vector launch instability

[CrashTestDanny]

So it seems that every time I launch anything on top of a vector engine the rocket goes all wonky (sorry for the technical jargon) for a few seconds before the gimballing kicks in and straightens it out...  Is this a known bug?  Or is it by design and just thrown in to make life exciting?  Or is it one of those things that I'm the only one experiencing?

Danny

[Mjarf]

Did you adjust the gimbal range down? The vector engine has extreme Vector range, if you don't adjust it you risk the engine ripping the entire rocket apart in my experience. I usually set it to 10-15% gimbal range.

[Snark]

Moving to Gameplay Questions.

[CrashTestDanny]

33 minutes ago, Mjarf said:

Did you adjust the gimbal range down? The vector engine has extreme Vector range, if you don't adjust it you risk the engine ripping the entire rocket apart in my experience. I usually set it to 10-15% gimbal range.

Yeah, even at 10% when I launch the rocket will take an immediate turn in a random direction - sometimes as much as 40 degrees before SAS fixes it.

Danny

[Mikki]

Definetly too much gimbal, 2-3% should be sufficient to take care of a common rocket launch.
The vectors high gimbal caps are made for being used as shuttle SSME (Space shuttle main engines)

[Mjarf]

Are you sure the COM is perfectly centered longitudinally? Maybe some part is causing excessive drag on one of the sides of the rocket? Do you have a craft file so maybe one of us can test run your rocket? 

[CrashTestDanny]

42 minutes ago, Mikki said:

Definetly too much gimbal, 2-3% should be sufficient to take care of a common rocket launch.
The vectors high gimbal caps are made for being used as shuttle SSME (Space shuttle main engines)

I'll try that and see if it fixes it...

2 minutes ago, Mjarf said:

Are you sure the COM is perfectly centered longitudinally? Maybe some part is causing excessive drag on one of the sides of the rocket? Do you have a craft file so maybe one of us can test run your rocket? 

I have dozens of crafts that do this.  If reducing the gimbal further does not fix it, I'll post a couple up...

Danny

[CrashTestDanny]

Tweaking the gimbals down to under 5% seems to correct this issue - thanks guys!

Danny

[Mjarf]

I'm glad it worked out, I know how how frustrating a non-compliant rocket can be.