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When I deconstruct a part of a base wholesale with construction robots, the robots have to move not only the "buildables" but also any items that are on belts, in chests or inside machines. This can add up very quickly to thousands of items for the robots to move and for me to decide what to do with afterwards.
Construction robots put all these leftovers in storage chests. But they don't prioritize the closest chests. If a storage chest on the other side of the logistics network already has that item type, the bots can make very long trips with multiple stops to recharge, multiplied by thousands of items. They prioritize these over storage chests with filters set by the player, so that doesn't help. If I use requester/buffer chests to try to make the construction bots deposit the leftovers in a sensible place, the logistic bots will start carrying in materials from somewhere else. I've found it can take robots hours to deconstruct (for example) a smelting column.
After that, I also have the reverse problem. Storage chests can hold massive amounts of materials from a deconstructed build (such as ore and metal plates from the smelting column) and logistic bots would take a lot of time and power to move these somewhere where they can be useful. Because these are all mixed materials and buildables, in different places, it's not simple to sort them onto belts or trains. Furthermore, construction robots are available before the "advanced" logistics chests, so I tend to accumulate mountains of stuff in storage chests before logistic network research.
I haven't found any tutorials or strategies on this in youtube videos etc. But people seem to take mass-deconstructing and moving builds with construction robots for granted, so it seems there's some obvious solution or strategy I don't see. Can anyone explain how they cope with these problems?

I try to empty sub-factories as far as possible. Like cutting off the inputs, but keep consuming the output. But with often uneven input amounts it's not perfect with the more complex items.

In my base, storage chests do not store anything, they just moves all content on belts, and then items arrive to The Great Recycling Station where every single item is sorted and redirected to corresponding consumer or to the shopping mall and other output chests and buffers. Recycling station also has large intermediate buffers to deal with bursts from large deconstructions.

Buffer chests can play a role in your sorting and recycling facility, because they are requester chests and passive provider chests at the same time. They can request items for sorting purposes and at the same time provide them to the network.

The first storage tier can be a huge number of unfiltered storage chests distributed more or less over your factory. They will first take the huge unsorted heap of deconstructed stuff.

Build your mall so manufactured items end up in buffer chests(*). Place one or more chests for each item. Configure the buffer chests to request the item they are supposed to contain, so the chests in the mall will be filled by inserters from the mall as well as from the big unsorted heap in the storage chests. To limit mall production, connect the output inserters that pull manufactured items from their assemblers to the logistic network and make them activate only if there are less items in the network than you want.
This way the mall immediately stops producing an item as soon as there are enough of them somewhere in the logistic network, no matter the placement. And the mall buffer chests request items from the heap, so the items are pulled from the huge heap, so the heap is being sorted and emptied into the mall storage.
If you place enough buffer chests for items used in bulk, for example walls, belts, furnaces, inserters and so on, you will see how all these items are migrated from the storage chests to the buffer chests near the mall. Or near wherever you place the buffer chests.

For ore and other intermediate material, place requester chests near belts where the intermediate material is being transported for consumption. Empty the chest with inserters onto that belt to merge with the regular items. Well, not directly but create a branch belt you fill from the chest and merge with the main belt with a splitter, giving the belt priority that's emptying the chest. So the intermediates are going back into the regular production cycle.
If it's difficult to do this for ore due to your base layout, you could create a phantom ore mine that's not fed by mining drills but by requester chests. The same goes for plate production that uses requester chests instead of furnace lines.

If you use buffer chests this way, take heed of the "Request from buffer chests" setting in requester chests - you will usually need to activate this, otherwise you will not get items out of your buffer chests.

(*) using buffer chests for mall item storage has the additional advantage that robots will never place unwanted items in them, which would be the case if you use storage chests without filter. I often had the case that if other storage chests got full, the bots started to fill up my mall output chests with junk, effectively stalling mall production for the item the chest was supposed to contain.

