The problem with using the FSUIPC mod with the NGX is that PMDG have already adjusted engine thrust at low N1 so that taxiing thrust and breakaway thrust are representative. This compensates for the higher friction. If you apply friction is reduced so now the engine thrust is too high and the aircraft will roll with very little extra thrust. On system with the mod enabled, the fully loaded -700 won't move at idle but begins to move at 22% N1.

 

However it's still worth using the mod because the lateral tyre forces and contaminated runway effects are much improved. you can adjust the effects and choose which you want to use. So you could keep the rolling friction as it is and have the modified sliding and/or braking effects. Best of both worlds.

I doubt that PMDG has included friction in their aircraft.

The PMDG 737-800 NGX does not start rolling with throttles at idle and half load.

A real 737-800 NGX does...

 

Bob Scot ( cockpit specialist ) and Johan Dees ( FDE developer for Phoenix and PSS ) have studied the friction in Fs compared to reality and developed this LUA script.

I use it in my full size cockpit too.

Imho a must.

The reason i delete set friction (WHEEL ROLLING) is personal preference because with this line you just need to give the NGX a bit of juice and takes off and keeps rolling. So DELETE WHEEL ROLLING and you'll see the difference

 

Trying to get this working on works PC in FSX

Its not working

 

DynamicFriction.lua    added to Modules folder

 

[Auto]

1=Lua DynamicFriction

 

added into config

 

Does it work when your not registered? 

 

 

It does require a registered copy of FSUIPC to work.

 

There are two ways of altering the runway friction--one is with a FSUIPC.ini setting, but that changes the friction for all flight regimes.  The reason I wrote the DynamicFriction lua script is to change the "sticky ramp" friction behavior only at low (taxi) speeds, and then switch back to normal values above that so that takeoff, landing, and stopping distances are not altered appreciably from what the FDE designer intended. 

 

As to realism, I can tell you from experience that modern bigh-bypass turbofans produce a lot of thrust at idle, and low to no power breakaway and acceleration during taxi is a fact of life.  In the Gulfstream V we used the thrust reversers all the time during ground ops to keep taxi speeds under control because of the high idle thrust from the Rolls-BMW BR710 fans.  I've watched lightly loaded 777s (i.e. Air France on their Santiago Chile to Buenos Aires leg) initiate taxi with no discernable increase in power.

 

Regards

I bought/registered a copy today because of the comments here. I have to say its now gone in my "must have" list, its really does make a huge difference. 

 

Great for taxiing and brake away "feels" so much more natural. 

 

Thank you Bob.

 I have to say its now gone in my "must have" list, its really does make a huge difference. 

 

 

And from this day on you will discover a lot of features that you will wonder how you managed without FSuipc.

 

One a quiet weekend morning, grab a cup of coffee and read through the documentation, amazing stuff.

It does require a registered copy of FSUIPC to work.

 

There are two ways of altering the runway friction--one is with a FSUIPC.ini setting, but that changes the friction for all flight regimes. The reason I wrote the DynamicFriction lua script is to change the "sticky ramp" friction behavior only at low (taxi) speeds, and then switch back to normal values above that so that takeoff, landing, and stopping distances are not altered appreciably from what the FDE designer intended.

 

As to realism, I can tell you from experience that modern bigh-bypass turbofans produce a lot of thrust at idle, and low to no power breakaway and acceleration during taxi is a fact of life. In the Gulfstream V we used the thrust reversers all the time during ground ops to keep taxi speeds under control because of the high idle thrust from the Rolls-BMW BR710 fans. I've watched lightly loaded 777s (i.e. Air France on their Santiago Chile to Buenos Aires leg) initiate taxi with no discernable increase in power.

 

Regards

Thanks for the script Bob ...

It does require a registered copy of FSUIPC to work.

 

There are two ways of altering the runway friction--one is with a FSUIPC.ini setting, but that changes the friction for all flight regimes.  The reason I wrote the DynamicFriction lua script is to change the "sticky ramp" friction behavior only at low (taxi) speeds, and then switch back to normal values above that so that takeoff, landing, and stopping distances are not altered appreciably from what the FDE designer intended. 

 

As to realism, I can tell you from experience that modern bigh-bypass turbofans produce a lot of thrust at idle, and low to no power breakaway and acceleration during taxi is a fact of life.  In the Gulfstream V we used the thrust reversers all the time during ground ops to keep taxi speeds under control because of the high idle thrust from the Rolls-BMW BR710 fans.  I've watched lightly loaded 777s (i.e. Air France on their Santiago Chile to Buenos Aires leg) initiate taxi with no discernable increase in power.

