Tutorials/Flying machines

Flying machines are mechanisms that use s and/or s, redstone blocks, observers, and s to move a structure of blocks in one or more directions, moving freely through air or water without support. They can also be designed to carry along a player and/or other entities, which may be riding in a minecart or towed along by honey blocks.

The mechanics of such machines vary slightly between the Java and Bedrock Editions of Minecraft; The first section of this page covers Java Edition, the second setion covers Bedrock Edition.

Java Edition Flying Machines
There are two main components of slime block flying machines:

The engine provides the basic control and motion, based on the idea that a slime block pushed by a piston will move adjacent movable blocks, including other slime blocks, when pushed or pulled. However, each piston is limited to moving 12 blocks total.

The splitter uses additional pistons to let tow along additional segments of a larger machine. Honey blocks can also be used to bypass the piston push limit by using adjacent slime block and honey block flying machines to divide the number of blocks in a structure among pistons.

The following video shows a complex example, an infinitely expandable flying machine with a 2-way engine and multiple splitters (each carrying 2 TNT Duplicators):

Engines


Engines are mechanical parts of slime-block based flying machines used to move them.

In all cases, a major issue is control, especially how to start and stop the machine. There are several options here:
 * A semi-automatic engine needs player's intervention to move it, generally by updating a piston -- e.g., using flint and steel on it, or rapidly placing tripwire against it.
 * A fully automatic engine can be started by a single update, say by breaking a block (perhaps a sign). As switch can be used, but is likely to be left behind once the machine starts to move. Stopping them can me more difficult -- many engines will stop only when they run into an obstacle.  If the obstacle is wrongly shaped, it may break the machine, thus a prepared docking station may be needed.
 * A few "drivable" machines take advantage of the point that a note block produces an update when played, so a player riding the machine can trigger note blocks to start and/or stop the machine.
 * Engines can also differ in available directions and speed. The simplest can only move in a single direction, but two-way and even diagonal motion are possible.  Again, dedicated docking stations are sometimes needed.

A two-way engine can be made with as few as 6 blocks – 2 Observers, 2 Slime Blocks, and 2 Sticky Pistons. Two-way engines A and B (see gallery above) show two different ways to do this. In both cases, the direction of flight depends on which observer is updated first. Note that in the diagram shown, each observer directly powers a slime block.

A compact "rideable" full-auto two-way engine adds a couple of honey blocks, where you can safely transport 2 players. It can be made with 14 blocks – 8 slimeblocks, 2 honey blocks, 2 sticky pistons and 2 observers. Getting on and off is another problem....

Turbo Engine A (see gallery) is a high-speed single-direction engine. It fits into 2×2×6 dimensions and uses 14 blocks. Since zero ticking pistons is not possible on bedrock edition, this kind of flying machine will still be the same speed on bedrock edition as normal flyers, however, several 2.5 meters per second flying machines have been created for specific use on bedrock edition.

Diagonal engine
Some engines can move diagonally by moving alternately along 2 axes.

More complex engines
A 4-way engine (2 vertical directions) that switches directions upon contact with a few blocks.

A 6-way engine that requires dedicated stations.

Splitters
Splitters are mechanical parts of a fully-automatic flying machine used to push an independent part of a large flying structure. A single piston only can push or pull up to 12 blocks. Splitters split a structure into multiple independent pushable parts (hence the name).

One-way splitters
A one-way splitter has 2 parts: a normal piston in the rear, and a slime block (or more) with a power source in the front with space between them.

Once the rear part with the piston is pushed, the piston will be activated by a power source from the front part. It will push the slime block (and thus the next part of the flying contraption and its splitters), which pulls the power source with it. The piston will then deactivate and prepare for another push.

Some simple engines are just made of looped splitters, such that, at any given time one piston is always powered (in these machines it is important to place the redstone blocks last).



Two-way splitters
A two-way splitter consists of an observer powering at least one sticky piston which pushes or pulls a part of the flying contraption. This is possible only in Java Edition because it's the only version where sticky pistons (upon receiving a short redstone pulse) can push a block and then retract quickly without pulling it back.

