Rotate from volume from horizontal to vertical psition


I have build all my volumes in HandsOn2. I would like to turn the cylinder inside from the horizontal (position 1) to the vertical position (position 2). I have use G4RotationMatrix* rotationMatrix = new G4RotationMatrix(90*deg,0,0);
but it does not walk. What to do please?
thank you in advance

The rotation matrix rotates a volume about its own internal center. You then use the position vector in the Placement to put the rotated shape where you want it.

thank very much for you response