[Solved] Why aren't my fuel lines working?

[notasurgeon]

The middle stage of this rocket uses aerospikes, which I've attached to 1m fuel tanks with a connection to the 2m central one. The fuel line icons are green while the 1m tanks burn, but once they're empty the icons go grey and the 2m tank never gets used. I don't have this problem with the top stage, which is basically designed the same way. What's going on?

Edited October 14, 2012 by sal_vager

[sal_vager]

The 1 meter boosters aren't drawing from the main tank all the time then? They should stay fully fueled if the center tank is feeding them.

If they are feeding the center tank, then once they are expended they will be useless, have you tried placing the fuel lines the other way round?

[notasurgeon]

Oh, I didn't realize they were one-way only. Let me switch them around and try it again!

[vexx32]

They go from the first-chosen point to the second-chosen point, and are painted with little arrows to help you work out which way they're going

[Jason_25]

Fuel line routing can be very confusing. Sometimes it helps to split the rocket down into basic parts in separate save files for testing fuel flow.

[r_rolo1]

They go from the first-chosen point to the second-chosen point, and are painted with little arrows to help you work out which way they're going

I do remember the time they worked backwards

[sal_vager]

Wow that was ages ago

Yeah, fuel lines where changed, and now work opposite to the old way, plus decouplers no longer allow fuel flow and fuel won't flow between tanks that are attached radially to each other.

Adding fuel lines will make those parts capable of fuel crossfeed again though.

[notasurgeon]

Wow that was ages ago

Yeah, fuel lines where changed, and now work opposite to the old way, plus decouplers no longer allow fuel flow and fuel won't flow between tanks that are attached radially to each other.

Adding fuel lines will make those parts capable of fuel crossfeed again though.

Fuel lines are fun! There's so much more I can do now that I understand how they work

[foamyesque]

Tracking down errors in complicated fuel flows can be a real pain, though. =(