Useful Landing Gear Adjustment

[Corona688]

Discovering backwards values in the configs sounds very important.  Kudos to digging into this and figuring out which does what.

[foamyesque]

1 hour ago, Rocket In My Pocket said:

Wheres option #3?

"I haven't experienced any issues with takeoffs/landings."

 

I've experienced issues, but they're generally owing to design. The smallest gears are awkward to work with, though. No suspension traverse, no spring strength.

[Znath]

hopefully they can use this information to find an actual fix to the problem.

 

I've been doing tests to try and figure things out once in a while.  I've noticed that the game rapidly destabilizes with continual ground travel on kerbin.  It seems I can get about 8-10km before the game CTD's on me.  That's at a speed of around 20-30m/s

 

On the flip side, I've flown for well over an hour before and at high speed warp.  And I've had a lot fewer crashes in air/space. 

[AdmiralTigerclaw]

As an update for this thread, I've settled for a while on modified gear steering settings.

Overall, the biggest problem I encountered at the start was the steering being unstable at higher takeoff roll speed.  A simple lack of control resolution leads to overcompensation and see-sawing left and right until the oscilation becomes lethal.

The reduction in the turn curve by velocity in the part file helped significantly.  I've got new settings I'll put down at the end of this post.

Other than that, I've increased friction on the aft gear further, but actually reduced the friction settings on the steering gear.  In practice, any sharp inputs to turning are dampened by the fact that the nose gear will 'slip' at low friction settings.  Thus, a yaw input will require significant input to force any turns at speed.    Conversely, the increased friction to the aft gear will help keep the tail-end of any aircraft pulled aft, like the feathering of an arrow-shaft.  Thus an aircraft at speed during takeoff roll resists major yaw inputs for turns, and is very unlikely to doughnut.

 

Note the following, I will run refreshers as to what I think does what:

 

		steeringResponse = 4		
		steeringCurve
		{
			key = 0 20
			key = 5 2
			key = 15 0.5
		}

 

Steering Response is 4, higher than stock (2).

The Steering Response is how fast the gear itself rotates in relation to your input.  Stock is kind of slow.  Probably in anticipation of a keyboard 'all or nothing' input rather than something like that of a flight stick.  The result is that the wheel reacts to input, or release of input, slowly.  What that will do to your vehicle in a takeoff roll is that you will turn to correct, but when you release as the correction lines up, it will not straighten fast enough, and will overcorrect.  Increasing the response from 2 to 4 makes the gear steering react faster to inputs.  Meaning you don't have to react just ahead of your steering.

 

Steering Curve:

I'm pretty sure that each key on the curve is a value for velocity in m/s, and the amount the gear is allowed to rotate off center left or right.

Thus, the value of 0, 20 should mean that at a speed of zero m/s, the gear rotation should turn to 20 degrees left or right.  The next value, 5, 2, should mean that by the time you're traveling at five meters a second (11 mph), the steering range should have dropped to 2 degrees, dramatically dropping how much turn you can put into a vehicle as you gain speed.  By value 15, 0.5, well...  Fifteen m/s (33 mph), half a degree turn on the wheel.  If you're traveling 33 mph, your input shouldn't even ALLOW you to make hard turns.  Especially if you're likely in a tricycle configuration with aircraft landing gear.  I don't take 90 degree corners at 40 MPH in my car, why would I do it while taxiing in a plane?

[gilflo]

I think the best way to perform a take run at high speed is to disable nose steering. As on real plane, the rudder should be very efficient very soon.

If plane is aligned with runway you should not have to steer at all. My 455T SSTO take off at 110m/s (220 kts) without needing to steer on runway.

I use only steering on landing under 50m/s and i use strong braking plus chutes to minimize landing roll.

[AdmiralTigerclaw]

7 hours ago, gilflo said:

I think the best way to perform a take run at high speed is to disable nose steering. As on real plane, the rudder should be very efficient very soon.

If plane is aligned with runway you should not have to steer at all. My 455T SSTO take off at 110m/s (220 kts) without needing to steer on runway.

I use only steering on landing under 50m/s and i use strong braking plus chutes to minimize landing roll.

 

My aircraft actually have to Taxi quite a bit.  I run missions to Kerbineside bases as well as land in the field.  Turning on the ground is required.

[gilflo]

Yes, but you can disable steering just before take off, once aligned on runway.

[Dr.K Kerbal]

I believe you are using JavaScript

[AdmiralTigerclaw]

6 hours ago, gilflo said:

Yes, but you can disable steering just before take off, once aligned on runway.

Which I have no desire for.  I prefer speed-limiting the steering.  Which is what I programmed the gear to do.  It's almost like hard-disabling the steering, except it eases in and I get adjustment performance as I start my roll.

[foamyesque]

Me, I remapped rover steering (which includes gear) so that it isn't overloaded with flight steering. The reason for that was actually low-g rovers, so that I could use the rover keys to provide forward and reverse control without making the reaction wheels I use for stability and attitude control flip out, but it means I can use gear steering at low speeds and rudder steering as things pick up.

 

 

Edited July 20, 2016 by foamyesque

[whale_2]

Have you guys seen this - http://bugs.kerbalspaceprogram.com/issues/9853 ?

[Samniss Arandeen]

Good list, but may I add more?

1. Soften the rear suspension in a tricycle arrangement. This will help absorb the shock of a landing and prevent bouncing off the ground. It will also help with the next hint, which is...
2. Arrange your landing gear so the nose points slightly up at rest. This will give you a slight AoA on your takeoff roll and give you an extra bit of lift as a result. In my experience, it also cuts down on tailstrike risk at takeoff. There's no easy way to check this in the editor, but shoot for 3-5 degrees pitch up when stationary on your wheels.
3. Remember that steering is enabled by default for the gears that have it. If you're using smalls or mediums all the way around, be sure to disable steering on the rear gears.
4. This may be counterintuitive, especially if you're into cars or motorcycles like I am, but you want a rear brake bias on the landing gear. That's where most of the weight is if you positioned your gears correctly, and less/no brakes on the front wheel reduces its likelihood of slipping when trying to yaw.