Maybe you're looking for this lane balancer?
http://i.imgur.com/qAzhijB.png
If one lane of the output is blocked/only one lane moves, it makes sure both input lanes move.
0eNqVlEtugzAQhq8SzaqVTIV5pMTL3KGrqqqAWJElY1vGTosQd+8QmpQ0bgUr8DD ...

I think the splitter is really the problem. But it might just be me that is don't fully understand how a splitter works. :)
Splitters take items from the input belts and alternately direct them to the two output belts *ON THE SAME SIDE* -- if the selected side is full, it will direct the item to ...

Reason i am sideloading is to get all on one side, and the "false" underground belt was a solution to prevent belt priority on top belt lane.

I think the splitter is really the problem. But it might just be me that is don't fully understand how a splitter works. :)

It basically do not alternate ...

Maybe I should have shown how the full assembly line looks like now, it's not just science packs 1 being produced there. The thought is to produce 1-3 in this area. Preferably w/o dedicated resource belts.

Hi,

New to Factorio ... totally love it.

However, I've run into a problem that i thought i'd ask around if someone can help me solve.

I have a two lane output from my furnace's for copper and iron that ...

http://3.1m.yt/TPSr7SG.png

... i want to balance both lanes from over two mixed lanes ...