## Help with designing factory bus

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dev-cyprium
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### Help with designing factory bus

I have a 2 lane bus I'm trying to build inside a factory, to keep things organized, but when I try to grasp the actual ratios I can't comprehend why do we need so many spitters, and also, how does someone come up with a decision like this?

I'd like to keep my factory throughput going, so I understand balancing and spitting of the main bus has something related to that, but I'm really having a hard time grasping these concepts, so I'd love for someone to actually explain how such concepts work in practice, and how can I come up with my own design?

The design in question I fail to understand is this one:

So I have questions to summarize:
• how do people actually come up with decisions like this, and splitter layouts, as researching this only led to complex graph problems and really hard math
• did I label the throughput correctly on my image?
Additionally, how do the balancers even help?
I've tested out a few builds and noticed those spitters never actually change the lane of the item. So how does the "lane balancer" I found actually help?

For example having:

Code: Select all

- belt
I - iron
S - sppliter

--------I--I--III-I  S ------III
------------------  S ----IIIII

------------------  S  -------III
----IIIIIIIIII------   S  -----IIIII
I was kinda expecting the same balance over lanes. And even the one I've linked doesn't handle lane balancing, right?

theolderbeholder
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### Re: Help with designing factory bus

As long as input is compressed, the upper lane will still carry 100% after the first splitter. The lower as well, but there you split off 50% right afterwards onto an empty output lane. The other 50% go into the underground belt. Then the next two splitters move 50% from the upper belt to the output belt. As long as the output uses a full belt, you could then remove one of you bus lanes. And the first splitter can go as well.

disentius
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### Re: Help with designing factory bus

Lanebalancers make sure the input is balanced when the output is unevenly consumed. splitters dont do this , they treat every lane separate.
example:
lanebalancing example.gif (5.87 MiB) Viewed 1239 times

Premu
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### Re: Help with designing factory bus

Your first splitter just acts a balancer - so afterwards you have a 50:50 distribution on your two lanes.

The fourth splitter is actually just a "merger" which makes sure that you draw from both lower and upper belt equally. The other two split up half of the lower and upper belt as already described by theolderbeholder.

The question is - do you actually intend to consume a full belt in your side factory? In this case you could simply take the lower belt and lead it directly there, continuing with only one lane on the main bus. In case that you need less than a full belt, or the demand may be variable (e.g. in a mall where you only produce stuff while actually building something), this design is a good choice split up two lanes, allowing maximum throughput for your side belt.

coppercoil
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### Re: Help with designing factory bus

There’s one question related to main bus design: do you really need to have balanced split? Does it really need to share resources if general supply is too low for all branches? If not, you can use very simple “semi-greed” splitting, just keep the first belt compressed:
SemiGreedySplit.jpg (215.57 KiB) Viewed 1218 times
You may think: supply is always too low , so first branches will consume almost all materials leaving nothing for the rest. Here’s the trick: can you limit the production output? If you produce to the chest, just limit its stack. Greedy production line will take most of resources but for limited time, and after that it will pass resources for others. BTW it’s a good way to prioritize various production.
Note 1: this will not work for continuous production like a science. You may want to balance it.
Note 2: some production (e.g. blue belts, modules) are incredibly hungry for resources regardless of output limits. Balance it.
Note 3: if you build large base, don’t put green circuit production on the man bus. Make separated bus for it. You will need an insane amount of green chips and it will ruin any main bus balancing.
Note 4: some splitter setups you can find in internet are obsolete for today because they were designed before splitter input/output priority was introduced.

astroshak
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### Re: Help with designing factory bus

I tend to do what Coppercoil pictured, except I also output prioritize that first splinter, to the side.

Output priority means that that side will get as much of the splitter’s input as it can handle. Yes, this starves stuff further on, but that’s honestly what the second splitter there is for (to move everything closer to the drawn upon belt).

I often find that I am drawing half a belt - one lane only - from the bus. After that I will have to rebalance the lanes, so that I’ve got a good smooth flow down the bus.

One thing you can do (not that I’d recommend it, but you can do it) would be to have dedicated lines to each sub factory. No splitters from the bus, just straight lines of spaghetti. Put a Pair of big ol balancers (or one Unlimited Throughput Unlimited balancer) such that the smelting columns all feed into it and the output belts all stay compressed.