 

Regards

 

I love it when small independent developers produce something so small that it almost goes unnoticed - yet actually having such huge impact on the overall experience, that it becomes a must have.

 

Thanks Bob.  Great mod.

And from this day on you will discover a lot of features that you will wonder how you managed without FSuipc.

 

One a quiet weekend morning, grab a cup of coffee and read through the documentation, amazing stuff.

 

I'd be only half joking if I said that you can't really call yourself simmer if you aren't using a registered copy...

 

Pete Dowson has done more for this community down through the years with this seemingly infinitely adaptable tool than just about any other aftermarket developer. And it's continued development and adaptation to new uses means it's the `go-to` interactivity tool for all MS and ESP-based sims. And increasingly as a standalone tool in its own right. Never found a better calibration tool, and the LUA scripts are a must have for many of the complex sim products- although I must admit I thought the rolling friction in the sim had been addressed by L-M!

 

We really don't praise him often enough - especially with his knack of choosing vacation times when updates are coming out. You can set your watch by FSUIPC. You can probably set your watch WITH FSUIPC! 

Couldn't agree more Peter Dowson is really a huge contributor not only as developer but also in sharing the same passion of flight simulation.

SO thank you Peter

I just discovered this LUA friction, I have some questions about appreciate if someone could help,

 

1. Does it work properly with P3D v3 + PMDG NGX and 777?

2. Does it affect braking actions based on runway surface conditions as well?

3. Where to find the file DynamicFriction.lua?

 

Thanks in advance.

I just discovered this LUA friction, I have some questions about appreciate if someone could help,

 

1. Does it work properly with P3D v3 + PMDG NGX and 777?

2. Does it affect braking actions based on runway surface conditions as well?

3. Where to find the file DynamicFriction.lua?

 

Thanks in advance.

 

1.  Yes

2.  Yes, there are separate friction values for dry, wet, and icy conditions, but that's as fine as the granularity goes (i.e. no RCR/RSC adjustments)

3.  It's included with FSUIPC in the documents folder...there's a subfolder with a bunch of sample lua plugins there.

 

Regards

Thanks for the quick reply Bob, I will definitely play with that, sounds very interesting

I have been flying Flight1 B200 XP52 and using DynamicFriction for some time, mostly at KPHL, with no issues. I moved my aircraft to KMIV (asphalt) and I can't do my run-up procedures because as my props RPMs hit around 1600RPMs (prop gov test), the breaks don't hold. and the aircraft starts to move (drag) onto the runway. I have to put the throttle into reverse thrust to stop it. Once i removed Dynamic friction the issue went away. I haven't used the aircraft enough recently to see if there is a differance in ground movement as I am working on just the startup procedures at the moment. I would like your thoughts on this. I could increase the dry slide number but before I did that I found this thread.

The reason i delete set friction (WHEEL ROLLING) is personal preference because with this line you just need to give the NGX a bit of juice and takes off and keeps rolling. So DELETE WHEEL ROLLING and you'll see the difference

I looked at the lua fike and theres a ton of ROLLING lines and words. Quite frankly, i have no idea which to delete. Please help lol

FYI,

 

I have flown most of the Boeings from the 727 to the 747 and I think this mod is as close to the real thing as you will get in this sim. The 747-400 at max weight needed a small amount of breakaway thrust to get her rolling then she'd taxi along nicely at idle thrust at around 10-15kts. If the airplane was lighter for example 3/4 of the max take-off weight she would most likely role away very slowly from the ramp without any additional thrust and would need the occasional braking action to slow down to a reasonable taxi speed (15-20kts) as she gradually accelerated on long straight taxiways. Be careful here and check the brake temps because on long taxiways and constant braking and high taxi speeds the brakes will heat up very quickly. (you should see this on the PMDG 777 aircraft with its good modelling)

 

The T7 most of the time didn't need additional breakaway thrust and would roll away gently from the ramp even at high gross weights. (at Max Take-off weight maybe a little nudge of thrust)

 

With the smaller B737-800 aircraft they usually needed a bit more thrust to get them rolling and we would leave the thrust on a bit until the desired taxi speed was reached and then back to idle thrust.

 

After landing the aircraft (all the Boeings) would normally be light weight with only alternate and reserve fuel remaining so when taxiing to the terminal constant braking was needed to stop the aircraft from galloping away. Once again good braking technique was required to prevent wheel brake overheat. 

 

IM