Aircraft cfg adjustments

F

Fleet Canuck

SOH-CM-2016
I have Carenado's Cessna 185 Bush plane, and it bounces on default scenery in an extreme way. I downloaded the bouncing fix patch from the Carenado website, but it didn't fix it. I wrote to Carenado and they suggested altering the aircraft cfg file, and particularly the contact points for the tailwheel. I increased the fourth number on the tailwheel and then also the mains and saw no change. I increased the number for the empty weight pitch and saw no change.

So, do I change the numbers that relate to static compression and damping? Should I just substitute numbers from a similar taildragger's aircraft cfg file? I feel like one change will make this excellent plane flyable. Thanks for your suggestions. :salute:

P.S. It only bounces when moving faster than 30 knots or so.
 
I have some problems with the frame rate settings on some of my own aircraft - try increasing the frame rate if you do a lot of online simming 20 fps is the max, but make it 'unlimited' & see if that stops it. Also does the jumping stop if the engine is stopped? If so that is also a sign of frame rate.
HTH
Keith
 
Would you mind posting the contact points here?

Generally, bouncing occurs because of stiff suspension (indicated by a small static compression and a high max-static ratio). Another indication is overly-chirping tires. However it may also occur or be exacerbated by the CoG being too far from 25% MAC, and usually with too much weight on the center gear (tail or nose).

If too much tail weight, and too stiff (too little suspension) tailwheel, the problem is worse.

I may be able to help if you post the contact points but would also be interested if the CoG is near 25% MAC.

EDIT: BTW, I assumed you meant tires bouncing, but did you mean a landing bounce tendency?
 
[contact_points]
static_pitch = 9.0
static_cg_height = 3.5
gear_system_type=4
max_number_of_points = 9


tailwheel_lock=1
point.0 = 1, -22.35, 0.0, -0.70, 2500, 0, 0.42, 60, 0.15, 2.5, 0.6, 0, 0, 0
point.1 = 1, -2.67, -3.4, -4.11, 2500, 1, .90, 0, 0.38, 2.5, 0.6, 0, 0, 2
point.2 = 1, -2.67, 3.4, -4.11, 2500, 2, .90, 0, 0.38, 2.5, 0.6, 0, 0, 3


point.3 = 2, -4.60, -17.0, 3.28, 1500, 0, 0.00, 0, 0, 0, 0, 0, 0, 5, 0, 0 //LW
point.4 = 2, -4.60, 17.0, 3.28, 1500, 0, 0.00, 0, 0, 0, 0, 0, 0, 6, 0, 0 //RW
point.5 = 2, 1.2, 0.0, -2.2, 1500, 0, 0.00, 0, 0, 0, 0, 0, 0, 9, 0, 0 //tail
point.6 = 2, 1.2, 0.0, -2.2, 1500, 0, 0.00, 0, 0, 0, 0, 0, 0, 4, 0, 0 //Fslg
point.7 = 2, -18.75, 0.0, 6.45, 1500, 0, 0.00, 0, 0, 0, 0, 0, 0, 7, 0, 0 //Aux1
point.8 = 2, -14.12, 0.0, 0.01, 1500, 0, 0.00, 0, 0, 0, 0, 0, 0, 8, 0, 0 //Aux2

Maestro Milton, thanks for your attention!

The tailwheel bounces on take off roll, but when landing the mains bounce greatly. This is a tundra wheeled version, but the float and ski versions also bounce.
 
These are the numbers I have. When the aircraft was first released for FS9 several people on different forums tried to fix the bouncing before Carenado released their patch. I don't remember where I got these, but they seem to work for me.

