4) Brake fade at high brake temperatures, (for those that do not already do this).

(5) Random ICE patches on Runways in cold weather.

etc

[LHookins 3,103]

NGX's taxi power is too high? All I need is about 27% to break away and 22-24% to maintain. TO weight is about 140000-150000 lb. I see some people saying they use 40%?

 

Preston, could you test this with the clear weather theme and a stock airport somewhere with stock scenery? I'm not so much concerned that the friction values are wrong as that they are *different* for different users.

 

Hook

[willywonka 36]

Preston, could you test this with the clear weather theme and a stock airport somewhere with stock scenery? I'm not so much concerned that the friction values are wrong as that they are *different* for different users.

 

Hook

Sure I have (KEDW to be exact--no weather, stock livery). I remember PMDG discussing, before the release, that they were working around FSX's friction to make the ground handling as realistic as possible, so that we (supposed to) have low break away thrust. I'm completely surprised to see people using as high as 40% to taxi.

 

I really look forward to improving the side friction though.

[LHookins 3,103]

I'm completely surprised to see people using as high as 40% to taxi.

 

Person A has to use 40% to taxi. Person B only uses 24%. This apparently happens on dry runways for both.

 

Now... WHY so much difference? Two obvious possibilities. 1. Different versions of the NGX. 2. Different sim1.dll files. Any others?

 

There are a few reasons why the sim1.dll files could be different. You might have differences between FSX SP2 or Acceleration, for example.

 

As for the lack of side friction, this is necessary to land a large airliner in a crosswind condition. The preferred method is to crab with the nose pointed into the crosswind, touch down on the mains while still crabbing, use the rudder to straighten out the aircraft, then lower the nose wheel. You can find youtube videos of this. Imagine what happens if your side friction is too high in such a case.

 

It is not strictly necessary to actually modify the sim1.dll file to get the adverse effect people are seeing with other aircraft. It's possible that a saved flight, your default flight, might have these values modified, and any time you load FSX with your default save file, these values get loaded so that if you change aircraft to something smaller you still have friction values appropriate to an airliner.

 

What I'd want to know, long before hacking into the files, is why some people have problems while others don't. That way, I know exactly what to hack and why, and most importantly, when.

 

Hook

[Piggles 17]

Ignore post, was on page 1 without checking the rest of the thread, doh!

[Pete Dowson 558]

There are a few reasons why the sim1.dll files could be different. You might have differences between FSX SP2 or Acceleration, for example.

 

The values for the friction coefficients seem never to have changed in any of the SIM1.DLLs I've seen, actually. They are probably the same in FS9 -- in fact didn't I see a post somwhere near here that said as much?

 

Of course other aspects of the simulation engine might have changed which affects how these are used. That's a different matter.

 

As for the lack of side friction, this is necessary to land a large airliner in a crosswind condition. The preferred method is to crab with the nose pointed into the crosswind, touch down on the mains while still crabbing, use the rudder to straighten out the aircraft, then lower the nose wheel. You can find youtube videos of this. Imagine what happens if your side friction is too high in such a case.

 

Hmm. The twisting of the wheels on the tarmac would involve components of both rolling and slipping frictions. It isn't that straightforward. I would actually tend to think that more slipping friction would help straighten up rather than hinder. Lower slipping friction means the whole aircraft sliding sideways. More grip surely helps, not hinders?

 

Regards

Pete

[Ron Attwood 3,465]

This is all very interesting but must you have a knowledge of Lua, whatever that is? Sounds like something for programming whizz kids!

It makes me feel...trepidatious! :huh: