[1.2] Fix the (description of) extremely weak, breaking "LY-01 Fixed Landing Gear" (updated)

[Kerbal101]

I encountered this issue in 1.2 stable when doing Science career: the LY-01 gear will constantly break on landing.

From the evolved discussion, this is the root of the problem (by @regex ):

Quote

Eight tons is far more than those gear should be handling. They are equivalent to Cessna gear, perfect for small, light planes. Anything more than five tons is probably way too much. In fact, five tons may be too much.

TL;DR version:  Please, Squad, add "Maximum weight/wheel: xxx t" for all wheels in description text!  (perhaps also consider adding stock entry aircraft with LY-01)

1) The player (myself included) does not realize how extremely-little weight (2-3t max/wheel) the LY-01 can carry, even compared to LY-06.
2) Because I wasn't aware of the weight restriction, I initially solved the problem by copying the crashTolerance value from LY-06 to LY-01 (below).
3) Its realistic that LY-01 is weak. See this video to compare front and rear wheels. The change in (2) step makes game unrealistic.
 

Based upon discussion, I have created a stock plane in stock 1.2 KSP(no mods) that has a very good dV, speed (140m/s), maneuverability and very low weight (does not destroy LY-01 on landing, yay!).
I have tested it in career for few hours.   Kerbalx download link with more pictures for anyone interested.

  

 

--- outdated problem approach below ---

The LY-05 "Free" Landing Gear is very reliable and tolerates acceptable level of abuse (the stock values as such, that it often survives after extreme crashes), ...

but LY-01 Fixed Landing gear is extremely fragile: it requires very accurate, very slow landing at very low vertical speed. The LY-01 will break in 9 of 10 cases when landing on runway, no other gear has the fragility the LY-01 has.
After digging through this post by GoSlash27 and comparing gears, I nailed the issue and probably understand the reason.

Edit: sorry, previously I misspelled "LY" for "YT" in this thread before I noticed it. Nobody (all except Leafbaron) has noticed that too.

 

How to fix by direct editing:

1. Edit file /GameData/Squad/Parts/Wheel/LandingGear/GearFixed.cfg  in text editor
2. Find this variable crashTolerance = 125 replace the value with crashTolerance = 325, save.  "325" IS THE SAME VALUE WHICH YT-05 (free landing gear) HAS.

Play.

 

How to fix by creating a mod manually:

1. Create a directory /GameData/LY-01Fix and descend into it
2. Create a new empty file, called GearFixedFixer.cfg
3. Paste this inside:

Quote

@PART[GearFixed]
{
  @crashTolerance = 325
}

4. If you don't have the ModuleManager installed, download the latest ModuleManager.dll from official source and save the file directly in /GameData/

Start the game and you should see the NyanCat and "1 patch applied". Play.
I am not making this available as download anywhere, reason being that file/service could easily stop being available, nothing beats plain text. Google cache will help even if something happens to Squad Forums (God forbid!).

 

My findings:
- major difference between LY-01 and LY-05 is crashTolerance
- the wheelSuspension section seem to have no effect
- while the LargeLandingGear has CrashTolerance of only 70, near end of file in section ModuleWheelDamage - it has huge stress and impact Tolerance values (18000 and 4800   vs 2000 and 1000 on YT-01 fixed.)

So I think that the LargeGear, while having low tolerance (70), simply survives a lot of abuse; while the basic free gear (YT-05) has much higher crashTolerance - never getting affected by abuse in first place.
The LY-01 currently however, has both low crashTolerance and (when it easily surpasses that) - a very low stress/impact Tolerances, unusually low compared to every gear

(Final edit: this is supposed to be puny by design.    ¯\_(ツ)_/¯ )
Hence it breaks literally everywhere and on every occassion.

Edited October 26, 2016 by Kerbal101
craft to prove concept of weight limit added

[Kerbal101]

1 hour and nobody replied... this can't be serious.. has nobody been using basic landing gear in 1.2 career?

[GluttonyReaper]

1 minute ago, Kerbal101 said:

1 hour and nobody replied... this can't be serious.. has nobody been using basic landing gear in 1.2 career?

I really haven't had any issues with the landing gear. Built a few planes with them, landed fine. A little bouncy, perhaps, but not particularly weak.

[Leafbaron]

I have been using them. Haven't really noticed them being extremely weak. 

In fact. I used them on my first space glider. They survived the vigors of re-entry and spashing down in the ocean at around 45 m/s horizontal velocity and ~5 m/s vertical velocity.

