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shaker effects

michaelvader

michaelvader

Members +
Hallo the experts of flight dynamics

on some of my aircraft I have sometimes a crazy effect:
here especially on the Fokker T V
at speeds around 270 to 370 km/h (167M/h to229M/h) (145knots/H to 199knots/h)
the aircraft begins to shake on all axes.
under and over all gets slowly to normal
Does some one know to what is isdue
What entries in the aircraft.cfg or/andairfile must be changed to eliminate this undesirable and damned effect?
I hope that some one can propose me a solution
Best regards
Michael
 
Good evening Wolfebee,
do you mean these entries in the aircraft.cfg ?
;Moments of Inertia
empty_weight_pitch_MOI=24265
empty_weight_roll_MOI=26806
empty_weight_yaw_MOI=35439
to stop the shaker effects should I
increase or decrease the values?
In fact what are these entries?
the explanations I found until now sounds for me as "bohemian villages"
Best regards
Michael
 
My two cents: Just double the first digit. 2 becomes 4, 3 becomes 6. It's worked for me many times to get an older model flyable. Play with it. The experts can explain the functions and estimates.

normb
 
Hi Michael,

Indeed that's it! I would like to point you to the following resources, the associated documentation for which, have the complete relevant explanations: https://fsdeveloper.com/forum/resources/aircraft-container-sdk.29/ and https://fsdeveloper.com/forum/resources/fsedit-sdk.33/

You can try the MOI calculator built into the freeware release of airwrench available here at SOH, but note that the program modifies both the air and cfg files; feel free to also try the built in MOI calculator found in aircraft container manager (ACM), ex-payware, and available here: https://simviation.com/1/search?submit=1&keywords=aircraft+container+manager - it exclusively modifies the cfg file; the air file is left unaltered. The FSEdit program, part of the FSEdit SDK also has a calculator for calculating the MOI. Of course, for all such calculations, the correct weights, dimensions and station load distributions of the a/c have to be provided. Stephan Scholz had also provided a series of forumale to correctly compute the MOI, and which should be in your PM; check your messages ;)

So as a first attempt, I would recommend increasing the MOI by arbitrary amounts along all the relevant axes you experience said shaking/vibrations until they cease; it is a bit of trial and error - and as @normb suggests, play with the numbers! If nothing appears to work, I would recommend the aforesaid MOI calculators and Stephan's formuale.

best,
wb
 
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