Urgent-help needed from fellow heli simmers please!

Hello Guys, I am working on a Heli sim for a client. The sim is based on P3d V4.2-64. Everything works great, except I am experiencing an Engine RPM surge especially on the R-22. This only happens upon engaging the governor (otherwise is very smooth) once the governor is engaged, the engine rpm goes up to 104% (normal) but then starts fluctuating up and down from about 95-105 % constantly. I believe this is more of a visual thing other than actual, because the engine noise seems stable (or maybe the sound file used is only one). I understand this is a common issue, many suggest setting the realism to easy. Others have commented out a line in the CFG file. I understand the 2 lines responsible are (mostly) the following:

governed_pct_rpm_ref =

governor_pid =

Does anyone have any suggestions? any help will be greatly appreciated.

Marco.

boeing747sim.com

IF you're gauges show the engine fluctuations, then they're more than visual.

You can TRY the various solutions you already have found for this. You don't need to set the Realism sliders all the way to zero (full left). Actually, there's generally no difference, as far as the sim's concerned, between setting them to 99%, and 10%. The sim adjusts it's mathematical formulae in the .air and aircraft.cfg files the same for either setting. 100% is a different adjustment. In other words, if a particular setting in the .air file is to adjust the fuselage's forward face's drag, at 100% realism, the adjustment is utilized at 100% of it's value. If, on the other hand, the Realism sliders are at 99%, it utilizes 50% of the formula's value.

This affects the line in the aircraf.cfg file

[Helicopter]
low_realism_stability_scale=.45, .30, .35             //Pitch , Bank, Yaw Scalars on Stability in Low Realism Settings

as well as everything else under the [Helicopter] section.

Like the two lines you mentioned,

governed_pct_rpm_ref =

governor_pid =

If your instruments are showing the surging, adjusting the governor_pid =

settings can eliminate it entirely. But you must be cautious. PID controllers are tricky little buggers! :confused:

If they're NOT showing the surges, try just setting your realism settings SLIGHTLY lower, and see what the effect is.

I'm not entirely certain just how well, if at all, Helicopter Total Realism, a superior add-on for helicopter fliers in the sim, wroks in the v4.X P3D versions, but I suggest trying it out. It might be a huge help!

By the way, you mentioned activation of the governor. Are you certain you're activating, not DE-activating it?

Just a thought. The helo's load in with it activated. The R22 is the only helicopter with one, that you can switch on or off, by the way.

You might want to look through the forums over on Hovercontrol for solutions. I am certain you're not the first.

Actually, I've read it has a lot to do with your controllers. Are you using a joystick? If so, is the throttle slider properly aligned?

I've never run into this other than the EH101, so I can't be a LOT of help...

Pat☺

Thank you so much Sargent!! I appreciate your help so much, but unfortunately I have tried all that you suggest.

Like the two lines you mentioned,

governed_pct_rpm_ref =

governor_pid =

 

If your instruments are showing the surging, adjusting the governor_pid =

settings can eliminate it entirely. But you must be cautious. PID controllers are tricky little buggers! :confused:

 

If they're NOT showing the surges, try just setting your realism settings SLIGHTLY lower, and see what the effect is.

 

I'm not entirely certain just how well, if at all, Helicopter Total Realism, a superior add-on for helicopter fliers in the sim, wroks in the v4.X P3D versions, but I suggest trying it out. It might be a huge help!

 

By the way, you mentioned activation of the governor. Are you certain you're activating, not DE-activating it?

 

You might want to look through the forums over on Hovercontrol for solutions. I am certain you're not the first.

Actually, I've read it has a lot to do with your controllers. Are you using a joystick? If so, is the throttle slider properly aligned?

 

I've never run into this other than the EH101, so I can't be a LOT of help...

Pat☺

Now, when you say that the Governor_pid= eliminates the surging... I was under the impression that that is to be set at the percent of constant trust we want to stay at - in our case 104%. most of the tweaking we are doing are with the other line, and believe me I have been trying for over a week. We do get some improvement but the needle jumps up and down and the manifold pressure sways wildly. I also tried HTR, it is a great little program, and I noticed improved over handling but no difference as far as our issue is concerned. Yes we use real controls lookalike wired tom potentiometers controlled by Bodnar cards. I also tried to bypass them and use a brand new joystick and the problem is the same. This is an actual full heli cockpit which we train students in a flight school with. I do know the issue is not with our sim (it is totally rebuilt) because many-many folks on the web are having the same issue. It seems to be a P3d never fixed from way back FSX. The heli flies smooth like oil without the governor engaged, the only problem is the without the governor, the RPM soon redline (because these is nothing to stop it. Plus, we cannot really do that because in real life you must use the governor which purpose is to "govern" the RPM within the green zone. If you can think of something else I would highly appreciate it. Unfortunately the company who originally built the sim, (FlyIt) are out of business, so we cannot ask them for help. What I think they did, was to make their own XML file to bypass the FSX/P3d issue. Thank you.

Well, for what they're worth, I found THIS THREAD.

There are a few fixes for this given, and they say they work well. Also, explanations are given which may help you find your own solutions, should these not help. The whole thread is quite informative, actually.

Finally, the FSX EH101V2 has a fix to the surge problem, so you may want to take a look at it's [Helicopter] section in particular, to see what was done for it.

I am glad you discovered the joys of HTR. Just make sure that you a) use the correct .cfg file or, alternatively b) read the included documentation with HTR to make one of your own. The documentation is actually extremely well written, and explains in detail what each setting does, how to set it, and how to test it.

Hope something in here helps a little...

Pat☺