Parts & Vessels Wheels And Legs Detach From Rover XS Truss When Decoupler Fired [Physicsless Parts Cause Parts To Fall Of When Decoupler Activated]

Anonymous Bug Reporter · December 21, 2023

I've been messing around with rovers in my exploration playthrough and I've been trying to design a rover that can get decoupled off the bottom of a lander just before it lands on Duna. Testing it at the KSC, no matter what decoupler/docking port I use, when I try to decouple an I beam off the top of my rover all of the wheels fall off. I tried setting the impulse to 0, shooting the entire rover up into the air, and firing off the decoupler and I beam with separatrons with the same result every time. I then moved the wheels to be attached to the XS panels on my rover instead of the XS truss hubs on the bottom and they did not fall off.

Included Attachments:

20231220162728_1.jpg.7f61ffbf946488d8e0c

Edited December 22, 2023 by The Space Peacock

The Space Peacock · December 22, 2023

@HyenaDae merged your report and added Legs to title

The Space Peacock · January 8

@Brahms_IV merged your report

Edited January 8 by The Space Peacock

Zaccy200 · December 22, 2023

I was designing a simple Mun rover and when testing the rover around the KSC everything was working fine. However, when I went to launch the rocket to take it to the mun the wheels on the ST-Micro-1 parts would fall off when the rocket launched and about 20 seconds into the flight the camera would start to pan down below the rocket as if the centre of mass was moving and I would experience strange phantom forces that would tip the rocket in strange directions. After removing the wheels from the rover and launching the rocket behaved as expected so I started looking for the root cause. As the wheel attached to the probe core stayed in place, I attached the other four wheels to ST-Micro-4 parts that make up the centre frame of the rover and translated them into a similar position. After launching this version, the issues disappeared however I had to take an extremely steep ascent as the rover would overheat and explode 65km up when traveling around 1800m/s. I've attached a video showing the strange wheel behavior on the original rover design.

Included Attachments:

RoveyBoiMK-1Broken.json

Edited December 22, 2023 by The Space Peacock

The Space Peacock · December 22, 2023

@Zaccy200 merged your report

HyenaDae · December 22, 2023

You'd expect them to hold unless you're really abusing them, but nope. They just fall right down and into the ground. Doesn't matter the orientation, they simply refuse to stick the moment you press 'launch' even at low throttle!

Included Attachments:

HyenaDae · December 22, 2023

Yeah that's exactly what happens to me, ooof

Kass_Is_Legend · December 23, 2023

i expected the landing legs to stay on the trusses attatched to the 2nd stage all the way through the mission. What actually happened is during any staging event the trusses act like decouplers and jettison the legs.

this appears to happen with any type of truss.

Science gamemode

Included Attachments:

Why.mp4

Smallpayloadlaunchermoon.json

Edited December 23, 2023 by Spicat

EchoNovemberDelter · December 23, 2023

When a rover wheel (or potentially some other parts, i've only tested it with the Rovemax M1 and S2) is radially attached to the St-Micro-1 then offset until off of the St, the wheel will fall off on launch. When the wheel falls off and is inevitably destroyed, the craft state will be set to 'landed.' That might be unrelated, but the destruction and state seem to happen simultaneously. No 'structural failure' or other report is present in the flight log, besides the launch of the vessel and overheating/destruction of the wheels.

Included Attachments:

IkeLanderPlusDunaRoverbrp.json

Edited December 24, 2023 by The Space Peacock

The Space Peacock · December 24, 2023

@EchoNovemberDelter merged your report

The Space Peacock · December 25, 2023

@Kass_Is_Legend merged your report

Ghosty141 · December 27, 2023

Really odd bug. I attached a craft file that works as a minimal reproducible example. Just launch it and press space to see the bug in action.

The screenshots show the before and after of the separator firing. It does not happen with a fuel tank attached to the hub for example.

Included Attachments:

BROKEN_HUB.zip

The Space Peacock · December 27, 2023

@Ghosty141 merged your report

Brahms_IV · January 7

Attaching landing gear to hub connectors (see VAB image) will often result in them falling off the craft as soon as the vessel is on the launchpad. When attaching multiple trusses and/or hubs, the break will occasionally occur between these parts rather than the gear. Adding struts to the trusses and hubs does not resolve the issue.

Included Attachments:

Anonymous Bug Reporter · January 10

In short:
When firing a TD-12 any equipment (e.g. landing legs, science jr. jr., chutes) attached to a STJ-3125 which is close to the decoupler falls off.

