Things gone big - no bots factory

[thirstyhirsty14]

Relatively-new-to-Factorio me cannot for the life of me comprehend how you manage to firstly need that much production of raw materials and secondly actually fill up 8 blue belts worth xD

[quinor]

1) modules. They need ton of stuff. 2) trains. And robots in order to automate building factory modules.

[Koub]

Well, imagine you want to build some level 3 modules, let's say productivity ones. But you don't want them just for the rocket defense, but to feed your furnaces so that they pollute less.
You want ... let's say 10 of them every minute, because you have many furnaces, and you don't want to take years to achieve your goal.
You'll need 50 red circuits a minute, plus 50 blue circuits a minute, plus 50 level 2 modules a minute ... level 2 modules will need level 1 modules, + red and blue circuits, and level 1 modules will need red and green circuits.
To feed all that, you will have to produce (and convey) over 10k green circuits per minute, which nets 20k copper and 10k iron plates per minute.

A straight express belt can output around 1775 items per minute, so you need 6 express belts for the iron and 11 for the copper.

And just with that setup, you'll have needed around 1100 furnaces to keep up with the demand, so to equip them with 2 level 3 efficiency modules, it will take almost 2 hours (even if you craft 10 level 3 modules a minute, which is a tremendous lot !)

... Did I say you also wanted modules for your mining drills ? because you need around 2200 of them just to feed your 10 modules a minute