Originally shared on the public FactorioPrints / Factorio School archive (factorioprints.com · factorio.school). Authorship preserved from the public catalog.
Balances items between the two lanes of a single belt
Size: 14Lx2H (If you trim off the little tails on either end outside the balancers)
Very helpful if you have OCD (probably).
Works in any configuration: 1-1, 1-2, 2-1, or 2-2. In every case, it will pull input from each lane of input in a round-robin style, where a given lane will not have its item pulled unless the other lanes have all already had theirs pulled once.
At 14 belts, 3 sets of undergrounds, and 4 splitters (screwed that up in the description in-game - it says 2 but it's actually 4), it is relatively expensive for a 1-1 balancer, but not too bad.
Will not affect throughput (as far as I can tell, anyway)
Useful for adding to the output of mines to help pull the resources more evenly. For example, if you have a mining field with miners on either side of a belt providing a total of 6 items/sec, and on the other end you have inserters pulling 6/s off one side of that same belt: You can stick this on the output of your miners and be guaranteed that you will be drawing the ores evenly.
