Why does my rocket fall apart like its made of glue?

[crazyewok]

Another queation!

I am building a tall 3 stage rocket yet it seems to come apart like its made of glue? Im putting supports on it yet it still happens? Am I missing something? Or do I have to make flat stupid looking vessels?

[Sirrobert]

We are going to need some more info on the rocket if you want any more than 'put struts on it'

A picture would help

[Trueborn]

Screenshots are helpful for diagnosing rocket failures. You may have too much thrust, or may not be strutting properly, or have things too far out of balance. Hard to know without a better description or, preferably, a picture.

[celem]

Check your flight log with f3 to see where the very first failure occured. Any entries after that may be subsidiary problems caused by the first failure.

Could be lack of struts, could be exceeding terminal velocity while in thick air.

While drag doesnt work like it should you can have issues when adding lots of weight far from the center of mass. Levers and moments is pretty accurately mapped. So big flat pancake rockets can also fail for this reason.

[crazyewok]

I think its the terminal velocity. I switched from solid to liquid fuel and scaled down the thrust ands it seems to keep together better.

[celem]

You can find a table with some guideline speedlimits@altitudes for Kerbin here.

You dont want to fall too far behind this either or you are losing energy to gravity rather than drag. Sweetspot is as close as you can get.

Generally once you pass about 15-16km you can floor it with most sane designs. Certainly by mid to upper atmosphere the terminal velocity is increasing far faster than anything you can build, its really only an issue below 20km. If you have a really high TWR though you may shake the rocket to bits if you accelerate too violently. Mainsails in particular are destructive buggers at 100% and high TWR

[FenrirWolf]

Solid rockets have a rather high thrust by default. Luckily the ability to scale their thrust down was added in the most recent update, which is something g you might want to try out. Just right click them during construction a d try different settings.

[Mystique]

If your rocket is too tall (it's relative, there is no actual "too" tall) and paylod and too heavy (same thing) and/or large/disbalanced, it may start wobbling when phisics kick in. Even if you manage to engage SAS fast, it may be too late, it'll act like a lever from the top of your tall rocking, cracking it in weakest spot. Consider making your rocket a bit shorter and a bit wider using larger diameter fuel tanks and adapters. Also avoid sticking parts of different diameters in places where they act as structural elements. I.e. don't stick 1,25 m engine to 2,5 m tank, and then 1,25 m decoupler below them. Most likely connection between engine and tank will fail on wobble. Also avoid upper parts being wider that lower. And don't forget about center of mass for each stage, it's not that important as for planes, but may still cause lots of pain. Position your SAS close to CoM, this may also help. First stage, when heavy, could use its own SAS, because initial CoM will be low and payload SAS will be inefficient.

[Ahmed]

1st add more space tape

2nd add more space tape

3rd add more space tape!

It works everytime.