A method for operating the 3D printing tool includes positioning a first material distribution barrel within a first barrel orifice, where a first barrel tip is disposed at a first end of the first material distribution barrel. The method further includes positioning a second material distribution barrel within a second barrel orifice, where a second barrel tip is disposed at a first end of the second material distribution barrel. The method further includes dispensing building material from the first material distribution barrel when the first material distribution barrel is substantially vertically oriented and a second material distribution barrel is oriented at an angle from the vertical.