Doc #91 — Machine Shop Operations and Training

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RECOMMENDED ACTIONS

First week:

1. Classify all machine shop operators and experienced machinists as critical-skills personnel (Doc #1)
2. Issue guidance to machine shops: preserve all consumable stocks (cutting tools, abrasives, bearings, measuring instruments). No disposal of any tooling or materials.
3. Contact MSL (Measurement Standards Laboratory) to confirm status and security of national measurement standards

First month:

4. Begin national census of machine shops, equipment, and skilled personnel (Doc #8 — machine shops as a specific census category)
5. Inventory all precision measuring instruments (gauge blocks, micrometers, surface plates) in NZ machine shops, polytechnics, and calibration laboratories
6. Inventory distributor stocks of cutting tools, bearings, abrasives, and V-belts (Category A requisition, Doc #1)
7. Identify all machinists aged 55+ with manual machining experience — these are the priority knowledge-capture subjects
8. Begin structured knowledge-capture interviews and filming of experienced machinists demonstrating manual techniques (tool grinding, manual threading, workpiece setup, scraping)

First 3 months:

9. Assess all CNC machines nationally for manual convertibility
10. Establish emergency machining training programs at Te Pūkenga polytechnics, prioritising Phase A curriculum (Section 7.2) for existing tradespeople
11. Pair experienced manual machinists with 2–4 learners each in working shops (master-apprentice model)
12. Allocate gauge block sets and surface plates to regional centres as backup measurement standards
13. Begin testing tallow and plant oil cutting fluid substitutes in working shops

First year:

14. First cohort of retrained machinists reaches useful basic competence (Phase A–B complete)
15. Establish regional machining capability in all NZ regions — ensure no region is without functioning manual machine tools and trained operators
16. Standardise priority replacement parts lists for agricultural equipment, hydro maintenance, and gasifier production — pre-plan the most common jobs
17. Develop NZ-specific HSS tool grinding curriculum and distribute to all training centres
18. Begin assessment of NZ abrasive mineral deposits (garnet, emery) for grinding wheel production

Ongoing:

19. Continue training pipeline — maintain throughput of new machinists entering the trade
20. Monitor machine tool condition nationally. Establish maintenance standards and inspection schedules.
21. Develop machine tool repair capability (way regrinding, spindle bearing replacement, lead screw replacement) at regional centres
22. Begin foundry production of machine tool castings (Doc #93) in preparation for eventual machine tool bootstrap
23. Develop and maintain NZ-specific machining reference manual: speeds and feeds for NZ-available materials, tool geometry for HSS and carbon steel tools, heat treatment procedures for NZ steel grades

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Economic Justification

Person-years required: building and maintaining NZ’s machine shop network

The machine shop network is an ongoing human capability that must be built, maintained, and expanded across all recovery phases. The labor investment has two components: operating the existing shops, and training the next generation of machinists.

Operating labor (existing shops):

Role	Estimated current NZ count	Recovery-period function
Experienced manual machinists (55+)	Unknown — census required; rough estimate 500–1,5002	Primary production and knowledge transmission
CNC machinists (all ages)	Unknown — probably 2,000–5,000	Production on CNC (finite), retraining to manual
Agricultural repair engineers	Unknown — probably 800–1,500 (rural distribution)	Farm equipment repair — highest-volume demand
Automotive machine shop operators	Unknown — probably 100–300	Engine reconditioning, brake and shaft work
Industrial maintenance machinists	Unknown — embedded in major facilities	Plant-specific maintenance at Fonterra, NZ Steel, etc.

All “unknown” figures above reflect the genuine current state of NZ data. The census (Doc #8) must establish these numbers. The estimates given are rough order-of-magnitude figures based on manufacturing sector employment data and industry observation, not verified counts.³

Training pipeline investment:

To maintain NZ’s machining capability through the recovery period — replacing the machinists who retire, die, or become incapacitated — requires a sustained training pipeline. A rough model:

• If NZ has approximately 1,000 working manual machinists aged 55–75, and the average productive years remaining is 10–15, NZ needs to train approximately 70–100 new manual machinists per year to maintain current capacity.
• Under recovery conditions, demand for machining will increase (every piece of equipment that breaks needs a machined part) while CNC capability declines (controllers failing). The training requirement almost certainly exceeds steady-state replacement.
• Plausible target: 200–400 new machinists trained per year at Phase A–B level (6–12 months each), with 40–80 progressing to advanced competence (Phase C–D) per year.
• At an average of 6–12 months to basic competence per trainee (depending on prior trade background), training 200–400 machinists per year requires approximately 100–400 person-years of trainee time per year — plus instructor time at roughly 1 instructor per 3–5 trainees, adding 40–130 person-years of skilled machinist time per year diverted from production.
• Net training cost: approximately 150–500 person-years per year at full pipeline, declining as the trained cohort matures and can train others. The wide range reflects uncertainty in trainee throughput rates and the instructor-to-trainee ratio achievable in practice.

