Tutorials/Mechanisms

Mechanisms are complex systems of blocks used to perform certain tasks, such as opening a door from afar or revealing a hidden staircase. These systems are built from simple components and normally involve some kind of user input, such as breaking a torch, which generates some kind of result, like a door being revealed. Mechanisms can range from simple switches that open and close doors from a safe distance, to complex devices such as combination locks that prevent intruders from entering your fort.

Components
These are the basic, modular parts that can be combined to form any complex mechanism. Please note that individual items in the game are not considered components. Also, not all of these components have to be used when making a mechanism.

Physical components

 * Water Channel: A channel in which water can flow. Water is commonly used to break torches, causing things to fall, or washing away crops, as well as to transport items or mobs.


 * Tube: A long three by three structure that can be used for launching TNT.


 * Piston Switch: Block 1 above ground level with redstone on top, with a piston that moves across to stop circuit. Used so pressing a button or lever will stop another circuit.


 * Pipe: A pipe of hoppers or clock-fed droppers used to transport items.

Redstone components
See redstone circuits for an overview of simple components and advanced redstone circuits for more complicated redstone mechanisms.

Mechanisms
Mechanisms are useful devices made from the combination of components. Here are some examples:

Basic mining explosive device
Make a railway of powered rails being powered with redstone, ending in an activator rail. To activate, send TNT minecarts along the rails. This can be used to dig a large mine.

Advanced MED
Build a circuit that involves a piston being shut off by a button, then build an obsidian tube with a hole in the middle to store carts. Be sure not to make the tube too tall, or else the minecarts will blow at the bottom. Then make a single rail at the top of the tube, surrounded by walls, so you can push the cart in. When it's at the bottom, get down to the button and watch it ride the rails. This also works as a minecart storage unit.

Minecart storage system
This is a storage system that allows a user to call a minecart and return them.

Efficient mob farm
This mob farm, using tripwire and pistons, yields 5364 drops per hour and enough gunpowder to make over a stack of TNT in 20 minutes.

Visitor counter
A piston, redstone and pressure plate door that counts which way someone went through a door.

Pitfall trap
This device uses pistons to push entities into a pit.

Lighthouse
This lighthouse uses a sequence of redstone lamps to mimic the lighting of a working lighthouse. See the video below.

Potion dispenser
For this device, you can stand on a pressure plate and make splash potions shoot out of a dispenser. See the following steps for how to make it:


 * 1) First, make a dispenser dispense splash potions. Then, place a dispenser one block over the floor level.
 * 2) Place a fence on the side the dispenser will shoot the potion out from. Finally, put pressure plates on top of the fence.

See the following video for a better demonstration:

Vending machine
This is a customizable vending machine that is relatively easy to make. Unfortunately, it does require a lot of iron.

Notes:
 * 1) The leftmost top hopper in the side view is the "input/output" hopper. Put items into this hopper and get items out.
 * 2) The droppers hold the "purchase" items.
 * 3) The chest at the bottom collects the "payment" items.
 * 4) Fill the leftmost bottom hopper with 19-  items in the first slot, and 1 in each remaining slot. These items will be payment items.
 * 5) Repeat the upper-right 2 tall by 4 wide section upwards to add more items to the number purchased. (The number of droppers is this number.)
 * 6) Delay the signal from the redstone torch to the hopper by 4*(price)-5 ticks (if the price is 1, simply don't delay it). The repeater here is showing 1 tick as an example.

Hidden floor staircase
By breaking a torch, you will reveal a hidden staircase.


 * 1) Make an inverted sand or gravel staircase in the floor of a room (one block wide), supported by torches.
 * 2) Make a water channel or water channels adjacent to the torches so that when they are filled, the torches break and the stairs will fall. (IMPORTANT: make sure that that the sand or gravel will cover the water hole after it falls to avoid flooding)
 * 3) Make a sand switch that opens a reservoir allowing water to flow down a short channel to a pit. The pit allows the water to drop beneath the floor and run to the torches holding the staircase.

Look at the following video:

Hidden wall staircase
This design features a hidden staircase in the wall, revealed by triggering a redstone signal in some way, such as pulling a lever or pressing a button. There are many ways of making this. look at the following 2 videos for some examples:

Redstone Lamp floor
A redstone wired sequence of redstone lamps to mimic the lighting of a working floor. Video below.

Rapid pit bomber
To make this design, make a dispenser attached to a redstone clock mechanism and hopper to feed it items. In front of the dispenser, place a powered rail on a block of redstone and fill a chest above the hopper with minecart with TNT. This will rapidly dispense those TNT minecarts onto a powered rail and into a massive crater of their own. It can even tunnel down to bedrock given enough carts.

Programmable Item store / Cash Register system
This is a system that will let you program what items you want to sell, how many you will give, what you want to be paid and how many of those to be paid. It will lock when it's empty. This is a very compact system that is also tile-able.

Combination Lock
A door that is opened by using levers to input a certain combination. The levers are wired to an “AND” gate, with hidden redstone circuitry to open the iron door.

Keyed Lock
An iron door that will only open when the player has the key. A good key is a renamed item.

Cobblestone Farm
A farm that uses a clock circuit, water, lava and pistons to farm cobblestone.

Item Activated Door
A door that only opens when an item is dropped into a pit.
 * 1) Make three-deep a pit near an iron door. Build a level channel away from the base of the pit.
 * 2) Place a wood pressure plate in the channel no more than 8 blocks from the base of the pit. Wire the plate to the door (not through the channel). You will have to run the wire back up to the surface, or very nearly so, but it can be concealed under well-placed walls.
 * 3) Cover the channel. Any item thrown in the pit should fall down to the plate and cause the wire to activate, thus opening the door.

Flashing Indicator Light
A blinking redstone torch is activated when a pressure plate is stepped on. Can be used to tell if mobs are sneaking through your caves. See the following example:
 * 1) Make a pressure plate wired to the input of a redstone torch. Wire the output of the first torch to the input of a new redstone torch. Run the output of the new torch to its own input, creating a blinking loop.
 * 2) Wire the output of the new torch to the input of any other redstone torch to carry the blinking effect.



The loop in the image will flicker on and off when the plate is stepped on.

Warning: This burns out quickly if a single torch is used. You can also use a redstone repeater to slow down the process on the loop back to the torch so it does not burn out

Multiple torches hooked up:



Sound could be added to make an alarm by wiring note blocks to the flashing torches.

Block Destruction as a Trigger
It is possible for a redstone output to be generated as a result of a block being destroyed. To achieve this, place a redstone torch on the side of a block facing away from you. Next, set up an inverter between the block and your mechanism. When the block is destroyed, the torch will fall, the lack of input will be inverted, and the mechanism will activate.

Redstone Tower
The bottom torch powers the block above it, powering it and all redstone torches attached to the block. Each level (block with torch on top) acts as its own repeater. This also can go upward until the sky build limit while still producing power. If you want to dispose of this quickly or are making experiments just use gravel or sand for the block type.

GlassSwitch
The glass allows the redstone current to pass through while the other moveable blocks do not. This can be used to operate doors, bridges, etc. The best part is you can use multiple buttons and make doors that open from both sides using the same circuit. The tutorial can be viewed here:. There are also images with pistons.

2 Wire Control
With a lot of repeaters and AND-gates it is possible to control multiple outputs with only 2 wires. It can be very tricky to get the timing right. You need a pulse generator in both wires to get a pulse with a defined length and in most cases, the output pulse needs to be made longer. As shown in this video you have a top wire and a bottom wire with repeater. On one side you have repeater between the buttons on the top wire and none (or as needed) in the bottom wire. On the other side none (or as needed) on the top wire and matching repeater (to the other top side) on the bottom one. between which you place AND-gates (matching the buttons). The idea is that the signals only meet at one AND gate at the same time. Video tutorial: Example use:

Fast clock
When working redstone, when activating the wire, it only does its job once. Sometimes this is good, like with doors, but sometimes this isn't good, like with note blocks. A simple way to repeat the current is the "clock" as follows: Dig four 1 block holes in the shape of a cross without the center. Place redstone torches in the holes. Place blocks on top of the red stone torches. This is not part of the process, but is need when actually powering something. Place one block of redstone in the center of the cross. This will cause the redstone to restart rapidly, which can be useful when working with note blocks.

