Fuel Line not working?

[Steve7893]

Tried to get asparigus stage to work, but this now appears impossible.  In this image I am attempting to illustrate that the Fuel Line does not seem to be working right in this case.  It has an effect, because without it the left tank would remain full since the fuel would have no way to get out.  But what is causing the fuel in the two tanks to remain balanced?   That being the case, I cannot drop the empty tanks.  There does not seem to be any setting to affect fuel tank priority that I can find anywhere.

Help?

 

[kiz82]

There are a few reports of problems with fuel lines on Reddit and this forum. Seems they're either unreliable or not working, just another bug with Early Access I believe.

[Steve7893]

I just finished a lot of various tests with cross feed and fuel lines.

Enabling cross feed on a radial adapter does not equate the fuel flow priority of the connected tanks.   The system assigns separate priorities that you could change in KSP1 that you cannot change in KSP2.   This might not have been a problem if the VAB had assigned fuel flow priority in a senible way, but it actually assigns them backwards from what you need and expect.

Lets say that you have a rocket with a single central tank and connected engine.   To that you add two radial adapters and two tanks with no engine.  To _that_ you add another two radial adapters and two tanks with no engine.   (So it sort of looks like a rocketized plane, sort of.)

With crossfeed disabled, of course, on all radial adapters, the engine burns all the fuel out of the central tank and stops.   As it should.

If you then enable crossfeed on all radial adapters, then the engine first burns the fuel in the central tank, until thats empty, (Leaving the outer tanks full and therefore undroppable), then it uses the next outer tank, and then the most outer tank.   Thus you have to carry all the tanks all the way.

The fuel flow priority should be the reverse of that.   It should burn the outer-most tanks first.   Thats so you can stage them.  Then the next outermost, and last the central tank.

Adding the fuel line does not make it work, because the fuel line in KSP2 is (in my view) broken from the working one in KSP1.   First, that fuel line is NOT a 2-way connection.   It is only suppose to allow fuel to travel in one direction.   When you attach it, you alway attach the from side first and then the TO side.   The fuel line is NOT suppose to affect tank priority in any way.    It is merely a conditional  IF (destination tank has space) AND (source tank has fuel) THEN transfer whatever possible from the source to the destination.    In KSP2, attaching the fuel line is causing tank priorities to be equated.   

Therefore, in KSP2 it is now IMPOSSIBLE to do asparigus staging, unless there is something strange, weird and unintuitive that works which I have not thought of.

 

[Gorby1]

I don't get how the fuel priority is supposed to work either. I assumed we'd be able to change it like before, but... well hopefully they add option back in. I'd argue that currently there's no way to make the game "guess" correctly 100% of the time for everyone's needs.

[CbadCruiser]

Has anyone figured out a workaround for this issue yet?

[CbadCruiser]

I'm trying to do a manned EVE mission and I need asparagus staging to leave the planet. But fat chance of me doing that if I can't get the fuel flow working