Snark

I don't actually know, since I haven't run it myself in a long time. The only way for me to find out would be to install it on my current KSP and see for myself, which you could do as easily as I could. This was written for KSP 1.3, which was quite a few versions ago, so I suppose it's not out of the question that it could have gotten broken in the meantime. Only way to know is to try it and see. If someone does try it out on current KSP, do me a favor and post here whether or not it works? If it does, I can update the compatibility info in the OP, and if it doesn't, maybe I could get off my duff and update it when I can.

Is it possible you're not getting enough intake air to run both the engines? I've noticed that when a multi-engine jet plane isn't getting enough intake air, the symptom is typically not that all the engines uniformly start losing thrust. Rather, it ends up starving one engine before the other-- e.g. one engine is firing at full power but the other is cutting in and out. So you end up with differential thrust and it can flip you around. If that's what's happening... bear in mind that different intakes are sensitive to relative airspeed along their axis in different ways. Those intakes you've got atop the wings really want air to be flowing into them, which they won't be getting a lot of in this orientation. Whereas, IIRC, some other intake types, like the engine "precooler", may be less sensitive to airflow velocity and might work well in this scenario. I'd suggest some experimenting to see if adding other intake types might help.

Moving to Add-on Discussions.

Since this question was asked over five years ago, presumably everyone involved has gotten what they needed and moved on to other things. (Not to mention that KSP has been through quite a few major version releases since then.) Accordingly, locking the thread to prevent further confusion. If anyone has a current question about working with fuel ducts (or anything else), please feel free to spin up a new thread! Thank you for your understanding.

(Moving to Kerbal Network, since this is about working with websites and the forum, rather than about KSP itself.)

You're presumably referring to Red Shell. Yes, they removed that over three years ago, in KSP 1.4.4: ... with a follow-up post here: If you search for Red Shell references in the forums, you'll find plenty of people chattering about these events. But the above release announcement goes straight to source.

Moving to Technical Support. (Glad you had a backup!)

Moving to Add-on Discussions.

The question was asked and answered eight years ago, and presumably everyone involved in the conversation has long since moved on to other things. Accordingly, locking the thread to prevent further confusion. Thank you for your understanding.

No worries, can happen to anyone. Locking thread to prevent any further confusion.

Moving to Add-on Discussions.

Moving to Add-on Discussions.

Some content has been removed and/or redacted due to personal remarks, off topic digressions, and other problems. Folks, it's fine to disagree with one another, but let's please keep it civil. Name-calling and finger-pointing doesn't win any arguments, and makes the forum a less pleasant place for everyone. Thank you for your understanding.

Fair 'nuff. My own solution to that problem is "never approach a maneuver quickly", i.e. get the ship pointed correctly well in advance.

Moving to Gameplay Questions. Alt+F12 menu -> Cheats -> "Infinite Propellant" checkbox.

Moving to Gameplay Questions.

Moving to Gameplay Questions.

Since, as you observe, this is in fact a 9-year-old thread, I think it's safe to assume that everyone involved in the original discussion has long since gotten the problem figured out and moved on to other things. Not to mention that KSP has changed so much in the meantime that any pre-1.0 advice would be very wrong today. Accordingly, locking the thread to prevent further confusion. If anyone has current questions about how to get to orbit, feel free to spin up a new thread. Thank you for your understanding.

This is kind of a digression from your main concern about the gimbal, but... is there a reason you've got your RCS thrusters turned on for attitude control? i.e. there are two ways to control the attitude of a ship in orbit: RCS thrusters, and reaction wheels. Reaction wheels are "free" (just electricity), whereas RCS uses consumable fuel. So, since it's not free... any reason why you're using it? (If you like to have it turned on for realism, then never mind.) RCS thrusters let you configure which actuators are enabled. I like to always set all my RCS thrusters to be enabled for translation only, and have them disabled for pitch / yaw / roll. Saves on monopropellant quite a bit. (Of course, remembering to always turn off the rotation actuators every time I place an RCS thruster in the VAB is a hassle. Fortunately, it's easy to make rotation "off by default" with a simple ModuleManager config patch. Here's config that does that, if you're interested.)

