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, like 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.

This page is a work in progress, so feel free to add your own components and mechanisms as you build and the game develops. Pictures are encouraged, but not required.

Components
These are the basic, modular parts which can be combined to form any complex mechanism. Please note that individual items in the game are not considered components.

Physical Components

 * Sand Switch (Also known as Airlocks)
 * Sand placed above a torch will not fall until the torch is broken. This can be used to control water flow above the user or cause torches connected to the falling sand to break.


 * Pit
 * Pit into which sand or water may fall.


 * Reservoir
 * Natural or user-made lake which stores water to be used in a mechanism.


 * Water Channel
 * A channel in which water can flow. Often used to break torches, causing things to fall


 * Tube
 * A long three by three structure that can be used for launching TNT or shockwaves

Electrical Components
See Crafting and Redstone circuits for these components and Advanced Electronic Mechanisms for more complicated electronic mechanisms.

Mechanisms
Useful devices made from the combination of components.

Standard Mechanisms
To make a simple automatic door, place a pressure plate on the floor on the inside of the door, remembering that doors swing inward. Now, whenever you approach the door from the outside, you can open the door and it will automatically close behind you when you pass through it. When approaching the door from the inside, it will open the door in front of you and will automatically close it behind you. This is great for making one-way doors that mobs can enter but not exit, or exit but not enter, depending on the set up. This will only work on right-handed doors; left handed doors have a glitch where they will invert the input and stay perpetually open with this method.
 * Airlock
 * Automatic Doors

Hidden Mechanisms

 * Traps


 * Hidden Door
 * Simple hidden opening revealed by breaking a torch.
 * Make a sand switch which opens a reservoir allowing water to flow down a short channel to a pit. The pit allows the water to drop below floor level and break torches supporting a sand wall above a pit. When the sand wall falls, an opening is revealed.




 * Picture Door
 * Larger pictures can be placed in front of doors and physically hides their presence. The pictures can be broken by hitting them or throwing snowballs, etc.


 * Hidden Floor Staircase
 * Hidden staircase in the floor revealed by breaking a torch.
 * Make an inverted sand or gravel staircase in the floor of a room(one block wide), supported by torches. 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) Make a sand switch which 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.


 * Hidden Ceiling Staircase
 * Hidden staircase in the ceiling of a room
 * Make a gravel or sand staircase in the ceiling of a room supported by torches connected to blocks of sand supported by more torches. Make a channel run next to the lower torches and back to a reservoir. Make a sand switch that can open the reservoir. When the torch in the sand switch is broken, water should flow down the channel breaking the first set of torches causing the sand to fall. The sand would both close off the channel to negate flooding and break the torches attached to it, causing the staircase to fall.
 * Example of one 'step' and the reservoir system

%%%%%%%%%%%%%%%%%%%% %%+%%%%%%%%%% %%             %%+%%%%%%%%%%+ ~ %%  %%+%%%%%%%%O + ~ %% %%^+%%%%%%%%%+%%%%%% %% ^O%%%%%%%%+%%%%%% %% %%%%%%%%%%+%%%%%% %           %+%%%%%%                   %           %+%%%%%%                   %            ^%%%%%%                    %           % %%%%%%                   %%%%%%%%%%%%%%%%%%%%


 * % = Stone
 * + = Sand
 * ~ = Water
 * ^ = Torch
 * O = Channel running 'into the page'


 * Assuming the two channels in this picture are connected, when the torch near the floor level is broken water from the resivour will flow to the other torchs and drop the 'step' down to the floor. other sequential steps can be added to make a staircase.


 * Hidden Sand Stairs
 * Look at it properly to understand.
 * hidden sand stairs.jpg

Electronic Mechanisms

 * Combination Lock
 * A door which 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 metal door. Once inside, a lever is placed next to the metal door to close it behind you. A step-by-step tutorial on how to build one can be found here.


