Bug #7332
TVR-400L Stack Quad-Adapter to weak in combination with Vector engines
0%
Description
Description: The TVR-400L Stack Quad-Adapter (2.5m to 4x1.25m) is to weak in combination with Vector engines running at 100%
Steps to Replicate:
1) Build a simple craft using the TVR-400L and mount 4 vectors below it (or use the one i uploaded)
2) Load it onto the launchpad/runway
3) Leave the throttle at 50% and press space to activate the engines. Nothing should fall off, all engines fire.
4) Press X to cut the engines.
5) Press Z to set all engines to 100% immediately. The TVR-400L (and its engines) fall off, everything else stays on.
Expected: The TVR-400L stays on the craft like all the other adapters.
Result: TVR-400L falls off, making it useless (more or less) in combination with the Vector.
Workarounds:
- Use another adapter
- Use struts
- Use cubic octagonal struts to mount the engines. Looks (almost) the same, but works
Notes:
I don´t know if this is really a bug, 4 Vectors are damn powerful and put a lot of stress on that part. But all the other adapters don´t show this behaviour.
I tested the same thing with swivel engines. They don´t cause it to fall off.
History
#1
Updated by Kasuha about 8 years ago
Updated by Vector is very powerful engine, I would even say it's overpowered - it is the most efficient engine for lifters, you can place any amount of it below any fuel tank, and its power and its gimbal are constant source of dynamical issues such as rocket bending and oscillations, or (like in this case) joint snapping, that make players install Kerbal Joint Reinforcement mod because they're lazy to take care of it in a realistic way (such as gradually increasing thrust or reducing unnecessarily large gimbal range of the engine; SAS has issues with it too though).
When I tested this, joint above the bottom fuel tank was snapping before the joint between the adapter and the fuel tank. That suggests there is a shockwave propagating through the ship caused by abrupt introduction of thrust and that causes these problems.
The only surprising observation I made was that when I used the "Mk2 stack quad adapter" (1.25 m variant quadcoupler) it was not happening. Greater length of the adapter might have played role in dampening the impulse here.
#2
Updated by TriggerAu almost 8 years ago
Updated by 
- Status changed from New to Needs Clarification