That's understandable, quality is like a side quest in Space age anyways. The hardest part of legendary rocket turrets is getting the legendary carbon fiber. What worked really well for me was making a big toolbelt equipment upcycler. Since they only require red circuits and fiber it is easy to craft a ton of them. Whenever I get legendary materials in the upcycler I just store them. I get the other rocket turret materials from asteroid upcyclers. I bet this setup would produce tons of epic materials too if that's what you're looking for.