Transport belts unbalanced

[vonmese]

Hi everyone, I'm new to the game and is on my 3rd playthrough after scraping the first two with so many lessons learned. In this one, I think I'm having problems with belt balancing as you can see in the attached pics.

So far, I had

• One smelting belt for iron
• One smelting belt for copper -> I do recognise that I need to add more furnaces for copper but it's not the problem here.

From these main belts, I split them whenever I need them somewhere, I understand that this might cause shortage down the line when there's not enough iron plates/copper plates to transfer further downstream. But what I don't understand is that why the belts aren't balanced...

Could you any give me some advice here? What should I do to make my production more efficient?

TIA

https://ibb.co/4njN0Khh
https://ibb.co/tTvMJ9fx
https://ibb.co/6RSN9Nx3

[NineNine]

What exactly do you mean by "unbalanced"? And what do you mean by "efficient"?

[miska666]

When you are dropping the copper for red potion factory with the splitter the right lane goes first on the belt. Consumption on the gear\copper belt is so low that the left lane backs up because the right lane has filled it already.
If you dont like that buffer, you can wire up the splitter to the output belt and set priority based on number of copper there. But you should probably just make more furnaces.

[Ogro]

I am getting better at the game, even diving into circuits, although sometimes I not even sure why they do/don't work
But the point is, I notice my train station belts and others getting "unbalanced", and it seems the way inserters grab from far side of belt, and splitters have internal order of which belt lane goes first, causes those. I have been reading and it seems just using belt to the left or to right can cause differences due to internal workings!
So it will be hard to make the belts drain equally from both lanes. But I am finally getting that Factorio is a game of ratios! If you get the ratios right then things should work nice