3 Questions.

[gEshAdve]

My first question is why isn't fuel being used by my 2 nuclear engines from my other tanks ? PIC1 PIC2

Second question. Why does my rocket break in flight ? I am just flying and suddenly it just breaks apart. PIC1 PIC2

And my third question is why do my rovers, sometimes (I've only seen this in rovers for now), accelerate without me doing anything ?

Edited May 3, 2014 by gEshAdve

[lionblaze63]

to answer the first one. make sure the fuel lines are going from the center tank to the outer tanks. to answer the second i would need to see how it's breaking apart, the third is because it is on a slight incline.

[Taki117]

1. my guess is you dont have your fuel lines placed correctly. you could probably get away with sliding them down and attaching the fuel lines to the lower tank. they also function where the first point of attachment is where you want fuel coming FROM and the second is where you want it going TO.

2. sounds like a weak connection, try more struts and hit F3 as soon as something breaks in flight to find the exact point of failure.

3. your rover is probably going down a slight incline, this is normal, just tap the brakes if you are going too fast.

[Wooks]

1.- Fuel lines might be backwards, you need to start attaching them from the tank you want to pump fuel to the recipient tank, fuel lines have little black arrows that point the way fuel flows.

2.- You need more struts, tall structures need them the most. Try adding a couple and test, if it breaks again then add a couple more.

3.- Have you tried to put the brakes on? Rovers tend to follow curvatures on the terrain.

Edit: freaking ninjaed

[Kasuha]

1 - fuel lines work in just one direction. Also, notice they do not actually transfer any fuel (between fuel tanks), they're just used as hints for engines how to select fuel tanks to draw fuel from.

2 - more detailed description or in-flight screenshots might help more. But in general, as your fuel tanks get empty and your ship gets lighter, the force causes the ship to accelerate more and that may break something. What helps in such situation is usually to use stronger connections, use more struts in correct places (as to spread the strain, not to concentrate it), or to throttle down.

3 - On runway, it may be because the runway is perfectly flat while Kerbin is a sphere - relative to its spherical surface, the runway is slightly U-shaped. In other places there sometimes is "bad terrain" which may accelerate your rovers in weird directions, sometimes even uphill. Again, more detailed description or picture might help.

[gEshAdve]

So I fixed the first problem. I have recorded a video of my rocket breaking though I did not check what was the cause. For the third problem - it's probably what Kasuha said. It's accelerating even when I am going uphill without me doing anything.

PS: I know that rovers have inetria when they are going downhill and that they have breaks

VIDEO :

[Sirrobert]

So I fixed the first problem. I have recorded a video of my rocket breaking though I did not check what was the cause. For the third problem - it's probably what Kasuha said. It's accelerating even when I am going uphill without me doing anything.

PS: I know that rovers have inetria when they are going downhill and that they have breaks

VIDEO :

Well it broke because you decoupled a stage that was still thrusting.

Though I have no idea why your rocket is turning like that. Probably some error in the fuel lines. I also have no idea why you couldn't right click the other tanks. You should be able to do that

It also seems the fuel lines in the stage are wrong, going from the central tank TO the outer tanks. They need to go FROM the outer tank TO the inner tank

[SRV Ron]

Well it broke because you decoupled a stage that was still thrusting.

Though I have no idea why your rocket is turning like that. Probably some error in the fuel lines. I also have no idea why you couldn't right click the other tanks. You should be able to do that

It also seems the fuel lines in the stage are wrong, going from the central tank TO the outer tanks. They need to go FROM the outer tank TO the inner tank

I noticed shortly after staging that the camera COG suddenly moved upward and he lost control of the flight at that point. You can see that the rocket engines are not gymboling to the steering commands. Also, fuel lines were backwards to the core stage which ran out of fuel before the boosters on the side. I believe that the bulkhead below the coupler to the top orange fuel can is where the break occurred. Needless to say, when he did finally staged, it all fell apart.

[gEshAdve]

Well it broke because you decoupled a stage that was still thrusting.

Though I have no idea why your rocket is turning like that. Probably some error in the fuel lines. I also have no idea why you couldn't right click the other tanks. You should be able to do that

It also seems the fuel lines in the stage are wrong, going from the central tank TO the outer tanks. They need to go FROM the outer tank TO the inner tank

The staging and the fuel lines are correct, but what changed them is that weak point (the decoupler above the orange tank) that my rocket has. Sometimes the gray tanks on the boosters just fall off, but it doesn't happen that frequently. Yesterday I tried to this same craft into a 120km orbit around Kerbin, but the weak point and the gray tanks didn't allowed me to do so. I haven't had any malfunctions (except for the one in the video) after about 5 tries, strangely enough.

Anyway, now I'm on my way to Gilly toghether with my lander. Not that I need a lander for Gilly

Thank you all for your help !

[Kasuha]

VIDEO :

The connection breaks at about 0:55 in that video. You should be able to see that in the flight log that you can open by pressing F3. The problem is, the whole payload is sitting on single 1.25 m decoupler and it couldn't handle the load. Adding some struts from the lifter to the payload should help. If you start your struts on the lifter, nubs remaining after disappeared struts will also disappear after reload.

[LordQ]

From what I saw in the video, apart from what others have mentioned, you also lack control surfaces on your fins. I recommend adding control surfaces, or adding smaller winglets instead, which should help to keep you stable and do your gravity turn.

[SRV Ron]

The connection breaks at about 0:55 in that video. You should be able to see that in the flight log that you can open by pressing F3. The problem is, the whole payload is sitting on single 1.25 m decoupler and it couldn't handle the load. Adding some struts from the lifter to the payload should help. If you start your struts on the lifter, nubs remaining after disappeared struts will also disappear after reload.

Looking at it closer, I saw the upper stage drop at the coupler about 48 seconds into the launch shortly after staging the first booster pair. The camera view moves up to reflect the new center of mass under control as the rocket continues to fly unresponsive to any input by the SAS or the user.

[DeMatt]

So I fixed the first problem. I have recorded a video of my rocket breaking though I did not check what was the cause. For the third problem - it's probably what Kasuha said. It's accelerating even when I am going uphill without me doing anything.

VIDEO :

What broke was the connection between the two orange tanks in the center stack. As to why... I suspect it's to do with your thrust-to-weight ratio. You have two G's acceleration off the pad, which is a lot for any rocket.

My recommendations are as follows:

1. Replace the wings with AV-R8 winglets. I doubt you need THAT much aerial control, particularly if you then add one or two winglets to each of the outer boosters.
   
2. Move the boosters' decoupler connections to the upper tank. One less joint to pass force through.
   
3. You've got a Mobile Processing Lab. Assuming you actually put kerbonauts into the thing, that means you can clean Science Jr's and Goo capsules, allowing you to reuse them. So you don't need FOUR Science Jr's and SIX Goo capsules... one Science Jr on the centerline, and two Goo capsules (to be symmetrical) will do.
   
4. You have a ridiculously large amount of RCS fuel and RCS thrusters. You have five rings of RCS blocks (at 4x symmetry); two rings is plenty for the size of ship you're flying. The 2.5m RCS tank is also overkill.
   
5. I'd suggest switching from the two long 1.25m tanks to one 2.5m tank. Then, you can use the 2.5m decoupler between your booster and your orbiter, instead of slimming down to 1.25m and back up.
   
6. If this craft is supposed to dock and fly with a different craft... then I recommend switching from the standard-size Clampotrons to the large Clampotron Sr's.
   
7. Finally... take it easy when you launch. Don't hesitate to throttle back. You have information readouts from MechJeb... find the Terminal Velocity readout and try not to go over it.