FM Help

[ShrikeHawk]

Looking for some advice here.

 

The P-40E FM attached below, flies pretty much like I want it, but at high speed (240kts+) the pitch control stiffens a lot. I've looked this thing over time and time again and I cannot see why it's happening. I want to know why for several reasons: 1) My A6M2 FM doesn't do this, and it should. A6Ms could not follow American fighters in high-speed turns. The controls stiffened up so much. I'd like to duplicate this effect in the A6M2. 2) I don't want to eliminate this effect from the FM, but I'd like to control it and push the effect out to a higher speed. I can model compression with this.

 

Any FM experts, please have a look at the attached FM and tell me what's doing this. Any help appreciated.

 

P-40E1-CU_DATA.zip

[+baffmeister]

You could try adjusting the MaxControlSpeed for the elevators:

 

[LeftElevator]

SystemType=CONTROL_SURFACE

InputName=PITCH_CONTROL

MaxDeflection=30.0

MinDeflection=-20.0

CLiftdc=0.0366

CDdc=0.0118

Cmdc=-0.2285

CmdcAlphaTableNumData=37

CmdcAlphaTableDeltaX=10.00

CmdcAlphaTableStartX=-180.00

CmdcAlphaTableData=0.000,-0.014,-0.029,-0.047,-0.064,-0.060,-0.052,-0.035,-0.015,0.000,0.019,0.055,0.104,0.155,0.224,0.636,1.000,1.000,1.000,1.000,1.000,0.646,0.233,0.185,0.131,0.082,0.042,0.000,-0.015,-0.035,-0.052,-0.060,-0.064,-0.047,-0.029,-0.014,0.000

ControlMachTableNumData=4

ControlMachTableDeltaX=0.13

ControlMachTableStartX=0.60

ControlMachTableData=1.000,0.976,0.115,0.000

ControlRate=2.0

MaxControlSpeed=104.15................................HERE

ModelNodeName=Elev_L

ReverseModelOrientation=TRUE

 

I'm away from my home computer at the moment so don't have any files to compare with but the number seems a bit low.

[Fubar512]

I'd suggest experimenting with something along the the line of this:

 

ControlMachTableNumData=7
ControlMachTableDeltaX=0.10
ControlMachTableStartX=0.10
ControlMachTableData=1.000,0.976,0.895,0.855,0.0.610,0.505,0.306

[ShrikeHawk]

Thanks gentlemen. I really appreciate the replies.

You could try adjusting the MaxControlSpeed for the elevators:

[LeftElevator]
SystemType=CONTROL_SURFACE
InputName=PITCH_CONTROL
MaxDeflection=30.0
MinDeflection=-20.0
CLiftdc=0.0366
CDdc=0.0118
Cmdc=-0.2285
CmdcAlphaTableNumData=37
CmdcAlphaTableDeltaX=10.00
CmdcAlphaTableStartX=-180.00
CmdcAlphaTableData=0.000,-0.014,-0.029,-0.047,-0.064,-0.060,-0.052,-0.035,-0.015,0.000,0.019,0.055,0.104,0.155,0.224,0.636,1.000,1.000,1.000,1.000,1.000,0.646,0.233,0.185,0.131,0.082,0.042,0.000,-0.015,-0.035,-0.052,-0.060,-0.064,-0.047,-0.029,-0.014,0.000
ControlMachTableNumData=4
ControlMachTableDeltaX=0.13
ControlMachTableStartX=0.60
ControlMachTableData=1.000,0.976,0.115,0.000
ControlRate=2.0
MaxControlSpeed=104.15................................HERE
ModelNodeName=Elev_L
ReverseModelOrientation=TRUE

I'm away from my home computer at the moment so don't have any files to compare with but the number seems a bit low.

Thanks Baff. But this is a constant value. My issue changes depending on speed. At lower speeds, this FM responds exactly as I want it to. This P-40E isn't super-fast in angles turning, but in my estimation that reflects the reality. The P-40E was a steady gun platform. A slightly lower value in MaxControlSpeed makes this plane respond calmly and predictably to the stick, making it easy to establish a firing solution. Thus, a steady gun platform.  I appreciate you offering a solution though.

 

I'd suggest experimenting with something along the the line of this:

 

ControlMachTableNumData=7
ControlMachTableDeltaX=0.10
ControlMachTableStartX=0.10
ControlMachTableData=1.000,0.976,0.895,0.855,0.0.610,0.505,0.306

Thanks Fubar. Turns out, this was it. I commented out this section from the elevator as a test and now the plane turns uniformly at all speeds. Now I can apply this to the A6Ms and get a realistic AI behavior.

 

Problem solved. Thank you.

Edited July 11, 2014 by ShrikeHawk