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PostPosted: Tue Jan 27, 2015 1:13 pm 
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Joined: Wed Nov 13, 2013 2:53 am
Posts: 362
It wasn't an idea to make it go away, but a effect steming from trying to properly model the torque of an engine. Its overcoming autopilot....twasn't done on purpose, and we working the issue now


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PostPosted: Tue Jan 27, 2015 1:15 pm 
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Hawk wrote:
Whose nutty idea is it to do away with the Auto Pilot? :roll:


Absolutely no one's idea.

The constant hair trigger circuit breaker trip to "The sky is falling, its a conspiracy." is not helpful. It is just this kind of reaction that drags development to a standstill and should be soundly discouraged by anyone wanting THIS game to move forward.

Trim, which is the autopilot, affects the entire flight model.

The IDEA is to UNTIE trim from the autopilot functionality in order to retain autopilot functionality without severely compromising the flight model.

We are having to travel the hardest path possible to get there precisely because of people who respond in the manner above.

Please feel free to continue.
:roll:


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PostPosted: Tue Jan 27, 2015 2:16 pm 
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Joined: Sat Nov 09, 2013 5:28 am
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timos wrote:
its kinda like biting into a baby grand and splitting a tooth

:lol:


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PostPosted: Tue Jan 27, 2015 8:11 pm 
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Joined: Sat Nov 09, 2013 3:00 pm
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Location: Florida
Salute!

Sleepy!!! The problem is torque and p-factor are more than the real world. So the autopilot ( AP) won't engage in one axis or the other, as it detects more "trim" or "stick" input than it's programmed for. To see this, just put in aileron trim to get a decent roll rate and try to engage AP. There is a limit before either roll rate or control input prevents AP from engaging.

Then there's the trim speed for climbs. Brought this up on the Tech forum, and maybe we could go there or I could get back into the beta team forum. Been lax there last two years due to family medical problems and one of mine.

Gums sends...


"God in your guts, good men at your back, wings that stay on - and Tally Ho!"


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PostPosted: Tue Jan 27, 2015 8:41 pm 
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Good answer Dawger... I think.... :roll:


Capt Hawk
CO - The Knights Who Say Ni!


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PostPosted: Tue Jan 27, 2015 11:59 pm 
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Hawk wrote:
Good answer Dawger... I think.... :roll:


My aim and indeed the entire reason i returned is to move the game forward, which means change.

I do not imagine that I have all the answers or ever believe any aspect of any flight model is right just because I worked on it.

The situation with the Wildcat sucks because after several people working hard to get it close to real world performance, because of a flaw in how the autopilot works, the autopilot is less capable than it used to be.

It was a predicted result with proposed solutions that were not considered until a completely avoidable crapfest occurred.

It would be nice to avoid the crapfest but if progress by crapfest is the only path available I will wear hip waders I suppose.


And a query for Gums..( and anyone else who wants to chime in).what percentage of control deflection in roll and yaw should be required to maintain heading in a Wildcat in a 150 mph climb at 100% power?

This is a real question. I would like as many answers to that question as possible for two reasons.

1. I would like to see how my expectations line up with others.

2. I would like to generate feedback that has folks thinking in quantitative terms.

There are no numbers for this sort of thing. The present level of torque is a compromise of "feels close", prevents unrealistic vertical performance and a SWAG.


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PostPosted: Wed Jan 28, 2015 12:44 am 
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Could be gums, 1 issue being the biggie, and that's how to untie the auto pilot from the trim controls to give the flight modelers better control of what they do..and mayhap it does have to much torque, easy enough to work on, but kinda focused on untieing trim to autopilot as that will effect all FM's as we progress.
Blessing in disguise in one way, the wildkitty got perhaps to much torque, and pointed out the underlying issue. It's ok, a fair amount of the crap we throwing at the wall is starting to stick, but its messy :)
We will get thru this, the world ain't gonna end.
I'm with Dawg here in that
Defining how much is "right" ( a very subjective term) needs to be definable in some way shape form or another. I'd like to trade my hip boots for some of the shorter variety..like ......Gum boots :)


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PostPosted: Wed Jan 28, 2015 1:19 am 
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Location: Florida
Salute!

Nice reply Sleepy.

