Compact Machines

20,388,977 Downloads Last Updated: May 5, 2019 Game Version: 1.7.10

Compact Machines 3

Minecraft Mod. Adds one simple game mechanic: Small rooms inside of blocks.

Compact Machines

These are the main component of this mod and they allow you to build complicated machine contraptions and hide them within a single Compact Machine block.


There are 6 different sizes of machines:

Name Description
Tiny 3x3x3
Small 5x5x5
Normal 7x7x7
Large 9x9x9
Giant 11x11x11
Maximum 13x13x13

Personal Shrinking Device

This little tool allow you to enter your Compact Machines. Right clicking a Compact Machine world will teleport you inside.

It also doubles as the integrated documentation. Just right click it anywhere else.

Spawn location

By default you spawn in the center of the room. You can change this by shift-right-clicking a Personal Shrinking Device at the location you want to set the spawn to.

Make sure not to obstruct the spawn location, there is currently no mechanic that automatically searches a better spawn location. And you don't want to have to break the blocks you spawn in.


If you accidentally deleted your Compact Machines block with all your stuff still inside the Machine it can be recovered using the /compactmachines3 machines view command.

It allows browsing through all existing Compact Machines and also provides a button to give yourself a Compact Machine Block linked to the viewed machine. Be aware that this breaks already existing links, i.e. if the machine should already exist somewhere it is being disconnected from the room.

This command only works for server operators.

Technical aspects

  • The inside of Compact Machines are rooms in another dimension (id=144 by default)
  • The rooms in the other dimension are automatically chunk-loaded when the Compact Machine itself is chunkloaded
  • They only trigger chunk reloads when a block next to one of the tunnels changes. There is also no redstone signals being transferred between the tunnels and the machine block.
  • There are two kinds of Compact Machine Wall blocks. The actual machines are made out of unbreakable blocks (you can still break them in creative mode while holding a Personal Shrinking Device), while the machine structures you build for crafting are made out of breakable Wall blocks.
  • Right clicking a Compact Machine renders the contents of the machine in a GUI. On multiplayer games this is handled by sending the chunk contents to the client every time he opens the GUI. There is currently no auto-refresh of the machines content.
  • Compact Machines can be nested
  • Compact Machines spawn along the x-axis in the Compact Machine dimension at y=40, x=1024*machine-id, z=0. This means they all fit in exactly one chunk.
  • Currently mobs can not spawn within Compact Machines. This will probably change in the future, but there will be a config option to turn this back off.
  • Players can not leave the machine block they should currently be in according to the last one they've entered using a Personal Shrinking Device. Trying to enter a Compact Machines with other means results in the player being thrown out of the machine and getting some bad status effect applied. They might even die.
  • If players die without a bed in the CM dimension or with the "allowRespawning" config option disabled, they'll be teleported out of the machine dimension.


Use these inside your Compact Machine room to create connections to the outside faces of your Compact Machine blocks. You can place them by right-clicking one of the wall blocks inside your Compact Machine with a Tunnel Tool.

By right-clicking them again you can cycle through the outside faces it is connected to - Waila/The One Probe helps with that by showing the face as well.

No face can be connected to twice, which means you can place a total of six tunnels anywhere in your Machine.


Tunnels are basically proxy blocks utilizing Forge Capabilities to provide a connection between the two blocks. This means that TileEntities using capabilities to talk to each other will work out of the box, this includes e.g. items, fluids and forge energy.

Other systems, usually multiblock-structures like cables and pipes, most of the time require custom implementations to work properly. This is why e.g. EnderIO conduits, Refined Storage or Applied Energistics connections do not work. This might change in the future when they either switch to a fully capability based system or when this mod adds compatibility layers itself. Both are lots of work, so don't expect this to happen.

Miniaturization Crafting

This is a crafting mechanic added to create the Compact Machine blocks and some of the utility blocks and items it provides. This can also be easily extended by pack makers for custom recipes.


You will require 4 Miniaturization Field Projectors placed in a cross shape creating a odd-sized cube structure. Right click a Field Project to let it tell you where you need to place the next projector - missing locations will be highlighted in the world. You might have to dig out the floor or place the projectors on pedestals.

Once you placed the projectors correctly and no blocks are obstructing the miniaturization field, the field should visualize.

Watch this youtube video for a basic crafting example:

Watch video on youtube

You can disable the field projection by applying a redstone signal to any of the projectors.

Creating custom recipes

Recipes are added by placing .json files in the config/compactmachines3/recipes folder.

  • All recipes in that folder are being loaded additionally to the recipes shipped within the jar file.
  • If you want to disable a recipe simply create a recipe json file with the same filename and add a "disabled": true,property to the recipe object.
  • You can also extract all recipes in the jar using the /compactmachines3 recipe unpack-defaults command.
  • Use the /compactmachines3 recipe copy-shape command to copy the shape in the field of the field projector you are looking at into your clipboard.
  • If you need to specify custom NBT data for the catalyst item, e.g. the following line would make the catalyst required to be enchanted with "Holding III":
      "catalyst-nbt": "{StoredEnchantments: [{lvl:3s,id: 11s}]}",
    The value is just the JSON encoding of the nbt tag, you can view those e.g. by enabling Advanced Tooltips (F3 + H) and running ActuallyAdditions.
  • The rest of the format should be intuitive enough that it does not require further explanation. If it isn't feel free to open an issue.

World Gen

"Broken" Compact Machines sometimes generate in the overworld. Harvest their blocks to use for your own machines.

This can be disabled in the config files.