You're probably already familiar with Mass Relocating Robots (MRR). Here we'll talk about how to use those with "weapons" in the name. Apart from Intimidating Tango Dirk, there isn't much demand for such tradeskills, but a proper tradeskiller is always prepared (like boy-scouts, they have both the tools and the knowledge). With a single exception, which we'll address at end of this guide, every tradeskill process listed below takes 3.5x Mechanical Engineering in regards to the QL of the weapon.
And the exception? It involves a Broken Immortal Katana, which drops from a QL 77 boss named Commander Jocasta, located in the Cyborg Barracks. What stands out in this process is that besides having a tradeskill requirement of just x3.5 Mechanical Engineering, you also need x4.5 in Weapon Smithing.