Bug #5138
Center of thrust off when adding radial engines to a craft
100%
Description
The center of thrust-vector is pointing in the wrong direction when (symmetrically) adding radial engines to a craft (note that I used radial symmetry here). It seems at least the Twitch and Puff rocket engines are affected by this bug, while the Thud and Spider engines does not seem to be affected. The bug seems to affect the center of thrust vector not only in the VAB, but also when launching. The radial engines also scewers the vector of other engines attached to the craft (even when the radial engines are turned off!).
A friend of mine (also Windows user) was able to reproduce the bug.
| bug.jpg (520 KB) bug.jpg | |||
| screenshot138.png (1.71 MB) screenshot138.png | Vertical LV-1 added at full thrust (2 kN), horizontal added second at half thrust. | ||
| screenshot139.png (1.71 MB) screenshot139.png | Horizontal LV-1 added second at half thrust. | ||
| screenshot140.png (1.71 MB) screenshot140.png | Horizontal LV-1 added second at half thrust. | ||
| screenshot141.png (1.64 MB) screenshot141.png | Horizontal LV-1 added second at half thrust. | ||
| screenshot142.png (1.63 MB) screenshot142.png | Horizontal LV-1 added second at full thrust. | ||
| screenshot144.png (1.65 MB) screenshot144.png | Horizontal engine added second | ||
| screenshot143.png (1.64 MB) screenshot143.png | Horizontal engine added second |
History
#1
Updated by jonatkins over 9 years ago
Updated by I've had problems in this area too - mounting the "Twitch" engines in mirrored symmetry on self-landing rovers built from Mk2 parts.
In this case the thrust is directed to one side. Rotating the engines inwards (5 degrees?) seems to fix the problem.
#2
Updated by TriggerAu over 9 years ago
Updated by - Status changed from New to Confirmed
- Severity changed from Critical to Normal
- % Done changed from 0 to 10
I can confirm these steps here as well, have adjusted the priority appropriately
Placing a similar vessel in orbit and thrusting I can see the off axis thrust.
#3
Updated by RexRectumIV over 9 years ago
Updated by TriggerAu wrote:
I can confirm these steps here as well, have adjusted the priority appropriately
Placing a similar vessel in orbit and thrusting I can see the off axis thrust.
Yes, sorry about the priority (forgot to change it when I looked at the alternatives). I think, however, that it is actually quite a huge problem because it severly cripples lander designs. The proposed fix above does not work (if you look closely the thrust vector is still off).
#4
Updated by Squelch over 9 years ago
Updated by - Platform Win32 added
- Platform deleted (
Windows)
#5
Updated by Kasuha over 9 years ago
Updated by 
- File screenshot138.png screenshot138.png added
- File screenshot139.png screenshot139.png added
- File screenshot140.png screenshot140.png added
- File screenshot141.png screenshot141.png added
- File screenshot142.png screenshot142.png added
- File screenshot143.png screenshot143.png added
- File screenshot144.png screenshot144.png added
I tried playing with the issue and my conclusion is that when determining the thrust vector, the value collected so far is normalized to 1 kN before another engine's full thrust is added. That normalization should be dropped.
#7
Updated by Kasuha almost 9 years ago
This issue appears to be resolved in 1.0.5
#8
Updated by TriggerAu over 8 years ago
- Status changed from Confirmed to Needs Clarification
- % Done changed from 10 to 0
#9
Updated by TriggerAu over 8 years ago
- Status changed from Needs Clarification to Closed
- % Done changed from 0 to 100
Closing this report out for now. If you find it is still occuring in the latest version of KSP please open a new report (and this one can be linked to it.) For best results, the wiki contains really useful info for when creating a report http://bugs.kerbalspaceprogram.com/projects/ksp/wiki.
You can also ask questions about the bug cleanup in the forum here: http://forum.kerbalspaceprogram.com/index.php?/topic/143980-time-to-clean-up-the-bug-tracker/ and tag @TriggerAu to get my attention