Kind of what you should be doing fro Green Circuits (dedicated belts of Iron and Copper in) but with a larger balancer in front (which is not really needed with a good Green Circuit design).

dev-cyprium
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### Re: Help with designing factory bus

disentius wrote:
Sun Dec 01, 2019 10:12 am
Lanebalancers make sure the input is balanced when the output is unevenly consumed. splitters dont do this , they treat every lane separate.
example:
lanebalancing example.gif
Oh, yea, this is what actually started my little confusion. I wanted to take one arm off my bus and process it as steel, but once I did that, only the right side of the belt got consumed, even though I had a lane "balancer" before that. Since I had no idea what to do I ended up back-feeding the other lane onto the bus. Is that a good idea to keep the throughput?

So, what I understood was, the steel line was causing only one lane to be consumed because when you merge a 2-lane into a 1-lane, only one gets priority. So to combat this, I back-feeded the rest of the iron back to the main belt. Else it would cause a really long column of iron at one side of belt, and empty column on the other.

dev-cyprium
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### Re: Help with designing factory bus

coppercoil wrote:
Sun Dec 01, 2019 2:34 pm
You may think: supply is always too low , so first branches will consume almost all materials leaving nothing for the rest. Here’s the trick: can you limit the production output? If you produce to the chest, just limit its stack. Greedy production line will take most of resources but for limited time, and after that it will pass resources for others. BTW it’s a good way to prioritize various production.
Note 1: this will not work for continuous production like a science. You may want to balance it.
Note 2: some production (e.g. blue belts, modules) are incredibly hungry for resources regardless of output limits. Balance it.
Note 3: if you build large base, don’t put green circuit production on the man bus. Make separated bus for it. You will need an insane amount of green chips and it will ruin any main bus balancing.
Note 4: some splitter setups you can find in internet are obsolete for today because they were designed before splitter input/output priority was introduced.
Oh, thanks for the notes, especially Note 4
I haven't realized some of the designs are in fact obsolete, since I'm yet to figure out how to use input/output priority.

dev-cyprium
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### Re: Help with designing factory bus

disentius wrote:
Sun Dec 01, 2019 10:12 am
Lanebalancers make sure the input is balanced when the output is unevenly consumed. splitters dont do this , they treat every lane separate.
example:
lanebalancing example.gif
This is exactly what I was looking for too. Thank you very much

The only problem @disentius is, what do I do now with the extra underground belt now that I have one that's not paired hehe. Is this only achievable with underground belts blocking off one side?

Premu
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### Re: Help with designing factory bus

dev-cyprium wrote:
Mon Dec 02, 2019 11:15 am
disentius wrote:
Sun Dec 01, 2019 10:12 am
Lanebalancers make sure the input is balanced when the output is unevenly consumed. splitters dont do this , they treat every lane separate.
example:
lanebalancing example.gif
Oh, yea, this is what actually started my little confusion. I wanted to take one arm off my bus and process it as steel, but once I did that, only the right side of the belt got consumed, even though I had a lane "balancer" before that. Since I had no idea what to do I ended up back-feeding the other lane onto the bus. Is that a good idea to keep the throughput?

So, what I understood was, the steel line was causing only one lane to be consumed because when you merge a 2-lane into a 1-lane, only one gets priority. So to combat this, I back-feeded the rest of the iron back to the main belt. Else it would cause a really long column of iron at one side of belt, and empty column on the other.
Hm, this is a way to do it - but it looks overly complicated.

You could have simply applied the lane balancer after branching off the iron plates to have the lanes balanced again.

coppercoil
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### Re: Help with designing factory bus

BTW I think lane balancers are overrated. There's nothing bad if lanes are slightly disbalanced. Even if disbalance starts to impact general throughput, I check first, a) what production line is affected, b) are there any other delivery design errors, c) is it a temporary shortage, and d) is it really important line at this moment. B is the most frequent case for me . I have no single lane balancer in my base.

astroshak
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### Re: Help with designing factory bus

To me, lane balancing is not so much about maintaining a full downstream belt (that’s what using Splitters to shift materials is for) but rather, to ensure full use of the belt upstream.

Its not so much about trying to make a full belt out of a half belt of materials downstream, but ensuring equal draw upstream so that my trains don’t unload oddly.

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