Tundra:
point.0 = 1, -22.35, 0.0, -1.00, 3500, 0, 0.44, 60, 0.1247, 1.052, 0.9, 0, 0, 0
point.1 = 1, -2.67, -3.4, -4.11, 2500, 1, 1.115, 0, 0.164, 1.12, 0.6, 0, 0, 2
point.2 = 1, -2.67, 3.4, -4.11, 2500, 2, 1.115, 0, 0.164, 1.12, 0.6, 0, 0, 3

Amphib:
point.0 = 1, 3.5, -4, -5.8, 2500, 0, 0.2952, 40.0, 0.15, 1, 0.7, 5, 5, 2
point.1 = 1, 3.5, 4, -5.8, 2500, 0, 0.2952, 40.0, 0.15, 1, 0.7, 5, 5, 3
point.2 = 1, -6.8, -4, -5.65, 2500, 1, 0.55, 0.0, 0.13, 2, 0.7, 2, 2, 2
point.3 = 1, -6.8, 4, -5.65, 2500, 2, 0.55, 0.0, 0.13, 2, 0.7, 2, 2, 3

Ski:
point.0 = 1, -22.35, 0.0, -0.71, 2500, 0, 0.42, 60, 0.15, 2.5, 0.6, 0, 0, 0
point.1 = 1, -2.67, -3.4, -3.99, 2500, 1, 0.75, 0, 0.38, 2.5, 0.6, 0, 0, 2
point.2 = 1, -2.67, 3.4, -3.99, 2500, 2, 0.75, 0, 0.38, 2.5, 0.6, 0, 0, 3


Maybe they will work for you.
 
Thanks for the Numbers!

pfflyers, thanks for these numbers.

With the new numbers, the take off roll for the amphibian is smooth, but it still bounces on the gentlest touch down on the water. The tundra is still bouncing on take off and landing, but it is better than before. Meanwhile, the ski version seems to be smooth, if I do an exceptionally gentle landing. Maybe I can tweak from here and get things right. It's great to have good advice close at hand. :salute:
 
Fleet Canuck said:
pfflyers, thanks for these numbers.

With the new numbers, the take off roll for the amphibian is smooth, but it still bounces on the gentlest touch down on the water. The tundra is still bouncing on take off and landing, but it is better than before. Meanwhile, the ski version seems to be smooth, if I do an exceptionally gentle landing. Maybe I can tweak from here and get things right. It's great to have good advice close at hand. :salute:
Click to expand...

I am thinking of purchasing this aircraft just to fix the contact points. However, before I do that, please try the following (save a copy of the aircraft.cfg first):

Tundra:
point.0 = 1, -22.35, 0.0, -1.00, 3500, 0, 0.44, 60, 0.292, 1.28, 0.9, 0, 0, 0
point.1 = 1, -2.67, -3.4, -4.11, 2500, 1, 1.115, 0, 0.380, 1.12, 0.9, 0, 0, 2
point.2 = 1, -2.67, 3.4, -4.11, 2500, 2, 1.115, 0, 0.380, 1.12, 0.9, 0, 0, 3


Amphib:
point.0 = 1, 3.5, -4, -5.8, 2500, 0, 0.2952, 40.0, 0.38, 1.2, 0.9, 5, 5, 2
point.1 = 1, 3.5, 4, -5.8, 2500, 0, 0.2952, 40.0, 0.38, 1.2, 0.9, 5, 5, 3
point.2 = 1, -6.8, -4, -5.65, 2500, 1, 0.55, 0.0, 0.33, 1.2, 0.9, 2, 2, 2
point.3 = 1, -6.8, 4, -5.65, 2500, 2, 0.55, 0.0, 0.33, 1.2, 0.9, 2, 2, 3


Ski:
point.0 = 1, -22.35, 0.0, -0.71, 2500, 0, 0.42, 60, 0.292, 1.28, 0.9, 0, 0, 0
point.1 = 1, -2.67, -3.4, -3.99, 2500, 1, 0.75, 0, 0.38, 2.5, 0.9, 0, 0, 2
point.2 = 1, -2.67, 3.4, -3.99, 2500, 2, 0.75, 0, 0.38, 2.5, 0.9, 0, 0, 3

If the landings and takeoffs are better, then the distance to ground may have to be adjusted to compensate for the suspension changes. No need to mess with that unless the landing/T/O's are improved.

