This is setup to make the parts for rail gun ammo, but the approach is generalizable to any recipe that does not use the same signal for its recipe & its output. For example, you can't use this approach as-is if you were making green circuits on assemblers, as the same "green circuit" signal is used to represent both the recipe and the green circuit item itself. You can work around that by setting quality recipe signals and then using another selector combinator to transform the output quality.