Splitter not working properly

[XKnight]

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[rk84]

That is cool. I was bit confused until i saw those items in closed loops.

Old bug report about splitter's "feature" and counters getting tweaked:
[Resolved 0.3.2] Splitter error - not splitting

[vanatteveldt]

Pure curiosity, but is there any word on why splitters would have such a complicated memory setup (a counter of up to five per item type, with past unbalance compensated when a lane gets free)?

I would have just put a single boolean to remember if the next item should go left or right, certainly given that a splitter is not even supposed to be smart (no electricity usage -- although it does use an electric circuit, there's something magical going on there )

I can imagine that it is "nice" that lanes balance out even if they were clogged up, but isn't it the player's fault if s/he lets a lane clog up? And anyway, I would have expected that a basic splitter just does a left/right alternation, with optionally a "smart splitter" doing more advanced balancing stuff (requiring electricity, possibly allowing some sort of control via circuits - maybe the ability to close either exit with a signal to allow balancing based on e.g. the amount of items downstream?)

[ratchetfreak]

If you have an item per lane then in the plain alternation each belt tends to only get one item. One of the output belts needs to backlog until a good split is achieved

[vanatteveldt]

Right, so I guess a boolean state per lane would be needed. But that should be enough to function properly, right?

[Zeblote]

The way it works now also produces nonsense like this on compressed belts:



But appearantly that is how the devs want it to look. https://forums.factorio.com/forum/vie ... 23&t=16801

[XKnight]

Don't even ask "why?"

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[RavenHexx]

This is just beautiful

[vanatteveldt]

Okay, I officially don't get it. Why does the second splitter produce such a neat sorted pair? How can the "symmetric" rule that keeps track of a side per type give an "assymetric" outcome?

Or does it depend on the order of the input ?

[daniel34]

Okay, I officially don't get it. Why does the second splitter produce such a neat sorted pair? How can the "symmetric" rule that keeps track of a side per type give an "assymetric" outcome?

Or does it depend on the order of the input ?

Note that at first the items are all on the top lane (what I will now call left, as seen from the belt direction).
The first splitter that then sideloads from the right onto the belt makes it so that the iron (or any other item) alternates from the left lane to the right. That is because one item stays on the belt, the next gets sideloaded, the next one stays on the belt, the next gets sideloaded, ...
Now the belt is doubled using a splitter, then you have the iron on the outside lanes and the copper on the inside lanes because the right-left altering items are distributed by the splitter so that the left items go to the top belt and the right items to the bottom belt (for iron, for copper it is the opposite).
Then you only need to get the lanes to go to the same side of the belt, this is done by using the underground belt trick (if you fill it from the side only one lane gets through, the other one is blocked).

It doesn't depend on the order of input. That's actually the whole point: to separate a belt with arbitrary input of 2 item types into a belt where the item types are ordered by lane, no matter what input is given.

I hope that explains it good enough to understand it, it seems a little long and confusing written out.

[roy7]

I find this thread fascinating.

[XKnight]

I hope these pictures will help everyone to understand this amazing feature

You will need this explanation to understand the following gif (watch for control signal)

Pic1.png (333.82 KiB) Viewed 22177 times

lets start

Animation4.gif (16.67 MiB) Viewed 22177 times

P.S.
And yes, from this moment you can control your item-flow without any inserters.

One single item can change everything...

[roy7]

So you could repeat this multiple times in a row (same setup, inputting from the prior section's output) but drop in a different control item to toggle each section for the item you want to spit out. And thus, say, sort every type of ore in Bob's mods from a single input belt. Horribly inefficient, but amazingly cool?

[XKnight]

So you could repeat this multiple times in a row (same setup, inputting from the prior section's output) but drop in a different control item to toggle each section for the item you want to spit out. And thus, say, sort every type of ore in Bob's mods from a single input belt. Horribly inefficient, but amazingly cool?

No, I will be very upset if you use this setup for such purpose.

For your task it will be better to use static build, it means you don't need to use control signal at all.
Just add 2 splitters per each item type which you want to filter (if you are using blue belt you will need 8 smart inserters per item type to do the same job, so this setup is very efficient for fast belts).

I suggest to use control signal for dynamic manipulating with parts of your factory... For example: you decided to switch off some production and you don't want to leave there any item inside. You can send signal using combinators from command center and the entire part of your factory will be switched off. And this is the simplest application of this setup.

[XKnight]

I forgot to mention:

Appropriate filter will be applied If you send one item in the control signal, but second item (of the same type) will turn this filter off.
Example:
input: copper, iron, gear; output: copper, iron, gear; filtered: -;
Send one gear in the control signal...
input: copper, iron, gear; output: copper, iron; filtered: gear;
Send one iron in the control signal...
input: copper, iron, gear; output: copper; filtered: iron, gear;
Send one gear in the control signal...
input: copper, iron, gear; output: copper, gear; filtered: iron;

[Danielv123]

Ah, this was nice info. Thanks to Daniel for explanations that made sense after a while! If anyone still don't get it, I will link to this stream of mine where I figured most of it out.

http://www.twitch.tv/danielv1234/v/36275843

I didn't realize that splitters were that dumb.
I think the best part of this concept is how it overflows: When one item backs up, it will flow out everywhere including the filtered output, and I guess this can be used in some way smart inserters cannot.

[roy7]

XKnight thanks so much for sharing these designs. They've been so much fun looking at and multiple people on reddit have been experimenting with them. Using the 2nd static design of yours, exactly as shown, will fail if the loop-back line backs up all the way (into the interior loops). If you side load the main input, so the loop-back never stops, it's rock solid.

First example

Second example

Forgive the power poles, lights, and long Dytech underground belt. Was my only map I had handy to test this on.

[V453000]

This stuff is totally sick XD I love it

[ssilk]

It surprises me all the time, how the belts can be "missused" to make something cool. Good find.

Could you share links to other interesting belt usages?

Uh, just read that now.

The wiki is a good source:
https://forums.factorio.com/wiki/inde ... port_belts

(and all the linked pages in the bottom, especially https://forums.factorio.com/wiki/inde ... =Splitters or https://forums.factorio.com/wiki/inde ... _splitters
but that is a bit outdated)

[roy7]

I made a video explaining the magic of XKnight's static sorter design.

https://www.youtube.com/watch?v=FQGFhebyrSI