Not balanced ironworks

[TheoMarque]

Hey,

I build iron works using steel furnaces. Idea for this deign is simply, max flow. Iron ore input is yellow belt (compressend to half red belt), output is the same, yellow belt (undergorund).
But... Ise something strange. Furnaces selected lime circle sometimes run out of iron ore. Is ok, because efficency of this setup is 11,66 furnace per yellow belt. But problem is with furnace selected by red circle. This furnace storage iron plates because inserter can't put it on belt. Belt was choked by yellow underground belt but is not matter where I set yellow belt choke, it will be overfilled later. But ofter choke I saw tiny holes. I think that splitter directing iron ore to steel furnaces not split ores by 50/50 but 50,5/49,5.

There is a bug or this layout is bad?

[Loewchen]

Use a faster underground belt.

[TheoMarque]

Is not resolve problem, iron plates pushed further and stacking on near splitter.

[vanatteveldt]

My guess is that you might consume one of the lanes quicker than the other. You can try inserting a lane balancer and see if it helps?

[Zavian]

One yellow belt isn't quite enough input to keep 24 steel furnaces working. It can only feed about 23.5 furnaces.

[TheoMarque]

Zavian, ok, but input is equal 13,33 items per second (yellow belt) divided by two lanes (6,665). If splitter before furnaces (with coal and iron ore) split half of red belt (13,33/s) it will be ok, but now... higher part of furnaces get more iron than lower. Problem is only with this one in red circle. After few hours, this furnace will be full and not consuming iron ore which start filling next until all of higher furnaces get overfilled.

How to >precise< count items flow on belt?

[Frightning]

Is not resolve problem, iron plates pushed further and stacking on near splitter.

That means that you're producing Iron plates faster that whatever is downstream from that splitter is consuming them. At some point, it's typical to be overproducing basic materials and then eventually have them backlog on the belts. If anything, that backlogging not happening is a sign that your need to expand your production of the item in question (or perhaps supply of more basic items used to make it).

[mrvn]

You are still missing the point.

Input is one yellow belt of ore. Iron plat production is one plate per ore. So the output should be exactly one yellow belt of plates.

Problem is the top half of furnaces gets more ore than the bottom half so the top half of the output belt overfills while the bottom half has gaps.

I think this broke with the new splitter code that no longer splits each item type separately. Instead sometimes an iron ore will go to the top, a coal to the bottom and the next iron or to the top again. If then later a coal goes to the bottom an iron ore to the top and a coal to the bottom again you end up with more iron ore at the top than the bottom. So this might just be a unlucky race condition. You could try removing the coal from the belt, manually give each furnace a stack of coal and see if it then remains balanced to verify my theory.

A simple fix though would be a lane balancer before the choke point. Then when one lane backs up the extra plate gets put on the other lane to even things out.

[apoptosis]

My guess is that the inserters have a different chance to grab an item depending if they are facing south or north. Therefore you get an imbalance of the two sides of the belt causing one side to be packed full while the other is missing plates sometimes.

[mrvn]

My guess is that the inserters have a different chance to grab an item depending if they are facing south or north. Therefore you get an imbalance of the two sides of the belt causing one side to be packed full while the other is missing plates sometimes.

While that is true (one of them has to switch lanes before grabbing stuff) it still makes no sense.

Assume the splitter splits the iron ore equally. The, since no ore is backing up, both sides would produce exactly the same amount of iron plates. Yet one side has more iron plates than the other.

[gsezz]

The problem is that both partially active furnaces (the last ones in the row, that sometime don't get an item) are taking from different lanes, but put their output on the same lane. one output lane gets to many items and doesn't leave enough for the other one.
You have 12 constantly active furnaces on one output lane, and only 11.32 on the other one. So one lane is output blocked with 0.34 items too much, and one input blocked with 0.34 items missing. One stacks up iron in the furnace, the other has gaps on the belt.
You should rearrange your belts so that there is a partially inactive furnace (input blocked) on both output lanes to maintain the 11.66/11.66 ration instead of 12/11.34.
However, when the output blocked furnace is filled up and stops taking from the input, this should balance itself.

[Engimage]

One yellow belt isn't quite enough input to keep 24 steel furnaces working. It can only feed about 23.5 furnaces.

This

It means that one of furnaces will periodically stall causing gap. And which furnace exactly will most probably be random or tend towards one particular furnace based on the order in which entities are processed. No matter what you will end up with random gaps here and there if you don't back up your output or create some kind of a buffer like good old lane balancer if one does work these days.

[gsezz]

Nope, it would not cause gaps. If you have 23.32 items input, and 24 furnaces in a proper setup, they are only input limited and produce full 23.32 output. 23 furnaces are working 100% of the time and one only 32% of the time.
Problem is that south facing inserters pick the ore faster than north facing ones. -> both last furnaces in the rows with south facing inserters are operating on the same output lane. -> So this lane gets full 12 items, and can handle only 11.66. -> One furnace on the left lane gets output limited while it still takes input which should go tho the furnaces on the other lane.
Like I said, this should balance itself as soon as the furnace in the red circle has a full stack of plates and stops taking from the input.

[mrvn]

Ahh, I just noticed that the top furnaces don't all output on the same side of the belt and the bottom furnaces on the other side.

So I retract my post about the splitter being uneven. You need to change the belt layout so all the top furnaces put iron plates on one side of the output belt and all the bottom ones on the other side. Then the output will match the 50:50 split of iron ore that the splitter makes and the gap should disappear.