hud indicator shows uncorrect left fuel

[antipro]

hi, as the title: the fuel/deltaV hud indicator shows I have no more fuel.
it seems like the last fuel tank isn't considered.

Edited July 20, 2020 by antipro

[king of nowhere]

it happens sometimes. it happened to me too. it generallly happens when the game misinterprets staging. in your case, i think i'm seeing some decouplers between the central tank and the rockets? the game may be thinking that you intend to detach the rockets before burning anything.

i can tell you you don't need to worry, the rocket will work normally. unfortunately you won't be able to see your remaining deltaV.

as for how to fix this, though, i'm not sure.

[antipro]

29 minutes ago, king of nowhere said:

i think i'm seeing some decouplers between the central tank and the rockets?

of course there are 2 radial decouplers with crossfeed enabled.

 

29 minutes ago, king of nowhere said:

the game may be thinking that you intend to detach the rockets before burning anything.

ok, but it's the first time I see this behavior. it's quite weird.

I attach another couple of vessel ss, may be useful:

Edited July 20, 2020 by antipro

[Grogs]

It's not all that uncommon unfortunately. I see it a lot with complex staging like asparagus setups. I usually keep the MechJeb Delta V stats up and it's not uncommon when it disagrees with the stock numbers. But sometimes both of them are wrong. In your case, I think it's the fact you're using crossfeed through the decouplers. It sees that there's no fuel in the outer tanks where the engines are and reports 0 dV remaining. If the fuel was in the outer tanks, or if there were actual hoses then I think the game would pick up on it.

[Spricigo]

2 hours ago, king of nowhere said:

the game may be thinking that you intend to detach the rockets before burning anything.

That is exactly what the game is assuming.  So, we have the current stage with engines but no fuel left and the next stage with fuel but no engines left. 0+0 =0

Which bring up the question: Why is @antipro using decouplers there?

It serves no purpose, since the side tanks can be directly attached, with the advantage of a less bendy connection. If its for spacing it's just a matter of a small adjustment with the gizmo (put some cubic struts there if the disconnected look bother you). You may also use structural/wing parts , use a MK0 Fuselage, which can have some effect in drag/weight but hardly a big one. At the very least, disable staging for those decouplers.

I know, whatever works for you, but i fail to notice how messing with the dV readout and  giving an opportunity to dropping all your engines by mistake before using all your fuel can be called "working".

And just to not waste my "criticizing momentum": For that last craft, you really need 5x Advanced Inline Stabilizer?  And an extra in the LV? If yes, is probable you are piling up steering losses during launch.

2 hours ago, antipro said:

I attach another couple of vessel ss, may be useful

That is quite different, there you have both the fuel and the engines in the current stage and none of it the last stage. You can make the same in the other vessel pumping the fuel from central stack to side tanks.

[king of nowhere]

4 hours ago, antipro said:

 

ok, but it's the first time I see this behavior. it's quite weird.

 

it's quite common. only a week ago i had the same issue: i had an onion command module (they have a decoupler incorporated), and the game assumed that i would drop it immediately. even if it wasn't even part of the staging.