How to reproduce
Open attached craft file, go to launchpad and enable the bottom TD-12 decoupler (the one close to the landing legs).

Notes:
The landing legs fall off. This happens despite decoupling force being set to 0, and the legs not being attached to the decoupler itself (they look to be about a small tank diameter away)..

Included Attachments:

bug_report.json

borfo · January 11

What: when firing the first stage on all vertical rockets, i have found that all varieties of rover wheels will explode from overheating even when protected by a fairing or cargo bay. seems like there is a value off here.

judging by the timing in the mission report, the wheels explode within 1 second of firing the first stage. seems to be when the rocket actually starts moving upwards, imho.

Severity: Medium - I cant launch rovers, cuts out a significant part of the game.

Frequency: high, has happened with multiple designs many days apart, and is reproducible.

seems like this occurs mostly when i have a rover that is built as a separate assembly and then rotated to attach to rocket.

Included Attachments:

marsattack.json

Edited January 11 by The Space Peacock

kuroshimo · January 18

Engines can also fall off if they are attached to trusses and a decoupler fires, but the behavior seems to change based on if my lander is part of a larger vessel with other decouplers.

DibzNr · January 24

@borfo Your issue is directly related to this post so I've merged your report, micro truss parts currently cause massive physics issues sometimes, especially when mixed with wheels

Anonymous Bug Reporter · January 31

Like the title says, when legs are attached to truss, they fall of when staging is used.

Included Attachments:

SuperBoots · January 31

I'm trying to build a rover that has a little launchable drone for taking atmospheric surveys, whenever I detach the drone the front wheels fall off the rover though. The rover is pretty basic construction, the frame is an RC-R "RoveMate" with some STJ-3125 Square Truss Junctions and ST-Micro-1 Square Micro Trusses attached to the front and back. The RoveMax M1 wheels are attached to the trusses. Then I've slapped a bunch of batteries, fuel tanks, fuel cells, antennas, and science equipment on it.

I tried to reproduce by just taking the RC-R and putting the M1 wheels on it and a pair of docking ports but that didn't reproduce the issue, then I added the trusses and attached the wheels to them and that still didn't reproduce the issue. Then I rebuilt the rover from scratch with all the batteries, fuel tanks, fuel cells, etc, and then I was able to reproduce the issue.

If I get time I'll try taking the parts off one by one and see if I can identify a specific part that causes the issue.

Included Attachments:

KerbalSpaceProgram22024_01.31-12_23.15_01.mp4

The Space Peacock · January 31

@SuperBoots moved this report out of the archive and merged your report

SuperBoots · January 31

@The Space Peacock Thanks, I'm not seeing it when browsing the KSP 2 bug reports though, does it just take time to show up or is there maybe something funky going on with un-archiving?

The Space Peacock · January 31

7 minutes ago, SuperBoots said:

Thanks, I'm not seeing it when browsing the KSP 2 bug reports though, does it just take time to show up or is there maybe something funky going on with un-archiving?

try filtering categories in the menu on the right. it's under "parts and vessels"

Spoiler

SuperBoots · January 31

doh, parts and vessels was the only thing unchecked in the filter, I can see it now, thank you!

ShadowZone · February 26

Reported Version: v0.2.1 (latest) | Mods: BepInEx/SpaceWarp, UitkForKsp2, MicroEngineer, LazyOrbit, AlarmClockForKSP2, DockingAlignmentDisplay, node_manager, maneuver_node_controller, flight_plan, K2D2 | Can replicate without mods? Yes
OS: Microsoft Windows 11 Pro 10.0.22631 64-Bit | CPU: AMD Ryzen 9 3900X 12-Core Processor (24) | GPU: NVIDIA GeForce RTX 3090 (24340MB) | RAM: 65459

Got my rocket on the pad. I hit "go" and one pair of rover wheels just falls off. Flight Report claims that they overheated. When I turn off part overheating, the message claims that they crashed. Logs, save file and workspace are all in the bug package I uploaded.

Included Attachments:

ForSci_Bug40.mov

ForSci_Bug40_logs.zip

DibzNr · February 26

@ShadowZone Merged your report with this post

Parts & Vessels Wheels And Legs Detach From Rover XS Truss When Decoupler Fired [Physicsless Parts Cause Parts To Fall Of When Decoupler Activated]

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