Once you do, you'll gain access to the device that lets you take different items and literally grind them together to produce a new one. Here, she'll provide you with a side mission called Grinders, which you should be able to complete with some friends. The first thing you'll need to do before you access the Grinder is find Janey in Concordia. On that note, here’s everything you need to know about the Grinder.
With it, you can gain better Legendary weapons, along with secondary Luneshine enhancements that make a difference in battle. In addition, The Pre-Sequel lets players grind unwanted weapons using a special device located in Concordia.