There may also be other issues if this does not correct it. If so, I will purchase the aircraft to sort it out.
 
Well Well!

I thought the problem was unique to my computer, but I see beana51 had the same issues, now solved.

However, in my case:
Amphib: Takes off smoothly, does some porpoising on landing, but much better than before.
Ski: Takes off smoothly, but bounces gently on landing.
Tundra: Bounces on take off and landing.

Milton, thanks for your work on this. If you have any further suggestions, I'd be glad to try them. I should go fly your Beech 18, Commander or Dash 7 now to enjoy problem free flying.
 
Fleet Canuck said:
I thought the problem was unique to my computer, but I see beana51 had the same issues, now solved.

However, in my case:
Amphib: Takes off smoothly, does some porpoising on landing, but much better than before.
Ski: Takes off smoothly, but bounces gently on landing.
Tundra: Bounces on take off and landing.

Milton, thanks for your work on this. If you have any further suggestions, I'd be glad to try them. I should go fly your Beech 18, Commander or Dash 7 now to enjoy problem free flying.
Click to expand...

Okay, if this is an improvement, its a good start, but keep in mind I was adjusting these values blindly without an aircraft to test. I will purchase the aircraft now and do it right, and correct all 3 versions. For a quality aircraft like this, these things need to work very well. I'll get back to you with better results.

EDIT: Also, I believe this aircraft needs to be landed in a 3-point fashion, not a main wheel landing, so just above stall speeds.
 
I purchased the C-185 and put the Tundra version through lots of torture. It did not like that at all. The crash points are part of the issue but the main problem is that there is so little suspension movement in the mains and the tail-wheel. The second issue is CoG is too far to the rear putting too much weight on the tail-wheel causing easy tail-wheel breakage and making handling cumbersome. I wanted to move CoG to 25% but that would require too many other changes to the FM. I commented out some of the crash points (after adjusting them to the visual model) as they were not responding correctly with the visual model.

So, the changes I'm recommending below correct these issues for a much better result. Try them if you wish but keep your original. I have no issues now on rough terrain or concrete runways, rough landings, wheeled or 3-point landings. Replaces only the Weight and Balance and Contact Points Sections.

Tundra Version Only

[weight_and_balance]
max_gross_weight = 3350
empty_weight = 1700
reference_datum_position = 4.3, 0, 0
empty_weight_CG_position = -3.0,0,0 //chgd CoG to 29% MAC from 45%
empty_weight_pitch_MOI = 1800
empty_weight_roll_MOI = 1500
empty_weight_yaw_MOI = 2300
empty_weight_coupled_MOI = 0
max_number_of_stations = 7

[contact_points]
static_pitch = 10.17
static_cg_height = 3.55
gear_system_type=4
max_number_of_points = 9


tailwheel_lock=1


point.0 = 1, -21.85, 0.0, -0.90, 2500, 0, 0.44, 60, 0.10, 1.52, 0.6, 0, 0, 0
point.1 = 1, -2.67, -3.8, -4.21, 3500, 1, 1.115, 0, 0.35, 1.12, 0.9, 0, 0, 2
point.2 = 1, -2.67, 3.8, -4.21, 3500, 2, 1.115, 0, 0.35, 1.12, 0.9, 0, 0, 3


point.3 = 2, -4.60, -17.0, 3.28, 1500, 0, 0.00, 0, 0, 0, 0, 0, 0, 5, 0, 0 //LW
point.4 = 2, -4.60, 17.0, 3.28, 1500, 0, 0.00, 0, 0, 0, 0, 0, 0, 6, 0, 0 //RW
//point.5 = 2, -21.8, 0.0, 1.2, 1500, 0, 0.00, 0, 0, 0, 0, 0, 0, 9, 0, 0 //tail
//point.6 = 2, 1.2, 0.0, -2.2, 1500, 0, 0.00, 0, 0, 0, 0, 0, 0, 4, 0, 0 //Fslg
//point.7 = 2, -18.75, 0.0, 6.45, 1500, 0, 0.00, 0, 0, 0, 0, 0, 0, 7, 0, 0 //Aux1
//point.8 = 2, -14.12, 0.0, 0.01, 1500, 0, 0.00, 0, 0, 0, 0, 0, 0, 8, 0, 0 //Aux2


