EDIT
My mechanical spider is not as simple as the pistons of the tutorial, the legs have different angles of rotation in relation to each other, when I put the armature and I can move the individual meshes in pose mode but I have to move the view so is completely perpendicular to the armature I want to rotate in order to avoid weird rotations.
My question now is if there is a way to make the lock the bones in the armature to just let them rotate in only one way from any view. Thanks.