Assemblers and logistic chests

[zOldBulldog]

I am working to make my mall smarter. Could someone review my thinking and answer a couple questions?

Regular chests (wood or steel): Are not smart, so I plan to only use them as intermediates in a chain of builds.

Provider chests: Are fine to get resources to me or my trains, but do not help with excess.

Storage chests: I can set them to accept a single item type, and logistic bots can both receive and send items.

Buffer chests: Request a specific number of items and then makes them available when bots need them for construction or to deliver to me.

Questions:

(1) Is my understanding above correct?

(2) Based on the above, it seems to me that Storage chests are the best option for assembler output that needs to be stored and made available to me, my trains and construction.

(3) Coming out of an assembler it is common to limit the stacks of the output chest. For example, I might want to limit the output of the assembler that makes stone furnaces to 1 stack. What happens if I have 2 stacks of stone furnaces in my trash slots? Will they go back to the storage chest that has it as a filter, or will the 1-slot limit prevent it?

(4) I could work around issue (3) by wiring the output inserters and putting a condition there. While that is tedious, my concern is that a mall blueprint would break if I use it in the early game before I research circuit network, and any chests used (wood at that time even if they were to be replaced with storage chests later) would effectively have no limits. Is this correct? In other words wiring the inserters is not so good of a solution, except later in the game.

CONCLUSION?

Based on all of the above it seems to me that I should:
- Use Buffer chests with a stack limit and logistic request for that limit level.
- Setup a bank of generic Storage chests to handle excess.
- So... when I request items they will come out of Storage chests first, then from the Buffer chests next to the assemblers, and if a belt consumes items from the Buffer chests there will be an attempt to refill them from the storage chests if any of those items are there. And I should set any Requester chests in the area to "request from buffer chests" so that they don't ignore the buffer chests if the storage chests don't have the needed items.

Are my conclusions correct?

Is there a better way to do it?

[Tertius]

In general, your understanding is correct. I'd try to give a more practical explanation:

• use regular chests if bots aren't supposed to deal with the content, neither with filling nor with fetching
• use requester chests at the input side of an inserter to supply that inserter with an item, which is the inserter feeding into an assembling machine.
• use passive provider chests at the output side of an inserter that pulls manufactured items from an assembling machine. "Passive" means an item stays in the chest until something requests the item, for example some requester chest or the integrated player logistics.
• use active provider chests at the output side of an inserter, and the items are supposed to not stay in that chest. Instead, they are supposed to be fetched as fast as possible and sorted in some storage chest or directly used by some requester chest. An idle active provider chest is empty.
• use storage chests as independent storage device where robots might store random or specific items. It can also be used at the output side of an inserter that pulls manufactured items from an assembly machine, however if you don't set a filter it might happen robots will fill random items into it, and the assembling machine will stall if the chest gets full.
• use buffer chests to collect items from all over your factory and provide them at some central distribution point. This allows fast burst delivery from that chest, for example for player logistics.

I recommend you don't limit the stacks of some output chest. Instead, use a condition in the inserter. It seems you didn't find it yet, but you can not only connect an inserter to the circuit network, you can also connect it to the logistics network and use its complete inventory for the activation condition. Click on the wifi-icon in the top right corner of the inserter GUI. It will magically connect to the local logistic network without wire.

This way you can limit the output of an assembling machine not only according to the immediate chest content - that condition magically counts every item of that kind within the logistic network. So if you take 50 furnaces into your inventory, the inserter might activate and let the assembling machine produce more furnaces. However, if you put the furnaces into the trash slots and the trash is emptied, the 50 inserters are back in the logistic network, and no matter where they are stored, the inserter will detect them and will stop outputting items. As inserter condition just set furnaces < 50 for the logistic network connection (there can be 2 conditions: one for the logistic network connection and one for the circuit network connection. According to the wiki, both must be true for the inserter to activate, however I never used both in combination).

The chest the inserter is outputting into should be a passive provider chest. Not a storage chest, because as I said above the logistic network might store other items into the chest, so it fills completely and leaves no space for furnaces. You can set a filter with storage chests of course to avoid this, but you can just use a passive provider chest and don't need to explicitly set a filter. Less work and more universal.

Imagine a mall completely without belts.

• place requester chests for requesting input items.
• place passive provider chests for storing output items with a condition in the inserter to limit the amount of items. Depending on the kind of input items, it might be better to set the condition into the inserter for some expensive input item, not into the inserter for the output item.
• Additionally, place a bunch of storage chests nearby to take any excess that might show up from your trash slots or from you moving chests around (deconstructing non-empty chests).
• Use buffer chests to collect items you regularly request into your player inventory. Can be placed near a station you often use for a personal train, for example. In the wiki, there is another example for turret support and supply.

[astroshak]

Generally speaking I prefer to use Passive Provider chests, with the output inserter controlling how much gets put into there based on logistics network contents.

Exceptions are for things that are both ingredient, and infrastructure. Yellow belts, regular and fast inserters, etc. These get Buffer Chests, with the same logistics network limitation on production. They request a full chest worth of whatever item they are there for. This is so I can use that one chest as both output for yellow belts and input for red belts (or whatever other infrastructure ingredient chain you care to use it for).

Sometimes I only use Buffer Chests in my mall. Sometimes I only use Storage Chests. Both have their benefits and drawbacks. But I tend to use the Passive Providers with only a few Buffers.