This type of splitter will either continuously pull or push depending on whether the part it's supposed to move is initially retracted or not. If the part is initially retracted and the splitter is continuously pulled, the sticky piston will continuously pull the part. On the other hand, if the part is one block away ("not retracted") and the splitter is continuously pushed, the sticky piston will continuously push the part. This mechanism necessitates a switch within the flying machine to independently retract and extend the splitters before flight, because otherwise, the engine will most likely be unable to push due to the "stuck" retracted splitters adding extra load to the engine's pistons.

Harvesting
2-way Flying machine with long wings for Harvesting

Drivable flying machines
A flying machine can be designed to not only carry a player along, but allow them to control the machine in flight, starting, stopping, or changing directions. Often due to lag, slime engines can bug allowing the player to fall through the machine. This can be solved by placing the player in a vehicle such as a minecart or by standing on top of a honey block.

Braking method
Starting the engine of a flying machine often involves updating a piston or observer. Braking, on the other hand, isn't as straightforward to do in survival because a piston-immovable block must be present to stop the engine. A reliable braking method that was first popularized by SethBling is to attach a noteblock (or any similar redstone component movable by pistons) to the "face" of an observer that powers a piston. The piston is placed on the front of the engine, and since extended pistons cannot be pushed by other pistons, activating the noteblock at the right time will stop the engine.

Brake component extension
By using sticky pistons instead of pistons for the braking components, they also become 2-way splitters. These can be used to carry extra blocks, such as holders for minecarts/minecart chests, passenger roofs, TNT duplicators, etc.A modified version of the previous machine, with minecart chests and a roof attached to the 2 two-way spliiters. ''A compact 4-way drivable flying machine that carries minecarts and minecart chests on its splitters. Flies North-South or East-West, depending on the placement of the two splitter pistons and two engine observers.''

Bedrock engine designs
Flying machines are much more restricted $$ due to the lack of quasi-connectivity and other piston behaviors. $$, a sticky piston powered with a 1 tick pulse will drop the block it is carrying. The absence of these behaviors makes it difficult to create complex flying machines.

Simple engine 1
These are basic flying machine designs. The shown examples will move to the viewer's left.

Removing the block of redstone, or placing obsidian in front of the observer, will cause the machine to stop. This may be hard to do, unless in creative mode. For players who want to ride their flying machine, it may be hard to add and remove the obsidian or redstone block (especially in survival mode). A slightly easier way is to add layers of another material (such as wood plank) to the machine, stopping just before the limit of what a piston can move and doubling as a practical gondola for the player at the same time. From a position sitting on the machine somewhere, the player may add another wood plank block to the machine, killing the speed. Removing the final block causes the machine to start again.

Simple engine 2The simple engine 2 provides a narrower but longer design, which requires less redstone than others (less redstone blocks). In this example, the machine would begin moving to the left once the observer on the right is activated. This can be done with a redstone pulse, or just lighting the face with flint and steel.

To reverse the direction of this machine, simply move one of the slime blocks to the back, and switch the piston and sticky piston.

This design is ideal when redstone is scarce, or when up to 9 blocks need to be placed on the front end (the front half only consists of 3 blocks, with a total of 12 blocks able to be pushed by the piston).

Trailer

By placing an observer and a sticky piston onto the side, one can build off of the Simple engine 2 design to make the machine bigger as a whole. Keep in mind that multiple trailer attachments can be placed on the side, up, and/or down simultaneously without exceeding the push/pull limit of 12 blocks. This is one way of creating a splitter in Bedrock Edition.

This addition can be used to hold more cargo, whether it be entities, chests (which are only movable in bedrock edition), or TNT (which can be detonated by a following machine equipped with a redstone block).

Multi-directional engine
This design is multi-directional but it does require a return station to change the direction. The observers are 1 block higher than everything else and have slime blocks below them. The return station is only an example, anything that pushes the machine over so that the other sticky piston is unable to pull the terracotta should work. It may help to watch the videos below to see some more examples.

Splitters
In Bedrock Edition, it is possible to create splitters, however they are only functional in one direction. This first is the trailing splitter (Trailer, shown above), and the leading splitter. The leading splitter can be made by attaching a backwards-facing observer directly behind a forward-facing normal piston, both attached to slime blocks.

Video
Bedrock Edition: