messiahua

Thanks everyone for answers. Here are my comments: I didn't know about this feature. I've searched and found that to use it you need to enable "Advanced tweakables" in settings. I've tried some more variations and found two solutions: 1. Split fuel in two stages. As far as I see it's more stable solution, but not very optimal financially, because you need to use decoupler and second engine. 2. Lower fuel flow priority for higher tank, which I guess is the best solution. That's how it looks right now: At last I can get to orbit! The only problem is strange constant instability at launch, when rockets slowly tilts in one specific direction (west, south-west) and I'm using Skipper engine. It's hard to keep ascend at 90 degrees. I've also tried Launch Stability Enhancer, but it doesn't help. FullMetalMachinist and DD_bwest gave the best answers IMHO.

I've always used SAS, but right now I'm trying to get relatively simple unmanned rocket to orbit completely without SAS using gravity turn to finish one contract. I've tried dozens and dozens of times with different design changes. I've tried lowering speed, switching to less powerful boosters, more fins/winglets, but it's unstable even at launch and rocket tends to tilt in one direction without me pressing any buttons. I don't understand why, it is perfectly symmetrical, nothing special at all. If I try to correct course manually it is hard and very imprecise, at some point (usually when I detach boosters) I completely lose control and can't do anything. Right now it looks like this: I've search all possible information, read several tutorials and can't get any solution. I'm really tired of this. What's wrong with this design?