 * Item Activated Door
 * A door that only opens when an item is dropped into a pit of water.
 * Make three-deep a pit near an iron door. Build a level channel away from the base of the pit. 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. Cover the channel and place a block of water at the top of the pit, allowing water to flow down the channel. Any item thrown in the pit should flow down to the plate and cause the wire to activate, thus opening the door.


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




 * The loop on the right will flicker on and off when the plate is stepped on.

Warning: This burns out quickly if a single torch is used, so take this fact in mind.


 * 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 an electronic 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. This can be used to make traps, as shown in this video.

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 like its own repeater. This also can go upward until the map ends 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.
 * Redstone Tower

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.
 * GlassSwitch


 * 2 Wire Control
 * With a lot repeater 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 generators 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. At the other side none (or as needed) on the top wire and matching repeater (to the others 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.
 * Videotutorial: watch
 * Example use:

Piston Doors
Piston doors can be as easy as 2 sticky pistons attached to blocks that move inwards revealing a 2x1 passage way, or as complicated as the one seen in the original piston revealer that mojang released. (as seen here http://www.youtube.com/watch?v=uZJr86d2IUo&feature=feedu )



More complicated Redstone circuit mechanisms are on Tutorial/Advanced Electronic Mechanisms.

Piston One-Way Elevators
Although making an elevator with pistons in 1.7 is extremely difficult, this can be overcome by creating a spiral staircase of pistons that propels the user upwards very fast. These elevators also work as a dumb waiter, any block or item that is placed or dropped on the first piston will be pushed all the way to the top. Please note that a pulse limiter is needed to make the pistons properly extend and retract.

How to make your very own elevator!!!

Piston Two-Way Elevators
Two-way elevators can be built, but they are slower and much more complex than the previous ones. They also waste a lot more space and resources. Even though it was slightly modified, the design we are about to show is credited to CxoLethe:

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 assume 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:

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:

S S @~%~@ S%S %%&%% S%S @~%~@  S S


 * ~ = Water
 * S = Water source block
 * @ = Building block
 * % = Building block with Redstone on top
 * & = Building block with pressure pad on top

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

Cannons
A cannon is a mechanism that uses TNT to launch TNT or other entities. Cannons come in many sizes with many additional features including multiple shots, and semi-automatic reloading. Cannons have two main TNT groups, the Charge and the Shot. The Charge is primed first and the Shot is primed before the Charge explodes. Simple Cannons don't require much redstone knowledge, but as features are added (variable delay, for example), the redstone component can become much more advanced.

Anti-Grief Sensors
The following are circuits designed to prevent changes to your structures without the use of Admin Powers.

Wall Protections
There are multiple ways of protecting a wall. Firstly being the easiest which is to protect the bottom of a two high wall, players going through it would break both and ergo the bottom as well, this trips the circuit giving you a positive redstone circuit.



(X) stands for a floor / wall of any material that redstone can be placed on. (-) stands for redstone. 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.

XXXX XXXX X X-- X-XX XXXX

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 which can be used.

X stands for ground. w stands for water. I stands for torch. - stands for wire

XwXXXXX | | I--- XXXXXXX

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.

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.

Light Sensor
As detailed in http://www.minecraftforum.net/viewtopic.php?f=1020&t=165642, flowers and mushrooms can be used to make light sensors.

Block Updates
See Tutorials/Block update detector.

Bank System
After the 1.5 update came out, it became much easier to make stations, banks and other minecart related buildings with the use of powered rails. As you can see on the video example, you can choose from either a empty minecart or a Storage minecart from the two buttons. Also in the video you get a glimpse of how it was made.

This is an updated, better, expandable bank system. This video also has an older bank system showing how to make one without using powered rails.

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

Making items travel upwards
Using this system you can use pistons to throw items upwards. Then the water catches the items, and pushes them a little forward, then the items are pushed by the water to another pistons. And it repeats.

Note: This system uses the piston mod. The normal pistons do not throw items in this way.