Prop Rotation Speed

[Skittles]

Hello,

   I found out that if I adjust the starter torque, I can adjust the amount of time from the starter being engaged to the engine kicking over (Pistion Engine).  I have it synchronized with the Prop_Blurred effect taking affect.

   The problem, during spin down, the prop stops spinning before the sound of the engine stops.  What, if anything, can I adjust to adjust the spindown time?

Thanks,

Joe

[Milton]

prop_tc may be of some help ....

For a fairly quick stop, a few seconds, try .01.  Increase the number toward 1.0 to spin down more slowly.

[Skittles]

Well Milton, no such luck.
 I tried many numbers from .001 to 10.  No change.  The propeller stops in about 3.5 seconds everytime.
 Just in case, here is my Prop section. Maybe there is an association with another setting?


[propeller]
thrust_scalar = 1.0                             //Propeller thrust scalar
propeller_type= 0                               //0=Constant Speed, 1=Fixed Pitch
propeller_diameter= 9                           //Propeller Diameter, (feet)
propeller_blades= 3                             //Number of propeller blades
propeller_moi= 6.9                              //Propeller moment of inertia
beta_max= 30.0                                  //Maximum blade pitch angle for constant speed prop, (degrees)
beta_min= 0                                     //Minimum blade pitch angle for constant speed prop, (degrees)
min_gov_rpm= 500.0                              //Miminum governed RPM
prop_tc= .1                                     //Prop time-constant
gear_reduction_ratio= 1.0                       //Propeller gear reduction ratio
fixed_pitch_beta= 20.0                          //Fixed pitch angle of fixed pitch prop, (degrees)
low_speed_theory_limit= 80.0                    //Speed at which low speed theory becomes blended in (feet/second)
prop_sync_available= 1                          //Prop synchronization available? 0=FALSE, 1=TRUE
prop_deice_available= 1                         //Prop de-icing available? 0=FALSE, 1=TRUE
prop_feathering_available= 1                    //Prop feathering available?  0=FALSE, 1=TRUE
prop_auto_feathering_available= 1               //Prop auto-feathering available?  0=FALSE, 1=TRUE
min_rpm_for_feather= 100.0                      //Minimum RPM for prop feathering
beta_feather= 22.5                              //Feathering pitch angle (degrees)
power_absorbed_cf= 0.2                          //Coefficient of friction for power absorbed by propeller
defeathering_accumulators_available= 0          //Defeathering accumulators available? 0=FALSE, 1=TRUE
prop_reverse_available= 0                       //Prop reverse available?  0=FALSE, 1=TRUE
minimum_on_ground_beta= 30                      //Miminum pitch angle on ground, (degrees)
minimum_reverse_beta= 0                         //Minimum pitch angle in reverse, (degrees)
rotation =  -1, 1                               //-1=CCW, 1=CW


Thanks for the suggestion though.

[SilverFox441]

Change the propeller_moi= 6.9     //Propeller moment of inertia entry.

To be safe record the original value before fooling around.

If memory serves higher values increase run down time and lower values decrease it.

[Milton]

Not sure of your aircraft but there are some things I would change in those settings that will make a difference in a small constant speed prop:

beta_max= 45.0  
beta_min= 8  
min_gov_rpm= 700.0  
beta_feather= 82.5  
power_absorbed_cf= 0.8  

[Skittles]

SilverFox,  That's the ticket.  Set it to 15 and it's perfect.

Milton,  Don't know what it is you told me to do, but my "aircraft" handles a little better.

Thanks to both of you,

Joe