I will work on the other versions tomorrow.
 
FLOAT VERSION ONLY

Similar issues with float points, static pitch, height, spread of points and hardness, and CoG.

Changes to the weight and balance and to the contact points:

[weight_and_balance]
max_gross_weight = 3350
empty_weight = 1700
reference_datum_position = 4.3, 0, 0
empty_weight_CG_position = -3.00, 0 ,0
empty_weight_pitch_MOI = 1800
empty_weight_roll_MOI = 1500
empty_weight_yaw_MOI = 2300
empty_weight_coupled_MOI = 0
max_number_of_stations = 7

[contact_points]
static_pitch = 5.11
static_cg_height = 4
gear_system_type=4
max_number_of_points = 11

point.0 = 4, 0.7, -3.80, -4.75, 1650, 0, 0, 0, 0.5, 1.5, 1.0, 0, 0, 2, 0, 0
point.1 = 4, -8.00, -3.80, -4.15, 1650, 0, 0, 0, 0.5, 1.5, 1.0, 0, 0, 2, 0, 0
point.2 = 4, 0.7, 3.80, -4.75, 1650, 0, 0, 0, 0.5, 1.5, 1.0, 0, 0, 3, 0, 0
point.3 = 4, -8.00, 3.80, -4.15, 1650, 0, 0, 0, 0.5, 1.5, 1.0, 0, 0, 3, 0, 0


point.4 = 5, -16.30, -3.80, -3.50, 1650, 0, 0, 45, 0, 0, 1, 2, 2, 0, 0, 0
point.5 = 5, -16.30, 3.80, -3.50, 1650, 0, 0, 45, 0, 0, 1, 2, 2, 0, 0, 0


point.6 = 2, 2.5, 0.0, 1.2, 1600, 0, 0.00, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 4,
point.7 = 2, -4.3, -16.8, 3.5, 1600, 0, 0.00, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 5,
point.8 = 2, -4.3, 16.8, 3.5, 1600, 0, 0.00, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 6,
point.9 = 2, -21.3, 0.0, 0.6, 1600, 0, 0.00, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 7
point.10 = 2, -20.3, 0.0, 6.00, 1600, 0, 0.00, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 7

Backup you original before you try these changes.
 
FLOAT VERSION ONLY Minor Adjustments to Contact Points

[contact_points]
static_pitch = 4.5
static_cg_height = 4
gear_system_type=4
max_number_of_points = 11

point.0 = 4, 0.7, -3.80, -4.70, 1650, 0, 0, 0, 0.5, 1.5, 1.0, 0, 0, 2, 0, 0
point.1 = 4, -6.5, -3.80, -4.20, 1650, 0, 0, 0, 0.5, 1.5, 1.0, 0, 0, 2, 0, 0
point.2 = 4, 0.7, 3.80, -4.70, 1650, 0, 0, 0, 0.5, 1.5, 1.0, 0, 0, 3, 0, 0
point.3 = 4, -6.5, 3.80, -4.20, 1650, 0, 0, 0, 0.5, 1.5, 1.0, 0, 0, 3, 0, 0


point.4 = 5, -16.30, -3.80, -3.50, 1650, 0, 0, 45, 0, 0, 1, 2, 2, 0, 0, 0
point.5 = 5, -16.30, 3.80, -3.50, 1650, 0, 0, 45, 0, 0, 1, 2, 2, 0, 0, 0


point.6 = 2, 2.5, 0.0, 1.2, 1600, 0, 0.00, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 4,
point.7 = 2, -4.3, -16.8, 3.5, 1600, 0, 0.00, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 5,
point.8 = 2, -4.3, 16.8, 3.5, 1600, 0, 0.00, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 6,
point.9 = 2, -21.3, 0.0, 0.6, 1600, 0, 0.00, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 7
point.10 = 2, -20.3, 0.0, 6.00, 1600, 0, 0.00, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 7

