Optimus Prime is the leader of the autobots, considered as having strong moral character, being an excellent leader, with brilliant military tactics, powerful martial arts, and advanced alien weaponry.
This last skill is known for first time in the 1st chapter of the 80s animated serie, when Optimus Prime unsheathe an energy axe to fight against Megatron outside the power plant that is about to explote. (see the scene below)
One of the best sites on internet to download models for 3D printing is Cults3D, and Optimus Prime is not an exception. BigLiL design is de author of this 3D model and has several precedents for fantastic designs as Astroboy, the Incredible Hulk or Mazinger Z.
Download here the OPTIMUS PRIME model and the ENERGY AXE.