Two-Switch Door
Opening and closing a door with two levers is normally impossible; with one lever on, the door is always open. With the use of a redstone XOR gate though, that isn't the case. A door can now be opened on one side, then closed from the other (think of a light with two light switches).

Piston Doors
1x2 flush with the wall piston door. Fitting in a 2x4x4 space.

1x2 Hidden Piston Door

Piston doors can be as easy as 4 sticky pistons attached to blocks that move inwards revealing a 2x2 passageway, or as complicated as the one seen in the original piston revealer that Mojang released. (as seen here )

These "Jeb doors" can also be referred to as flush-inset piston doors. Here is an example of one of these, with a redstone torch key system added on. Once broken down, it's not extremely difficult to build.

For an easy piston door with no sticky pistons:

For a piston door with no pistons visible:

For a 3x3 spiral door see: Automatic Opening Door Tutorial

5x4
This design allows one to get a great view on the surroundings and enables you to connect and stop on any floor you want. The video also contains horizontal piston transport.

4x4
or

This design is even more compact than the previous one; however, it blocks sight. It's great for building elevators in shafts. Note: you need to set the pistons to 3 instead of 2. The first is still to be set on 4.

Piston Two-Way Elevators
Two-way elevators can be built, but they are slower and much more complex than the previous ones. They also require a lot more space and resources.

The two-way elevator can be built the following way:

The engine shown below of this text uses wool between the pistons and the fence gates/trapdoors. However, instead of wool any other block can be put there, as long as pistons can push it.

The schematics for the wiring assuming that you know how to make a 1 tick long impulse. A 1 tick long impulse can be obtained using a pulse limiter. In both of the schematics, empty squares represent air blocks, and repeaters all have the minimum delay possible.

A screenshot of an implementation of this design:

Also, see this video for a larger two-way elevator:

Launcher Pads
A launchpad is similar in design to a TNT cannon, but instead of launching horizontally, it launches vertically either straight up or at an angle, depending on the design. There are many ways to create them, but some methods are more efficient than others. For instance, a simple design would be the cross pattern, as shown below.

This is what it would look like from above:

To load it, place TNT on the flowing water blocks.

The above design can easily be expanded in size and improved, but it is one of the easiest designs to build. Another simple design, yet much more powerful, is here:

Another powerful design, using dispensers to place the TNT is built as following:

The dark blocks on the last two on the right represent dispensers, facing the center. If you want this to be reusable, place a water source between them. A pressure plate delay is enough for each dispenser to shoot twice. An interactive version is here:

Redstone Battery
A redstone battery is a device to constantly output redstone power without requiring a power source.

It's a contraption that, when activated, cannot be deactivated unless broken.

The simplest one is as following:

If you want to make a battery with a delay on portions of it, use a clock, but don't deactivate the signal.

This will still work as a battery, but half of it will have a small delay upon starting.

Building Protection Sensors
The following are circuits designed to prevent changes to the structures without the use of Operator right.

Wall Protection
There are multiple ways of protecting a wall. Firstly being the easiest which is to protect the bottom of a two-high wall, because players going through it would break both the top and the bottom blocks, which trips the circuit, giving you a redstone output.



Below is a 2D cut of a piece of the wall. The principle of it is that when the lower block is broken the circuit is then connected.

Door Protection
Iron doors are good and strong; however, their ability to be broken is their major problem. One of the best ways of avoiding this is as follows.

To avoid the problem with a torch being placed to open the door easily, place an iron door in a position so that its ON state blocks the entrance, then by powering it from beneath, you can stop it from being opened.

To then avoid someone breaking the door, place a block of water above it, then another torch a block away behind the door. When the door is broken, the water falls down and breaks the torch, giving you a negative signal which can be used.

Also, instead of water, try lava.

However, due to the slowness of lava (and water), it may be beneficial to make a sand or gravel block drop, dislodging a piece of wiring or a torch, or having another iron door behind the trapped door that will slow them further. The possibilities are endless.

Liquid redirection technology
Redstone circuits can be used to redirect the flow of lava or water in the following manner:

These systems can be useful in many complicated mechanisms, or simply for aesthetic value.

Compact block swapper
This is a quick video tutorial on how to make a compact block swapper.

