Fuel routing in VAB?

[Zild]

Every time I build any kind of lander I always make the same mistake: the lander's fuel gets sucked through the docking ports and used before the transit stage's fuel, leaving me with a lander that cannot move. (Obviously I have not unlocked resource transfer yet.)

Is there any way I can prevent this from happening in the VAB?

Once in flight I know I can disable cross-feed on the docking ports and that does the job, but I have to remember to do that at the start of every single flight. I cannot find a corresponding option when right-clicking the docking port in the VAB (unless I just happened to right-click the wrong port, as I now know only one in the pair has this option...)

By any chance does this have something to do with the "Routing" facility in the VAB? I tried to play around with that but could make no sense of it. (Am off to look for a tutorial now...)

[AlexinTokyo]

The usual, and probably best, way to deal with this is to disable resource flow from the lander's fuel tanks.

Right click on the tanks and you should see a small, green check mark next to the resource gauge. Click this and it will change to a red, slashed-out circle. This means that no resource of that type can be drawn from the tank.

Do this for all the lander's tanks, and it will launch without using its fuel. If you do this in the VAB, the status will be saved with the ship, avoiding your problem of having to do it every flight.

Caveat: You will have to un do this (for all tanks) when you want to use the lander's engines, so be careful if you need to fire it up to complete and orbit circularisation or breaking burn.

[magnemoe]

I put one of the square plates below the docking port, this block fuel flow.

[mrclucks]

You should be able to disengage crossfeed from the VAB

[cicatrix]

Here:

Green arrow means that resource will be fed from this tank, red stop sign means the resource is locked and it won't be supplied anywhere until you unlock it. Just click these icons to toggle between the two states.

[Zild]

The usual, and probably best, way to deal with this is to disable resource flow from the lander's fuel tanks.

Right click on the tanks and you should see a small, green check mark next to the resource gauge. Click this and it will change to a red, slashed-out circle. This means that no resource of that type can be drawn from the tank.

Do this for all the lander's tanks, and it will launch without using its fuel. If you do this in the VAB, the status will be saved with the ship, avoiding your problem of having to do it every flight.

Caveat: You will have to un do this (for all tanks) when you want to use the lander's engines, so be careful if you need to fire it up to complete and orbit circularisation or breaking burn.

D'oh! So obvious now you mention it! I've used this so many times (mostly for electricity on probe cores) I can't believe I forgot about it... PS: Howdy, neighbour!

Thanks all!