Edited October 25, 2016 by Leafbaron

[Kerbal101]

@GluttonyReaper @Leafbaron  Thanks for reply guys! Was this with 1.2? Maybe this is effect of enabled G-stress on parts... But I never apply any crazy G.

This is the craft I have problem with: https://kerbalx.com/Kerbal101/lolplane , its designed for long range/high economy/maneuvr./science.

The "1" action group will toggle engines.

 

Regardless of what, its always rear gear breaking - and single front wheel always survives/never breaks.

11 minutes ago, GluttonyReaper said:

A little bouncy, perhaps, but not particularly weak.

(been there) thats dampfer, move the setting all way to the right (maximum) and it will not bounce.

[Leafbaron]

@Kerbal101 My experience is in 1.2. I do not play with G-force part limits. so this may be why I am not experiencing what you are. 

Have you tried flying that plane with only 2 juno engines instead of 4? the extra weight may be causing your gear to explode. That plane should fly adequately with the reduced thrust. Made one very similiar to it last night that flew exceptionally well with only 2 juno engines. 

Edited October 25, 2016 by Leafbaron

[Kerbal101]

10 minutes ago, Leafbaron said:

@Kerbal101 My experience is in 1.2. I do not play with G-force part limits. so this may be why I am not experiencing what you are. 

Have you tried flying that plane with only 2 juno engines instead of 4? the extra weight may be causing your gear to explode. That plane should fly adequately with the reduced thrust. Made one very similiar to it last night that flew exceptionally well with only 2 juno engines. 

Thanks! Have you tried landing it anywhere except airfield? The plane main weight is one 2.5m liquid fuel tank.
Yesterday I used just pair of (juno with intake connected together via girder). Girder was to be able to surface attach it to sides - but it didn't make any difference - YT-01 always broke on landing, I only used a pair. This plane has double rear gear only for break power,  to make it stay stable and not roll down from the (flat) top of the mountain.

[HafCoJoe]

I've found these wheels to be pretty underwhelming myself too. I'm not playing in career mode, but I have a small cessna style plane that uses these wheels. They don't usually break on my plane but it's very common for me to bottom out the suspension on them when landing causing them to grind along the ground and then jump back into place. My main concern has been that they rock back and fourth infinitely once I'm landed on the ground without the aid of SAS. I made a bug report for 1.2 on wobbly wheels which wasn't addressed as well as a general report on certain suspension appearing weaker in U5 which wasn't addressed. This issue isn't new though - I made a report in 1.1.3 which also wasn't addressed. Kryten made a much more detailed report on  wheels just feeling underwhelming but it appears to have been ignored as well. It's possible these reports where read but there was never any official words on the matter. @SQUAD? @TriggerAu?

EDIT: Rephrased a bit more

Edited October 25, 2016 by Avera9eJoe

[Leafbaron]

4 minutes ago, Kerbal101 said:

Thanks! Have you tried landing it anywhere except airfield? The plane main weight is one 2.5m liquid fuel tank.
Yesterday I used just pair of (juno with intake connected together via girder). Girder was to be able to surface attach it to sides - but it didn't make any difference - YT-01 always broke on landing, I only used a pair. This plane has double rear gear only for break power,  to make it stay stable and not roll down from the (flat) top of the mountain.

Is the fuel tank behind the Science Jr. a fuel tank or a structural fuselage? I can't imagine you would need so much fuel. with the Junos and the mk0 fuel tanks that should give quite a fair bit or range. 

I have landed the gear on rougher terrain such as the grasslands and shoreline around ksc. Have not tried to land on a mountain though. 

[Kerbal101]

1 minute ago, Leafbaron said:

Is the fuel tank behind the Science Jr. a fuel tank or a structural fuselage? I can't imagine you would need so much fuel. with the Junos and the mk0 fuel tanks that should give quite a fair bit or range. 

I have landed the gear on rougher terrain such as the grasslands and shoreline around ksc. Have not tried to land on a mountain though. 

Well, can I ask you to download my craft and try to land anywhere or find out the reason for it to constantly break?
The YT-01 seem to be overwhelmed by weight, because even slightest vertical speed and they break off. Funny part is really single YT-05 front wheel always surviving no matter what.

Now after YT-1 adjustment to same crash tolerance value  as YT-05 (as #1 post), it behaves perfectly.

The landing includes any typical terrain height differences, mountains are just most difficult case.

Yesterday I built a "flying bus" using mk3 parts and large gear - and landed it without any problems on 1st attempt in mountains. That part has even lower crash tolerance than YT-01, but much much higher break tolerance.
Here the landing gear is up and "bus" is standing on rover wheels.