Adjusted the "step" points to get a little closer to the visual model.
 
AMPHIBIAN VERSION ONLY
Replace like sections only. Backup your version first.

[weight_and_balance]
max_gross_weight = 3350
empty_weight = 1700
reference_datum_position = 4.3, 0, 0
empty_weight_CG_position = -3.0, 0 , 0
empty_weight_pitch_MOI = 1800
empty_weight_roll_MOI = 1500
empty_weight_yaw_MOI = 2300
empty_weight_coupled_MOI = 0
max_number_of_stations = 7

[contact_points]
static_pitch = 4.5
static_cg_height = 5.65
gear_system_type=0
max_number_of_points = 15

point.0 = 1, 3.5, -4, -5.9, 2500, 0, 0.2952, 40.0, 0.25, 1.2, 0.7, 5, 5, 2
point.1 = 1, 3.5, 4, -5.9, 2500, 0, 0.2952, 40.0, 0.25, 1.2, 0.7, 5, 5, 3
point.2 = 1, -6.8, -4, -5.75, 2500, 1, 0.55, 0.0, 0.23, 1.5, 0.7, 2, 2, 2
point.3 = 1, -6.8, 4, -5.75, 2500, 2, 0.55, 0.0, 0.23, 1.5, 0.7, 2, 2, 3
point.4 = 4, 0.7, -3.80, -4.7, 1650, 0, 0, 0, 0.5, 1.5, 1, 0, 0, 2, 0, 0
point.5 = 4, -6.5, -3.80, -4.2, 1650, 0, 0, 0, 0.5, 1.5, 1, 0, 0, 2, 0, 0
point.6 = 4, 0.7, 3.80, -4.7, 1650, 0, 0, 0, 0.5, 1.5, 1, 0, 0, 3, 0, 0
point.7 = 4, -6.5, 3.80, -4.2, 1650, 0, 0, 0, 0.5, 1.5, 1, 0, 0, 3, 0, 0
point.8 = 5, -15.3, -3.80, -4.0, 1650, 0, 0, 50, 0, 0, 1, 2, 2, 0
point.9 = 5, -15.3, 3.80, -4.0, 1650, 0, 0, 50, 0, 0, 1, 2, 2, 0
point.10 = 2, -4.60, -17.0, 3.28, 1500, 0, 0.00, 0, 0, 0, 0, 0, 0, 5, 0, 0
point.11 = 2, -4.60, 17.0, 3.28, 1500, 0, 0.00, 0, 0, 0, 0, 0, 0, 6, 0, 0
point.12 = 2, 2.5, 0.0, 1.2, 1500, 0, 0.00, 0, 0, 0, 0, 0, 0, 9, 0, 0
point.13 = 2, -20.45, 0.0, 6.25, 1500, 0, 0.00, 0, 0, 0, 0, 0, 0, 4, 0, 0
point.14 = 2, -21.0, 0.0, 1.5, 1500, 0, 0.00, 0, 0, 0, 0, 0, 0, 7, 0, 0

This changes CoG, static pitch, height, wheel suspension, and float points. This should end the runway bouncing and give you a better water experience.
 
Thank You Milton

You've really gone to a lot of time, effort and even expense to help someone you don't know! Here's what I've found from testing:

Tundra: Still bounces on takeoff roll, and bounces vigorously on landing until it's stopped.
Float and Amphibian: Smooth takeoff, bouncy landing, right until it's stopped.

