Document V · Aotearoa New Zealand · 2026

THE MACHINE COMMONS

Mechanical and Electronic Knowledge for the Community
The lathe, the welder, the circuit board, the motor, the 3D printer — these are human tools that capitalism captured. This document returns them. Not as a manual for mass production, but as a preservation of the knowledge required to build, repair, and eventually reproduce the machines that make all other production possible.
Document V in the series. The 30–50 year timeline is honest. Some sections are immediately actionable. Others are generational projects. All of them need to be understood now — before the knowledge becomes inaccessible — because the village that understands its machines is sovereign over them. The village that does not is permanently dependent on whoever controls the supply chain.
I
The Philosophy of Community Technology
Industrialisation in service of life — not in service of accumulation
The distinction that changes everything
"The problem was never the machine. The problem was who owned it, what it was made to serve, and who bore the cost of its operation. A lathe in a community workshop making tools for the community's use is a fundamentally different object from a lathe in a factory making profit for a shareholder. The steel is identical. The meaning is not."
The governing principle
Every machine and every piece of knowledge in this document is evaluated by the same test used throughout this series: does it serve life, does it serve the community, and does it reduce dependency on systems that do not serve them? A CNC router that allows a community to make precision parts for its water pump, its windmill, and its solar array is an instrument of sovereignty. The same machine used to manufacture consumer goods for sale in a market is an instrument of the system this series is building an alternative to. The machine is neutral. The intention behind it is everything.
The knowledge preservation imperative

The people who know how to wind a motor coil, read a circuit schematic, set up a metal lathe, or program a microcontroller are aging. The apprenticeship systems that once transmitted this knowledge have been replaced by just-in-time supply chains — why learn to repair when replacement is cheap? That calculus is changing. The replacement is becoming expensive, unreliable, and increasingly controlled. The window for capturing this knowledge from the generation that holds it is narrowing.

This document is not primarily a how-to manual — it is a map of what needs to be known, a guide to where the knowledge lives, and a framework for how a community builds and maintains this capability across generations. Every section points toward sources in the offline library (Kiwix/Wikipedia, Appropedia, and the specific texts named) that provide the depth this document cannot. Read this document to understand the territory. Read the referenced materials to learn the craft.

The build sequence — what to prioritise
Now — Years 1–5
Basic electrical knowledge and safe wiring. Repair culture — fixing what exists before replacing it. A community workshop with hand and power tools. One person trained in basic welding. Basic electronics understanding. An Arduino or Raspberry Pi in every community system. Download all referenced technical literature to the offline library now, while internet access exists.
Years 5–15
A metal lathe acquired and in use. Basic machining skills in two or more community members. A welding station with MIG and arc capability. A 3D printer for making replacement parts. Basic PCB fabrication capability. Motor repair and rewinding understood. Community vehicles maintained internally.
Years 15–30
A full community machine shop: lathe, milling machine, drill press, grinder, and welding. CNC capability for precision parts. The ability to make most replacement parts for all community systems internally. A trained electronics technician who can diagnose and repair circuit boards. Motor winding from salvaged wire.
Years 30–50
The capability to reproduce basic machines from raw materials. Casting iron and aluminium from scrap. Making new motors. Fabricating solar panels from first principles (long-term, genuinely difficult). Computing hardware from salvage and community fabrication. The knowledge of how everything works, held by multiple people, documented and taught continuously.
· · ·
II
Electricity Fundamentals
The understanding that makes all other electrical work safe and possible
The foundational concepts — voltage, current, resistance, and power
Foundation
Ohm's Law — the single most important equation in electrical work
V = I × R. Voltage (V, in volts) equals Current (I, in amperes) multiplied by Resistance (R, in ohms). From this one relationship, every electrical calculation follows. Rearranged: I = V/R (current equals voltage divided by resistance) and R = V/I. Power: P = V × I (watts = volts × amps). Know these four relationships and you can calculate anything you need to know about any circuit.
The essential concepts — what they mean in practice
Voltage (V)The electrical pressure — the force pushing electrons through a circuit. A 12V battery pushes electrons with 12 volts of pressure. Mains power in NZ is 230V AC. Higher voltage = more potential energy available, but also more danger. Voltage alone does not kill — current through the body kills.
Current (I, amperes)The flow rate of electrons through a circuit — how many electrons per second. 1 amp = approximately 6 × 10¹⁸ electrons per second. 50–100mA (milliamps) through the heart can cause ventricular fibrillation and death. The resistance of dry skin is 100,000Ω — which at 230V produces 2.3mA, survivable. Wet skin resistance drops to 1,000Ω — 230mA, potentially fatal. Water and electricity must always be kept apart.
Resistance (Ω, ohms)Opposition to current flow. Every conductor has some resistance. Thin wire has more resistance than thick wire. Longer wire has more resistance than short wire. Resistance converts electrical energy to heat — this is what fuses and heating elements exploit. Undersized wire has excessive resistance, overheats, and starts fires.
AC vs DCDC (direct current) flows in one direction — batteries, solar panels, all electronics. AC (alternating current) reverses direction 50 times per second (50Hz in NZ) — grid power, generators. AC is used for long-distance power transmission because voltage can be transformed up and down easily. All electronics internally runs on DC — AC is converted to DC by a power supply at the wall. Understanding the difference matters for wiring, tools, and safety.
Power (W, watts)The rate of energy use. P = V × I. A 100W light bulb running on 230V draws 0.43A of current. A 2kW kettle draws 8.7A. Know the current draw of every device to size wiring correctly. Energy = Power × Time: 1kW running for 1 hour = 1kWh. This is what your electricity meter (or battery monitor) measures.
Grounding / earthingA conductor connecting the metal chassis of equipment to the earth. In a fault condition (live wire touching metal casing), without earthing the casing becomes live at 230V — touch it and the current flows through you to earth. With earthing, the fault current flows through the low-resistance earth wire, trips the breaker, and saves your life. Never remove earth connections.
Reading and drawing basic circuit diagrams

Circuit diagrams use standardised symbols to show how components connect. Every community member involved in electrical work should be able to read and draw basic circuits. The key symbols: straight line = wire, zigzag = resistor, two parallel lines (one longer) = battery, two parallel lines = capacitor, triangle = diode, circle with X = light bulb, circle with M = motor, coil = inductor/solenoid. These symbols are universal — a circuit drawn anywhere in the world uses the same language.

Simple circuit notation: Battery (+12V) → Switch → Fuse (5A) → LED + Resistor → Battery (GND) Reading left to right: power flows from positive terminal of battery, through a switch (open = no flow, closed = flow), through a fuse (sacrificial protection), through LED and resistor (the load), back to the negative terminal. If current exceeds 5A, fuse blows and protects the LED. This is every basic DC circuit in skeleton form.
· · ·
III
Wiring — Buildings, Systems, and Vehicles
Safe, correct, and inspectable wiring from first principles
House wiring fundamentals — NZ standard
Skill 2NZ Standard
NZ legal requirement
  • In NZ, all fixed household wiring (anything beyond plugging in a lamp) must be installed by a registered electrician and inspected by an electrical inspector before being covered or energised. This is not bureaucratic obstruction — it is because incorrectly wired buildings kill people and burn down. The knowledge here is for understanding your own systems, diagnosing faults, and working safely on low-voltage (12V/24V/48V) off-grid systems. Mains (230V) installation requires registration.
  • Off-grid DC systems below 50V are generally exempt from the registered electrician requirement in NZ but must still comply with wiring standards (AS/NZS 3000 — the Wiring Rules) for safety. Understand the law before picking up a screwdriver.
NZ mains wiring colour code
Active (Live)Brown (new standard) or Red (old). This wire carries the voltage — it is the dangerous one. Never touch this wire without confirming power is off AND the circuit is isolated at the board.
NeutralBlue (new) or Black (old). Returns current to the supply. Not at voltage relative to earth in normal operation, but can be lethal if a fault exists on the neutral — treat as live.
Earth (Ground)Green/yellow stripe. The safety wire. Connected to all metal equipment housings. Never carry current in normal operation — only in fault conditions. Never cut or remove this wire.
Cable sizing — the most safety-critical calculation in wiring

Undersized cable is the primary cause of electrical fires. The cable must be sized to carry the maximum expected current without overheating. Use this as a starting guide for 230V AC copper cable in free air:

1.5mm²Up to 15A. Standard lighting circuits. Maximum load approximately 3.5kW.
2.5mm²Up to 20A. Standard power outlet (GPO) circuits. Maximum load approximately 4.6kW.
4mm²Up to 25A. Larger loads — electric stove circuits, large water heaters.
6mm²Up to 32A. Main sub-circuits, large appliances, EV charging.
10mm²+Main incoming supply cables. Always sized by a qualified electrician with load calculation.
Cable in conduit or bunchedDerating required — enclosed cable cannot dissipate heat as freely. A 2.5mm² cable in conduit may only safely carry 15A rather than 20A. The AS/NZS 3000 Wiring Rules tables give exact derating factors.
DC off-grid wiring — different rules from AC
  1. DC systems carry the same power at lower voltage — which means higher current. A 1kW load on 230V AC draws 4.3A. The same 1kW load on a 12V DC system draws 83A. At 83A, even a short length of undersized wire becomes a fire starter. DC wiring must be significantly heavier than AC wiring for the same power level.
  2. Always use a dedicated DC cable sizing calculator for any off-grid system. The online calculators at victronenergy.com and solarpowerworldonline.com are reliable references — download the calculation tables to the offline library.
  3. Fuse every positive DC conductor as close to the power source (battery) as possible — within 150–300mm of the terminal. A fault anywhere in the circuit is contained by the fuse. An unfused DC circuit connected to a large battery bank is an incendiary device.
  4. Use ring lugs and proper crimping tools for all battery and high-current connections. Wire nuts and tape are not adequate at high DC currents — the resistance of a poor joint generates heat. Proper lugs crimped with a ratchet crimping tool produce a gas-tight, low-resistance joint that lasts decades.
Fault finding — systematic diagnosis
  1. A multimeter is the single most important diagnostic tool in any electrical system. Buy quality — a Fluke or equivalent. It measures: voltage (V), current (A with clamp meter or in-line), resistance (Ω), and continuity (beeps when connected). Every community electrician needs one.
  2. For a circuit that does not work: first check voltage at the source (is power present?). Then check voltage at the load (is voltage reaching the load?). If no voltage at load — the break is somewhere between source and load. Check fuse first (resistance across fuse should be near zero — if infinite, fuse is blown). Then check switch (resistance across switch contacts when closed should be near zero). Then check wire continuity (disconnect both ends, measure resistance — should be near zero for good wire).
  3. For a circuit that trips the breaker: something is drawing too much current. Disconnect loads one by one until the breaker holds. The last load removed is the fault. Check that load for a short circuit (resistance from active to neutral should be high — above 1kΩ for most appliances when switched off). A reading near zero indicates a short circuit — internal wiring fault.
  4. For intermittent faults: these are the hardest to diagnose. Wiggle wires while monitoring voltage. A joint that causes a drop when moved is a high-resistance connection — strip and remake. Thermal faults (something that fails when warm but not when cold) require a heat gun and careful testing.
· · ·
IV
Electronics — Components, Circuits, and PCB Fabrication
From individual components to working circuit boards
Electronic components — what they are and what they do
Foundation
ResistorLimits current flow. Value in ohms (Ω), read from colour bands. Use: protecting LEDs, setting reference voltages, voltage dividers. A resistor in series with an LED is the simplest possible useful circuit.
CapacitorStores electrical charge. Value in farads (F) — usually microfarads (µF) or picofarads (pF). Use: smoothing power supply ripple, filtering noise, timing circuits. Electrolytic capacitors are polarised — positive and negative must be connected correctly or they fail explosively.
DiodeAllows current in one direction only. Use: preventing reverse polarity damage in circuits, rectifying AC to DC (in power supplies), protecting circuits from voltage spikes. LED (light-emitting diode) is a diode that produces light as a byproduct of current flow.
TransistorAn electronically controlled switch or amplifier. A small current at the base controls a large current from collector to emitter. The foundation of all digital electronics — a processor contains billions of transistors. Use: switching motors, amplifying signals, building logic circuits.
Integrated Circuit (IC)Thousands to billions of transistors in a single package. The 555 timer IC, the LM7805 voltage regulator, the LM358 op-amp, and the ATmega328 microcontroller (the heart of the Arduino) are all ICs. Reading datasheets — the technical documentation for ICs — is the core skill of electronics.
RelayAn electromagnetically controlled switch. A small voltage at the coil energises an electromagnet that physically closes or opens a switch. Use: controlling mains voltage from a microcontroller output, switching high-current loads from low-power signals. The interface between the world of microelectronics and the world of power.
Voltage regulatorMaintains a constant output voltage regardless of input variation. The LM7805 takes any DC input from 7–35V and outputs a stable 5V — power supply for almost any microcontroller or logic circuit. The L7812 outputs 12V. Critical for powering electronics from variable sources like solar panels and batteries.
MOSFETA field-effect transistor — controlled by voltage rather than current. More efficient than standard transistors for switching. The basis of all modern motor controllers, solar charge controllers, and inverters. Understanding MOSFETs unlocks power electronics — the interface between low-power control signals and high-power loads.
Soldering — the fundamental joining skill of electronics
Skill 1$ Low
  1. Equipment: a temperature-controlled soldering iron (350–380°C for standard electronics solder), rosin-core solder (60/40 tin-lead or lead-free), flux, a brass wire tip cleaner, and a helping-hands clamp or PCB holder. A desoldering pump or desoldering wick for removing components.
  2. Prepare the iron: bring to temperature, tin the tip (melt a small amount of solder onto the clean tip until it coats evenly). A well-tinned tip transfers heat efficiently. A dirty, oxidised tip transfers heat poorly and produces cold joints.
  3. Heat the joint — not the solder: apply the iron tip to the junction between component lead and PCB pad simultaneously. Hold for 1–2 seconds until both are heated. Then apply solder to the joint (not the iron). The solder should flow into the joint by capillary action.
  4. A good solder joint is shiny, smooth, and volcano-shaped — drawn up to the component lead. A bad (cold) joint is dull, grey, and balled — it has not flowed properly and has high resistance. Re-heat cold joints and add a touch of fresh solder or flux.
  5. Remove the iron, let the joint cool undisturbed for 2–3 seconds. Movement while cooling produces a cracked cold joint. Clean residual flux from the board with isopropyl alcohol and a stiff brush.
  6. Practice on sacrificial components and scrap PCBs before working on anything you cannot replace. The skill develops quickly — an hour of practice produces significant improvement.
PCB fabrication — making circuit boards without industrial equipment
Skill 3$$ Med
What a PCB is
A printed circuit board is a substrate (usually fibreglass, or in community production, copper-clad board) with conducting copper tracks that connect components. The tracks replace individual wires — a complex circuit that would require hundreds of hand-soldered wires becomes a repeatable, reliable, compact board. Making your own PCBs closes the loop on circuit manufacturing.
Method 1 — Toner transfer (most accessible)
  1. Design your circuit in free software — KiCad (recommended, full-featured, open source) or EasyEDA (browser-based). Design the PCB layout with all component footprints and copper tracks. Print the PCB layout mirror-image onto glossy paper (magazine paper or dedicated transfer paper) using a laser printer.
  2. Cut a piece of copper-clad board to size. Clean the copper surface thoroughly with fine abrasive (Scotch-Brite or fine sandpaper) to remove oxidation, then wipe with acetone or IPA. The surface must be shiny, clean, and grease-free for transfer to work.
  3. Place the printed transfer paper face-down on the copper surface. Apply firm, even heat with a clothes iron at maximum setting for 3–5 minutes. The toner (laser printer ink) contains plastic that melts and bonds to the copper at iron temperatures.
  4. Soak the board in warm water until the paper softens and can be gently rubbed away. The toner remains on the copper, masking the tracks. Inspect carefully — if any tracks are incomplete, touch up with an etch-resist pen.
  5. Etch the board: submerge in ferric chloride solution (available from electronics suppliers, or prepare from ferrous chloride and hydrogen peroxide for a home-made etchant). The etchant removes copper not protected by toner, leaving only the circuit tracks. This takes 5–15 minutes depending on temperature. Agitate the solution or rock the tray for faster, more even etching.
  6. Remove from etchant when all unprotected copper is gone (inspect carefully — over-etching undercuts the tracks). Rinse thoroughly in water. Remove the toner with acetone to reveal the bright copper tracks.
  7. Drill component holes with a drill press and PCB drill bits (0.8mm–1.5mm carbide bits). Apply a thin coat of rosin flux or PCB lacquer to protect the copper from oxidation. The board is ready for component insertion and soldering.
Method 2 — CNC routing (once CNC is available)

A CNC router with a 0.1–0.2mm V-bit can mill PCB isolation routes directly from the board design file exported from KiCad — no chemicals required. This is faster, more precise, and cleaner than toner transfer, and becomes the preferred method once community CNC capability is established (Section IX).

Method 3 — Hand-drawn with etch-resist pen

For simple circuits: draw tracks directly onto the copper-clad board with an etch-resist pen (a permanent marker works for a single-use board, though the ink quality varies). Etch as above. Simple, no computer or printer required, but limited to straightforward layouts. An excellent entry point for learning the process before investing in computer-aided design.

Chemical safety
  • Ferric chloride is a corrosive acid that stains skin and clothing permanently and is toxic to aquatic life — do not pour it down drains or into waterways. Neutralise spent etchant by adding sodium carbonate (washing soda) until fizzing stops, then dispose of as chemical waste or contact your local council for disposal guidance.
  • Ferric chloride on skin: rinse immediately with large amounts of water. Staining is cosmetic, not toxic at normal exposure levels.
  • Work in a ventilated area — the etching process produces small amounts of hydrogen chloride vapour.
Microcontrollers — Arduino and the programmable layer
Skill 2$ Low
Why microcontrollers matter
A microcontroller is a small computer on a single chip. It reads inputs (sensors, switches, signals) and controls outputs (motors, relays, LEDs, displays) according to a program you write. The Arduino ecosystem made microcontrollers accessible to non-specialists. For a community, they provide the intelligent control layer for solar charge systems, water monitoring, biogas pressure sensing, automated irrigation, temperature control for fermentation, and any other system that benefits from automated monitoring and response. They are inexpensive, widely available, and critically, the knowledge to program them is preserved in thousands of community-accessible online resources — all of which should be downloaded to your offline library.
The basic Arduino setup
  1. Hardware: an Arduino Uno or Nano (both use the ATmega328P microcontroller — the most documented and supported in the world). A USB cable for programming. A computer running the free Arduino IDE software. Basic components: LEDs, resistors, a breadboard for prototyping without soldering.
  2. The structure of every Arduino program: a setup() function that runs once when power is applied (initialise pins, communication), and a loop() function that runs continuously (read sensors, make decisions, control outputs). This two-function structure is the entire framework for most community applications.
  3. Digital pins: can be set as input (read a button, a switch) or output (control an LED, a relay). Read with digitalRead(), written with digitalWrite(). The 14 digital pins on an Arduino Uno are sufficient for most simple control tasks.
  4. Analogue pins: read continuously variable signals (0–5V) and convert them to numbers (0–1023) using analogRead(). Connect a temperature sensor, a soil moisture sensor, a current sensor, or a pressure transducer to an analogue pin. The Arduino reads it and can respond — turn on a pump when soil moisture drops, sound an alarm when biogas pressure exceeds safe limits.
  5. Communication: the Arduino communicates with a computer or display over serial (USB). It can communicate with other modules over I²C, SPI, or UART. A basic 16×2 LCD display shows readings in the field. A data logger shield saves readings to an SD card for later analysis.
  6. Offline programming reference: the complete Arduino language reference, all official tutorials, and the community library documentation should be downloaded and stored on the community's Kiwix server. The Arduino documentation is one of the most important technical references to preserve offline.
Community applications
Solar battery monitoringCurrent sensor on battery terminals + voltage divider + Arduino + LCD display = a battery monitor that shows state of charge, current in/out, and daily energy totals. Builds on the basic electrical knowledge in Section II.
Water level and qualityFloat switches in water tanks trigger pump control. pH and turbidity sensors monitor filter output quality. Temperature sensor alerts to Legionella risk (water held above 18°C for extended periods).
Biogas pressure monitoringA simple pressure transducer connected to the gas storage, monitored by Arduino, can trigger an alert when pressure is dangerously high or when the system needs feeding. Prevents the explosion risk described in The Practical Guide.
Fermentation temperature controlDS18B20 temperature sensors (waterproof, accurate, inexpensive) connected to Arduino control a relay that switches a heating pad or heat lamp. Maintains koji, tempeh, yoghurt, and mead at precise temperature setpoints automatically.
· · ·
V
The Community Fabrication Workshop
What to build, what to acquire, and in what order
Building the workshop — from hand tools to machine tools
Skill 2
"The workshop is the community's second most important infrastructure after the food system. Every other system eventually needs something made, repaired, or modified. The community that can fabricate is sovereign over its equipment. The community that cannot must wait for a supply chain to deliver."
Acquisition priority — hand tools first, machines second
Stage 1 — Now
Basic hand tools
Hammers, chisels, planes, squares, measuring tape, screwdrivers, spanners, hacksaws, files, levels. Buy quality — a good hammer lasts 50 years. A cheap one fails in months.
Stage 2 — Year 1–3
Power hand tools
Angle grinder, drill, jigsaw, circular saw, orbital sander. These extend hand tool capability dramatically and can be powered from the community solar system.
Stage 3 — Year 3–7
Stationary power tools
Bench drill press, bandsaw, bench grinder, wood lathe. Precision, repeatability, and safety beyond hand tools. Acquire secondhand — NZ has excellent secondhand tool availability.
Stage 4 — Year 5–15
Metal working
Metal lathe, milling machine, metal bandsaw, angle plate and vices. This is where the community gains the ability to make precision metal parts — the foundation of mechanical independence.
Stage 5 — Year 10–20
Digital fabrication
3D printer, CNC router, laser cutter. Makes precision reproduction of complex parts possible and enables rapid prototyping of new designs.
Sourcing machines in NZ — where to look
Trade MeThe primary source for secondhand machinery in NZ. Old lathes, milling machines, welders, drill presses, and woodworking machinery appear regularly — often from retiring tradespeople and closing small workshops. A South Island or North Island search covering a wide area is worth the travel cost for the right machine.
Rural auctions and farm salesWaikato farm dispersal sales regularly include engineering equipment. Old machinery is sold by weight rather than by capability — old lathes and mills have often never been worn out and will outlast modern equivalents. Graysonline NZ runs regular online industrial auctions.
Gifted and donated equipmentMany retired tradespeople with workshops have quality equipment they want to see used rather than scrapped. The community that is known in its area often receives equipment donations. Be visible, be trustworthy, and be patient — the right machines tend to appear.
New from China via freight forwardersMachinery from Chinese manufacturers (Sieg, Chester, Grizzly equivalents) is significantly cheaper than European or US equivalents and adequate for community workshop use. A Sieg SC4 metal lathe imported via a freight forwarder is a fraction of the cost of a comparable NZ-sourced machine. Quality varies — research specific models before purchasing.
· · ·
VI
Machining — The Metal Lathe and Milling Machine
The tools that make all other tools
The metal lathe — the most important machine in the workshop
Skill 3
Why the lathe comes first
The lathe is the only machine that can make parts for itself. It makes round things: shafts, bearings, bushings, threaded fasteners, pulleys, gears. Every other machine in the workshop contains these components. A lathe in skilled hands can reproduce almost any round or cylindrical part from raw stock. The community with a lathe and a trained machinist can maintain its own equipment indefinitely. Without one, every broken shaft and worn bearing is an external purchase.
Basic operations — the learning sequence
  1. Facing: cutting the end of a bar perfectly flat and perpendicular to its axis. The first operation on any turned part. Sets the datum from which all measurements reference.
  2. Turning between centres: reducing a bar's diameter along its length. The fundamental turning operation. Sets the habit of measuring, taking a light cut, measuring again — the machinist's discipline of removing material in controlled increments rather than guessing.
  3. Boring: enlarging a hole that already exists, to a precise diameter. Used to make bearing housings, bushings, and any precision bore. A boring bar extends the tool holder into the work.
  4. Threading: cutting external or internal threads to standard specifications (metric: M6, M8, M10 etc). The ability to make your own fasteners and threaded fittings from stock material. Requires a threading dial, a correctly ground tool, and careful coordination of feed and spindle speed.
  5. Parting off: cutting a completed part free from the bar stock. A parting tool is narrow and prone to chatter — slow speeds, adequate lubrication (cutting oil), and a confident feed rate prevent the tool digging in.
  6. Knurling: pressing a diamond or straight pattern into a cylindrical surface for grip. Used for tool handles, adjustment knobs, and any surface requiring hand grip without slipping.
Safety — non-negotiable at the lathe
Lathe safety
  • Never wear gloves at the lathe — loose material wraps around rotating work and pulls fingers or hands into the machine. Bare hands or tight-fitting skin-contact gloves only.
  • Never leave the chuck key in the chuck while the lathe is powered — if the spindle turns, the chuck key becomes a projectile. Remove immediately after adjusting the chuck.
  • Swarf (metal chips) from turning is razor-sharp. Clear with a brush or hook, never with hands. Flying swarf requires eye protection at all times.
  • Long bar stock extending behind the headstock requires outboard support or a guard — unsupported long bar whipping at speed is lethal.
  • Coolant and cutting oil: use adequate cutting fluid (even canola oil works well for aluminium). Dry cutting generates heat that ruins tool edges and dimensional accuracy.
Reference to download: "The Amateur's Lathe" by L.H. Sparey — the most accessible English-language lathe manual ever written. Available on Project Gutenberg and various archive sites. Download to the offline library. Also: "How to Run a Lathe" by South Bend Lathe — a classic beginner's reference, also freely available.
The milling machine — making flat and complex surfaces
Skill 3

Where the lathe makes round things, the mill makes flat things — slots, keyways, flat faces, holes at precise locations, and complex profiles. Together, lathe and mill can make almost any mechanical component. The milling machine moves the workpiece on a precise X-Y table under a rotating cutter. Operations include face milling (flattening surfaces), end milling (cutting slots and profiles), and drilling/boring to precise locations using the machine's calibrated handwheels.

Fundamental milling concepts
Climb milling vs conventional millingIn climb milling, the cutter rotates in the same direction as feed — produces a better surface finish but requires a rigid machine with no backlash. In conventional milling, the cutter rotates against the feed direction — safer on older machines with worn leadscrews. Use conventional milling by default until comfortable with the machine.
Depth of cut and feed rateRemove material in multiple light passes rather than one heavy cut. A 0.5mm depth of cut with moderate feed rate produces better surface finish, less tool wear, and less stress on the machine than a 3mm depth of cut. The machine will tell you when you are asking too much — listen to the sound.
WorkholdingA vice bolted to the table holds most work. Tee-nuts and clamps hold awkward shapes. The work must not move during cutting — a loose workpiece becomes a projectile. Check holding before every cut and after any tool change.
IndicatingA dial test indicator (DTI) mounted in the spindle is used to align the vice, set up workpieces square to the table, and locate precise positions. Learning to use an indicator accurately is as important as learning to operate the machine itself — it is the measurement layer that makes precision possible.
· · ·
VII
Welding
Arc, MIG, and gas welding — joining metal permanently
The three welding processes — which to learn first and why
Skill 2–3
Stick welding (MMAW/Arc)The simplest and most robust process. A consumable electrode coated in flux creates the arc and provides the filler metal. Equipment is inexpensive, durable, runs on any power source (including generators), and welds through rust, paint, and contamination better than other processes. Learn this first — it teaches the fundamentals of arc control, puddle manipulation, and travel speed that all other processes build on.
MIG welding (GMAW)Wire fed automatically through the gun, with a shielding gas (CO2 or argon/CO2 mix) protecting the weld puddle from atmospheric contamination. Faster than stick welding, produces less spatter, and is easier to learn for clean material. Requires gas supply and a wire feeder — more equipment, less portable. The workhorse process for fabrication on clean steel.
Oxy-acetylene (gas welding)A flame from burning acetylene and oxygen melts the base metal and a separate filler rod. Very versatile — can weld, cut, braze, bend, and heat-treat metal. No electricity required. The oldest modern welding process. Useful as a portable cutting and heating tool even if the welding skill is never fully developed. The gas bottles are the significant infrastructure cost.
Learning the arc weld — progressive skill development
  1. Set up: connect work clamp to the workpiece (as close to the weld as practical). Select electrode diameter for material thickness: 2.5mm electrode for material up to 6mm thick, 3.2mm for heavier material. Set current: approximately 90–100A for 2.5mm electrode, 120–130A for 3.2mm as a starting point.
  2. Strike the arc: touch the electrode to the work and withdraw slightly (2–3mm). An arc bridges the gap. If the electrode sticks, rock it side to side and break it free immediately — a stuck electrode overheats rapidly. Practice striking on scrap until starting the arc is automatic.
  3. Travel speed and arc length: maintain a consistent arc length of approximately one electrode diameter. Too long an arc produces a wide, flat, porous weld. Too short an arc extinguishes or sticks. Travel at a speed that keeps the puddle circular and uniform — too fast produces a thin, high weld; too slow produces a wide, flat, penetration-limited bead.
  4. Watch the puddle, not the arc: the molten pool behind the arc tells you everything about what is happening. A smooth, circular puddle with a clean trailing edge means correct parameters. Spatter, porosity, and undercut all have specific causes and specific corrections that are learned by watching the puddle.
  5. Joint preparation: clean metal welds better than dirty metal. Wire brush or grind rust and mill scale from the weld area. A V-groove prepared on material over 6mm thick allows full penetration — a flat butt weld on thick material may look fine on the outside while having no fusion in the root.
Welding hazards
  • UV radiation from the arc causes arc eye (photokeratitis) — like sunburn on the cornea. Painful, temporary, but avoidable entirely with a proper welding helmet. Use an auto-darkening helmet (shade 10–11 for stick/MIG) or a fixed-shade helmet. Never view the arc with unprotected eyes, even briefly.
  • Welding fumes contain metal oxides, flux compounds, and ozone. Welding galvanised steel produces zinc oxide fumes — causes metal fume fever, symptoms similar to severe flu. Never weld galvanised, cadmium-plated, or lead-painted material without exceptional ventilation or respiratory protection.
  • Fire: welding spatter travels 10m or more and ignites combustibles. Clear the area of all flammable material, have a fire extinguisher accessible, and check the area 30 minutes after welding for smouldering fires.
  • Electrical: welding current is low voltage but very high current. The work clamp must make solid contact — poor clamp connection causes arcing at the clamp and can cause burns and fires. Never weld near fuel, gas bottles, or any pressurised container.
· · ·
VIII
3D Printing
Replacing parts, making tools, and prototyping designs — from digital file to physical object
3D printing in a community context — what it is good for and what it is not
Skill 2$$ Med
The honest assessment
A 3D printer does one specific thing extremely well: it produces complex plastic shapes from a digital design file without any tooling, moulds, or machining. For a community, the primary use is replacement parts — the specific bracket, the gear, the housing, the impeller that broke and is no longer available from the manufacturer. The secondary use is making new tools and jigs designed for the community's specific needs. It is not a solution for structural metal components, high-temperature applications, or high-strength load-bearing parts. Within those limits, it is genuinely valuable.
What to print and what not to print
Print: replacement plastic partsKnobs, handles, housings, clips, brackets, gear covers, fan blades, irrigation fittings, pump housings. Anything that is broken, unavailable, or expensive to source and is not subject to high load or temperature.
Print: jigs and toolsDrill guides, marking gauges, PCB holders, assembly jigs, custom wrenches for specific fasteners, and template guides for repetitive operations. These are often more immediately useful than replacement parts.
Print: prototype designsDesign a part in software, print in plastic, test fit and function, iterate. Printing a test piece before committing to machining in metal saves significant time and material.
Do not print: structural load-bearing partsStandard PLA and PETG do not have the strength for structural applications. Do not print load-bearing brackets, connectors, or any part where failure causes injury. Use machined metal or welded steel for these.
The closed loop — 3D printing from community-produced filament

Standard 3D printer filament is PLA (derived from corn starch — compostable) or PETG and ASA (petroleum-derived). The community that runs a plastic pyrolysis operation (Layer Zero Section XVII) has access to a hydrocarbon stream from which HDPE and PP filament can be extruded using a filament extruder (a machine that heats plastic and extrudes it through a die to produce filament). This closes a loop: community-collected plastic waste → pyrolysis (fuel) OR filament extruder (printing material). The filament extruder hardware is a buildable community project using a metal lathe, a heating element, and a motor controller — exactly the capabilities described in this document.

Printer selection and offline operation
  1. For a community workshop printer: a Bambu Lab P1S or Prusa MK4 (both robust, well-documented, repairable). The Prusa is fully open-source and every part can be replaced or printed. The Bambu is faster but less serviceable — for a community that prioritises repairability, Prusa is the better long-term choice.
  2. Printer operation offline: all slicer software (Prusa Slicer, Bambu Studio, Cura) runs entirely offline on any computer. Models can be stored on SD card. No internet required for operation — the printer is a fully functional offline fabrication tool.
  3. The Printables and Thingiverse model libraries (download a bulk archive to the offline library while internet is available) contain millions of free models including replacement parts for common machinery, tools, and household items. This library alone makes a 3D printer immediately useful before any in-community design capability is developed.
· · ·
IX
CNC — Computer Numerical Control
Precision cutting and routing from digital design files
CNC routing and milling — from digital file to physical part
Skill 3$$ Med
What CNC does

A CNC (Computer Numerical Control) machine moves a cutting tool in precisely programmed paths through a workpiece. A CNC router cuts wood, plastic, and aluminium from flat sheet stock — producing complex 2D profiles and 3D surfaces automatically. A CNC mill does the same with greater precision on metal. Both receive instructions in G-code — a standardised machine control language that has not fundamentally changed since the 1950s and that all modern CAM (Computer Aided Manufacturing) software generates automatically from your design.

The workflow
  1. Design: create a 2D or 3D design in free CAD software. FreeCAD (open source, full 3D CAD) and LibreCAD (2D only, simpler) are both available offline. KiCad for PCB layouts. Inkscape for 2D cutting paths.
  2. CAM: convert the design into machine toolpaths in CAM software. FreeCAD has an integrated CAM workbench. EstlCAM is a simple, inexpensive option excellent for beginners. The CAM step specifies: which tool to use, how deep to cut, how fast to feed, and in what sequence to cut the profile.
  3. G-code: the CAM software exports G-code — a text file of machine instructions. Every line is a movement or a command: G0 X100 Y50 (rapid move to X=100, Y=50), G1 Z-5 F300 (linear cut move to Z=-5mm at 300mm/min feed rate). Understanding G-code at a basic level allows manual editing of programs and diagnosis of unexpected machine behaviour.
  4. Machine control: send G-code to the machine via GRBL (open-source CNC controller firmware for Arduino) or Mach3/LinuxCNC (more advanced). UGS (Universal G-code Sender) and bCNC are free, offline machine control programs that run on any laptop.
  5. Set up the workpiece, set the work zero (the reference point from which all movements are measured), and run. For first operations on any new setup, use air cuts — run the program with the tool above the material to verify the path is correct before cutting.
Building a community CNC router

A functional CNC router for wood and aluminium cutting can be built from steel tubing, linear rails, leadscrews, stepper motors, and an Arduino-based GRBL controller. Total material cost for a 600×900mm cutting area machine is approximately NZD $800–1500 in parts — far less than purchasing a commercial equivalent. The V1 Engineering MPCNC (Mostly Printed CNC) design uses 3D printed connectors and standard hardware — buildable by any community with a 3D printer and basic workshop skills. Build files, BOMs, and complete instructions are available on v1e.com and should be downloaded to the offline library.

· · ·
X
Motors, Generators, and Rewinding
Understanding, repairing, and eventually reproducing the machines that convert between mechanical and electrical energy
How motors and generators work — the same machine in two directions
Foundation
The electromagnetic principle
A motor and a generator are the same machine. Apply electrical current to a coil in a magnetic field — it rotates (motor). Rotate a coil in a magnetic field — it produces electrical current (generator). This principle, discovered by Faraday in 1831, is the foundation of almost all electrical power generation and use on earth. Understanding it in its physical reality — not just as an abstract fact — is the beginning of being able to repair and eventually reproduce these machines.
Types of motor — what exists in community systems
AC induction motorThe most common motor in all industrial and domestic applications. No brushes, very durable, low maintenance. Found in pumps, fans, compressors, and most machine tools. Speed is determined by the AC frequency (50Hz in NZ) and pole count — fixed speed, or variable speed with a Variable Frequency Drive (VFD). Fails most often from bearing wear and winding insulation breakdown from overheating.
DC brushed motorSimple, controllable, cheap. Speed controlled by varying voltage. Found in older power tools, automotive applications, and small appliances. Brushes (carbon contacts) wear and require periodic replacement — the most common failure point. Easy to repair and rewind.
BLDC (brushless DC) motorElectronically commutated — no brushes. Very efficient, high power density, long life. Found in modern power tools, electric vehicles, and drones. Controlled by an electronic speed controller (ESC). Harder to repair than brushed motors but increasingly dominant.
Stepper motorMoves in precise incremental steps — used in 3D printers, CNC machines, and precise positioning applications. Driven by a dedicated stepper motor driver IC. Fails rarely — usually outlasts the machine it is in. Winding insulation breakdown or bearing failure are the primary failure modes.
Motor repair and rewinding
  1. Bearing replacement is the most common motor repair and requires no special knowledge. Identify the bearing number printed on the outer race, order a replacement (or press a new one from a standard bearing catalogue — all dimensions are standardised), and press the new bearing in with the appropriate driver. A bearing puller and press are the required tools.
  2. Winding insulation testing: a megohmmeter (megger) tests the insulation resistance between winding conductors and the motor frame. Readings below 1MΩ indicate insulation breakdown — the winding is absorbing moisture or has been thermally degraded. Motors with degraded insulation run, but will fail. A reading above 100MΩ is healthy.
  3. Rewinding a motor coil: strip the burned or failed winding from the stator slots (heat helps release the varnish). Count and record the number of turns, wire gauge, and winding pattern (search for the motor's nameplate data and the standard winding configuration for that frame size). Wind new coils of identical specification from magnet wire (enamelled copper wire, available in a range of gauges). Varnish and bake the finished winding to cure the insulation.
  4. This is skilled work requiring practice and the correct winding pattern documentation. The Motor Rewinding Handbook and the texts available on the Electrical Engineering Portal (download to offline library) provide the detailed guidance required. A community with one person trained in motor rewinding has the capability to repair almost any motor — extending equipment life by decades.
Building a simple generator from salvaged parts
  1. A permanent magnet DC generator can be built from salvaged motor components, neodymium magnets (recoverable from old hard drives, speaker magnets, and salvaged motors), and hand-wound coils. The principle: magnets rotate past stationary coils, inducing voltage.
  2. For a wind generator: mount magnets on a rotating disc (rotor), stationary coils on a fixed plate (stator), connected to a shaft driven by wind blades or a water wheel. This axial flux alternator design is well-documented in the open source wind energy community. Hugh Piggott's "A Wind Turbine Recipe Book" is the definitive community-accessible guide — download it to the offline library.
  3. Output is AC (alternating current as the magnets pass the coils) — rectify to DC using a diode bridge and filter with capacitors for battery charging. This is the same circuit used in every automotive alternator.
· · ·
XI
Computing for Long-Term Continuity
Keeping hardware alive, understanding what is inside it, and the long road to community-fabricated computing
Extending hardware life — maintenance, repair, and salvage
Skill 2
Why computers fail and how to address each cause
Storage failure (most common)HDDs fail from mechanical wear of spinning platters — typically 3–5 year mean time between failures. Replace with SSDs (no moving parts, 10+ year life). Clone the drive before it fails — CrystalDiskInfo (Windows) and smartmontools (Linux) read the SMART health data and provide advance warning of impending failure. A failed drive means data loss, not necessarily computer death — replace the drive and reinstall.
Thermal throttling and overheatingDust accumulation in heatsinks and fans reduces airflow and causes thermal throttling (CPU reduces speed to prevent damage) or thermal shutdown. Open every computer annually, blow out dust with compressed air, replace thermal paste on CPU and GPU heatsinks (Thermal Grizzly Kryonaut lasts 5+ years). A computer running 20°C cooler lasts significantly longer.
Battery degradation (laptops)Lithium batteries hold approximately 80% of original capacity after 500 full charge cycles — roughly 2–3 years of daily use. Laptop batteries are replaceable — most unibody laptops require only screwdrivers. 18650 lithium cells (standard rechargeable battery used in laptops, power tools, and EVs) can be sourced individually and battery packs rebuilt. Learning to rebuild battery packs extends laptop life from 3 years to indefinite.
Capacitor failure on motherboardsElectrolytic capacitors on motherboards and power supplies bulge and fail over time, especially when run hot. Visible as swollen or leaking capacitor tops. Easily replaced by soldering in identical value replacements — this repair has saved thousands of otherwise dead computers. An inexpensive repair that requires only basic soldering skill.
Power supply failureThe component most likely to fail in a desktop. Replace rather than repair in most cases — the internal voltages present during operation are lethal. A quality power supply (Seasonic, Corsair, be quiet!) lasts 10+ years. A cheap one lasts 2–3.
Software rotOperating systems accumulate cruft, vulnerabilities, and compatibility issues over time. Linux (Ubuntu, Debian, Linux Mint) is the correct long-term operating system for community computers — free, maintained indefinitely, repairable from command line, runs well on older hardware, and requires no licence fees. Windows 10 support ends October 2025. Begin migrating community computers to Linux now.
The community salvage strategy

Every computer that leaves mainstream use still works — it is merely obsolete for commercial software that requires ever-increasing resources. A 2015 laptop running Linux Mint and hosting the community's Ollama AI, Kiwix library, and local server is a perfectly capable community infrastructure node. Build a relationship with local schools, businesses, and councils who refresh their computers on 3–5 year cycles — the machines they send to e-waste are functional infrastructure for a community that knows what to do with them.

Understanding what is inside a computer — a practical map
Foundation
CPU (Central Processing Unit)The main processor — performs all calculations. Speed measured in GHz (clock cycles per second). Cores: multiple processors in one chip allowing parallel computation. The CPU is almost never the failed component — it is the last thing to die. Modern CPUs last 20+ years if not overheated.
RAM (Random Access Memory)Temporary working memory — where the CPU stores data it is actively using. If RAM fails, the computer crashes randomly or fails to start. Test with MemTest86 (free, boots from USB). RAM is user-replaceable in most computers — slot in more to upgrade, or replace a failed module.
Storage (SSD/HDD)Permanent storage — where the operating system, programs, and data live. The component most likely to cause data loss when it fails. Regular backup to a second drive is mandatory. An SSD is the single most impactful upgrade for an older computer.
MotherboardThe main circuit board connecting all components. Rarely fails if kept clean and cool. When it does fail, capacitor replacement (see above) resolves the majority of cases. The BIOS/UEFI chip on the motherboard contains the firmware that starts the computer — replaceable by soldering in a new chip.
GPU (Graphics Processing Unit)Processes visual output and, critically, AI computation. The local AI server runs significantly faster with a GPU. Modern GPUs are expensive — salvage is the primary community source. A failed GPU often has overheated solder joints that can be reflowed.
Power supplyConverts mains AC or battery DC to the voltages the computer needs (12V, 5V, 3.3V). The most common cause of a computer that powers off immediately or fails to start. Replace rather than repair.
The long road — community semiconductor fabrication (50+ years)
50+ year horizon
"Modern semiconductor fabrication requires cleanrooms, photolithography equipment, and supply chains of exotic chemicals that are among the most complex industrial achievements in human history. A community cannot replicate a modern processor. But it does not need to — it needs to understand the principles well enough to make decisions wisely as the technology evolves."
What is actually achievable at community scale in 50 years
The transistor was invented in 1947. The first integrated circuits were made in university labs with relatively simple equipment. The community-scale semiconductor capability worth targeting is not cutting-edge processors — it is simple circuits: diodes, transistors, basic ICs, and microcontrollers equivalent to 1970s–1980s technology. This is sufficient to control motors, process sensor data, manage power systems, and implement communication protocols. It does not require a billion-dollar fab — it requires clean working conditions, basic photolithography, and specific chemical processes that are documentable and teachable.
The prerequisite knowledge chain
  1. Solid state physics: the quantum mechanical behaviour of semiconductors (silicon, germanium) that makes transistors possible. This is undergraduate physics — teachable, understandable, and preserved in every physics textbook. Download "Semiconductor Physics and Devices" by Neamen to the offline library.
  2. Crystal growth: silicon must be grown as a pure single crystal from molten silicon — the Czochralski process. Requires a high-temperature furnace (1,415°C for silicon) and very high purity source material. The Czochralski process is well-documented and has been replicated at university scale. Silicon from sand (SiO2 reduced with carbon at high temperature) is the starting point.
  3. Doping: introducing controlled impurities into silicon to create N-type and P-type regions. Boron (P-type) and phosphorus (N-type) are the primary dopants. Diffusion doping from a source gas at elevated temperature is the simplest approach — no ion implanter required.
  4. Photolithography: using light through a patterned mask to expose photosensitive resist on a silicon wafer, then etching to create the desired structures. The PCB toner transfer process (Section IV) is a macro-scale equivalent of this exact process. The PCB experience builds directly applicable intuition.
  5. The community that understands steps 1–4 — even if it cannot yet execute them — makes far better decisions about technology adoption, maintenance priorities, and the long-term direction of its technical development than one that treats computing as a black box. This is the knowledge worth preserving, teaching, and keeping alive across generations until the material capability becomes accessible.
· · ·
XII
Repair Culture
The most important and most neglected skill — fixing what exists before replacing it
Building a repair culture in the community
Now
"The consumer economy survives by making repair seem harder than replacement. This is a design choice, not a technical reality. Most things that break can be fixed. The knowledge required is not exotic. What has been lost is the habit of trying."
The repair hierarchy — in order of priority
  1. Maintenance before repair: most mechanical and electrical failures are preventable with regular maintenance. Lubrication of moving parts, cleaning of electrical contacts, checking fastenings, replacing worn seals and filters before they fail — the cost is minutes and pence rather than hours and dollars.
  2. Diagnosis before action: the single biggest cause of failed repairs is incorrect diagnosis. Before disassembling anything, establish clearly what the failure mode is. What specifically does it not do? What has changed? What happened immediately before it failed? A correct diagnosis usually makes the repair path obvious.
  3. Repair in place before removing: many faults can be repaired without full disassembly. Tighten a loose fastener, clean a dirty contact, replace a single worn component. Save full disassembly for when it is genuinely necessary.
  4. Document the repair: photograph before disassembly. Note what you find. Record what you replace. This documentation is the community's growing repair manual — specific to the actual equipment the community owns. After ten repairs on the same type of pump, the community has institutional knowledge that no manual can replace.
  5. Parts salvage from irreparable items: a washing machine with a dead motor but perfect bearings and a good timer is not a dead machine — it is a bearing store, a wire source, and a component bank. Establish a community salvage parts store separate from the waste stream.
The community repair event

The Repair Café model — a regular community gathering where people bring broken things and skilled volunteers help fix them — is one of the most effective tools for building repair culture. It does several things simultaneously: transfers skills between generations, reduces waste, saves money, builds community relationships, and surfaces what the community's most common repair needs are (which then informs what skills to prioritise developing). Repair Cafés exist throughout NZ. The model is documented at repaircafe.org and the setup guide should be in the offline library.

Offline repair resources to download now
iFixit repair guidesiFixit.com publishes free, community-contributed repair guides for thousands of devices. Their full guide archive can be downloaded as a ZIM file for Kiwix. Includes teardowns, part identification, and step-by-step repair for laptops, phones, appliances, and tools.
Service manualsManufacturers publish service manuals for their equipment — detailed schematics, parts lists, and repair procedures. Manualslib.com, Schematics.com, and manufacturer websites. Download manuals for every piece of community equipment now, while internet access is reliable.
YouTube repair channelsThe practical repair knowledge held by channels like Louis Rossmann (electronics), AvE (mechanical and electrical), This Old Tony (machining), and dozens of others represents an enormous repository of experiential knowledge. youtube-dl and yt-dlp allow bulk downloading of these channels to local storage while internet is available. Do this now.
Haynes manualsFor every vehicle the community operates. Workshop-level repair procedures for every system. The community that maintains its own vehicles internally saves thousands of dollars annually and is not dependent on automotive labour availability.
· · ·
XIII
Coding and Software
Computing without language is meaningless — the skill that makes all other digital systems purposeful
The programming foundation — logic, structure, and language choice
Foundation
"A computer is a tool that does exactly what it is told, and nothing more. The quality of what it does is entirely determined by the quality of the instructions given to it. Coding is the practice of giving precise, purposeful instructions. Without it, the machine is furniture."
The logic layer — before any language

Every program, in every language, is built from a small set of logical structures. Understanding these before learning any specific language means the language itself becomes straightforward — syntax varies, but the logic underneath is identical everywhere.

SequenceInstructions execute in order, one after another. Line 1 runs, then line 2, then line 3. This is the default behaviour. Most of what a program does is sequence.
Selection (if/else)The program chooses between different paths based on a condition. IF the water level is low, THEN start the pump, ELSE stop the pump. Every decision in a program is a selection.
Repetition (loops)Execute a block of instructions repeatedly — either a fixed number of times (FOR loop) or until a condition changes (WHILE loop). Read the sensor every 5 seconds. Process every item in a list. Almost all useful automation is a loop.
VariablesNamed containers that store values. temperature = 32.5. If temperature changes, the variable holds the new value. All data a program works with is stored in variables.
FunctionsNamed, reusable blocks of code. Define once, call many times. read_sensor(), send_alert(), log_to_file(). Functions are the building blocks of any non-trivial program.
Data structuresWays of organising multiple values. A list (array) holds many values in order. A dictionary (hash map) pairs labels with values: {"temperature": 32.5, "humidity": 65, "timestamp": "14:32"}. Choosing the right data structure for a problem is one of the most important programming decisions.
Language selection — the community programming stack
Python — the primary community languageReadable syntax that closely resembles plain English. Runs on everything from a Raspberry Pi to a server. The language of scientific computing, data analysis, AI/ML, automation, and system administration. The Arduino AI server (Ollama), data logging, sensor processing, and all community automation scripts should be written in Python. Free, open source, offline documentation available in full. Start here.
C/C++ — for microcontrollersArduino programming is C/C++. Lower-level than Python — more control over hardware, faster execution, smaller memory footprint. Required for any embedded system (Arduino, ESP32, ATtiny). Learn alongside Python, not instead of it — they serve different purposes and complement each other.
Bash — the Linux command layerThe language of the Linux command line and shell scripts. Automates system tasks: backups, file management, starting services, scheduled jobs. Every community Linux server benefits from basic Bash scripting. Short to learn, immediately useful.
HTML/CSS/JavaScript — for community interfacesThe languages of web pages and web applications. The community dashboard (showing solar power production, water levels, biogas pressure, temperature readings) is a web page. Accessible from any browser on the local network. JavaScript makes it interactive and live-updating.
Learning to code — offline resources
  1. Download the following to the offline library now: Python documentation (docs.python.org — full offline download available), Arduino language reference (docs.arduino.cc — download as PDF), "Automate the Boring Stuff with Python" by Al Sweigart (free online, download as PDF — the best beginner Python resource that exists), the Linux command line tutorial (linuxcommand.org — download), and the MDN Web Docs HTML/CSS/JavaScript reference.
  2. Start with Python and a problem the community actually has: log temperature readings from a sensor to a CSV file. Read that file and calculate daily averages. Send an alert when a value exceeds a threshold. These three tasks teach variables, loops, file I/O, conditionals, and functions — the complete foundation — in the context of something immediately useful.
  3. The Raspberry Pi is the ideal community learning computer: inexpensive, runs Linux natively, has GPIO pins for connecting hardware sensors directly, and is the same hardware running the community AI and library servers. Learning to program on the same hardware that runs community systems means every lesson is directly applicable.
  4. Version control with Git: every piece of community code should be stored in a Git repository. Git tracks every change, allows reverting to previous versions, and documents the history of every decision. This is not complexity for its own sake — it is the difference between recoverable and unrecoverable when code breaks, which it always eventually does. Set up a local Gitea server (self-hosted Git) on the community server as the code repository. Fully offline.
Community coding projects — in order of complexity
Sensor logging dashboardPython + Raspberry Pi reads temperature, humidity, water level, and power sensors every 60 seconds. Writes to a local database. A simple HTML page with JavaScript reads the database and displays live readings, daily graphs, and threshold alerts. Every community system becomes visible and monitorable from any browser on the network.
Automated biogas alertArduino reads pressure sensor on gas storage. If pressure exceeds safe threshold, triggers relay to open relief valve AND sends serial message to Raspberry Pi which logs the event and activates an audible alarm. Two microcontrollers, one Python script, one critical safety outcome.
Irrigation controllerSoil moisture sensors in garden beds feed readings to Arduino. When moisture drops below threshold and time-of-day is within watering window, relay activates pump. Python script on Raspberry Pi logs all moisture data and allows remote adjustment of thresholds. Replaces commercial irrigation controllers with community-owned, locally repairable equivalent.
Local AI customisationPython scripts can call the local Ollama AI with custom system prompts, creating purpose-built assistants: a plant disease identifier (describe the symptoms, get diagnosis), a fermentation troubleshooter, a wiring calculation assistant. Fine-tuning local models on community-specific knowledge (the soil types, the local plant varieties, the specific systems in use) is a more advanced project but creates an AI genuinely adapted to the community's context.
· · ·
XIV
Internal Combustion Engines
The what, how, and why — maintaining, repairing, and understanding the machines that power the community
How internal combustion works — the four-stroke cycle
Foundation
The Otto cycle (petrol/gasoline engines)
A four-stroke engine converts the chemical energy of fuel into mechanical rotation through four piston strokes — two revolutions of the crankshaft per complete cycle. Understanding the cycle in physical terms (not just as a diagram) is the foundation for diagnosing and repairing any engine fault.
Stroke 1 — IntakePiston moves down. Intake valve opens. Air-fuel mixture (petrol engine) or air alone (diesel) is drawn into the cylinder. The intake valve closes at bottom dead centre (BDC). The quality of the charge entering the cylinder — its temperature, density, and mixture ratio — determines everything about the combustion that follows.
Stroke 2 — CompressionBoth valves closed. Piston moves up, compressing the charge. Petrol engines compress to approximately 9:1 (the mixture would ignite prematurely at higher ratios — knock). Diesel engines compress to 14–25:1, generating enough heat to ignite diesel fuel without a spark plug. This is why diesel is more efficient — higher compression ratio, more energy extracted from each combustion event.
Stroke 3 — Power (combustion)Near top dead centre (TDC), ignition occurs — spark plug fires (petrol) or fuel is injected and autoignites (diesel). Combustion expands rapidly, pushing the piston down with force. This is the only stroke that produces work. All others consume it. The timing of ignition relative to TDC — spark advance — critically affects power output and efficiency. Too early = knock. Too late = wasted energy in exhaust heat.
Stroke 4 — ExhaustExhaust valve opens. Piston moves up, pushing burned gases out of the cylinder. The exhaust valve closes, intake valve opens, and the cycle begins again. Incomplete scavenging (exhaust gas remaining in the cylinder) dilutes the fresh charge and reduces power. This is why exhaust system design matters — back pressure from a poorly designed exhaust reduces the engine's ability to expel burned gases.
Two-stroke engines

A two-stroke engine completes the same four events in one crankshaft revolution — power every stroke. Simpler (no camshaft, valvetrain, or oil pump needed), higher power-to-weight ratio, but less fuel-efficient and requiring oil mixed with fuel. Found in chainsaws, small generators, outboard motors, and some motorcycles. Community relevance: chainsaws and small generators are the most common community tools using two-stroke engines — understanding them is immediately practical.

Diesel versus petrol — community implications
Why diesel matters more for community independenceDiesel engines run on biodiesel (community-produced), plastic pyrolysis oil (community-produced), and vegetable oil (community-grown) with minimal modification. Petrol engines require a more refined, volatile fuel that is harder to substitute. For the community transitioning away from external supply chains, diesel-powered equipment is significantly more compatible with community energy production.
Engine longevityA well-maintained diesel engine will run 500,000–1,000,000km or equivalent hours before requiring major rebuild. A petrol engine typically requires major work at 200,000–300,000km. For community vehicles and generators expected to operate for decades, diesel is the long-term choice.
Engine maintenance and repair — keeping community machines running
Skill 2
Preventive maintenance — the hierarchy
  1. Oil and filter: engine oil lubricates every moving internal surface and carries away combustion byproducts. Change at manufacturer's interval or every 5,000km/250 hours of operation (whichever comes first) with quality oil of the correct grade. An engine run on degraded oil wears in months what would otherwise take years. Used oil can be filtered and re-refined for non-engine lubrication applications.
  2. Air filter: a clogged air filter reduces the air-fuel ratio, increases fuel consumption, and reduces power. Inspect and clean at every oil change. Replace when cleaning is insufficient. A community operating in dusty conditions (harvest, earth-moving) should inspect more frequently.
  3. Coolant system: check coolant level and condition regularly. Coolant degrades and becomes acidic over time, corroding the cooling system from inside. Drain and refill every 2 years regardless of appearance. Check hoses for cracking and softness — a failed coolant hose can destroy an engine in minutes through overheating.
  4. Timing belt/chain: the timing belt or chain synchronises the crankshaft and camshaft. If it fails, valves and pistons collide — catastrophic, immediate engine destruction. Replace timing belts at the manufacturer's specified interval (typically 60,000–100,000km or every 5 years). Do not extend this interval. Timing chains last longer but must be inspected for stretch and noise.
  5. Fuel system: diesel engines are sensitive to water contamination in fuel (causes injector failure) and to poor quality fuel. Drain water separators regularly. Use fuel filters appropriate for biodiesel blends — standard diesel filters may not be compatible at high biodiesel percentage.
Common faults and diagnosis
Engine does not startWork through the cranking systems: battery (sufficient voltage?), starter motor (turning the engine?), fuel delivery (is fuel reaching the engine?), ignition (spark present at plugs — petrol?), compression (engine building compression when cranked?). Each check eliminates a category of fault.
Engine starts but runs poorlyMisfiring (one cylinder not firing — check individual spark plugs or injectors), fuel mixture issues (black smoke = rich, white smoke = water/diesel cold start, blue smoke = oil burning), timing (engine knocks = too advanced, poor power = too retarded).
Engine overheatsCheck coolant level first. Then thermostat operation (stuck closed = overheating, stuck open = never reaches operating temperature). Check water pump belt and pump operation. Check radiator blockage (external dirt or internal scale). Check head gasket (white smoke from exhaust + coolant loss = probable head gasket failure).
Oil consumption (blue smoke)Worn piston rings (oil burning past rings from crankcase), worn valve stem seals (oil drawn down valve guides into combustion chamber), or turbocharger seal failure (turbocharged engines). Identifies rebuild requirement — not a quick fix but a known, manageable process.
Haynes and workshop manuals: Download the specific workshop manual for every engine the community operates — generator, vehicle, water pump, tractor. These manuals contain torque specifications, clearances, timing specifications, and step-by-step rebuild procedures that are impossible to work from memory. They are the most important reference documents for mechanical work. Store printed copies and digital copies in the offline library.
· · ·
XV
Metal Additive Manufacturing
Wire arc, paste extrusion, and the emerging capability to print in metal at community scale
Metal 3D printing — beyond plastic, into structural metal parts
Skill 3Emerging
Why this matters
Plastic 3D printing (Machine Commons Section VIII) produces complex shapes but not structural metal parts. The lathe and mill (Section VI) produce precision metal parts but require stock material of the correct profile. Metal additive manufacturing fills the gap: it builds complex metal shapes — bearing housings, custom brackets, impellers, tools — from metal wire or powder, using controlled deposition and fusion. The technology is transitioning from industrial-only to accessible-to-communities in the current decade.
Wire Arc Additive Manufacturing (WAAM)Uses a MIG or TIG welding torch (equipment already described in Section VII) controlled by CNC movement to deposit metal wire in layers, building up a 3D form. The hardware is a standard MIG welder + CNC motion system (already in Machine Commons) + software to generate the deposition toolpaths. No exotic materials or processes. Produces parts equivalent to cast or forged metal in mechanical properties. Resolution is lower than laser powder bed fusion — suitable for large structural parts rather than fine detail. This is the most community-accessible metal printing method and is buildable now from equipment already described in this document.
Metal paste extrusion + sinteringMetal powder mixed with a binder (wax or polymer) is extruded in the same way as plastic FDM — on a standard 3D printer with a high-temperature nozzle. The green part is then fired in a kiln (debinding removes the binder, sintering fuses the metal powder particles). Produces accurate, detailed metal parts. Suitable metals include stainless steel, tool steel, copper, and titanium. The sintering kiln requires reaching 1200–1400°C — within the same range as the glass furnace (Layer Zero Section XVI). The Metal X system (Markforged) was the first commercial implementation; open-source equivalents are now available. This method bridges the gap between the glass furnace/kiln skills in Layer Zero and the precision metal part production capability in the Machine Commons.
Cold spray depositionMetal powder is accelerated to supersonic velocity by a compressed gas jet and impacts a substrate, bonding by kinetic energy rather than heat. Produces dense, high-strength coatings and deposits without heat-affected zones. Used industrially for repair of worn or damaged parts — a bearing journal damaged by wear can be built back up by cold spray and re-machined to specification. Equipment for community-scale cold spray is currently expensive (NZD $50,000+) but cost is falling rapidly. The repair application is particularly valuable — it restores worn parts rather than requiring replacement.
Lost PLA casting (bridge method)Not strictly additive manufacturing, but using plastic 3D printing as a prerequisite for metal casting. Print the desired shape in PLA. Invest (surround) in casting plaster or investment compound. Burn out the PLA in a kiln (PLA combusts cleanly above 300°C, leaving a perfect cavity). Pour molten aluminium, bronze, or iron into the cavity. The result is an accurate metal casting of any geometry the 3D printer can produce. This method is immediately accessible to any community with a 3D printer and an aluminium melting furnace — and aluminium melts at only 660°C, well within the capability of a simple forge or kiln.
Building a WAAM system from existing equipment
  1. Hardware: an existing MIG welder (Section VII) + a 3-axis CNC gantry system. The gantry can be the same MPCNC described in Section IX with the router replaced by a MIG torch mount. The torch must be water-cooled for sustained operation (standard MIG torches overheat quickly in continuous deposition). Water-cooled torch kits are commercially available.
  2. Software: generate deposition toolpaths from a 3D model using slicing software modified for metal deposition (Weld3D and MELTIO software are commercial options; open-source WAAM slicers are emerging). The toolpath specifies: layer height (3–8mm for WAAM, much thicker than plastic printing), deposition speed (wire feed rate + travel speed), inter-pass cooling time, and shielding gas flow.
  3. Process parameters: WAAM produces high residual stress in the deposited metal from the repeated thermal cycles. This must be managed by: controlling inter-pass temperature (allow sufficient cooling between layers), alternating deposition direction each layer, and post-process stress relief annealing (heat to 600°C, hold 1 hour, cool slowly in the kiln).
  4. Post-processing: WAAM produces a rough surface finish that requires machining to final dimensions. The combination of WAAM (builds the near-net shape) + lathe/mill (brings to final dimension and finish) is the complete production cycle. This is why the machining skills in Section VI are the prerequisite for metal additive manufacturing — the two are inseparable in practice.
· · ·
XVI
Solar Panel Construction
How photovoltaic cells work, how panels are assembled, and the long road to community-fabricated solar
How photovoltaic cells work — the physics that makes solar possible
Foundation
The photoelectric effect
When photons (light particles) with sufficient energy strike a semiconductor material, they transfer their energy to electrons, freeing them from their atoms. In a photovoltaic cell, a P-N junction (a boundary between P-type and N-type doped silicon, as described in Machine Commons Section XI) creates an internal electric field that drives these freed electrons in one direction — producing a current. The voltage of a single silicon cell is approximately 0.5–0.6V regardless of size. Current increases with cell area. A standard 60-cell panel (6×10 cells in series) produces approximately 30–36V open circuit.
Panel construction — assembling from purchased cells

Solar cells are available individually from manufacturers and distributors. A community can assemble functional solar panels from purchased cells long before it can fabricate the cells themselves — the assembly process uses skills already present in the community (soldering, basic electronics, glass work).

  1. Source solar cells: monocrystalline or polycrystalline silicon cells are available from suppliers (AliExpress, solar component distributors). Standard 156mm×156mm cells produce approximately 4–4.5W each. For a 200W panel, you need approximately 48 cells. Purchase 10% extra for breakage — cells are fragile.
  2. Tabbing and stringing: solder tabbing wire (thin, tinned copper ribbon) to the bus bars on each cell front face, then to the back of the next cell in series. Work carefully — silicon cells crack easily under point pressure. Use flux, a temperature-controlled iron at 350°C, and a steady hand. Solder the negative (front) of each cell to the positive (back) of the next. This creates a string of cells in series.
  3. Arrange strings: multiple strings of cells in series are connected in parallel to achieve the desired panel voltage and current. Typical arrangement: 4 strings of 12 cells in series = 12 × 0.5V = 6V per string, then 4 strings in parallel for higher current. Adjust string length to achieve your target voltage (typically 18–20V for 12V battery charging, 36–40V for 24V systems).
  4. Encapsulation: the cell array must be protected from moisture and physical damage. Standard process: lay tempered low-iron glass face down. Place EVA (ethylene-vinyl acetate) encapsulant sheet. Lay cell array face down. Place second EVA sheet. Place back sheet (Tedlar/TPT or glass). The sandwich is laminated under heat and vacuum to bond all layers — a vacuum laminator is the industrial tool. DIY alternative: epoxy resin poured over cells on a glass substrate, allowed to cure slowly under a weighted flat plate. Less durable than industrial lamination but functional for community use.
  5. Framing: aluminium angle or channel around the perimeter of the laminated panel, sealed with silicone. Junction box (containing bypass diodes and connection terminals) attached to the back. The bypass diodes are critical — they allow current to flow around a shaded or damaged cell rather than the entire string being limited by the weakest cell.
  6. Test: measure open-circuit voltage (Voc) in direct sunlight — should be close to the sum of cell Voc values. Measure short-circuit current (Isc). Calculate expected power (Voc × Isc × fill factor of approximately 0.75). Compare to expected values. Significant shortfall indicates a broken cell or poor solder joint.
Silicon from sand — the long road to community-fabricated cells

Solar cells require electronic-grade silicon — silicon purified to 99.9999999% (nine nines) purity. The industrial process (Siemens process — chlorosilane distillation) requires specialist chemical equipment. Community fabrication of electronic-grade silicon is a 50-year horizon project at best. The intermediate goal is metallurgical-grade silicon (99% pure) from carbothermic reduction of silica sand in an electric arc furnace — achievable at community scale with the metal-working capability described in this document. Metallurgical silicon is used in aluminium alloys and has many community applications. Converting metallurgical silicon to electronic silicon is the step that currently requires industrial infrastructure.

The nearer-term community solar manufacturing goal

The realistic 15–25 year community solar goal is panel assembly from purchased cells (achievable now with the skills in this document), moving to encapsulant and glass production from community materials (glass from Layer Zero Section XVI, EVA replacement with community-produced epoxy), and eventually to wafer processing from metallurgical silicon as semiconductor knowledge deepens. Each step is meaningful. The community that assembles its own panels from purchased cells is significantly less dependent than one that buys complete panels. The community that produces its own glass for encapsulation is more independent still. Absolute fabrication independence in solar is a genuine long-term goal — not an illusion, but not tomorrow either.

· · ·
XVII
Nuclear Fission — Fundamentals
What it is, how it works, why it matters, and why governance matters more than the technology
The legal landscape — honest framing before the physics
Legal context
Two kinds of law — knowing the difference
Throughout this series, a distinction is made between laws that exist because the physics will harm you regardless of politics, and laws that exist because the current system benefits from your dependency. This distinction matters particularly in nuclear energy, where the two kinds are present simultaneously and easily confused. Being clear-eyed about which is which does not mean ignoring either — it means knowing what you are actually dealing with.
Safety law — the physics does not negotiateIonising radiation causes cellular DNA damage leading to cancer and acute radiation syndrome. The relationship between dose and harm is well-established. Shielding, containment, and controlled access to radioactive materials are requirements that exist because of physics, not politics. These are not obstacles to community nuclear energy — they are the engineering requirements of the technology. A community that takes these seriously is not complying with oppression; it is doing engineering correctly.
Control law — who it serves mattersNZ's nuclear-free legislation (Nuclear Free Zone, Disarmament, and Arms Control Act 1987) was written to exclude nuclear weapons and nuclear-powered naval vessels. It does not explicitly prohibit nuclear power generation. The political conflation of nuclear weapons with nuclear power has been used to prevent a legitimate energy option from being discussed seriously in NZ policy. This is control law — it serves the interests of fossil fuel incumbents and nuclear weapons states, not the interests of communities seeking energy independence. Knowing this does not make the law irrelevant — it means working to change it through legitimate means while building the knowledge base that makes informed change possible.
The practical position: No community in NZ is building a nuclear reactor in the next 20 years — the regulatory, financial, and technical barriers are real. What a community can and should do is understand the technology well enough to participate meaningfully in the public conversation about it when it becomes politically active (and it will, as climate and energy security pressures mount), and to advocate for community-governed rather than corporate-governed nuclear energy when it becomes available.
Nuclear physics fundamentals — what fission actually is
Foundation
The atomic nucleus and binding energy

Every atom has a nucleus containing protons and neutrons held together by the strong nuclear force. This binding energy — the energy required to break the nucleus apart — is enormous. When a heavy nucleus (uranium-235, plutonium-239, thorium-233) is struck by a neutron and splits (fissions) into lighter nuclei, the binding energy difference between the original heavy nucleus and the smaller product nuclei is released as heat, gamma radiation, and the kinetic energy of the fission products. This released energy — from Einstein's E=mc² — is approximately 2 million times greater per kilogram of fuel than burning coal or oil. This is the fundamental reason why nuclear energy is worth understanding: the energy density is in a completely different class from every other fuel.