The YT-01 has the worst parameters of any wheel, its 3x worse in crash tolerance than front wheel YT-05.
I had no problems with it in 1.0.5, but in 1.2 I started a career.

[Leafbaron]

9 minutes ago, Kerbal101 said:

Well, can I ask you to download my craft and try to land anywhere or find out the reason for it to constantly break? ...snip...

I will definitely download and try it out tonight if i have time. RL has a bad habit of interfering with my KSP time haha.

[HafCoJoe]

Just now, Leafbaron said:

RL has a bad habit of interfering with my KSP time haha.

Me too  gotta farm those crates

[Kerbal101]

@Avera9eJoe Well, I was not doing anything exceptional with YT-01. The fix just makes YT-01 as crash tolerant as YT-06 (aka front wheel) and that alone solves everything.
I found YT01/06 suspension to be okayish, the "jumpiness" is caused by too low damper setting - moving damper to max setting (right) causes the least jumpness.
Never had issue in taking off, but always problem with explode on landing ("Crashed into terrain" in F3 log).

The 1.5t payload suggested in this bug is unrealistic. Judged by gear looks,at very least the four of such wheels should be capable to land 4x MK1 LFF (which is around 8 tonnes), means 4-5t / wheel when landing under normal conditions (as in "nothing fancy" soft landing). Just having the same properties as YT-06 is fine. I don't understand why YT-01 is so much worse, YT-06 even has steering - they YT-01 is nerfed to the level they are literally useless for anything except remote-steered planes. IMHO.

Edited October 25, 2016 by Kerbal101

[HafCoJoe]

1 minute ago, Kerbal101 said:

@Avera9eJoe Well, I was not doing anything exceptional with YT-01. The fix just makes YT-01 as crash tolerant as YT-06 (aka front wheel) and that alone solves everything.
I found YT01/06 suspension to be okayish, the "jumpiness" is caused by too low damper setting - moving damper to max setting (right) causes the least jumpness.
Never had issue in taking off, but always problem with explode on landing ("Crashed into terrain" in F3 log).

The 1.5t payload suggested in this bug is unrealistic. Judged by gear looks,at very least the four of such wheels should be capable to land 4x MK1 LFF (which is around 8 tonnes), means 4-5t / wheel when landing under normal conditions (as in "nothing fancy" soft landing). Just having the same properties as YT-05 is fine. I don't understand why YT-01 is so much worse, YT-06 even has steering - they YT-01 is nerfed to the level they are literally useless for anything except remote-steered planes. IMHO.

I've been tempted to remove the YT-01s and replace them with additional YT-05

[Red Iron Crown]

55 minutes ago, Kerbal101 said:

(been there) thats dampfer, move the setting all way to the right (maximum) and it will not bounce.

Turning the damping all the way up may be contributing to why they break so easily for you. More damper = more stress on impact.

[Kerbal101]

11 minutes ago, Avera9eJoe said:

I've been tempted to remove the YT-01s and replace them with additional YT-05

Thats what I have done on my "exploration rover" in 1.0.5 career. The catch is that YT-05 has no breaks (B). I have no idea why,  perhaps I should "restore it" in the mod.

10 minutes ago, Red Iron Crown said:

Turning the damping all the way up may be contributing to why they break so easily for you. More damper = more stress on impact.

Hi, thanks for reply!
I have been experimenting with all gear values before digging into config files. They broke regardless of strength/damper setting, but plane started to jump wildly if damper was set to less than 0.6.

Edited October 25, 2016 by Kerbal101
spelling

[problemecium]

The reason people took forever to reply is that you posted this thread in the wrong place. In the future, please put request threads in the Suggestions & Development Discussion forum.

[Leafbaron]

5 hours ago, Kerbal101 said:

Edit: Sorry, but I noticed only now that I misspelled "LY" for "YT" in this post and below... :/ :/ On the other hand, nobody has noticed that too.
In my defense, officially the fixed gear is called "LY01" and free gear -"LY-05". Notice the absent "-" sign. (weee! I found some excuse and someone else to blame   )
:: Edit end

Let the record show, that I noticed, I didn't say anything because I'm not a dick and I still knew what you were referring too

[Kerbal101]

22 minutes ago, Leafbaron said:

Let the record show, that I noticed, I didn't say anything because I'm not a dick and I still knew what you were referring too

Doh!

 

@Avera9eJoe The breaks for LY-05.

[regex]

Eight tons is far more than those gear should be handling. They are equivalent to Cessna gear, perfect for small, light planes. Anything more than five tons is probably way too much. In fact, five tons may be too much.

