direct insertion from iron to steel furnace

[vanatteveldt]

It just struck me that you might as well dedicate an iron furnace to each steel furnace, since the ratio is 1:1 (5 iron are produced in 5*3.5=17.5 seconds, which is exactly how long steel takes).

In early game, that looks something like this:

With electric furnaces, it is a lot easier since you don't need the separate coal line, so the ore can be central with an iron furnace on both sides, both given directly to the steel furnace.

Advantage: No more juggling between iron to steel mills and iron to the rest of the factory. Automatically correct ratio for adding new steel furnaces.
Downside: iron is not fed to the rest of the factory if no steel is needed, and each iron furnace stores 100 plates (again, if no steel is needed).

What do most people do?

[DaveMcW]

Just merge some coal onto an iron plate belt. So a single inserter can feed both products into steel. That way you don't need to mess with smart inserters or underground belts.

You are right that it is a good idea to have dedicated iron furnaces for steel. The cost of furnaces and 100-plate buffers is a lot less than the cost of running out of steel when you need it.

[ssilk]

What do most people do?

To my observation it depends on the targets the players want to achieve.

Some just want to make an easy setup, so I would prefer to have each part of the production separated: Iron production and then there is a splitter cascade, which feeds about 1/2 to 1/4 or your production into the steel production.
[Which can be anywhere! It doesn't matter much, where you build it, cause at that time you already have enough iron to make long belts.
Long belts is only not useful, cause it takes so long between input and output, but for steel you spare also an extra buffer (the belt is the buffer then).]

Other people want to create very clever constructions, like here
https://forums.factorio.com/forum/vie ... f=8&t=5015
https://forums.factorio.com/forum/vie ... f=8&t=6139
https://forums.factorio.com/forum/vie ... =8&t=17378
https://forums.factorio.com/forum/vie ... 18&t=18689

[vanatteveldt]

Thanks for the links, some really cool stuff there!

I have to say that the "smart" solution to make one furnace double as iron -> steel is pretty nifty, but takes almost as much space as two directly connected furnaces.

It did make me realize that I can make a setup with controlled buffer, i.e. if I build

Input belt -> [smart inserter] -> Iron furnace -> steel furnace -> smart chest -> output belt

This takes another two rows of space for the extra smart chest, but by setting a [steel < X] limit on the smart inserter I solve the problem of buffering iron ore in the furnace, and I automatically create a controllable steel buffer.

Another option I guess is to combine all the buffers, i.e. collect the output belt of multiple furnaces into a single smart chest, and use that chest to control the smart inserters of all furnaces, saving resources and making it more space efficient.

As soon as my current factory gets electric furnaces I'll do some more experimentation and screenshots

[Linosaurus]

Another option I guess is to combine all the buffers, i.e. collect the output belt of multiple furnaces into a single smart chest, and use that chest to control the smart inserters of all furnaces, saving resources and making it more space efficient.

I did a similar thing with my steel furnaces. Smart inserters on input, some red wires, and this at the output:

Steel furnaces -> belt -> splitter -> fast inserter -> smart chest -> fast inserter -> splitter that rejoins the other half from the first splitter.

Having half the flow bypass the buffer chest seems neat. If the steel production is faster than one inserter can handle, it'll still flow past. If you need a *lot* of steel for a very short period, this gives a flow of (1 fast inserter + half the production), instead of just (1 fast inserter). Until the buffer runs out.