Exact raw input amount to produce exact output amount?

[TreeBearButt]

I'm starting to shift my gameplay focus from the main bus to trains. I want to build a base where every intermediate product has a specific train station to drop off the raw materials and be produced there. My idea is that trains would deliver the exact amount of input material and that station will produce the exact amount of output.

I tried this with a simple green circuit line where I gave it 100 iron plates and 300 copper wires.



I ended up with 91 circuits instead of 100 because a few of the materials were stuck in the other assemblers due to buffering.

Do I need to have some kind of design where it evenly splits the materials across all assemblers in order to get the 100 circuits every time?

[DaveMcW]

Solutions:

1. Don't bother. A few extra items left in the system are cheaper than the control logic you need to achieve this.
2. Splitter maze.
3. Put every item in its own chest. Connect all chests and add a constant combinator with a negative version of the recipe. Inserters feed the assembling machine have a custom stack size and operate when everything > -1. Inserters filling the chests also need some logic to only fill the chest with enough for 1 recipe.

[Koub]

Factorio is not usually a game where you will want to control things to the item level. It's not that you can't do it, it's just not usual (the same way veterans will faint seeing you transport copper wires by train), except maybe in very rare cases (like with Uranium enrichment, nuclear reactor feeding, or advanced multipurpose smelting arrays) ...
If you want that type of control, you'll need to feed each assembling machine the exact same number of items (you'll need some circuitery to count and keep track of that).

What people usually do when they want to control the number of items they are building not to overbuild, is count their output, and stop the inserters that take the items from the assembling machine when they reach their target. And when the input backs up, you're done.

[eradicator]

If you really want to bother: Prefill all the belts and assemblers until the buffers are full. Then use circuit controlled inserters to in/output stuff to/from the closed system. That design will break as soon as you notice that you want productivity modules though. So, "don't bother" really is the best solution.

(the same way veterans will faint seeing you transport copper wires by train)

Not all veterans build megafactories. And as long as you're not hitting the UPS limit centralized copper wire can be pretty neat (3 types of circuits, science, beacons, circuit wires...). :P

[zOldBulldog]

To continue on the previous thoughts: A better strategy can be to design your assembly lines so that they are expandable / tileable and eventually shift your focus toward keeping your bus belts full as you increase production to meet the ever increasing volume demands caused by the later science and then rocket.

And by the time you go to the megabase you'll use significantly different designs and strategies, in a separate base from the one you use for your first ricket,. So there is no point worrying about it too early.

[TreeBearButt]

1. Don't bother. A few extra items left in the system are cheaper than the control logic you need to achieve this.

Won't this eventually end up blocking the whole system if one material ends up being "left over" too much? My train conditions for dropping things off have always just been "leave only when empty" which if this happens would just stop the entire thing. I feel like I would need something in place to "drain" the excess materials before the next train arrives. That said I've never used trains for anything but ore/plate pickup/dropoff so I don't actually know if this would happen.

To continue on the previous thoughts: A better strategy can be to design your assembly lines so that they are expandable / tileable and eventually shift your focus toward keeping your bus belts full as you increase production to meet the ever increasing volume demands caused by the later science and then rocket.

That was how I played up until now. I'm just starting to get bored of the bus cause that's all I ever do. Once I learned how to use trains and signals it's like I discovered a new game.

[DaveMcW]

My train conditions for dropping things off have always just been "leave only when empty" which if this happens would just stop the entire thing.

"Leave when empty" only works for single item trains. For multiple items, use circuit condition "anything = 1" and a constant combinator with each item of interest set to 1. The station also needs to have "read train contents" and "send to train" checked.

[zOldBulldog]

To continue on the previous thoughts: A better strategy can be to design your assembly lines so that they are expandable / tileable and eventually shift your focus toward keeping your bus belts full as you increase production to meet the ever increasing volume demands caused by the later science and then rocket.

That was how I played up until now. I'm just starting to get bored of the bus cause that's all I ever do. Once I learned how to use trains and signals it's like I discovered a new game.

The basic concept still applies when you shift to trains instead of a bus. Your goods unload and either go through belts or through the logistic network. Either way you want to keep the assemblers they feed saturated with as many input materials as they can handle, and that Cascades through your belts or logistic network and to enough trains delivering them.