Dynamic Braking/Run 4

[chlacey]

On earlier (and some later) EMDs, the engine RPM advances to the equivalent of "Run 4" on the throttle and remains there, as soon as the dynamic brake is placed in "Set Up". During braking, the whining or growling increases or decreases, based on braking effort. Have any simmers tackled this topic, or better yet, how would one go about making this happen?

[chucksc]

RE: Dynamic Braking/Run 4

To my knowledge only 3DTrainStuff has with their SD70 sound set...
They did it by incorporating the sounds of the prime mover revving up into their dynamic brake wave samples (which were actually recordings of a SD40 dynamic braking IIRC)....
I suppose you could loop a Run4 sound sample in the SMS file triggered on the application of Dynamic Brakes....
But you should also be aware that there is not a limitless supply of sound streams that can be played at one time... There appears to be a practical limit just like there is with lights... with the exception that you can tweak around some of the sound limits by editing the appropriate config.dat file IF you have a sound card capable of supporting a higher number of streams.... AND enough memory available to hold all the active streams in memory.....

Chuck Schneider
(Virtual) CEO
North American (Virtual) Locomotive Works
[Link Expired]

[chlacey]

RE: Dynamic Braking/Run 4

Thanks, Chuck. How would I go about tying the Run 4 sound to "Set Up" and braking? I'm a novice at this sort of thing. I'm assuming that I would be doctoring some .sms or other similar files.

[chucksc]

RE: Dynamic Braking/Run 4

The stream would look something like this;

Stream (
Skip( **** Dynamic brakes **** )
Priority ( 6 )
Triggers ( 2
Variable_Trigger ( Variable3_Inc_Past 0.05 StartLoopRelease ( 1 File ( "SOME-ENGINE-RUN4.WAV" -1 ) SelectionMethod ( SequentialSelection ) ) )
Variable_Trigger ( Variable3_Dec_Past 0.05 ReleaseLoopRelease () )
)
FrequencyCurve(
Variable3Controlled
CurvePoints ( 2
0.0 12025
1.0 17800
)
Granularity ( 100 )
)
)



Chuck Schneider
(Virtual) CEO
North American (Virtual) Locomotive Works
[Link Expired]

[chlacey]

RE: Dynamic Braking/Run 4

Chuck,

Thanks for the help. When I attempted your fix, several interesting things happened: 1) The engine speed immediately increased; 2) The RPMs increased in proportion to the dynamic brake setting, instead of staying at Run 4. 2) The RPMs were also tied to ground speed, so that the engine RPMs dropped off as the locomotive came to a halt.

I guess this is one that will take a little more fine-tuning. By the way, I did the experimentation using the sound files f7cab.sms and f7eng.sms, from the funit.zip download originally created by the Aussies and converted to right-hand operation. Those files used the GP38 default sound file for Run 4(gp_power_cruise4.wav).

I'll continue to fiddle around with the idea, and look forward to any additional suggestions you may have. Thanks again!

[chucksc]

RE: Dynamic Braking/Run 4

Actually Craig that is how it is "supposed" to work IIRC....
More DB = More excitation needed = more prime mover rpm....
Ask Kro52 or one of the other "runners" on here and see what they say....

Chuck Schneider
(Virtual) CEO
North American (Virtual) Locomotive Works
[Link Expired]

[krswen]

RE: Dynamic Braking/Run 4

On the latest GE's the engine speed increases with dynamic braking setting. I thought I remembered seeing something in the 700s last time I ran Brake 8. I'll try to get some real numbers this week.

krswen

[krswen]

RE: Dynamic Braking/Run 4

Sure enough ..... if you put the left IFD (Integrated Function Display; the screens you see on the engineer's desktop in Dash9s and AC4400s) into "Locomotive Monitor" mode you can read the engine speed while you're running.

Turns out for GEs the speeds are 440, 580, 718, 888 and 995rpm for increasing levels of DB effort. I've created a new sound stream patterned after Chuck's suggestion above to model this in the sim.

I also opened the DB blower access hatch and counted the blades on the one of the fans so I can adjust the d9_dynb_dyn1.wav stream to the right frequencies as a function of DB effort.

I'm planning on releasing an update to gesnd10.zip this weekend which will include this new stream as well as Salem 824 and 975 air filter and dryer blowdown sounds.

If I get it working to my satisfaction I'll include improved Alerter script as well.


krswen

[chucksc]

RE: Dynamic Braking/Run 4

Hey Ken, ship it over to me too as I am working on updates for the NALW GE sounds including the Genesis units....
Save me some trouble....
BTW, thanks to Dan of Facing Point I have a set of GE air dryer sounds also....

Chuck Schneider
(Virtual) CEO
North American (Virtual) Locomotive Works
[Link Expired]

[krswen]

RE: Dynamic Braking/Run 4

Chuck .... it's probably going to be next weekend now.

I just spent the last day and a half installing a wireless network (including 0ver 4 hours with MS tech support!) and I'm migrating my MSTS stuff to the new computer. Using it as an excuse to do some thinning and house cleaning while I'm at it.


krswen

[xlspecial261]

RE: Dynamic Braking/Run 4

As I recall, EMD's rev up to run 4-5 and no higher.

They are not supposed to do this in set up, but when you advance the handle to about 4 or 5. Of course sometimes things don't work right and they do rev up right away. Red Barn 9013 is currently like this, but the Diesel Dr. now knows about it. (As he said; It isn't supposed to do that, eh? )

This is as much for the traction motor blowers as anything I have been told. Below 4 or so you don't really need the extra cooling.

Todd

[deejay1020]

RE: Dynamic Braking/Run 4

Chuck,
I also have some samples of the turbocharger and some more air dryer samples (faster and more random 'click' rate) if you are interested. Probably couldn't do much with the turbocharger on the internal audio, but you can sure hear it from the outside.

[chucksc]

RE: Dynamic Braking/Run 4

Please ship them to me Dan...
Thanks again...

Chuck Schneider
(Virtual) CEO
North American (Virtual) Locomotive Works
[Link Expired]

[chucksc]

RE: Dynamic Braking/Run 4

BTW, to clarify things the Fix I posted to Craig on here is from the GM Megapak we are currently working on, with some help from Dan. Just in case some one else decides to "invent" this technique....
Chuck Schneider
(Virtual) CEO
North American (Virtual) Locomotive Works
[Link Expired]

[chlacey]

RE: Dynamic Braking/Run 4

Chuck,

Thanks again for your help. It's good to see these minor improvements being worked into your new products. By the way, has any more been done about the issue of the engine RPMs remaining the same between IDLE and RUN 1 on the EMDs (but with the contactors dropping in and the main generator starting to load). It would seem to be a fairly straightforward fix. What do you think and how would you approach it? Thanks.

Craig