rocket always flips with liquid fuel engines

[run1235]

like the title says for some reason in my game i cant use LF engines (both vanilla and modded) at all as my rocket always flips onto it's side in flight but for some reason srb's work just fine.

*UPDATE* Seems it has something to do with FAR as removing the mod fixed the issue.

heres my mod list for you all

 

KSP: 1.1.3 (Win64) - Unity: 5.2.4f1 - OS: Windows 10  (10.0.0) 64bit
000_AT_Utils - 1.0.2
Filter Extensions - 2.6
Toolbar - 1.7.12
USI Tools - 0.7.4
Achievements - 1.9.3
B9 Animation Modules - 1.0.3
B9 Part Switch - 1.4.3
B9 Aerospace - 6.1.2
B9 Aerospace - 6.1.2
B9 Aerospace Procedural Parts - 0.40.7
CactEye 2 - 1.1.3.4
Community Resource Pack - 0.5.4
Contract Configurator - 1.19
CC-CP-SCANSat - 0.6.0.1
Contract Pack: Clever Sats - 1.3
Contract Pack: Field Research - 1.2
Contract Pack: Giving Aircraft a Purpose - 1.2.8
Contract Pack: Kerbal Academy - 1.1.4
Contract Pack: Bases and Stations - 3.4
Contract Pack: RemoteTech - 2.1.3
Contract Pack: Sounding Rockets - 1.2
Rover Missions - 0.1.6
Contract Pack: Tourism Plus - 1.5.1
Crowd Sourced Science - 3.0.2
Deadly Reentry - 7.4.7
DMagic Orbital Science - 1.3.0.2
Contract Parser - 1.0.4
Contracts Window Plus - 1.0.6.4
Progress Parser - 1.0.5
EditorExtensionsRedux - 3.2.14
Ferram Aerospace Research - 0.15.7.2
Firespitter - 7.3
Interstellar Fuel Switch - 2.1.4
RasterPropMonitor - 0.27.1
Kerbal Attachment System - 0.5.9
Kerbin Environmental Institute - 1.1.1
Kerbal Engineer Redux - 1.1.1
Kerbal Joint Reinforcement - 3.2
Kerbal Inventory System - 1.2.12
KSP-AVC Plugin - 1.1.6.1
KWRocketryRedux - 3.0.12
Infernal Robots - 2.0.5
MarkIVSystem - 2.2.1
Modular Rocket Systems - 1.12.8
ModularFlightIntegrator - 1.1.6
NearFutureConstruction - 0.6.4
NearFutureElectrical - 0.7.8
NearFuturePropulsion - 0.7.4
NearFutureSolar - 0.6.2
NearFutureSpacecraft - 0.5.1
NRAP - 1.5.1.1
Procedural Parts - 1.2.5
QuickSearch - 3.0.3
QuizTechAeroPackContinued - 1.3.3
RCS Build Aid - 0.8.1
RCS Sounds - 5.0
RealChute - 1.4.1.1
RemoteTech - 1.7.1
ResearchBodies - 1.8.1
SCANsat - 1.1.6.6
SETI-Contracts - 0.9.7.1
SETI-Greenhouse - 0.9.5.1
SETI-ProbeParts - 1.0.1.1
SETI-Rebalance - 0.9.7.2
SETI-RebalanceMaterialsGoo - 1.0.9
SETI-RemoteTechConfig - 1.0.9
SmartParts - 1.9
SmartStage - 2.9.4
TarsierSpaceTechnology - 6.4
TextureReplacer - 2.4.13
ThrottleControlledAvionics - 3.2.3
TAC Life Support - 0.12.4
TrackingStationAmbientlight - 0.3.3
Trajectories - 1.6.3
Alternate Resource Panel - 2.8.1
TweakScale - 2.2.13
USI Core - 0.2.4
Asteroid Recycling Tech - 0.8.4
USI Exploration Pack - 0.5.4
Freight Transport Tech - 0.5.4
Kolonization Core - 0.2.4
Konstruction - 0.1
Malemute Rover - 0.1.4
Sounding Rockets - 0.4.4
UKS - 0.40.4
Unmanned before Manned - 1.0.9.6
VenStockRevamp - 1.9.5
KSP Interstellar Extended - 1.9.11
Waypoint Manager - 2.5.3
[x] Science! - 5.0

 

Edited September 14, 2016 by run1235

[Jas0n]

It has to do with your center of mass moving as fuel is burned. It also occurs in the stock game, but FAR is less forgiving.

[run1235]

same rocket i've built before in previous versions, worked fine before. and with the size of the fins, it shouldnt move at all. it has a small fuel tank and a large structural tank to keep the weight at the back.

and, if it was a matter of the com changing as the fuel burns, the same thing would be happening with srb's.

http://steamcommunity.com/id/Lynlyn/screenshots/

Edited September 15, 2016 by run1235

[seeingeyegod]

You want the weight at the top, not the back. Like a dart, heavy part up front makes it fly stable.

[Harry Rhodan]

6 hours ago, run1235 said:

and, if it was a matter of the com changing as the fuel burns, the same thing would be happening with srb's.

No. You're forgetting that the SRB is one part while a tank and an engine are seperate parts. While the SRB burns its stuff the CoM has to move upwards because there's nothing below it. If you drain a tank while the engine below it is heavier than the stuff on the other end (like your probe core), the CoM will move downwards.