The chain reaction
  1. A neutron strikes a uranium-235 nucleus. The nucleus absorbs the neutron, becoming unstable uranium-236, which immediately fissions into two smaller nuclei (fission products) and releases 2–3 additional neutrons.
  2. Those 2–3 neutrons each strike other uranium-235 nuclei, releasing 4–9 more neutrons. Each of those releases 8–27 more. Left unchecked, this exponential multiplication — a supercritical chain reaction — occurs in microseconds, releasing all energy at once. This is a nuclear weapon.
  3. In a power reactor, the chain reaction is controlled to remain exactly critical — each fission event causes exactly one more fission event. This is achieved by: neutron-absorbing control rods inserted into the reactor core (absorb excess neutrons, slowing the reaction), a moderator material (water, heavy water, graphite) that slows neutrons to the speed at which uranium-235 fissions most readily, and engineering margins that keep the reactor in the stable, controlled regime.
  4. The heat produced by the controlled chain reaction is used to boil water, produce steam, and drive turbines — exactly the same Rankine cycle described in the steam section above (Practical Guide, Section IV·III). The nuclear reactor is simply a heat source of extraordinary energy density and very long fuel life.
Why different reactor types matter
Pressurised Water Reactor (PWR)The most common globally. Water under high pressure (150–160 bar) acts as both coolant and moderator. The high pressure prevents boiling and allows the water to reach 320°C. Pressurised water transfers heat to a secondary steam loop, which drives the turbine. The primary loop water is never released — the secondary steam is clean. Most safety incidents in PWRs have involved loss-of-coolant — water stopping flowing, causing overheating. Fukushima and Three Mile Island were both loss-of-coolant accidents in LWRs.
Liquid Fluoride Thorium Reactor (LFTR)The reactor design most relevant to community energy discussion. Uses thorium-232 as fuel (converted in-reactor to uranium-233, which fissions). The fuel is dissolved in a molten fluoride salt — already in a liquid state. If the reactor overheats, the liquid expands and the chain reaction slows automatically (negative temperature coefficient — physics-based safety). A freeze plug at the bottom of the reactor — kept frozen by active cooling — melts if power is lost, draining the fuel salt by gravity into subcritical storage tanks. The reactor cannot melt down because the fuel is already molten. Cannot produce weapons-grade material in the standard thorium cycle. Operates at atmospheric pressure (no high-pressure containment needed). Produces far less long-lived waste than uranium reactors. NZ has domestic thorium deposits. The technology was proven at Oak Ridge National Laboratory in the 1960s before being abandoned for political reasons (it cannot produce weapons-grade plutonium — making it useless to weapons programs). Currently being re-developed in China, India, and by several private companies.
Small Modular Reactors (SMR)Factory-built nuclear reactors in the 50–300MW range, designed for serial production and reduced construction time and cost. First commercial units entering operation internationally in the 2025–2030 period. PWR-based designs from NuScale, Rolls-Royce, and others. The key distinction for community energy: SMRs are designed for decentralised deployment — not requiring the massive grid-connection infrastructure of large reactors. A community cooperative owning and operating an SMR is not technically implausible — it is politically and financially implausible in the current decade, but the technology is moving in the right direction.
Nuclear fusion (for completeness)Fusing light nuclei (hydrogen isotopes — deuterium and tritium) rather than splitting heavy ones. Releases energy through mass deficit, same E=mc² principle. Fuel from seawater. No long-lived radioactive waste. No runaway chain reaction possible. The ITER project (France) is demonstrating feasibility. Commercial fusion is a 2040–2060 horizon for community-accessible scale. Included here because the community that understands fission is positioned to understand fusion — they are the same physics in opposite directions.
Radiation — types, effects, and protection
Alpha radiationHelium nuclei. Blocked by a sheet of paper or the outer layer of skin. Dangerous only if inhaled or ingested — then direct contact with sensitive tissue. The primary hazard in thorium and uranium handling.
Beta radiationHigh-energy electrons. Penetrates several millimetres of tissue. Blocked by 5–10mm of aluminium or similar. Burns skin on direct contact. Handled with gloves and distance.
Gamma radiationHigh-energy photons — the most penetrating. Requires centimetres of lead or metres of water or concrete for significant attenuation. The primary external radiation hazard from reactor operation and from spent fuel. Shielding design is the primary engineering response.
Neutron radiationPresent only near an active reactor or certain neutron sources. Penetrates almost everything. Requires hydrogen-rich shielding (water, polyethylene) — hydrogen nuclei are the same mass as neutrons and transfer the most energy per collision. Neutron activation — making surrounding materials radioactive by neutron bombardment — is a secondary hazard unique to reactor operation.
Dose and effectRadiation dose is measured in sieverts (Sv). Background radiation in NZ: approximately 2mSv/year. Chest X-ray: 0.1mSv. Cancer risk begins to increase measurably above 100mSv cumulative dose. Acute radiation syndrome (radiation sickness) begins at 1Sv acute dose. Lethal dose (50% probability) at approximately 4–5Sv acute dose. Worker limits: 20mSv/year averaged over 5 years. The dose-response relationship at low doses remains scientifically debated (linear no-threshold model vs threshold model) — but at community-governance level, maintaining doses As Low As Reasonably Achievable (ALARA) is the correct practice regardless of the debate.
Half-life and wasteRadioactive isotopes decay over time — the half-life is the time for half the atoms to decay. Uranium-235: 704 million years. Caesium-137 (fission product): 30 years. Iodine-131: 8 days. Nuclear waste concern is about long-lived isotopes — primarily actinides (plutonium, americium) from uranium reactors. Thorium reactors produce dramatically less long-lived waste because the thorium cycle does not produce significant transuranics. Most LFTR waste has decayed to background levels within 300 years — a fundamentally different waste management challenge than the 10,000+ year requirement for uranium spent fuel.
What communities should be doing now
  1. Build energy literacy through the systems already described. A community that has governed shared solar panels, a biogas digester, and a biodiesel operation has built the decision-making culture required to approach nuclear energy wisely. You cannot govern a reactor well without first having governed something simpler.
  2. Download and preserve the technical literature. The LFTR technical papers from Oak Ridge (available freely via the Molten Salt Reactor Experiment declassified documents), the NuScale SMR design documentation, and the IAEA Small Modular Reactors technical series are all public domain and should be in the offline library. This knowledge should not depend on internet access to exist in the community.
  3. Engage the public conversation actively. NZ's nuclear-free legislation will be revisited — the pressures of climate change and energy security will force it. Communities with technical literacy contribute substantively to that conversation. Communities without it have it decided for them by those with the most political power.
  4. Advocate for community ownership as the non-negotiable condition. When NZ eventually debates allowing nuclear power, the debate about who owns it is as important as the debate about whether to allow it. Corporate-owned nuclear reproduces every problem of corporate-owned fossil fuel. Community-owned nuclear, with full transparency, democratic governance, and binding accountability, is a genuinely different thing.
· · ·
XVIII
The Long Horizon
What a community with full machine commons capability looks like in 50 years
The destination — stated plainly so every earlier decision points toward it
Vision
"Industrialisation did not fail because it made machines. It failed because it put machines in the service of accumulation rather than in the service of life. The community that builds a lathe, a welder, and a CNC router is not repeating that mistake. It is correcting it."
Year 50 — what the community can do
A community with 50 years of building the Machine Commons can: manufacture every mechanical component required by its water, energy, and food systems internally. Repair and rewind every motor it owns. Fabricate circuit boards for its own monitoring and control systems. Program and maintain its own computing infrastructure on salvaged and eventually self-fabricated hardware. Train its own children in these skills through apprenticeship, not just in school. Build new machines from raw metal when existing machines fail. And — most importantly — make collective decisions about which technologies to adopt, at what scale, and in whose interest, from a position of genuine technical literacy rather than enforced ignorance.
What to do now — the most important actions in the near term
  1. Download everything. The iFixit archive, the YouTube repair channels, the Arduino documentation, the KiCad library, the lathe manuals, the winding handbooks, Hugh Piggott's wind turbine guide, the MPCNC build files, the FreeCAD tutorials. Do this while the internet is reliable. The offline library is the first and most critical investment.
  2. Find the people who know. In any rural community in the Waikato, there are retired electricians, mechanics, machinists, and electronics technicians who hold knowledge that is not written anywhere. Find them, respect them, learn from them, and record what they teach with their permission. This is the most time-sensitive action in this document — these people are aging and the knowledge ages with them.
  3. Start a repair night. Once a month, once a fortnight. Bring things that are broken. Fix them together. The skill builds faster in community than in isolation, and the culture builds with the skill.
  4. Acquire a multimeter, a soldering iron, and a set of quality screwdrivers. These three tools make 80% of electronic and electrical repairs accessible. They cost less than a single call-out fee for a tradesperson.
  5. When the community's first machine is acquired — a lathe, a welder, a 3D printer — make the learning of it a community project. Not one person's tool. Every member who is interested learns to use it. The knowledge distributes or it dies with the one person who holds it.
✦

All documents in this series are free. Share them, build upon them, correct them where they are wrong, deepen them where they are thin. No permission required. No attribution required. Take what is useful and pass it forward.

thecodex.co.nz

I — Foundations · The declaration · Start here
II — The Practical Guide · Food, water, energy, medicine, knowledge
III — Layer Zero · Prerequisites · Hemp, glass, lye, methanol, smithing, building
IV — Living Systems · Animals, fermentation, dairy, bees, salt, preservation
V — The Machine Commons · This document · Electricity, electronics, machining, welding, code, steam, computing
VI — Community Life · Emergency medicine, governance, education, textiles, weather, security

Written in Aotearoa New Zealand, 2026. The microcosm mapping onto the macrocosm.