No, this is probably an illegal CA law.

I'm a strong believer in 2a rights. However I think every type of weapon might require a license. So if you 3d print a gun that you would be allowed to own if you had already completed your background check, then you're gold.

If you end up 3d printing a nuclear bomb, the licensing requirements for that would be a billion times harder. (secure facilities, 24/7 guards, blood oath to the United States etc...)