Ya gotta fly some real planes to adjust the settings, as the values you/we are using for our models are not specified anyplace!!! So it's gonna be "feel" and "best I remember" and so forth. Gotta tellya, that Columbo and Pappy and Bomber and a few others will tellya that our trim/p-factor/torque stuff is not right. Current real plots include Wolfie, Mt-Dew, and who knows the other.

Try to fly Wild Bill's T-28, and I think it's a "D" model, with constant speed prop ( so three levers at your left hand - throttle, mixture and RPM). That thing is about like a P-51 for climb rate and such, but not as much p-factor due to progress in aero stuff over 40 years later.


All of us have to remember the damage done by Hotseat or whoever it was that had the calling card signature about SAE. He was the troop that gave us the uber B-24( he loved the Lib) and also porked numerous FM's to his own views. That was when we started to get those immense p-factors and torque effects.

I understand that this is a sim, but we don't need to characterize every plane and the plethora of models to 1% of actual performance, ya think? We should have realistic values for fuel burn, power, drag, stall, and so forth. Right rudder should be required for takeoff at max power or any other application of max power. But not to the degree we now see.

I promise to do a few profiles to show the actual WB flight model power versus speed/climb stuff. It's basic Chuck Yeager stuff, and very boring. But the values I got 12 or more years ago closely resembled the actual Fort graphs from the actual tech order CD I have.

All for now,

Gums sends...


"God in your guts, good men at your back, wings that stay on - and Tally Ho!"


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PostPosted: Wed Jan 28, 2015 11:49 am 
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I couldn't agree more, tis a tricky thing, quantifying a somewhat subjective thing in a flight sim


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PostPosted: Wed Jan 28, 2015 3:31 pm 
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"Torque" is a constant force, always present and always the same force for a given power level.

What changes is the effectiveness of the controls. The faster the indicated airspeed, the more effective the control surface so less is need to counteract the constant force of "torque".

I don't believe the "torque" is too much based upon the evidence gathered and my personal experience in a few high horsepower singles. In fact it is demonstrably too little in the Wildcat.

Here is a quote from Corky Meyer's Flight Journal: A Test Pilot's Tale of Dodging Disasters

Quote:
There were, however, four hidden pilot snares hidden in the Wildcat design. They were explained to the new pilot in both specific and anecdotal detail for his safety. As you will soon understand, they were easy to meet but not easy to manage.
The high torque of its 1,200 HP Pratt and Whitney R-1830-76 engine required the pilot to preset the rudder trim tab to three marks nose right (almost full right tab) prior to every takeoff. If the pilot failed to preset the trim tab and did not attend to the rudder properly, the aircraft would veer strongly to the left during a takeoff run, requiring an abnormal amount of right rudder force to counter the problem. I witnessed many Wildcats veer to the far left side of the Grumman runway when delivery pilots forgot to preset their rudder trim tabs. Once a pilot forgot to preset his tab, however, he never forgot it again. A later model Wildcat, the more powerful FM-2, had a 10-inch taller fin and rudder installed, but only after 3,147 small fin and rudder Wildcats had been delivered. However, it still mandated two marks of of nose right rudder tab preset prior to takeoff


I think the present Wildcat In Game doesn't come close to this description.

NOTE: each unit of trim represent 1 percent control surface deflection.

In the video in the link below takeoff with no trim and no control input DOES NOT veer strongly to the left. It is a gentle left carom. That doesn't sound anything like Corky's description.

With 15 units of rudder trim, the Wildcat goes right.

With 8 units it goes right.

With 4 units it starts left but stops the left drift when speed builds.

4 percent rudder input to counter 1200 hp doesn't sound too radical.

There are no control inputs except in the very last takeoff (watch the Yoke and Trim lines on the Left HUD data)

The Wildcat is a docile thing with no stick inputs whatsoever and could easily be flown off the ground with manual trim only.

So if it behaves as one would expect on takeoff the "torque" represented in game is close to correct. It doesn't behave that way. It is far more gentle so obviously the torque is set at a level well below real world.

The flight controls are as close to real world values as we can get using the FM code. The manual trim currently modeled allows the effects of torque to be countered easily at all times, including dialing in rudder for takeoff. In fact, half rudder trim will make the Wildcat go right during takeoff.

This is the thinking going into the FM. While I certainly appreciate input I certainly hope that my response in this fashion is equally appreciated. It isn't an attack on anyone. It is a presentation of the information available to use to build an FM and how this stuff is tested.



VIDEO

https://www.youtube.com/watch?v=0UnzeoD ... ata_player


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