So, I don't know how I can have problems that I assume are unique to my computer. I have five other Carenado aircraft (half price sales, couldn't resist) and this is the only one with issues. They make great aircraft.

So, looking back on the thread I notice your first fixes worked better on the amphibian, so I'll try them again. I'll even ignorantly experiment with the ski version contact points on the tundra version, since the ski version has almost no bouncing on landing.

Thanks again Milton for all your help. If you have other suggestions, I'll certainly try them. And, I hope you enjoy the 185 you bought!:salute:

Doug
 
Fleet Canuck said:
You've really gone to a lot of time, effort and even expense to help someone you don't know! Here's what I've found from testing:

Tundra: Still bounces on takeoff roll, and bounces vigorously on landing until it's stopped.
Float and Amphibian: Smooth takeoff, bouncy landing, right until it's stopped.

So, I don't know how I can have problems that I assume are unique to my computer. I have five other Carenado aircraft (half price sales, couldn't resist) and this is the only one with issues. They make great aircraft.

So, looking back on the thread I notice your first fixes worked better on the amphibian, so I'll try them again. I'll even ignorantly experiment with the ski version contact points on the tundra version, since the ski version has almost no bouncing on landing.

Thanks again Milton for all your help. If you have other suggestions, I'll certainly try them. And, I hope you enjoy the 185 you bought!:salute:

Doug
Click to expand...

Doug,

Are you using flaps on takeoff, and a little up trim?

On landing with flaps, you should not touch down till airspeed is less than 45kias. You should not fly this to the ground, after rotation at 45-47 full flaps and up trim, pull off power and allow the aircraft to slowly sink to ground and touchdown around 40ish.
 
Thanx Milton,Mr.Carenado would approve,I know I do. Taildraggers are a tricky thing.Over time they get out of rigging..Factory Fresh,and A Tundra work horse? big Difference....No Automatic Sure thing Landings Here...Stick and Rudder all the way! Again Thank you Sir
icon26.gif
 
beana51 said:
Thanx Milton,Mr.Carenado would approve,I know I do. Taildraggers are a tricky thing.Over time they get out of rigging..Factory Fresh,and A Tundra work horse? big Difference....No Automatic Sure thing Landings Here...Stick and Rudder all the way! Again Thank you Sir
icon26.gif
Click to expand...

Thank you; I do hope they work better than the originals for you. If not, let me know and I'll try to tweak them.

I also think the elevator response and authority is weak but I have never flown one. If you feel it is, just increase the elevator effectiveness scalar in the flight tuning section. The aircraft seems sluggish to me in roll rates but that is just my opinion and it may in fact be representative of RW aircraft.
 
Fleet Canuck said:
You've really gone to a lot of time, effort and even expense to help someone you don't know! Here's what I've found from testing:

Tundra: Still bounces on takeoff roll, and bounces vigorously on landing until it's stopped.
Float and Amphibian: Smooth takeoff, bouncy landing, right until it's stopped.

So, I don't know how I can have problems that I assume are unique to my computer. I have five other Carenado aircraft (half price sales, couldn't resist) and this is the only one with issues. They make great aircraft.

So, looking back on the thread I notice your first fixes worked better on the amphibian, so I'll try them again. I'll even ignorantly experiment with the ski version contact points on the tundra version, since the ski version has almost no bouncing on landing.

Thanks again Milton for all your help. If you have other suggestions, I'll certainly try them. And, I hope you enjoy the 185 you bought!:salute:

Doug
Click to expand...

Doug, please zip up the aircraft.cfgs and send them to me. Maybe you have something different than I do. I want to see if I have the same problem with your cfgs.

You can send thru my profile email access.
 
Does anybody by accident have contact points for tail wheel of Mr. Narcizos Super Cub V3, i only discovered this little gem yesterday and so far my own experiments to fix tail wheel have been fruitless?
 
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