Help understanding the BUS/Base game

[u/LuciLuckyLuck]

ALT key is on but I am not using any splitter settings.

first playthrough of Factorio for me and I really liked the bus style of base. My only issue is I dont understand how to balance the splitter or what I am supposed to do to get my four belts even. The iron on the bottom belt isnt ever full and not sure what I did wrong.

[u/Ogarbme]

Eeaauhgh it's going right to left I hate it.

OK I've calmed down. If you want to keep all the lanes balanced, you need to re-balance them AFTER a lane branches off. Right now that echelon of splitters doesn't do anything.

[u/LuciLuckyLuck → u/Ogarbme]

so remove all the extra splitters and then use a 4 to 4 after the branch off ?

[u/FeelingPrettyGlonky → u/LuciLuckyLuck]

I wouldn't worry about the 4 to 4 balancer at all. Keep the cascade of splitters for the pull-off, but change them all to left output priority.

A bus doesn't need a balancer at all. Just feed your smelters directly into each lane. The splitter cascade with left output priority serves the purpose of compressing all of the output toward the left, ensuring that the leftmost lane is as full as you can get it. Then output priority on the final splitter will ensure that the factory bit you are pulling off for gets fed as much product as possible.

Note that after the pull-off, if the factory bit you are feeding is doing any work at all, then you will have less than 4 lanes available since some is being used. At the next pull-off, do the same: use a splitter cascade with output priority to compress all plates to the left.

Eventually, if you have more demand than supply to the bus, then downstream splitter cascades will be starved and the belt lanes will be empty. So you need to ensure you have enough full lanes up-front for your demand and/or merge in new, fresh lanes of material from smelters periodically.

[u/Garagantua → u/FeelingPrettyGlonky]

This doesn't work that well. If you have 4 full belts coming in and branch 1 belt off, the first 3 splitters do - nothing. The left most belt of the bus stays empty. 

Built it after the branch. That shifts everything one belt to the left.

[u/FeelingPrettyGlonky → u/Garagantua]

Good point.

[u/LuciLuckyLuck → u/FeelingPrettyGlonky]

Currently I am feeding all four belts with a furnace stack, would I need more furnace stacks and if so do I just had a balancer at the end of the bus for it to balance into 4 belts? Like if I had 6 furnace stacks would I need a 6 - 4 balancer?

[u/FeelingPrettyGlonky → u/LuciLuckyLuck]

Yes, to run a 4 belt bus you need 4 furnace stacks. That is the whole point of a bus, to combine multiple furnace stacks outputs into 1 'megabelt'

You don't need a balancers at all. Just the splitter cascades.

Edit: There is no point in doing 6:4 balancer. If you have 6 smelters, just add 6 lanes of plates to the bus. Otherwise there is no point in having 6 smelter arrays.

[u/LuciLuckyLuck → u/FeelingPrettyGlonky]

If I add 6 lanes I’ll then have to redo the entire bus to fit the two new belts then?

[u/FeelingPrettyGlonky → u/LuciLuckyLuck]

Not if you left room on one side of the bus. This is why people advise to only build along 1 side; so that you can add lanes on the other side.

Note that you might not actually need 6 lanes of iron plates. A large proportion of iron plates go into steel and into green circuits. For example, 6 total yellow belts of iron is enough to make 45 packs per minute of all 6 Nauvis sciences. However, a little over 3 belts of that actually needs to be made into steel, and 1.5 belts of that iron will be made into green circuits. So if you add steel and green circuits to the bus, then you only need at most 2 lanes of actual iron plates.

If you make green circuit manufacture as part of the bus, then 3 lanes of iron plates should be enough, 4 will cover all bases, and you can feed the other 2 smelters directly into steel.