Balancing a VTOL

[Iguas]

Hey guys, i'm currently designing a BIG VTOL lander (600 T) that look like a plane , so perfectly unsymmetrical and i'd like to know if a mod can balance the fuel AROUND the center of mass, OR , if it doesn't exist, a mod that adjust the throttle to balance the craft ( i'd prefer the first solution, as for now i only have 2 engines, and it would be difficult to adjust power for landing.

Thank you ! have a good day

[Scarecrow]

I'm not aware of a mod to balance fuel, though that's not to say that there isn't one.  Whenever I have built a VTOL I try and make it so that the CoM is the same empty as it is full which means the issue of an unbalanced craft doesn't arise, but I understand that this isn't always possible.

[Iguas]

3 minutes ago, Scarecrow said:

I'm not aware of a mod to balance fuel, though that's not to say that there isn't one.  Whenever I have built a VTOL I try and make it so that the CoM is the same empty as it is full which means the issue of an unbalanced craft doesn't arise, but I understand that this isn't always possible.

Yea, that was pretty much impossible, i'll try to shop you a picture,  i mean, i COULD, but i'd like to keep the "plane" design (if you have any solution after i show picture, that's PERFECT ^^)

Edited August 18, 2018 by iguas

[Iguas]

16 minutes ago, Scarecrow said:

I'm not aware of a mod to balance fuel, though that's not to say that there isn't one.  Whenever I have built a VTOL I try and make it so that the CoM is the same empty as it is full which means the issue of an unbalanced craft doesn't arise, but I understand that this isn't always possible.

Album gallery/zOKutY3 will appear when post is submitted

(If you know how i can put picture directly on the forum, that would be cool too

 

Edited August 18, 2018 by iguas

[katateochi]

An invaluable mod is RCS build aid. It's not just for balancing RCS, infact that's the thing I use it for least. It helps you balance thrust and it adds markers for dry centre of mass and average centre of mass.

It doesn't do any auto engine adjusting and is only available in the editors, but it lets you get the initial balance setup nicely.

Looking at your design, you've got the engines positioned inline with the COM, but that prob shifts forward as it burns fuel. My suggestion would be to add another single VTOL engine in the front, move the current ones aft slightly and then tune the thrust of the front engine.  With RCS build aid you could then see what thrust value it would need to be when the craft is fully fuelled and when it's empty. Then during flight you can use the context menu for that single front engine and adjust it's thrust between those values. Depending on how much the COM moves, you might be able to get away with just balancing it for the average COM and adding more SAS modules to account for the differences.

[MisterKerman]

Sounds like you're F'd in the A. I hope the rocket engine balancing idea works. I recently made a V-TOL lander (The orientation or the engine in regards to it's docking ports I guess as all landers are... V-TOL...) but the fuel tanks are spread out evenly so balancing isn't an issue.

I've always admired the concept of a V-TOL plane and I'll most likely be in your shoes at some point soon.

Edited August 18, 2018 by MisterKerman

[degenerate]

Throttle Controlled Avionics is an amazing mod for VTOL ships.
https://forum.kerbalspaceprogram.com/index.php?/topic/97154-143-throttle-controlled-avionics/

[Laie]

2 hours ago, iguas said:

Hey guys, i'm currently designing a BIG VTOL lander (600 T) that look like a plane , so perfectly unsymmetrical and i'd like to know if a mod can balance the fuel AROUND the center of mass,

To the best of my knowledge you have to build the vessel that way; RCS build aid helps with design by showing both full and empty CoM, but it's still up to you to distribute the fuel load.

2 hours ago, iguas said:

mod that adjust the throttle to balance the craft

Mechjeb can basically do that, it's called "differential throttle" and can be found under utilities. I guess it would suffice for your purposes. Throttle Controlled Avionics is a mod dedicated to balancing craft around many engines and will let you do a lot of crazy things, but getting to understand it and use it well is an undertaking in it's own right.

[Iguas]

@Laie @degenerate @MisterKerman @katateochi @Scarecrow

Ok, i'll try all of this, thanks A LOT for your replies, this forum is god tier <3

 

 

 

 

 

[Mad Rocket Scientist]

TAC fuel balancer will keep fuel balanced in VTOLs:

And TCA will keep unbalanced VTOLs level with throttle control: