technic/manual.md

Minetest technic modpack user manual

The technic modpack extends the Minetest game with many new elements, mainly constructable machines and tools. It is a large modpack, and tends to dominate gameplay when it is used. This manual describes how to use the technic modpack, mainly from a player's perspective.

The technic modpack depends on some other modpacks:

• the basic Minetest game
• mesecons, which supports the construction of logic systems based on signalling elements
• pipeworks, which supports the automation of item transport
• moreores, which provides some additional ore types

This manual doesn't explain how to use these other modpacks, which ought to (but actually don't) have their own manuals.

Recipes for constructable items in technic are generally not guessable, and are also not specifically documented here. You should use a craft guide mod to look up the recipes in-game. For the best possible guidance, use the unified_inventory mod, with which technic registers its specialised recipe types.

substances

ore

The technic mod makes extensive use of not just the default ores but also some that are added by mods. You will need to mine for all the ore types in the course of the game. Each ore type is found at a specific range of elevations, and while the ranges mostly overlap, some have non-overlapping ranges, so you will ultimately need to mine at more than one elevation to find all the ores. Also, because one of the best elevations to mine at is very deep, you will be unable to mine there early in the game.

Elevation is measured in meters, relative to a reference plane that is not quite sea level. (The standard sea level is at an elevation of about +1.4.) Positive elevations are above the reference plane and negative elevations below. Because elevations are always described this way round, greater numbers when higher, we avoid the word "depth".

The ores that matter in technic are coal, iron, copper, tin, zinc, chromium, uranium, silver, gold, mithril, mese, and diamond.

Coal is part of the basic Minetest game. It is found from elevation +64 downwards, so is available right on the surface at the start of the game, but it is far less abundant above elevation 0 than below. It is initially used as a fuel, driving important machines in the early part of the game. It becomes less important as a fuel once most of your machines are electrically powered, but burning fuel remains a way to generate electrical power. Coal is also used, usually in dust form, as an ingredient in alloying recipes, wherever elemental carbon is required.

Iron is part of the basic Minetest game. It is found from elevation +2 downwards, and its abundance increases in stages as one descends, reaching its maximum from elevation -64 downwards. It is a common metal, used frequently as a structural component. In technic, unlike the basic game, iron is used in multiple forms, mainly alloys based on iron and including carbon (coal).

Copper is part of the basic Minetest game (having migrated there from moreores). It is found from elevation -16 downwards, but is more abundant from elevation -64 downwards. It is a common metal, used either on its own for its electrical conductivity, or as the base component of alloys. Although common, it is very heavily used, and most of the time it will be the material that most limits your activity.

Tin is supplied by the moreores mod. It is found from elevation +8 downwards, with no elevation-dependent variations in abundance beyond that point. It is a common metal. Its main use in pure form is as a component of electrical batteries. Apart from that its main purpose is as the secondary ingredient in bronze (the base being copper), but bronze is itself little used. Its abundance is well in excess of its usage, so you will usually have a surplus of it.

Zinc is supplied by technic. It is found from elevation +2 downwards, with no elevation-dependent variations in abundance beyond that point. It is a common metal. Its main use is as the secondary ingredient in brass (the base being copper), but brass is itself little used. Its abundance is well in excess of its usage, so you will usually have a surplus of it.

Chromium is supplied by technic. It is found from elevation -100 downwards, with no elevation-dependent variations in abundance beyond that point. It is a moderately common metal. Its main use is as the secondary ingredient in stainless steel (the base being iron).

Uranium is supplied by technic. It is found only from elevation -80 down to -300; using it therefore requires one to mine above elevation -300 even though deeper mining is otherwise more productive. It is a moderately common metal, useful only for reasons related to radioactivity: it forms the fuel for nuclear reactors, and is also one of the best radiation shielding materials available. It is not difficult to find enough uranium ore to satisfy these uses. Beware that the ore is slightly radioactive: it will slightly harm you if you stand as close as possible to it. It is safe when more than a meter away or when mined.

Silver is supplied by the moreores mod. It is found from elevation -2 downwards, with no elevation-dependent variations in abundance beyond that point. It is a semi-precious metal. It is little used, being most notably used in electrical items due to its conductivity, being the best conductor of all the pure elements.

Gold is part of the basic Minetest game (having migrated there from moreores). It is found from elevation -64 downwards, but is more abundant from elevation -256 downwards. It is a precious metal. It is little used, being most notably used in electrical items due to its combination of good conductivity (third best of all the pure elements) and corrosion resistance.

Mithril is supplied by the moreores mod. It is found from elevation -512 downwards, the deepest ceiling of any minable substance, with no elevation-dependent variations in abundance beyond that point. It is a rare precious metal, and unlike all the other metals described here it is entirely fictional, being derived from J. R. R. Tolkien's Middle-Earth setting. It is little used.

Mese is part of the basic Minetest game. It is found from elevation -64 downwards. The ore is more abundant from elevation -256 downwards, and from elevation -1024 downwards there are also occasional blocks of solid mese (each yielding as much mese as nine blocks of ore). It is a precious gemstone, and unlike diamond it is entirely fictional. It is used in many recipes, though mainly not in large quantities, wherever some magical quality needs to be imparted.

Diamond is part of the basic Minetest game (having migrated there from technic). It is found from elevation -128 downwards, but is more abundant from elevation -256 downwards. It is a precious gemstone. It is used moderately, mainly for reasons connected to its extreme hardness.

rock

In addition to the ores, there are multiple kinds of rock that need to be mined in their own right, rather than for minerals. The rock types that matter in technic are standard stone, desert stone, marble, and granite.

Standard stone is part of the basic Minetest game. It is extremely common. As in the basic game, when dug it yields cobblestone, which can be cooked to turn it back into standard stone. Cobblestone is used in recipes only for some relatively primitive machines. Standard stone is used in a couple of machine recipes. These rock types gain additional significance with technic because the grinder can be used to turn them into dirt and sand. This, especially when combined with an automated cobblestone generator, can be an easier way to acquire sand than collecting it where it occurs naturally.

Desert stone is part of the basic Minetest game. It is found specifically in desert biomes, and only from elevation +2 upwards. Although it is easily accessible, therefore, its quantity is ultimately quite limited. It is used in a few recipes.

Marble is supplied by technic. It is found in dense clusters from elevation -50 downwards. It has mainly decorative use, but also appears in one machine recipe.

Granite is supplied by technic. It is found in dense clusters from elevation -150 downwards. It is much harder to dig than standard stone, so impedes mining when it is encountered. It has mainly decorative use, but also appears in a couple of machine recipes.

rubber

Rubber is a biologically-derived material that has industrial uses due to its electrical resistivity and its impermeability. In technic, it is used in a few recipes, and it must be acquired by tapping rubber trees.

If you have the moretrees mod installed, the rubber trees you need are those defined by that mod. If not, technic supplies a copy of the moretrees rubber tree.

Extracting rubber requires a specific tool, a tree tap. Using the tree tap (by left-clicking) on a rubber tree trunk block extracts a lump of raw latex from the trunk. Each trunk block can be repeatedly tapped for latex, at intervals of several minutes; its appearance changes to show whether it is currently ripe for tapping. Each tree has several trunk blocks, so several latex lumps can be extracted from a tree in one visit.

Raw latex isn't used directly. It must be vulcanized to produce finished rubber. This can be performed by simply cooking the latex, with each latex lump producing one lump of rubber. If you have an extractor, however, the latex is better processed there: each latex lump will produce three lumps of rubber.

metal

Many of the substances important in technic are metals, and there is a common pattern in how metals are handled. Generally, each metal can exist in five forms: ore, lump, dust, ingot, and block. With a couple of tricky exceptions in mods outside technic, metals are only used in dust, ingot, and block forms. Metals can be readily converted between these three forms, but can't be converted from them back to ore or lump forms.

As in the basic Minetest game, a "lump" of metal is acquired directly by digging ore, and will then be processed into some other form for use. A lump is thus more akin to ore than to refined metal. (In real life, metal ore rarely yields lumps ("nuggets") of pure metal directly. More often the desired metal is chemically bound into the rock as an oxide or some other compound, and the ore must be chemically processed to yield pure metal.)

Not all metals occur directly as ore. Generally, elemental metals (those consisting of a single chemical element) occur as ore, and alloys (those consisting of a mixture of multiple elements) do not. In fact, if the fictional mithril is taken to be elemental, this pattern is currently followed perfectly. (It is not clear in the Middle-Earth setting whether mithril is elemental or an alloy.) This might change in the future: in real life some alloys do occur as ore, and some elemental metals rarely occur naturally outside such alloys. Metals that do not occur as ore also lack the "lump" form.

The basic Minetest game offers a single way to refine metals: cook a lump in a furnace to produce an ingot. With technic this refinement method still exists, but is rarely used outside the early part of the game, because technic offers a more efficient method once some machines have been built. The grinder, available only in electrically-powered forms, can grind a metal lump into two piles of metal dust. Each dust pile can then be cooked into an ingot, yielding two ingots from one lump. This doubling of material value means that you should only cook a lump directly when you have no choice, mainly early in the game when you haven't yet built a grinder.

An ingot can also be ground back to (one pile of) dust. Thus it is always possible to convert metal between ingot and dust forms, at the expense of some energy consumption. Nine ingots of a metal can be crafted into a block, which can be used for building. The block can also be crafted back to nine ingots. Thus it is possible to freely convert metal between ingot and block forms, which is convenient to store the metal compactly. Every metal has dust, ingot, and block forms.

Alloying recipes in which a metal is the base ingredient, to produce a metal alloy, always come in two forms, using the metal either as dust or as an ingot. If the secondary ingredient is also a metal, it must be supplied in the same form as the base ingredient. The output alloy is also returned in the same form. For example, brass can be produced by alloying two copper ingots with one zinc ingot to make three brass ingots, or by alloying two piles of copper dust with one pile of zinc dust to make three piles of brass dust. The two ways of alloying produce equivalent results.

iron and its alloys

Iron forms several important alloys. In real-life history, iron was the second metal to be used as the base component of deliberately-constructed alloys (the first was copper), and it was the first metal whose working required processes of any metallurgical sophistication. The game mechanics around iron broadly imitate the historical progression of processes around it, rather than the less-varied modern processes.

The two-component alloying system of iron with carbon is of huge importance, both in the game and in real life. The basic Minetest game doesn't distinguish between these pure iron and these alloys at all, but technic introduces a distinction based on the carbon content, and renames some items of the basic game accordingly.

The iron/carbon spectrum is represented in the game by three metal substances: wrought iron, carbon steel, and cast iron. Wrought iron has low carbon content (less than 0.25%), resists shattering, and is easily welded, but is relatively soft and susceptible to rusting. In real-life history it was used for rails, gates, chains, wire, pipes, fasteners, and other purposes. Cast iron has high carbon content (2.1% to 4%), is especially hard, and resists corrosion, but is relatively brittle, and difficult to work. Historically it was used to build large structures such as bridges, and for cannons, cookware, and engine cylinders. Carbon steel has medium carbon content (0.25% to 2.1%), and intermediate properties: moderately hard and also tough, somewhat resistant to corrosion. In real life it is now used for most of the purposes previously satisfied by wrought iron and many of those of cast iron, but has historically been especially important for its use in swords, armor, skyscrapers, large bridges, and machines.

In real-life history, the first form of iron to be refined was wrought iron, which is nearly pure iron, having low carbon content. It was produced from ore by a low-temperature furnace process (the "bloomery") in which the ore/iron remains solid and impurities (slag) are progressively removed by hammering ("working", hence "wrought"). This began in the middle East, around 1800 BCE.

Historically, the next forms of iron to be refined were those of high carbon content. This was the result of the development of a more sophisticated kind of furnace, the blast furnace, capable of reaching higher temperatures. The real advantage of the blast furnace is that it melts the metal, allowing it to be cast straight into a shape supplied by a mould, rather than having to be gradually beaten into the desired shape. A side effect of the blast furnace is that carbon from the furnace's fuel is unavoidably incorporated into the metal. Normally iron is processed twice through the blast furnace: once producing "pig iron", which has very high carbon content and lots of impurities but lower melting point, casting it into rough ingots, then remelting the pig iron and casting it into the final moulds. The result is called "cast iron". Pig iron was first produced in China around 1200 BCE, and cast iron later in the 5th century BCE. Incidentally, the Chinese did not have the bloomery process, so this was their first iron refining process, and, unlike the rest of the world, their first wrought iron was made from pig iron rather than directly from ore.

Carbon steel, with intermediate carbon content, was developed much later, in Europe in the 17th century CE. It required a more sophisticated process, because the blast furnace made it extremely difficult to achieve a controlled carbon content. Tweaks of the blast furnace would sometimes produce an intermediate carbon content by luck, but the first processes to reliably produce steel were based on removing almost all the carbon from pig iron and then explicitly mixing a controlled amount of carbon back in.

In the game, the bloomery process is represented by ordinary cooking or grinding of an iron lump. The lump represents unprocessed ore, and is identified only as "iron", not specifically as wrought iron. This standard refining process produces dust or an ingot which is specifically identified as wrought iron. Thus the standard refining process produces the (nearly) pure metal.

Cast iron is trickier. You might expect from the real-life notes above that cooking an iron lump (representing ore) would produce pig iron that can then be cooked again to produce cast iron. This is kind of the case, but not exactly, because as already noted cooking an iron lump produces wrought iron. The game doesn't distinguish between low-temperature and high-temperature cooking processes: the same furnace is used not just to cast all kinds of metal but also to cook food. So there is no distinction between cooking processes to produce distinct wrought iron and pig iron. But repeated cooking is available as a game mechanic, and is indeed used to produce cast iron: re-cooking a wrought iron ingot produces a cast iron ingot. So pig iron isn't represented in the game as a distinct item; instead wrought iron stands in for pig iron in addition to its realistic uses as wrought iron.

Carbon steel is produced by a more regular in-game process: alloying wrought iron with coal dust (which is essentially carbon). This bears a fair resemblance to the historical development of carbon steel. This alloying recipe is relatively time-consuming for the amount of material processed, when compared against other alloying recipes, and carbon steel is heavily used, so it is wise to alloy it in advance, when you're not waiting for it.

There are additional recipes that permit all three of these types of iron to be converted into each other. Alloying carbon steel again with coal dust produces cast iron, with its higher carbon content. Cooking carbon steel or cast iron produces wrought iron, in an abbreviated form of the bloomery process.

There's one more iron alloy in the game: stainless steel. It is managed in a completely regular manner, created by alloying carbon steel with chromium.

uranium enrichment

When uranium is to be used to fuel a nuclear reactor, it is not sufficient to merely isolate and refine uranium metal. It is necessary to control its isotopic composition, because the different isotopes behave differently in nuclear processes.

The main isotopes of interest are U-235 and U-238. U-235 is good at sustaining a nuclear chain reaction, because when a U-235 nucleus is bombarded with a neutron it will usually fission (split) into fragments. It is therefore described as "fissile". U-238, on the other hand, is not fissile: if bombarded with a neutron it will usually capture it, becoming U-239, which is very unstable and quickly decays into semi-stable (and fissile) plutonium-239.

Inconveniently, the fissile U-235 makes up only about 0.7% of natural uranium, almost all of the other 99.3% being U-238. Natural uranium therefore doesn't make a great nuclear fuel. (In real life there are a small number of reactor types that can use it, but technic doesn't have such a reactor.) Better nuclear fuel needs to contain a higher proportion of U-235.

Achieving a higher U-235 content isn't as simple as separating the U-235 from the U-238 and just using the required amount of U-235. Because U-235 and U-238 are both uranium, and therefore chemically identical, they cannot be chemically separated, in the way that different elements are separated from each other when refining metal. They do differ in atomic mass, so they can be separated by centrifuging, but because their atomic masses are very close, centrifuging doesn't separate them very well. They cannot be separated completely, but it is possible to produce uranium that has the isotopes mixed in different proportions. Uranium with a significantly larger fissile U-235 fraction than natural uranium is called "enriched", and that with a significantly lower fissile fraction is called "depleted".

A single pass through a centrifuge produces two output streams, one with a fractionally higher fissile proportion than the input, and one with a fractionally lower fissile proportion. To alter the fissile proportion by a significant amount, these output streams must be centrifuged again, repeatedly. The usual arrangement is a "cascade", a linear arrangement of many centrifuges. Each centrifuge takes as input uranium with some specific fissile proportion, and passes its two output streams to the two adjacent centrifuges. Natural uranium is input somewhere in the middle of the cascade, and the two ends of the cascade produce properly enriched and depleted uranium.

Fuel for technic's nuclear reactor consists of enriched uranium of which 3.5% is fissile. (This is a typical value for a real-life light water reactor, a common type for power generation.) To enrich uranium in the game, it must first be in dust form: the centrifuge will not operate on ingots. (In real life uranium enrichment is done with the uranium in the form of a gas.) It is best to grind uranium lumps directly to dust, rather than cook them to ingots first, because this yields twice as much metal dust. When uranium is in refined form (dust, ingot, or block), the name of the inventory item indicates its fissile proportion. Uranium of any available fissile proportion can be put through all the usual processes for metal.

A single centrifuge operation takes two uranium dust piles, and produces as output one dust pile with a fissile proportion 0.1% higher and one with a fissile proportion 0.1% lower. Uranium can be enriched up to the 3.5% required for nuclear fuel, and depleted down to 0.0%. Thus a cascade covering the full range of fissile fractions requires 34 cascade stages. (In real life, enriching to 3.5% uses thousands of cascade stages. Also, centrifuging is less effective when the input isotope ratio is more skewed, so the steps in fissile proportion are smaller for relatively depleted uranium. Zero fissile content is only asymptotically approachable, and natural uranium relatively cheap, so uranium is normally only depleted to around 0.3%. On the other hand, much higher enrichment than 3.5% isn't much more difficult than enriching that far.)

Although centrifuges can be used manually, it is not feasible to perform uranium enrichment by hand. It is a practical necessity to set up an automated cascade, using pneumatic tubes to transfer uranium dust piles between centrifuges. Because both outputs from a centrifuge are ejected into the same tube, sorting tubes are needed to send the outputs in different directions along the cascade. It is possible to send items into the centrifuges through the same tubes that take the outputs, so the simplest version of the cascade structure has a line of 34 centrifuges linked by a line of 34 sorting tube segments.

Assuming that the cascade depletes uranium all the way to 0.0%, producing one unit of 3.5%-fissile uranium requires the input of five units of 0.7%-fissile (natural) uranium, takes 490 centrifuge operations, and produces four units of 0.0%-fissile (fully depleted) uranium as a byproduct. It is possible to reduce the number of required centrifuge operations by using more natural uranium input and outputting only partially depleted uranium, but (unlike in real life) this isn't usually an economical approach. The 490 operations are not spread equally over the cascade stages: the busiest stage is the one taking 0.7%-fissile uranium, which performs 28 of the 490 operations. The least busy is the one taking 3.4%-fissile uranium, which performs 1 of the 490 operations.

A centrifuge cascade will consume quite a lot of energy. It is worth putting a battery upgrade in each centrifuge. (Only one can be accommodated, because a control logic unit upgrade is also required for tube operation.) An MV centrifuge, the only type presently available, draws 7 kEU/s in this state, and takes 5 s for each uranium centrifuging operation. It thus takes 35 kEU per operation, and the cascade requires 17.15 MEU to produce each unit of enriched uranium. It takes five units of enriched uranium to make each fuel rod, and six rods to fuel a reactor, so the enrichment cascade requires 514.5 MEU to process a full set of reactor fuel. This is about 0.85% of the 6.048 GEU that the reactor will generate from that fuel.

If there is enough power available, and enough natural uranium input, to keep the cascade running continuously, and exactly one centrifuge at each stage, then the overall speed of the cascade is determined by the busiest stage, the 0.7% stage. It can perform its 28 operations towards the enrichment of a single uranium unit in 140 s, so that is the overall cycle time of the cascade. It thus takes 70 min to enrich a full set of reactor fuel. While the cascade is running at this full speed, its average power consumption is 122.5 kEU/s. The instantaneous power consumption varies from second to second over the 140 s cycle, and the maximum possible instantaneous power consumption (with all 34 centrifuges active simultaneously) is 238 kEU/s. It is recommended to have some battery boxes to smooth out these variations.

If the power supplied to the centrifuge cascade averages less than 122.5 kEU/s, then the cascade can't run continuously. (Also, if the power supply is intermittent, such as solar, then continuous operation requires more battery boxes to smooth out the supply variations, even if the average power is high enough.) Because it's automated and doesn't require continuous player attention, having the cascade run at less than full speed shouldn't be a major problem. The enrichment work will consume the same energy overall regardless of how quickly it's performed, and the speed will vary in direct proportion to the average power supply (minus any supply lost because battery boxes filled completely).

If there is insufficient power to run both the centrifuge cascade at full speed and whatever other machines require power, all machines on the same power network as the centrifuge will be forced to run at the same fractional speed. This can be inconvenient, especially if use of the other machines is less automated than the centrifuge cascade. It can be avoided by putting the centrifuge cascade on a separate power network from other machines, and limiting the proportion of the generated power that goes to it.

If there is sufficient power and it is desired to enrich uranium faster than a single cascade can, the process can be speeded up more economically than by building an entire second cascade. Because the stages of the cascade do different proportions of the work, it is possible to add a second and subsequent centrifuges to only the busiest stages, and have the less busy stages still keep up with only a single centrifuge each.

Another possible approach to uranium enrichment is to have no fixed assignment of fissile proportions to centrifuges, dynamically putting whatever uranium is available into whichever centrifuges are available. Theoretically all of the centrifuges can be kept almost totally busy all the time, making more efficient use of capital resources, and the number of centrifuges used can be as little (down to one) or as large as desired. The difficult part is that it is not sufficient to put each uranium dust pile individually into whatever centrifuge is available: they must be input in matched pairs. Any odd dust pile in a centrifuge will not be processed and will prevent that centrifuge from accepting any other input.

industrial processes

alloying

In technic, alloying is a way of combining items to create other items, distinct from standard crafting. Alloying always uses inputs of exactly two distinct types, and produces a single output. Like cooking, which takes a single input, it is performed using a powered machine, known generically as an "alloy furnace". An alloy furnace always has two input slots, and it doesn't matter which way round the two ingredients are placed in the slots. Many alloying recipes require one or both slots to contain a stack of more than one of the ingredient item: the quantity required of each ingredient is part of the recipe.

As with the furnaces used for cooking, there are multiple kinds of alloy furnace, powered in different ways. The most-used alloy furnaces are electrically powered. There is also an alloy furnace that is powered by directly burning fuel, just like the basic cooking furnace. Building almost any electrical machine, including the electrically-powered alloy furnaces, requires a machine casing component, one ingredient of which is brass, an alloy. It is therefore necessary to use the fuel-fired alloy furnace in the early part of the game, on the way to building electrical machinery.

Alloying recipes are mainly concerned with metals. These recipes combine a base metal with some other element, most often another metal, to produce a new metal. This is discussed in the section on metal. There are also a few alloying recipes in which the base ingredient is non-metallic, such as the recipe for the silicon wafer.

grinding, extracting, and compressing

Grinding, extracting, and compressing are three distinct, but very similar, ways of converting one item into another. They are all quite similar to the cooking found in the basic Minetest game. Each uses an input consisting of a single item type, and produces a single output. They are all performed using powered machines, respectively known generically as a "grinder", "extractor", and "compressor". Some compressing recipes require the input to be a stack of more than one of the input item: the quantity required is part of the recipe. Grinding and extracting recipes never require such a stacked input.

There are multiple kinds of grinder, extractor, and compressor. Unlike cooking furnaces and alloy furnaces, there are none that directly burn fuel; they are all electrically powered.

Grinding recipes always produce some kind of dust, loosely speaking, as output. The most important grinding recipes are concerned with metals: every metal lump or ingot can be ground into metal dust. Coal can also be ground into dust, and burning the dust as fuel produces much more energy than burning the original coal lump. There are a few other grinding recipes that make block types from the basic Minetest game more interconvertible: standard stone can be ground to standard sand, desert stone to desert sand, cobblestone to gravel, and gravel to dirt.

Extracting is a miscellaneous category, used for a small group of processes that just don't fit nicely anywhere else. (Its name is notably vaguer than those of the other kinds of processing.) It is used for recipes that produce dye, mainly from flowers. (However, for those recipes using flowers, the basic Minetest game provides parallel crafting recipes that are easier to use and produce more dye, and those recipes are not suppressed by technic.) Its main use is to generate rubber from raw latex, which it does three times as efficiently as merely cooking the latex. Extracting was also formerly used for uranium enrichment for use as nuclear fuel, but this use has been superseded by a new enrichment system using the centrifuge.

Compressing recipes are mainly used to produce a few relatively advanced artificial item types, such as the copper and carbon plates used in advanced machine recipes. There are also a couple of compressing recipes making natural block types more interconvertible.

centrifuging

Centrifuging is another way of using a machine to convert items. Centrifuging takes an input of a single item type, and produces outputs of two distinct types. The input may be required to be a stack of more than one of the input item: the quantity required is part of the recipe. Centrifuging is only performed by a single machine type, the MV (electrically-powered) centrifuge.

Currently, centrifuging recipes don't appear in the unified_inventory craft guide, because unified_inventory can't yet handle recipes with multiple outputs.

Generally, centrifuging separates the input item into constituent substances, but it can only work when the input is reasonably fluid, and in marginal cases it is quite destructive to item structure. (In real life, centrifuges require their input to be mainly fluid, that is either liquid or gas. Few items in the game are described as liquid or gas, so the concept of the centrifuge is stretched a bit to apply to finely-divided solids.)

The main use of centrifuging is in uranium enrichment, where it separates the isotopes of uranium dust that otherwise appears uniform. Enrichment is a necessary process before uranium can be used as nuclear fuel, and the radioactivity of uranium blocks is also affected by its isotopic composition.

A secondary use of centrifuging is to separate the components of metal alloys. This can only be done using the dust form of the alloy. It recovers both components of binary metal/metal alloys. It can't recover the carbon from steel or cast iron.

chests

The technic mod replaces the basic Minetest game's single type of chest with a range of chests that have different sizes and features. The chest types are identified by the materials from which they are made; the better chests are made from more exotic materials. The chest types form a linear sequence, each being (with one exception noted below) strictly more powerful than the preceding one. The sequence begins with the wooden chest from the basic game, and each later chest type is built by upgrading a chest of the preceding type. The chest types are:

1. wooden chest: 8×4 (32) slots
2. iron chest: 9×5 (45) slots
3. copper chest: 12×5 (60) slots
4. silver chest: 12×6 (72) slots
5. gold chest: 15×6 (90) slots
6. mithril chest: 15×6 (90) slots

The iron and later chests have the ability to sort their contents, when commanded by a button in their interaction forms. Item types are sorted in the same order used in the unified_inventory craft guide. The copper and later chests also have an auto-sorting facility that can be enabled from the interaction form. An auto-sorting chest automatically sorts its contents whenever a player closes the chest. The contents will then usually be in a sorted state when the chest is opened, but may not be if pneumatic tubes have operated on the chest while it was closed, or if two players have the chest open simultaneously.

The silver and gold chests, but not the mithril chest, have a built-in sign-like capability. They can be given a textual label, which will be visible when hovering over the chest. The gold chest, but again not the mithril chest, can be further labelled with a colored patch that is visible from a moderate distance.

The mithril chest is currently an exception to the upgrading system. It has only as many inventory slots as the preceding (gold) type, and has fewer of the features. It has no feature that other chests don't have: it is strictly weaker than the gold chest. It is planned that in the future it will acquire some unique features, but for now the only reason to use it is aesthetic.

The size of the largest chests is dictated by the maximum size of interaction form that the game engine can successfully display. If in the future the engine becomes capable of handling larger forms, by scaling them to fit the screen, the sequence of chest sizes will likely be revised.

As with the chest of the basic Minetest game, each chest type comes in both locked and unlocked flavors. All of the chests work with the pneumatic tubes of the pipeworks mod.

electrical power

Most machines in technic are electrically powered. To operate them it is necessary to construct an electrical power network. The network links together power generators and power-consuming machines, connecting them using power cables.

There are three tiers of electrical networking: low voltage (LV), medium voltage (MV), and high voltage (HV). Each network must operate at a single voltage, and most electrical items are specific to a single voltage. Generally, the machines of higher tiers are more powerful, but consume more energy and are more expensive to build, than machines of lower tiers. It is normal to build networks of all three tiers, in ascending order as one progresses through the game, but it is not strictly necessary to do this. Building HV equipment requires some parts that can only be manufactured using electrical machines, either LV or MV, so it is not possible to build an HV network first, but it is possible to skip either LV or MV on the way to HV.

Each voltage has its own cable type, with distinctive insulation. Cable segments connect to each other and to compatible machines automatically. Incompatible electrical items don't connect. All non-cable electrical items must be connected via cable: they don't connect directly to each other. Most electrical items can connect to cables in any direction, but there are a couple of important exceptions noted below.

To be useful, an electrical network must connect at least one power generator to at least one power-consuming machine. In addition to these items, the network must have a "switching station" in order to operate: no energy will flow without one. Unlike most electrical items, the switching station is not voltage-specific: the same item will manage a network of any tier. However, also unlike most electrical items, it is picky about the direction in which it is connected to the cable: the cable must be directly below the switching station. Due to a bug, the switching station will visually appear to connect to cables on other sides, but those connections don't do anything.

Hovering over a network's switching station will show the aggregate energy supply and demand, which is useful for troubleshooting. Electrical energy is measured in "EU", and power (energy flow) in EU per second (EU/s). Energy is shifted around a network instantaneously once per second.

In a simple network with only generators and consumers, if total demand exceeds total supply then no energy will flow, the machines will do nothing, and the generators' output will be lost. To handle this situation, it is recommended to add a battery box to the network. A battery box will store generated energy, and when enough has been stored to run the consumers for one second it will deliver it to the consumers, letting them run part-time. It also stores spare energy when supply exceeds demand, to let consumers run full-time when their demand occasionally peaks above the supply. More battery boxes can be added to cope with larger periods of mismatched supply and demand, such as those resulting from using solar generators (which only produce energy in the daytime).

When there are electrical networks of multiple tiers, it can be appealing to generate energy on one tier and transfer it to another. The most direct way to do this is with the "supply converter", which can be directly wired into two networks. It is another tier-independent item, and also particular about the direction of cable connections: it must have the cable of one network directly above, and the cable of another network directly below. The supply converter demands 10000 EU/s from the network above, and when this network gives it power it supplies 9000 EU/s to the network below. Thus it is only 90% efficient, unlike most of the electrical system which is 100% efficient in moving energy around. To transfer more than 10000 EU/s between networks, connect multiple supply converters in parallel.

administrative world anchor

A world anchor is an object in the Minetest world that causes the server to keep surrounding parts of the world running even when no players are nearby. It is mainly used to allow machines to run unattended: normally machines are suspended when not near a player. The technic mod supplies a form of world anchor, as a placable block, but it is not straightforwardly available to players. There is no recipe for it, so it is only available if explicitly spawned into existence by someone with administrative privileges. In a single-player world, the single player normally has administrative privileges, and can obtain a world anchor by entering the chat command "/give singleplayer technic:admin_anchor".

The world anchor tries to force a cubical area, centred upon the anchor, to stay loaded. The distance from the anchor to the most distant map nodes that it will keep loaded is referred to as the "radius", and can be set in the world anchor's interaction form. The radius can be set as low as 0, meaning that the anchor only tries to keep itself loaded, or as high as 255, meaning that it will operate on a 511×511×511 cube. Larger radii are forbidden, to avoid typos causing the server excessive work; to keep a larger area loaded, use multiple anchors. Also use multiple anchors if the area to be kept loaded is not well approximated by a cube.

The world is always kept loaded in units of 16×16×16 cubes, confusingly known as "map blocks". The anchor's configured radius takes no account of map block boundaries, but the anchor's effect is actually to keep loaded each map block that contains any part of the configured cube. The anchor's interaction form includes a status note showing how many map blocks this is, and how many of those it is successfully keeping loaded. When the anchor is disabled, as it is upon placement, it will always show that it is keeping no map blocks loaded; this does not indicate any kind of failure.

The world anchor can optionally be locked. When it is locked, only the anchor's owner, the player who placed it, can reconfigure it or remove it. Only the owner can lock it. Locking an anchor is useful if the use of anchors is being tightly controlled by administrators: an administrator can set up a locked anchor and be sure that it will not be set by ordinary players to an unapproved configuration.

The server limits the ability of world anchors to keep parts of the world loaded, to avoid overloading the server. The total number of map blocks that can be kept loaded in this way is set by the server configuration item "max_forceloaded_blocks" (in minetest.conf), which defaults to only 16. For comparison, each player normally keeps 125 map blocks loaded (a radius of 32). If an enabled world anchor shows that it is failing to keep all the map blocks loaded that it would like to, this can be fixed by increasing max_forceloaded_blocks by the amount of the shortfall.

The tight limit on force-loading is the reason why the world anchor is not directly available to players. With the limit so low both by default and in common practice, the only feasible way to determine where world anchors should be used is for administrators to decide it directly.

subjects missing from this manual

This manual needs to be extended with sections on:

• substances
  • concrete
• powered machines
  • machine upgrades
  • how machines interact with tubes
  • battery box
  • processing machines
  • CNC machine
  • music player
  • tool workshop
  • forcefield emitter
  • quarry
• power generators
  • hydro
  • geothermal
  • fuel-fired
  • wind
  • solar
  • nuclear
• tools
  • tool charging
  • battery and energy crystals
  • chainsaw
  • flashlight
  • mining lasers
  • liquid cans
  • mining drills
  • prospector
  • sonic screwdriver
  • wrench
• radioactivity
• frames
• templates