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"Factorio": 10 Tips for Inserters

KatherineOfSky has over 2,000 hours in Factorio and has published many video guides, Let's Plays, and tutorials for the game on YouTube.

1. Placement of Stuff

Firstly, the basics! Inserters will place items on the far side of the belt, no matter if you orient it right or left. If you place it toward or away, note that the placement will be on the right side going in the direction of the belt.

Also note that inserters can grab from both sides of the belt.

factorio-10-tips-for-inserters
factorio-10-tips-for-inserters

2. Inserter and Belt Speed

Conveyor belts come in three different speeds:

  • Yellow belts (Transport Belts):15 items per second
  • Red belts (Fast Transport Belts): 30 items per second
  • Blue belts (Express Transport Belt): 45 items per second.

Thus, reds are twice as fast as yellows, and blues are three times the speed of yellow belts.

You'll want to make sure that you use inserters appropriate to the speed of the belt. In this illustration, I've put down three yellow inserters to grab from the three different speeds of the belts. On the right, the yellow inserter grabs easily from the yellow belt, but on the red and blue belts, it starts flailing around and cannot grab consistently.

Make sure to upgrade any inserters taking from belts to blue Fast Inserters. (Outputting is unaffected.)

factorio-10-tips-for-inserters
factorio-10-tips-for-inserters

3. Feeding Both Sides

If you have two materials that you want to put on opposite sides of the belt, you can position your assemblers exactly three tiles apart. Place the belt in the center tile, then place inserters outputting to the belt. Voila! You now have products on both sides of the belt!

You have many choices of where you want input material to come in: from the side or you can even thread it through the buildings with undergroundies! Make sure that inserters are not grabbing from the exit of an underground and trying to feed it backwards: instead, have it grab from a belt going toward it.

factorio-10-tips-for-inserters
This technique in use in a green science array

This technique in use in a green science array

4. The Squiggle

We know that inserters place items only on the opposite side of the belt, but what if we want one long line of assembly lines and don't want put machines on both sides? An easy trick that you can do is count up half of your machines, and do the next step between the first half and the second. Place a belt in front of the machines, as normal, and then squiggle it inward, then turn back around so that it will drop materials on the near side of the belt.

factorio-10-tips-for-inserters
In use in a battery array

In use in a battery array

5. The Long and Short of It

And other is another solution to this particular problem is to use both (red) Long Handed and regular yellow Inserters. All you need to do is put your output belt one more tile away, then place a Long Handed Inserter down, and a regular one next to it.

Then, add a tiny piece of belt so the material will drop onto the near side. In practice, you'll be able to fill both sides of the belt from any machine and therefore have full production at all times.

factorio-10-tips-for-inserters
In use in a concrete assembly line

In use in a concrete assembly line

6. Lane Balancers

The next trick is not a solution to production, but the feature it does have is that you store more output on the belts, called "belt storage". You'll need a splitter and a few squiggles to make either the Corner or Straight styles. (There are countless variations on Reddit and blueprint sites, but this design is the simplest and definitely gets the job done.)

Corner

Corner

Straight

Straight

7. A Long Reach

In this setup, I've placed several belts to show the distance that the long handed inserter reaches. With the chest, make sure that you place a Long Handed Inserter one tile away. (You can check this by seeing the white box appear around the chest, indicating that the inserter is reaching it.)

Assemblers are treated as giant chests, so you can grab from right next to the building or a tile away. They can also reach over pipes!

Look for the white box on the chest and belt to see where it interacts

Look for the white box on the chest and belt to see where it interacts

factorio-10-tips-for-inserters

8. Lotsa Train Loading!

There's one more tasty little tricky to do with Long Handed Inserters: you can have lots and lots of chests to put stuff into a train! By placing inserters two deep, and two chests behind them, you can have and 24 chests around each train car to help get the most stuff in each wagon. We use this in our building train where lots of small items are loaded into the cars.

Example setup with 24 chests

Example setup with 24 chests

Using Long Handed Inserters to add more types of items to the train

Using Long Handed Inserters to add more types of items to the train

9. Corner No No

One thing that is rarely mentioned is the detriment of inserters taking from a corner or curved belt. Because there's less space to grab from, the inserter can struggle and flails around a bit and will have issues with consistently supplying materials to the assembler. Make the belt a straight one, and the problems disappear!

Never grab from a corner

Never grab from a corner

10. Direct Insertion

A really neat trick you can use is to direct insert from one assembler to another. This can be accomplished with between one and three space between the machines using either a regular inserter or a Long Handed one. You can have belts or pipes running between the machines to deliver other materials. Assemblers count as a large chest, so inserters pick up their full stack size instantly and carry it over to the opposite building.

This technique is often used in a green circuit array where you would never want to belt Copper Wire because it takes twice the space of Copper Plate. Using direct insertion, you can easily achieve a perfect ratio setup. Another popular place to use Long Handed direct insertion is with engines to electric engines.

factorio-10-tips-for-inserters
In use at a green circuit array

In use at a green circuit array

11. Controlling with Circuits

If you want to go beyond box-limiting, you can limit chests and production by using a simple circuit connection to the inserter. In this setup, I would like to have up to 200 yellow undergrounds in the chest. I would like to have at least 50 for use for requests and building projects, so the red assembler must not take any over that amount.

Place inserters going out from the yellow machine into the chest, and one from the chest into the red machine. Connect each inserter to the chest with red (or green) wire. On the right side inserter (from the yellow assembler), create a condition of "Enable/Disable" and "Underground Belt < 200". This means that the inserter will turn on when there are less than 200 belts in the chest.

The condition for the left side inserter should be: "Enable/Disable" and "Underground Belt > 50".

The setup: one inserter on each side of the box facing left.

The setup: one inserter on each side of the box facing left.

Circuit condition for the right side inserter

Circuit condition for the right side inserter

Circuit condition for the left side inserter

Circuit condition for the left side inserter

Outro

I hope you've enjoyed this tips & tricks guide on inserters! Any other topics you'd like to see me cover? Please let me know in the comments!

© 2020 KatherineOfSky