:S Flipping Rockets

[RFK128]

Anyone else having problems with perfectly symmetrical rockets just randomly starting to flip end over end in this new patch? I'm not sure the reason for it, as I'm using very simple designs, and they are all freshly made on a new save, so no weird import from a previous patch bugs should be applying to these ships.

[Zeroignite]

It's impossible for us to debug a design without images.

[-RanZ-]

fuel lines all correct? Might be an issue with unbalanced fuel

[7499275]

Not only imbalanced fuel but also you may need more struts, if it has SRB's or liquid engines off set to the center stack strut the heck outta that thing. Also use winglets and are you using FAR?

[SRV Ron]

A picture of the rocket would help. You can use Imgar to host the images. It is a free service.

I found that the winglets were the culprit in my simple designs when they did what was described in the later stage of flight. Upon removal of those and the no longer needed SAS under the command capsule, those rockets made stable flight. Solar panels were then added to provide power during orbit.

[RFK128]

I'm not really interested in troubleshooting this particular ship, as its been happening to ALOT of my craft that are heavy. My light rockets never have a problem, but the heavier ones seem to get up to around 60km and then just rotate forever.

[maackey]

Are you going up to 10km and turning 45 deg to apoapsis? If you try to turn too quickly the drag on the front of the rocket (from going upwards so fast) can cause the rocket to flip out. This is better simulated in FAR but I've had it happen with stock aerodynamics as well. The solution is to try turning sooner and slower -- gradually turning till you are at about 45 degrees at ~12km.

[Mr. Scruffy]

I am not sure, but you might be getting them too fast. 4 mainsails seems like an awful lot of power for what they are carrying. Late in that stage, the orange tanks will be depleted, leaving very little too lift and most of it far on top of the rocket. My suggestion for the rocket displayed above would be:

- Try something less powerful than the mainsails - augment with SRBs for lift-off if needed.

- Try to lower that central coloumn so that it sits right between the boosters. Use seperators on the later, if needed.

[Scotius]

And your ship is top-heavy, with those fuel tanks way above Center of Mass. And apparently it gets only worse as fuel is drained out of four main tanks. Try placing the core/payload directly between the orange tanks. This way CoM will stay low during entire flight.

[Monkeh]

I concur. The centre of mass will shift so much as the tanks deplete it's flipping over as the top get's heavier than the bottom.

[Beeman]

Is your core a tri-coupled group of fuel tanks? Looks kinda like it. If that's the case, then the entire rocket's weight would be leaning a little bit toward the camera in that screenshot. When your bigger fuel tanks start to empty out, that weight imbalance would become more notable. Go with a quad or match the trio with your outer engines.

Then again, I tend to not know what I"m talkin' about so perhaps it's best you ignore what I say >_>

[DngrMse]

fuel lines all correct? Might be an issue with unbalanced fuel

I had something odd happen yesterday twice. I have a large lift vehicle that I've been playing around with, (something for my Duna-Ike land, and return mission), and on two separate launches out of several, one of the six orange tanks making up my outer ring didn't consume fuel at the same rate as the other five. When the other five were emptied, the one mainsail connected to that orange tank continued to fire. Flip, flip, flip, until the rocket came apart. The next launch was fine. The one after that was fine, (at this point I was tweaking my lander stage only). The one after that....flip, flip, flip.

I'll try to recreate the error, and post a screenie.

[RFK128]

Is your core a tri-coupled group of fuel tanks? Looks kinda like it. If that's the case, then the entire rocket's weight would be leaning a little bit toward the camera in that screenshot. When your bigger fuel tanks start to empty out, that weight imbalance would become more notable. Go with a quad or match the trio with your outer engines.

Then again, I tend to not know what I"m talkin' about so perhaps it's best you ignore what I say >_>

That, actually kind of makes sense.

[AntonioAJC]

Either your pod is upside down, or you just don't have enough wings attached to your rockets.

[allmappedout]

I had something odd happen yesterday twice. I have a large lift vehicle that I've been playing around with, (something for my Duna-Ike land, and return mission), and on two separate launches out of several, one of the six orange tanks making up my outer ring didn't consume fuel at the same rate as the other five. When the other five were emptied, the one mainsail connected to that orange tank continued to fire. Flip, flip, flip, until the rocket came apart. The next launch was fine. The one after that was fine, (at this point I was tweaking my lander stage only). The one after that....flip, flip, flip.

I'll try to recreate the error, and post a screenie.

I think this very occasionally happens when loading a craft with fuel lines where the fuel line doesn't spawn. It tends to happen with shorter fuel lines, I think. I've had similar instances which have been resolved by reloading the craft. As a result, I always try and make my fuel lines a bit longer, and often more visible, so I can check that they're all there.