I have question about game mechanic...

[TaTaRinBsB]

So i got a question....

When i start engine and fuel is burn, the weight is changing or not??? or its change when i start decupling sequence?

[Nooblet68]

Yes, your weight will change the less fuel you have in your engine.

[Phoxtane]

To be specific, your weight will go down as you burn more fuel

There was a bug a long time ago that caused SRBs to gain weight as they burned, however.

[socket7]

So i got a question....

When i start engine and fuel is burn, the weight is changing or not??? or its change when i start decupling sequence?

Liquid Fuel Tanks, SRBs ,and RCS tanks have a 'Full' and 'Dry' weight value. As fuel is consumed, the part will go from it\'s full weight to it\'s dry weight. (The tank itself has to weigh something after all, it can\'t be entirely fuel.)

This means that not only does your rockets weight go down as you burn fuel, but decoupling an empty tank will decrease your rockets weight even more..

[Ydoow]

Are you sure?

You\'re saying the Liquid Fuel Tanks linearly decrease their weight from full towards Dry Mass as they\'re used, right?

Whenever I use them I notice a very sudden acceleration when the tanks run dry; as if they instantly drop from Full Weight to Dry Mass.

[socket7]

Are you sure?

You\'re saying the Liquid Fuel Tanks linearly decrease their weight from full towards Dry Mass as they\'re used, right?

Whenever I use them I notice a very sudden acceleration when the tanks run dry; as if they instantly drop from Full Weight to Dry Mass.

I am 100% positive the way I described is how they are supposed to work. Then again, the SRB\'s burned from empty up to full weight for like 2 full revisions before anybody playing the game ever noticed.

If the behavior you are describing really is occurring from LFT\'s not decreasing their weight correctly, experimenting with LFT\'s could be a great way to find, reproduce, and document a possible bug. ;D

[socket7]

Now I just did a bit of testing with a mechjeb, 4.5 LFT\'s and an LV-T45 engine. What i found is a steady increase in velocity as fuel burns off. in order to hover, one has to constantly decrease throttle, rather then just decrease it when a tank runs dry. I\'m pretty sure they are working as intended, but you are welcome to check for yourself. 8)

[TwoHedWlf]

Are you sure?

You\'re saying the Liquid Fuel Tanks linearly decrease their weight from full towards Dry Mass as they\'re used, right?

Whenever I use them I notice a very sudden acceleration when the tanks run dry; as if they instantly drop from Full Weight to Dry Mass.

Yes, we\'re sure. Easiest way to confirm is to put a rocket with 4-5 tanks and 1 engine on the pad. It won\'t have enough thrust to lift off. But keep sitting there burning long enough it will slowly start to climb. Not suddenly jump into the air when an entire tank of fuel weight instantly disappears.