Thanks for your responses, this makes a lot of sense.
What I understand from coppercoil and Tertius is that storage and buffer chests are kind of used in the reverse of their names - storage chests as a temporary collection point while buffer chests are the long-term storage. Promptly emptying storage chests would help with the problem of construction bots prioritizing distant chests that have the same item type.
Having a central location for sending "recycled" stuff doesn't help with the problem of bots making long-distance trips, but I think that's a general problem of large logistics networks. I am trying to use smaller bases with separate networks, connected by trains or belts. Leftovers could be collected by storage chests in each network that empty onto a mixed train wagon or belt.
Then I could combine your solutions with a base that includes both the mall and recycling center, with the logistics bots there sorting the mixed items. The center would take the items that aren't stored or used by the mall.
The recycling center would need to have outgoing train stops or belts for different ores, plates, and circuits - things that come in large amounts. Buffer chests in the train stop would be the long-term storage into which these are sorted. A circuit could enable each train stop only when there's enough stored that a train trip would be worthwhile.
I might allocate a lot of space for dedicated stations (or belts) that will only be used when there's an excess of leftover stuff to send out. It's a balancing act between "wasting" space and "wasting" materials by storing instead of using them. This can be adjusted by adding/removing stations and storage.

I still have not used buffer chest yet once after they got introduced.
I still think that the original 4-chest system was more elegant.

My mall has the same logistic storage for all producers. All producers eject to passive or active, depending on if I care for the item to be in the storage area, where I come to to resupply, or if it is something strategic delivered to trains, where I don't care in saving flight time in advance.

Inserters on mall manufacturers are set to be active on item<target. That means, if some items/factories come back from deconstruction, it's over that cap, and does not manufacture items anymore, until the threshold is reached. In the end, assuming that your mall manufactures in a broad spectrum, you will sink all returning resources pretty soon, if you not only deconstruct, but build as well.
The only thing you have to solve is prioritising things from local storage over trained-in ressources. This is usually accomplished with inserters from the train having a condition not to unload, if the amount of that resource is higher, than you like.

Wood is simply burned by a boiler and two steam engines, that's it.

The idea is, that when bots "choose" where to grab items from, they will first go to storage, and only then to passive, so you don't overproduce at any point.

My strategy is : a few requester chests for every type of raw-ish materials inserting those materials at the beginning of a belt where they are regularly consumed.

Example : if I deconstruct my smelting area, I know I'll end up with excess iron and copper ores, and same for plate (maybe even steel).
So either at the place where I plonk the new smelting facility place, or at another smelting facility (if I have several of them), I place requester chests :
- I set up a bunc of iron/copper ore requesting chests at the train station (of the beginning of the blets if directly in an outpost) so that if there is excess ore, it's drawn from the whests insted of mined/delivered
- Same contraption at the beginning of my smelting line belts for the plates, so that I only start smelting when the excess has been consumed
...
And similar strategy for all the intermediates if any : store them temporarily in storage chests, set up requester chests wherever the intermediates are consumed en masse, and ensure what's stored is consumed first, before producing new stuff.
additionally, if I have a bot based production line,, I control my input inserters so that production is halted if excess intermediates are in the logistic network.

Mad Inventor wrote: ↑

Mon Jul 17, 2023 7:52 am

I might allocate a lot of space for dedicated stations (or belts) that will only be used when there's an excess of leftover stuff to send out. It's a balancing act between "wasting" space and "wasting" materials by storing instead of using them. This can be adjusted by adding/removing stations and storage.

I think you already received many good answers but no-one mentionned the use of rockets to help the robots deconstruct the old furnace array, those filled with coal burner inserter and yellow belt, nukes can do too, late game, if you are ok to trade "ressources" for "time" .

It works best on a isolated network, which make sure the robots will deconstruct things and leave them nearby, to reduce the amount of yellow chest you need to "store" the deconstruction leftovers when it's not modules or expensive things.

Then when you have less need for robots, you can fast replace / use upgrade panner on those yellow chest to make them purple chest and connect the networks, forcing the use of logistic robots instead of construction robots to do the long carrying. It drains energy but it looks great !

As mentionned, to "consume" those leftovers naturally, one need to have a factory where there is consumption of those material in the first place, and then you add logic to prioritize the existing material in the logistic network over the new input, either with stopping input belt when logistic network already hold 10K coal for example, or stopping inserters or not unloading train, whatever you prefer. After a deconsctruction storage may get up to 100 K coal, so it stop the new input for a while, until all the excess in consumed, and then to maintain 10K the newly mined coal would be used as normal.

When i play i have a lot of "trash chest" around the base from handcrafting and messing up construction and getting those in the inventory, i eventually replace them with purple chest when i have the setup described previously working same as deconstruction leftovers but i try to avoid moving part of my base for those reasons , i also tend to make small train station, because it takes less time to deconstruct/fix when something wrong happens.