Section Focus
Handle furnace columns, bus entrances, green-circuit demand, and split-off space first.
Quick Answer
A reliable Factorio main bus starts after iron plates, copper plates, gears, green circuits, and the first science chain can run without hand feeding. Keep the first bus narrow enough to expand: four iron lanes, four copper lanes, one or two green-circuit lanes, and empty splitter space on both sides usually beats a huge bus that blocks every future build.
Main Bus Readiness Table
| Symptom | What It Usually Means | First Fix |
|---|---|---|
| Science stops while miners still run | Smelting or belt split priority is wrong | Check the furnace column before adding more assemblers |
| Copper plates vanish before circuits | Green circuits are eating the whole line | Give circuits a dedicated copper feed or expand copper smelting first |
| Iron is full but gears are empty | Gear assemblers are too few or too far from iron | Add local gear production near belts, inserters, and science |
| Every new branch needs rebuilding | Splitters were packed too tightly | Leave space between bus lanes before adding another product |
| The bus reaches oil but feels brittle | Core materials are not stable enough | Finish the first iron, copper, steel, and circuit upgrades before widening |
Practical Bus Rule
Do not widen every lane just because one item is empty. Trace the shortage one step backward: miner output, furnace throughput, belt saturation, splitter priority, then assembler demand. Fix the earliest weak link first, then return to the relevant page below.
FAQ
Should gears go on the main bus?
Only if it simplifies your starter base. Many early factories are cleaner when gears are made locally beside belts, inserters, and science.
When should I switch from bus to blocks?
Switch when terrain, ore patches, or rail access make the bus stretch too far. If every expansion needs long belts and awkward turns, start planning blocks or rail-fed production.
Recommended Order
| Order | Page | Problem It Solves |
|---|---|---|
| 1 | Bus or Block by Map Shape | judge bus versus block expansion from the map shape and room available |
| 2 | First Furnace Column Upgrade | upgrade the furnace column that is actually choking throughput first |
| 3 | Green Circuit Lane Budget | read green-circuit appetite before it starves the whole base |
| 4 | First Copper Shortage Fix | decide whether the real copper issue is mining, smelting, or belt splits |
| 5 | Steel Too Early or Too Late? | balance steel timing so it does not choke science or arrive too late |
| 6 | Bus Splitter Spacing Rule | leave splitter space now so the next expansion does not force a rebuild |
How To Use This Hub
Map the live question to the first two or three pages in this hub, then keep following the cluster; switch to video only when motion, terrain, or timing needs confirmation.
Best Next Clicks
- Finish two or three pages inside this cluster before jumping to a different topic.
- If movement, route reading, or spacing still feels fuzzy, pair it with the matching video page.
