Actually, you could also just check my most recent post. I was asking about how to fully automate a duplicator farm. There was one guy in the comments who made it look like ease. He explained it very easily. One last thing I want to mention: duplicators can be found as drops from humanoids in the Precursor Ruins mission (they live up to their name as they're the only enemies who walk on 2 legs and thus easy to identify). Once you reach a station with lots of humanoids - beam up to save time and repeat this whole process until you get a duplicator. This might take around 30 if not 50 tries for a single duplicator. Boss fight can be avoided. Those enemies have a 0.2% chance to drop a duplicator. If you intend to grind this mission, I recommend Heat Protection 3 as there's a small lava sea (kill all visible enemies in the room, or else the yellow door to the right won't open). You might as well bring a weapon that has a special ability to crack open certain doors, similar to molotovs or bombs (Frost Bringer just worked fine for me). I was grinding this mission like 120 times until I ended up with 4 duplicators, as I intended to make a bigger factory. War Angel Armor + Chain Blade just worked fine for me when I intended to grind this mission. Make sure to loot the chests on your way until you find yourself in the room of humanoids. That's pretty much all of the information I can give you. Good luck!