Fw 190V-18/U-1 shakes at idle

BoeingvsAirbusNKL

BoeingvsAirbusNKL

Charter Member
Jorg Sparbrodt's FM update has the lower M.O.I. entries (which I use as the FM), but when I try to reduce the amounts on all four M.O.I. entries... The plane shakes on the ground.

What amounts should I use?

And on a side note... could someone make a better FM for the aforementioned plane?
 
Oh... if anyone wants to see the M.O.I. entries... Here they are.

empty_weight_pitch_MOI=9960
empty_weight_roll_MOI=5698
empty_weight_yaw_MOI=13775
empty_weight_coupled_MOI=0
 
I have found that is usually caused by numbers 8, 9, and 10 in the contact points. Just needs a little tweeking.

//0 Class //1 Longitudinal Position (feet)
//2 Lateral Position (feet)
//3 Vertical Position (feet)
//4 Impact Damage Threshold (Feet Per Minute)
//5 Brake Map (0=None, 1=Left, 2=Right)
//6 Wheel Radius (feet)
//7 Steer Angle (degrees)
//8 Static Compression (feet) (0 if rigid)
//9 Max/Static Compression Ratio
//10 Damping Ratio (0=Undamped, 1=Critically Damped)
//11 Extension Time (seconds)
//12 Retraction Time (seconds)
//13 Sound Type
 
Well... if it isn't MOI...

Here is the contact points

[contact_points]
point.0=1,-15.364000,0.000000,-3.100000,6153.305130,0,0.625997,48.540000,0.305390,2.500000,0.726310,5,5,0,0,0
point.1=1,9.219000,-8.833333,-9.007000,6153.305130,1,0.625997,0.000000,0.407181,2.500000,0.726510,5,5,2,0,0
point.2=1,9.219000,8.833333,-9.007000,6153.305130,2,0.625997,0.000000,0.407181,2.500000,0.726510,5,5,3,0,0
point.3=2,2.083333,-27.083333,2.083333,2475.912819,0,0.000000,0.000000,0.000000,0.000000,0.000000,0,0,5,0,0
point.4=2,2.083333,27.083333,2.083333,2475.912819,0,0.000000,0.000000,0.000000,0.000000,0.000000,0,0,6,0,0
point.5=2,-25.750000,0.000000,-1.333333,2475.912819,0,0.000000,0.000000,0.000000,0.000000,0.000000,0,0,9,0,0
point.6=2,11.250000,0.000000,0.000000,2475.912819,0,0.000000,0.000000,0.000000,0.000000,0.000000,0,0,4,0,0
static_pitch=0.000000
static_cg_height=6.0500000
 
I had a look in ACM and the standard contact points are really off; this is a bit of a "quick & dirty" fix, I'll try to have a longer look tomorrow, but see if these make a difference.

[contact_points]
static_pitch = 12.75
static_cg_height = 6.75
tailwheel_lock = 0
gear_system_type = 0
max_number_of_points = 7
point.0 = 1,-15.364000,0.000000,-3.100000,6153.305130,0,0.625997,48.540000,0.305390,2.500000,0.726310,5,5,0,0,0
point.1 = 1, 9.219, -6.333333, -9.007, 6153.30513, 1, 1.45997, 0, 0.407181, 2.5, 0.72651, 5, 5, 2, 0, 0
point.2 = 1, 9.219, 6.333333, -9.007, 6153.30513, 2, 1.45997, 0, 0.407181, 2.5, 0.72651, 5, 5, 3, 0, 0
point.3 = 2,2.083333,-27.083333,2.083333,2475.912819,0,0.000000,0.000000,0.000000,0.000000,0.000000,0,0,5,0,0
point.4 = 2,2.083333,27.083333,2.083333,2475.912819,0,0.000000,0.000000,0.000000,0.000000,0.000000,0,0,6,0,0
point.5 = 2,-25.750000,0.000000,-1.333333,2475.912819,0,0.000000,0.000000,0.000000,0.000000,0.000000,0,0,9,0,0
point.6 = 2,11.250000,0.000000,0.000000,2475.912819,0,0.000000,0.000000,0.000000,0.000000,0.000000,0,0,4,0,0
 
BoeingvsAirbusNKL said:
Andy, the plane still shakes even with your "quick and dirty" fix.
Click to expand...

It does, doesn't it. I've tweaked it a little further, and it is still there, so it is not the contact points (bad as they were) causing the issues; I'll have another look later and see if I can spot anything.
 
Experiment with the empty weight C of G - that can sometimes play up, but it can also upset flight trimming! It helped with my current project.
Good luck
Keith
 
Tried changing that, looked at control surface inputs, weights and dimensions .... nada, still shaking. Sorry guys, I'm stumped.
 
Whose aircraft is this? Where can I download it from? Happy to look at it but need more info guys.

Is the K. Ito's aircraft model? I found it at Simviation if so.

No issue with the original package dancing but ... it does need a new FM.
I'll see what I can do.
 
Milton, you are a star. There was a revised FM released, which dealt with some of the usual Itosan issues (vastly overpowered, wrong engine type etc) but introduced these shaking issues; if you can sort out the original that would be much better. :applause:
 
Optional Replacement FM for Ito's FW-190V18

Optional Replacement Flight Model for Kazunori Ito's FW-190V18


NOTE: I also included a replacement panel.cfg for those of you who are using the original Ito panel. This simply adds a


view adjustment to see better over the 2D and VC panels.


Flight Ops


Notes:


I completely redid the flight model as the original was not a good starting point. However, I only invested about 10-12


hours in this so it is not perfect and could use some tweaking in various areas.


1) I converted the tail wheel to castoring as the handling is much improved that way. If however you do not have pedals or


wheel brakes you can convert it back to fixed by changing the Contact Point.0 parameter 180 to 40.


2) Speeds at altitudes are acceptably in the ball park for me using GPS Groundspeeds or AFSD as a guide. She will climb out


at 2500 fpm to about 6-8000' and then reduce to 2000 fpm until speed decays to 140kias, then reduce by 500 fpm as necessary


in your climbout to FL350. (The real world climb was at 2987 fpm but I reduced that slightly.)


3) For takeoff, use a few degrees of up trim, no flaps required and pull her off around 95kias.


4) Landings can be bouncy if you land too fast. Slow your speed to 90 kias or less before your easy flare and allow the aircraft


to sink just above stall speed to a 3-point landing.


5) The FS Reference point for this model is about in the pilot's lap rather than at the CoG. I could not change that fact


as it's built in to the model. As a result, tight turns look a little strange with the pivot point being behind the main


gear rather than at the tires.


6) I am not pleased with the AoA at some speeds but improving on that would take more time than I have to give it. There are


other issues that could be improved upon like drag, pitch due to flaps and gear not spot on, some jitters when starting the


roll, etc. But what I have here is certainly flyable and enjoyable at least on my rig with my control sensitivities.


If anyone wants to improve on this base FM, please feel free to do so.


I hope this is an improvement over what you are using but be sure to keep a copy of your original.


Milton Shupe
November 2014

Please let me know here how this works for you or if there are glaring issues.
 
BoeingvsAirbusNKL said:
Thanks a lot, Milton. I have to say, this flight model is way better. :ernaehrung004:
Click to expand...

Thank you Sir. I admit the post above sounds a little negative but its because I am so picky about little things. Just flew it around the circuit again and I do really like it.

I may continue to tweak it as I have time to chip away at the nigglies. :)
 
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