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Nose Wheel Buries itself

Posted:
Tue May 12, 2009 7:37 pm
by alb469
On landing the nose wheel buries itself in the runway. I am pretty sure there is an adjustment for this but what is it? When on the runway and not moving the nose wheel is ok. just don't apply brakes on landing.
Re: Nose Wheel Buries itself

Posted:
Tue May 12, 2009 8:29 pm
by Brando14100
Are you touching down way too hard? Lowering the nose too fast maybe?
8-)
Re: Nose Wheel Buries itself

Posted:
Tue May 12, 2009 9:01 pm
by FuturePilot
It sounds like you are pushing forward on the stick too much.
Re: Nose Wheel Buries itself

Posted:
Tue May 12, 2009 9:12 pm
by Brett_Henderson
This is caused by an inconsistency between the animation and the contact points.
The total suspension travel defined in the aircraft.cfg file is greater than what was animated in the model.. when the nose continues to "dive", the model runs out of suspension travel, so the wheel is "driven" into the ground.
I've posted more than once about contact point definitions.. it's rather involved.. a forum search should find those posts..
If you cannot find those posts.. I'll search for them later.
Re: Nose Wheel Buries itself

Posted:
Tue May 12, 2009 9:23 pm
by Brett_Henderson
I searched and found this...
To do this accurately.. you have to have access to the original model file... or at least know the numbers (total travel animation for each gear)(keyframes 101-200). Trial and error can get you close though.
'Static Compression' , is how far the gear compress (full load) when the aircraft is sitting still.
'Max/Static Compression Ratio', tells FSX how much total suspension trave to use. It's just what it says.. the ratio of maximum travel to static compression. If the model has 1.0 foot of total travel animated.. and you set Static Compression to 0.5 feet.. the Max/Static Ratio needs to be 2.0 (1.0/0.5)
If you give FSX inaccurate data, that's when wheels start sinking and floating...
The "sogginess" comes from the Damping Ratio .. The smaller that number, the "softer" the suspension.
Re: Nose Wheel Buries itself

Posted:
Wed May 13, 2009 10:03 am
by alb469
Thanks Brett. I don't have a program to open the.mdl file so I experimented with the nose contact points. Adjusted the 9th point which raised up the nose Ithen brought the nose down on the ground with the 4th. Did a couple of test landings and surprise! it seems to be ok now. I have no idea what the 9th contact point is for, can anyone tell me?
Re: Nose Wheel Buries itself

Posted:
Wed May 13, 2009 10:17 am
by Hagar
I have no idea what the 9th contact point is for, can anyone tell me?
Look in the Aircraft.cfg of any default aircraft for a key to the different entries. Note that the entries start from 0 counting from the = sign.
#3 is the Vertical Position. #8 is the Static Compression.
Re: Nose Wheel Buries itself

Posted:
Thu May 14, 2009 8:48 am
by alb469
Thanks Hagar. I had a lucky guess I was not sure that those numbers referred to contact points when I read them. You learn something new every day.