I am designing my blueprints for express delivery and came to a point where I wanted a very specific filter inserter setup. To make quantum processors on Aquilo, I needed to move 4 ingredients from the landing pad to the EM plant. There are easier ways like using 4 belts, or using bots, but I decided to challenge myself to try and use only 1 belt and 1 inserter to move all of it.

Requirements for the solution are:

The filter needs to cycle between blue circuit, tungsten, superconductor and carbon fiber

The cycle should pause when ingredient is empty at the source (landing pad) In case production at other planets are not smooth and items aren't delivered on time

Ended up with the combinators setup like the image above and the belt fills up cleanly.

Constraints:

Ingredients must be in a 1:1 ratio; items would get stuck at the end if they are not consumed evenly

Player need to place an initial item inside the inserter item slot to kickstart it In this case, put 1 blue circuit…