A couple of other points: If you haven't done so already, turn off everything but yaw on the vertical stabilizer. You want it to be helping with yaw only; you need to turn off roll control. Doing this will help with stability, for reasons that I can explain if you're interested in, but it's a long paragraph so I won't bother unless you're interested. Your CoM is pretty far back, which is likely to make the craft want to flip. If you can move the CoM forward-- for example, by sliding the engines forward-- that may help.

Which TWR is "right" depends on a lot of factors, including how you like to fly and what sort of payload you have. In general, you never want to go higher than 2.0, and usually no lower than about 1.2. The optimal rocket design changes quite a lot based on the TWR. If you have a very "draggy" payload (which most of your rockets look to be-- you've got a lot of flat surfaces, these are not very aerodynamic), then usually a lower TWR tends to work better, at least for the first several kilometers of ascent. This is because a high TWR causes you to go too fast when you're still too low, so you're wasting all your fuel trying to shove a draggy thing through thick soupy atmosphere. Taking off a bit more slowly, to keep drag down, may help. (Normally, the solution people go for is to make their craft more aerodynamic and then raise the TWR, which is more fuel efficient. But if you have an awkward payload that has to be draggy, you may have better luck starting off a bit slower.) In general, the most efficient (and stable) ascent path is called a gravity turn (that's a good term to search the forums for, if you'd like to read about it). The basic idea of a gravity turn is that you nudge the craft just a little bit eastward, practically right off the pad... and then you just set SAS to hold all the way up. No steering needed, you're just going all the way, as your ship gradually and naturally pitches farther and farther eastward as it climbs. Just how much of an initial "nudge" you should give it is the tricky part, of course. There's no one right answer, because it depends on your TWR and how aerodynamic you are. But there's a fairly straightforward way to find out: Launch to the pad. Take off! Immediately upon lift-off, pitch a small amount eastwards. (Just take a guess, as to how much.) As soon as you do that, set SAS to hold Don't do any further steering. The only time your hands should touch the controls is to jettison empty stages when the time comes. Take a note of what your trajectory is like when you reach an altitude of 10 kilometers. Specifically, how fast are you going? what angle are you pitched at? Ideally, you should probably be pitched roughly 45 degrees at that point, and traveling something like 300-400 m/s. If (at 10 km) you are going too fast, or pointing too vertically: This means you didn't pitch quite enough in step 3. Revert to launch, and repeat, and pitch it a bit more this time. If (at 10 km) you are going too slow, or pointing too horizontally: This means you pitched too much in step 3. Revert to launch, and repeat, and pitch it a bit less this time. Keep repeating steps 2 through 7 until you're going about the right speed and angle when you're at 10 km. At this point, you're in the pipe and probably going to space, as long as your fuel holds out. The above is only a very rough rule of thumb, but I've found that it works pretty well for most people most of the time, and at least is a pretty good starting point for flying your ship. Really don't do that. Very very fuel inefficient, and will waste scads of dV. That's also very inefficient, and likely to cause control problems, as you have no doubt discovered. The moral of the story is: You want your rocket to be traveling at all times. Never point more than just a couple of degrees off while thrusting, if you can help it.

^ This. FWIW, I think there's a mod to help with this breakage. This may help?

I'd suggest adding a couple of small canards on the front end. Oversteering's a risk, so make them as small as possible (the advanced canards are good for this, the AV-R8 are kinda big), and set their control authority to about half the default, and set them to be pitch only (they shouldn't be engaged for roll). That ought to give you a bit better pitch control, especially when the CoM moves forward as you burn fuel. Might also help to give it a bit more reaction torque for control. If you add a Mk2 drone core, that has a fair amount of torque built into it. Actually, I would have said it isn't-- on the contrary, looks like it's about in the middle of the plane, maybe a bit too far in the rear for comfort. Farther forward might be safer-- there's some risk of aerodynamic instability with the CoM as far back as this is. Fortunately, it looks like the CoM will move forward as fuel is burned, so that should help.

Can you describe exactly what behavior you're seeing? What do you mean by "flipping like a bullet"? And which part are you talking about, the upper stage? Got a screenshot?

Several posts have been removed and/or redacted, due to off-topic content. Let's please remember that the topic of this thread is this mod, so discussions of player habits (or anything else that's not about this mod) don't really belong here. Thank you for your understanding.