[HafCoJoe]

29 minutes ago, regex said:

Eight tons is far more than those gear should be handling. They are equivalent to Cessna gear, perfect for small, light planes. Anything more than five tons is probably way too much. In fact, five tons may be too much.

They're handling 3 tons each to split my 6 ton cessna plane on landing (if I count the front wheel it's even less, leaving it out in this case though). I can bottom out the suspension on both sides when rocking back and fourth with SAS  - doesn't stop rocking once it starts too.

Edited October 25, 2016 by Avera9eJoe

[Kryten 2X4B 523P]

What Regex said.

I found with extensive testing that the comfortable spot for the LY-01 and LY-05 is around 1.5 tons per wheel (assuming a 3 wheel tricycle or taildragger setup). Anything over that and they get really fragile. Theyre also a little sensitive to vertical speed impacts when the plane is too heavy, although Ive landed a 3.5 ton plane at around 70ms on the grass around KSC, and usually 50ms is ok on flattish terrain. Even landed a plane on a flattish spot on a mountain to do an EVA  sample mission using these gear, and Im not a great pilot (keyboard / mouse player in case anyone is wondering). I dont change any spring / damper settings either, all default.

It doesnt help when the game is unclear as to what the weight tolerances are, has the tech tree arranged to encourage poor design choices, puts too wide limitations on the T1 runway and makes the T1 runway the equivalent of a building site - all of which make building first tier aircraft much harder than it probably should.

Overall though, once you know what weight range theyre intended to be used in, its easy to design around the limitation. Knowing theres a limitation is the main issue, right after knowing how to build a plane that can actually get off the runway properly / land properly.

Not saying theyre perfect (far from it, theres an odd suspension bug that appears on all the gears to varying degrees, but seems worse on these - beware tinkering with the damper settings), but they are perfectly usable in the correct context.

Heres a quick vid I made in 1.2 pre showing such, with a plane that tops in at a shade over 3tons and gets 2/3 of the way to the north pole on 50 units of fuel.

 

[sal_vager]

Something to bare in mind regarding braking, these gear are usually attached behind the CoM, with a single unbraked LY-05 in front.

When you're braking in a car or on a motorbike it's your front brakes that do the most work, as the vehicles inertia causes the vehicle to tilt forwards and push down on the front wheel(s) you can apply more braking force without losing grip, but the rear wheels will have a lot less weight on them, this is the number one cause for locking up the rear wheel on a bike, too much force too soon on the back brake when stopping.

Braking with the rear wheels only can be done, but takes longer unless you want to risk locking up the wheels, as there's less pressure on them against the road they will have less grip.

It's like this with the LY-01's behind the CoM, applying the brakes causes the craft to nose down a bit, putting more force on the (useless for stopping) LY-05, and a little less on the 01's, so it takes longer to stop.

Bigger brakes won't help much, as what you need are braked wheels in front of the CoM, you can see this yourself with any of the retractable gear, just disable the brakes on the front wheels and your stopping distance will increase, a lot.

Also, moved to Suggestions.

Edit:

Derp, breaking not braking :/

Btw, max take of weight of a Cessna 185 is 1,506 kg, no where near 6 tons, so I wouldn't expect the gear to be that strong.

[Kryten 2X4B 523P]

3 minutes ago, sal_vager said:

Something to bare in mind regarding braking, these gear are usually attached behind the CoM, with a single unbraked LY-05 in front.

When you're braking in a car or on a motorbike it's your front brakes that do the most work, as the vehicles inertia causes the vehicle to tilt forwards and push down on the front wheel(s) you can apply more braking force without losing grip, but the rear wheels will have a lot less weight on them, this is the number one cause for locking up the rear wheel on a bike, too much force too soon on the back brake when stopping.

Braking with the rear wheels only can be done, but takes longer unless you want to risk locking up the wheels, as there's less pressure on them against the road they will have less grip.

It's like this with the LY-01's behind the CoM, applying the brakes causes the craft to nose down a bit, putting more force on the (useless for stopping) LY-05, and a little less on the 01's, so it takes longer to stop.

Bigger brakes won't help much, as what you need are braked wheels in front of the CoM, you can see this yourself with any of the retractable gear, just disable the brakes on the front wheels and your stopping distance will increase, a lot.

Conversely, if the LY-01s are just in front of the CoM and you brake too hard, head over heels it goes :-)

Pros and Cons to both approaches. Personally I prefer rear braking on the first tier light aircraft, but thats just me. Usually when I get the retractables I split the braking bias a bit between front and rear.

[sal_vager]

@Kerbal101, if you have not already can you please report this on the tracker with your findings regarding tolerances.