Vertical switch
A vertical switch can be made using pistons and sand blocks. The uses are limited by the tower of sand placed in front of the piston. When the piston is activated, the sand gets pushed into a hole. At the bottom of the hole, place a powered repeater with the output facing where the sand will drop. By adding a second repeater two blocks in line from the first one, you will have a broken circuit that is activated by the sand block when it lands.

Additional pistons can be used to push the sand away at the bottom to reset the mechanism. By adding a torch where the sand falls when the mechanism is reset, you do not need to remove the blocks manually. There is still no way to generate Sand dynamically, so you are dependent on the tower of sand at the top. This tower can be as high as you want, up to the build ceiling. The number of sand blocks available could be increased by having a second sand tower supplied by another piston when the first tower is empty.

Redstoning with Command Blocks and Scoreboards
Here is a tutorial on how to use scoreboards and testfor commands to run redstone devices.

Pressure Plate Trap

 * 1) Make a 20 x 20 x 4 hole.
 * 2) Put a layer of water on the bottom.
 * 3) Put TNT on top of the water, except for one pathway which you can get across. You can make the pathway with any block unaffected by gravity.
 * 4) Put pressure plates on top of them.

Bank System
This is a simple bank system using powered rails, which should be helpful for Minecrafters less experienced with redstone.

Guaranteed Death Landmine
This form of landmine causes mobs to fall through a wide sand pit being supported by TNT. the mobs will then fall into the pit and will be killed by the TNT. NOTE: This is NOT guaranteed to kill spiders, as they can climb out of the pit. Simultaneously detonated TNT can kill a full-health player in diamond armor.

First, dig a 3x3x3 hole in the ground. Put a layer of torches on the bottom, then a layer of TNT, then a layer of either sand or gravel. Now, put pressure plates on top of the pit. To confuse players, put pressure plates around a large area. It should look like this:

NOTE: This is better to use on a beach or in a desert, because it is full of sand.

High speed item transportation & making items travel upwards
Since pistons came out, upwards item transportation became possible, and combining this with ice makes a high-speed item transportation machine. Ice under water streams makes the items go a lot faster, so if you are living in a tundra biome, you get a big speed boost. If you aren't living in a tundra biome, it is still possible for you to make the machine (using Silk Touch or without the ice).

Detecting Redstone Placement
The new silent BUD switch design updates not only when there is an update going on adjacent to it, but also updates when there is redstone wire placed 1 block away from the BUD switch.

Boat RS-NOR Latch
It is possible to make a boat-based RS-NOR latch and save up 4 redstone. Instead of the 6 redstone the old design uses, this design uses 2 pistons, therefore 2 redstone. It has a few disadvantages as well as advantages.

1 Wide ABBA switch
Basically, as compact as it gets, this design is a very compact design of a 1 wide ABBA switch.

One-Way Redstone Pulse
Since a piston takes 1 tick to extend, you can make a tiny monostable circuit that is activated by a pressure plate. Then, you build a sticky piston with a block attached one block away from the monostable circuit, in which the sticky piston is connected to another pressure plate, one block away from the other. Then you connect the blocks on the bottom layers with repeaters. The output is the block that is pushed by the sticky piston. In the diagram, it looks like this (the inputs are below pressure plates):

Christmas Lights
To do this, you will need:


 * x amount of redstone repeaters
 * x amount of redstone
 * 1 block of redstone
 * 1 redstone torch

A diagram is shown to do this.

8= Redstone repeater o= Redstone dust B= Block of redstone x= Redstone torch o o 8  o 8  o  8  o  o  o                     o  8                     8 o                    o  8                     8 o                    o  8                     8 o                    o  o o 8 o 8 o 8 o 8 o 8 o x B

Note that you can use any amount of redstone repeaters and dust, and you can place the block and the torch anywhere, but for this to work, you need to break the torch quickly, since when the current went back to the first repeater, it will stop transmitting power. Also, all repeaters should be on the highest delay.

Self-destructing mechanisms
Self-destruct mechanisms are useful when destroying critical buildings or creating secret areas.


