Optimal ratio of iron to steel smelters?

[Jonny Sparta]

Im not really sure where to look for these numbers but it seems like...

iron smelting - uses 1 iron ore to produce 1 iron plate
steel smelting - uses 5 iron plate to produce 1 steel plate

Sooo if I want balanced steel smelting I basically need a 5:1 ratio of iron smelting to support it? Have I got this right?

Here's a shot of my current setup (Im definitely a factorio beginner)
Figured I'd just try to brute force more steel production as I just got purple science producing for the first time.. now it seems I've got to start thinking more about how I design my production.

https://steamcommunity.com/sharedfiles/filedetails/?id=2375614212

Forgot to turn the icons on for the screenshot, in case someone's wondering :
from the left it's
4 lines of smelters for steel
4 lines of iron that feed the steel
6 lines of smelters for iron plate to bus
4 lines of copper to bus
and a bit of stone at the end

Having a blast tho :)

[AlexMBrennan]

Sooo if I want balanced steel smelting I basically need a 5:1 ratio of iron smelting to support it? Have I got this right?

If you want to make 100 steel per minute then you will need 500 iron per minute.

However, since the steel recipe takes 5x as long as the iron recipe you need exactly one iron smelter per steel smelter (until you add productivity modules, in which case you will need 5x iron smelters per 6x steel smelters which is obviously a huge pain)

[knighttemplar1960]

https://wiki.factorio.com/Stone_furnace
it takes 5 times as long for steel to smelt as it takes for iron plates to smelt so its a one to one ratio.

[Jonny Sparta]

Ah I didn't think about the time!

Much appreciated. The more I stare at my smelter setup the more Im starting to think there's a lot to think about here.

[knighttemplar1960]

With your smelting set up the way it is your iron smelters are going to be starving. The only reason they don't look to be starving is because they are backed up.

A yellow belt moves 15 items per second so one side only moves 7.5 iron ore per second. At a smelting speed of .3125 per second this set up is only good enough to supply 24 smelters in the row (12 once you upgrade to steel furnaces). The set up as you have it is fine you just need to set it up so that the split belts are on the outside of the array and the smelters feed the plates into a single belt on the inside. That will double your throughput for this set up so long as your input is a full belt of iron ore.

When you upgrade to red belts you'll have to switch to fast inserters or the furnaces near the end will fail to make their grabs due to the speed at which the ore is moving.

[Jonny Sparta]

Originally posted by knighttemplar1960:

With your smelting set up the way it is your iron smelters are going to be starving.

Yea.. I've been wondering about that as well.. felt like such a hotshot getting the ore/coal feed on a split belt. Im definitely seeing them starving under load.

Debating whether I want to setup them up with 2x input belts and long inserters.. I guess that just depends on how long i want to the smelter lines to be.

Edit: or wait i can't do 2x inserters per smelter anyway can I

[knighttemplar1960]

This will keep them from starving.
https://steamcommunity.com/sharedfiles/filedetails/?id=2375679349
and certainly you can use up to 4 inserters total on parallel belts for stone furnace input and output.
https://steamcommunity.com/sharedfiles/filedetails/?id=2375679267