As one might be able to tell i'm struggling a fair bit with custom weapons, so far my torpedoes have broken the laws of directional physics and now I have a problem with rockets.
the problem stems from the unguided part of the rocket, due to the inability of a rocket to correct its path it is useless once it's been effected by an external source. For some unknown reason when I added a case to the rocket, (Even though I removed all mass and drag from the case, and all drag from the rocket) It began to spin round and round in circles.
A second question about rockets:
WHAT DO THE FINS ACTUALLY DO???
The fins don't do anything, they're just for visual effect.
Don't set mass to zero, that causes bugs. Instead, try multiplying it by .01
What about the detacher? If it's not centre of mass of the rocket it also affects the flight (disable drag on it as well)