 * Lay TNT under critical areas of your base, about two blocks deep. This will prevent torches and other redstone contraptions from detonating your system early. Then, lay TNT to the surface in a 1x1 area and add a lever or button above it to complete the basic self-destruct system.
 * In creative mode, one could use dispensers filled with enderman spawn eggs wired to a 5-clock redstone circuit to release endermen into your house, slowly assuring a semi-complete destruction of your base provided that it is made from blocks that enderman can manipulate.
 * Remote dispensers could be wired to release fire charges upon your wood structures.
 * Pistons could be placed to release the floor below sand walls to quickly remove the walls of a structure. This can also be done by supporting the sand with scaffolding and breaking the main support scaffolds with pistons.
 * A dispenser with a lava bucket could be used to flood your base with lava.
 * Connect a mob farm to your base, and open it up. The mobs will cover your house. Creepers will detonate whenever anyone unwanted comes by, and the other mobs will fight and probably kill any intruders.
 * Use command blocks to really wreak havoc upon any sensitive areas. Use commands such as /fill, /summon PrimedTnt, or if you're really thorough, use /summon ~ ~ ~ wither. WARNING: These methods can and will destroy your base and anything near it.

Flashing redstone lamps
Flashing redstone lamps is an easy to follow redstone mechanism that can be created by new players to experienced redstone masters. This guide will make it even easier for the player.

Like the majority of redstone mechanisms, it is recommended to build this one in Creative to avoid errors and to save time. The only materials needed to achieve this are
 * Step 1: The Materials
 * Redstone torch
 * Redstone
 * Powered rail
 * Detector rail
 * Rail
 * Redstone lamp
 * Minecart
 * Any type of blocks excluding those that may interfere with the redstone. You may use one for decoration, and the other for placing redstone.

Build the road to your desired size and shape. Place detector rails parallel to the location you want the redstone lamps to be. Keep in mind to maintain the minecarts to have a constant speed by using powered rails, but be sure you are placing the redstone torches to a place where it does not interfere with the redstone.
 * Step 2: The road

Connect the detector rails to redstone, and connect that to redstone torches which you will put on top of a block that you may place inside or outside of the tracks. Be sure they do not interfere with each other, or the redstone torches that are connected to your powered rails, as they may not achieve your desired effect. After this step has been done, place another block with a redstone torch on top. Place a final block with redstone placed in it.
 * Step 3: A Redstone

After this, you will place your desired redstone lamps in their place, if you are connecting only one per redstone, place it next to it, either horizontally or diagonally to it. If you are connecting more than one, connect redstone to this pattern, R B R B, R representing the redstone lamp which is directly attached to redstone and B representing the redstone lamps that are blocked by a block to make sure they all light up. Make sure the area where you will place the redstone is 2 blocks long. If you are adding a second row, do a “zig-zag" pattern. After this has been completed, place the minecart and test. If it does not light up, be sure to make any corrections to make it work.
 * Step 4: Magic

Alternate way
You can achieve the same effect, with the use of redstone repeaters. This method is often called a “redstone clock".


 * You will need
 * Redstone dust
 * Redstone repeaters
 * Redstone lamp (Or another output device)
 * Switch of any sort

Arrange the repeaters and wire into a loop, set a delay of your choice. (note the lamps need 2 ticks before they turn off, and have no delay turning on)
 * Step 1

Hook up the output device.
 * Step 2

Activate and quickly deactivate or destroy the switch to create an on-and-off continuous cycle of redstone power.
 * Step 3

Variants
As with many other redstone mechanisms, flashing redstone lamps mechanism is open-sourced. In this section, you will learn how to customize it for your preferences.

Duration of delays between each flash
The simplest way to change how fast the flash between flash changes is to change the track distance. The longer the track has to go, the longer the delay. In contrast, the shorter the track, the shorter the delay will be.

Compact design
If you'd like to make your creation in a fun-sized package, you will have to place all the redstone torches for powering the powered rails below it. Then, be sure to have the detector rails power the redstone torches to the middle in a way that it does not interfere with the rest.

One flash
In this variant, all of the lights will flash at the same time. To achieve this, you must connect all the detector rails to one redstone torch that is on top of a block, in the middle, via redstone. Repeat the previous method of placing a block on top, and placing another redstone torch. Place the final block on top that will contain the redstone, and connect it to the lamps. For the effect to be noticeable, you may need to expand your tracks.

Gallery
Earliest known uploaded to media.