my plane moves around despite brakes

[king of nowhere]

i was trying to experiment loading/unloading stuff from the cargo bay, but could not do it because the plane keeps moving. i activated brakes, and the plane rotates around its center of mass. it does not move forward. it rotates. slowly, but fast enough that it disrupts my operation. and i don't want to know what will happen over a prolonged time.

i tied putting a landing strut to act as brake, but it still turned. i thought maybe it was a problem of stress on wheels, so i added more wheels and removed all the fuel, still it rotates.a bit more slowly, but still. the paw says stress on wheels is 0 now. at least it starts at 0, though it increases over time.

how do i fix that?

EDIT: i take this chance for a related question: those large airplane wheels will only go forward and backwards. if i want to turn around while on land, do i have a good way to do it?

Edited September 3, 2020 by king of nowhere

[Wobbly Av8r]

First, the obvious - have you tried to set the "Parking Brake" (the icon near the altimeter, a triangle with an exclamation point) ?

Gonna go out on a limb here and guess that you have a lot of reaction wheels on your vessel and you're seeing the  result of all of them 'reacting' to the movement of Kerbin (it seems to be a PhysX thing).

 Among things to try might be turning off the torque of each component that has a reaction wheel. Hope one of those suggestions helps...

Good luck!

Edited September 3, 2020 by Wobbly Av8r

[bewing]

The way that the "ground" works in games is that when a part of your vehicle is below the ground, the game engine forces it back above the ground with some small upward velocity. Things do not actually ever "rest" on the surface. Due to the transmission of stresses and strains to other parts in a multipart craft, this causes unbalanced rotational or translational forces. Which causes a slow rotation or translation. I call this "microbouncing". I don't think it can ever be completely fixed for a particular craft. However, using the wrong sized wheels or the wrong spring values will make it worse. Which implies that sometimes fiddling with your choice of wheels on the craft, or their spring values can moderately improve the situation.

Edited September 3, 2020 by bewing

[Serenity]

4 hours ago, king of nowhere said:

how do i fix that?

If you are ok with using a light mod, i use this and its great.Apparently its an old bug.

 

[eatU4myT]

I often find that turning off the SAS once the brakes are on is helpful.  There are still phantom forces acting on your craft, but at least your own reaction wheels etc. are not trying to correct them, over-correcting, and actually making things worse!

[steve_v]

5 hours ago, king of nowhere said:

how do i fix that?

With mods, or not at all. You're playing Kerbal Jank Program.

Maja's Parking Brake works around it tolerably well.
Lisias has found and mostly fixed one of the causes, and is working on the other.
Squad has offered a large helping of hype for new versions, but that's about it.

[maja]

2 hours ago, steve_v said:

Maja's Parking Brake works around it tolerably well.

If you have a craft, which stil drifts (or rotates) in KSP 1.10.x even with my Parking brake, send it my way. I tested it and all looked well.

[Serenity]

1 hour ago, maja said:

If you have a craft, which stil drifts (or rotates) in KSP 1.10.x even with my Parking brake, send it my way. I tested it and all looked well.

I tested most of my crafts in Kerbin, Mun, Minmus and all was fine.

Some of them touch the ground with structure panels other with wheels, landing legs etc, i didnt notice any sliding.

I am taking a break right now waiting for the fuel bug fix but as soon that comes i will make sure i pay more attention and report if i find something.

i just wanted to thank you once more for a very useful mod that fixes a very annoying and sometimes gamebreaking bug(cant scan in Kerbin the trees etc because it says the vessel is moving).

Edited September 3, 2020 by Boyster

[steve_v]

4 hours ago, maja said:

 I tested it and all looked well.

Indeed it does.

The "tolerably well" bit was because we really shouldn't need a mod like this in the first place.