Inserters
For the common yellow electrical inserter, see Inserter.
Inserters are devices which are used to move items over short distances. When placed, they have a fixed direction. They can move items from behind and place them in front of them. By doing this, they can move items from one transport belt to another, but also extract items from, and insert items into machines or storage devices. There are seven types of inserters, all requiring electricity to run (except the Burner Inserter, which burns fuel).
Types of inserters
- Burner inserter - The only fuel-powered inserter.
- Inserter - The standard yellow electrical inserter.
- Fast inserter - The much faster blue inserter.
- Long handed inserter - Capable of inserting and removing from a greater range.
- Filter inserter - Purple inserter used for filtering.
- Stack inserter - New inserter available with V0.13, allows much greater throughput.
- Stack filter inserter - A filtered version of the Stack inserter.
Mechanics
Inserters will:
- Pick up Items off the ground, off of a Transport belt, or from any object that has storage space, including chests, furnaces and assembling machines.
- Place the item onto the ground, onto a transport belt, or into any object that has storage space.
- Inserters can place items on all types of conveyor belts.
- Try to pick up items from all types of belts (as of v0.12 there is no limitation anymore).
- Inserters will run at slower speeds when starved for energy.
Inserters will not:
- Pick up any items that can not be inserted into the connected entity.
- Pick up items into an entity with a full inventory.
- Place more than one item at a time onto the same ground tile.
- Place items into a stack limited inventory, beyond the stack limit (red slots).
Inserters act differently depending on what they are moving items to/into so as not to monopolize all of the items being picked up. This allows other machines and inserters on the same transport belt to pick up a share of the items. If two inserters are picking up from the same tile, the first placed inserter has priority.
Insertion limits
Inserters will stop inserting items into certain buildings if they already have enough of that item. For example, if a boiler has 5 or more items of fuel in it, an inserter will not insert additional fuel. When the fuel drops below 5 items, the inserter will continue to insert more fuel, up to the limit of 5 items.
This is to allow for all machines to receive their share of items. The common limits on insertion are shown in the table below.
| Entity | Item type | Inserter limit | Comment |
|---|---|---|---|
| Boilers, Burner inserters, Furnaces | Fuel | 5 | |
| Gun turrets | Bullet Magazines | 10 | Since v0.8.4. Allows for 100 shots before depleting. |
| Assembling machines | Items needed for the recipe | Double the number of items needed in the recipe | |
| Furnaces | Items needed for the recipe | Double the number of items needed in the recipe | |
| Labs | Science packs | Double the number of items needed for one research point |
An inserter that takes items from an object containing stacks of items (such as a chest) can overfill the target building due to the Inserter item stack size bonus research. Overfilling can also happen if multiple inserters are used to insert items into one building.
Inserters and transport belt interaction
Transport belts have two lanes on which items can travel. Inserters only place items onto one side of the belt. Which side they place it on depends on the orientation of the inserter and the belt, as described below.
- Inserters will always place the item on the furthest lane.
- Inserters prefer taking items from the nearest lane. If the nearest lane is empty, the inserter will take from the far lane.
- If a belt is in the same orientation as the inserter, the item will be placed on the right-hand lane, from the belt's perspective.
- If the item is placed on a corner piece, it will be put on the inside of the curve, regardless of orientation.
Potential issues
Inserters may have problems picking up items:
- From very fast belts, because the items are moving too quickly. (basic inserters cannot pick up from express transport belt for example)
- From the entry or exit of an underground belt (because the time they have to pick up is shorter)
Inserter Item Stack Size Bonus
If an inserter moves items from inventory to inventory (for example from an assembler into a chest), or (as of v0.13) from an inventory to a belt, it is able to transport more items at once. The secret behind this is the Inserter item stack size bonus research.
Power usage
- Electric inserters drain energy even when they are not moving, as idle power
- The amount of energy used is the same for every movement
- The Burner inserter does not drain energy when idle, but uses more energy when it is active. It is quite useful for situations where the inserter does not need to move very often.
Inserter speed
MAINTAINER NOTE: The below info (up to Rotation speed) has not been updated to reflect v0.13. Values will likely not be correct, and must be re-tested.
| Type | Rotation-speed (turns per Tick) Extension-speed (Tiles per Tick) |
Turns per Game-second Tiles per Game-second |
Game-second per full turn Game-seconds per Tile |
|---|---|---|---|
 |
0.01 0.02 |
0.6 1.2 |
1.667 0.833 |
| |
0.014 0.03 |
0.84 1.8 |
1.191 0.56 |
| |
0.02 0.04 |
1.2 2.4 |
0.833 0.416 |
| |
0.04 0.07 |
2.4 4.2 |
0.417 0.238 |
 |
0.04 0.07 |
2.4 4.2 |
0.417 0.238 |
Rotation speed
Convention: 2π rad = 100% of a circle rotation = 1 turn (or one full rotation).
Note: an Inserter doesn't always need to make full turns. When grabbing from a transport belt, it is slightly faster when grabbing items from the closest lane.
Extension speed
The extension-speed is normally not visible (only when compared to other inserters), but there are measurable speed differences when taking - for example - from the near or the far side of a belt.
This effect is also important for Train stations, when unloading items from wagons, because the inserter needs to stretch out to the center of a wagon, which is some tiles long and leads to visible slower speed.
The extension speed is especially important for train unloading.
Inserter throughput
MAINTAINER NOTE: The below info (up to See also) has not been updated to reflect v0.13. Values may not be correct, and should be re-tested.
For an inserter removing items from a chest and placing them on a straight, empty belt (experimentally measured to ±0.004, valid at least thru 0.12.33):
| Type | Items per Game-second Inserter facing East/West/South |
Items per Game-second Inserter facing North |
|---|---|---|
| |
0.588 | 0.579 |
| |
0.831 | 0.820 |
| |
1.153 | 1.129 |
| |
2.306 | 2.220 |
|
2.306 | 2.220 |
Actual rates may vary for different types of transfers (see also the note about inserter paths in the inserter speed section above).
See also
- Electric network
- Transport network
- Inserter Power Efficiency: Movements per energy and exact power usage numbers. See also this thread, where energy per movement is explained.
- Small Inserter Test: Comparison if energy usage per item.
- Inserter heartbeats: In some situations it is not possible to calculate the needed power usage.
Special behavior
- Inserters/Interaction with other Entities
- Inserter item stack size bonus: Inserter moves more than an item per turn.
- Pick up only if everything else is full
- Inserter experiments
- Use inserters instead of belts