Total labor investment (rough estimate):

Component	Person-years (Year 1)	Person-years (Years 2–5, per year)
Operating existing shops (all categories)	4,000–8,000 (existing workforce)	4,000–8,000 (declining as CNC fails)
Training new machinists	100–150 (ramp-up phase)	250–350 (full pipeline)
Knowledge capture (filming, documenting experienced machinists)	10–20	5–10 (ongoing)
Census of shops, equipment, and personnel	5–15 (one-time)	—
Consumables management and allocation	5–10	3–5
Net new investment above current baseline	~120–200	~260–370

The “operating” labor is already employed — it is not new investment. The new investment is training, knowledge capture, and management. At 300 person-years per year at full pipeline, this is a significant but not extraordinary commitment relative to the recovery value produced.

Comparison: functional machine shops vs. inability to repair or fabricate

The alternative to investing in machine shop capability is systematic failure to maintain every piece of mechanical infrastructure in NZ. The comparison is not abstract:

Agricultural equipment: NZ has approximately 65,000 farms operating tractors, milking machines, feed-out wagons, and other mechanical equipment.⁴ Each piece of equipment will eventually fail and need machined parts — shafts, bushings, hydraulic components, bearings housings. Without machine shops, these machines break and stay broken. At even a 5% annual failure rate requiring machined parts, that is 3,250 farm machinery repair jobs per year that cannot be done. Each failed machine represents lost food production.

Hydro generation: NZ’s hydro stations generate approximately 55–65% of NZ’s electricity in a normal year, depending on rainfall.⁵ Turbine components — runner blades, shaft seals, bearing journals, gate valve seats — all require precision machining for maintenance and repair (Doc #65). Without machine shop capability, maintaining the hydro fleet becomes increasingly impossible as components wear out and cannot be replaced. The consequence is progressive loss of generating capacity — which cascades into everything else that depends on electricity.

Wire production: Drawing wire (Doc #105) requires machined dies of precise geometry. A die failure that cannot be replaced halts wire production entirely. Wire is needed for fencing (which contains livestock, which is NZ’s primary food export), electrical connections, and dozens of other applications. No machine shop capability = no wire drawing replacement dies = progressive degradation of NZ’s wire-dependent industries.

The cascade: Because machine shops are the meta-capability underlying all other manufacturing and repair, the failure to invest in them does not produce a single specific shortage. It produces a cascade of parallel failures across every sector simultaneously — agriculture, energy, transport, maritime, construction — as each sector progressively loses the ability to repair its own equipment.

Breakeven

Machine shops are not an investment that has a breakeven point in the conventional sense — they are foundational infrastructure, like roads or water supply. The more useful framing is: what is the first repair job that a trained machinist makes possible that would otherwise have been impossible?

For the knowledge capture programme specifically (the most time-sensitive component), the breakeven is extremely short. If one experienced machinist teaches manual thread cutting to four apprentices before dying or becoming incapacitated, and those apprentices each train four more, the investment of one instructor-year preserves a capability that would otherwise be lost permanently. There is no substitute for this once the knowledge holder is gone.

For the training pipeline: a machinist trained over 6–12 months and working productively for the following 15–25 years produces an estimated 14–24 person-years of machining labor for a cost of 0.5–1 person-year of training plus 0.15–0.30 person-years of instructor time. This is a return ratio of roughly 10:1 to 20:1 on the training investment, depending on career length and training duration — before accounting for the multiplier effect if the trained machinist later becomes an instructor.

Opportunity cost

The primary opportunity cost of the training pipeline is the instructor time diverted from production. At the recommended scale (40–130 person-years per year of experienced machinist time as instructors), this represents perhaps 3–15% of NZ’s total experienced manual machining capacity diverted from production to teaching, depending on the actual size of the experienced workforce (unknown without the census). This is the correct tradeoff: a 5–10% short-term production reduction in exchange for a sustained training pipeline that prevents the collapse of NZ’s entire machining capability over the following decade.

The opportunity cost of knowledge capture (filming and documenting experienced machinists) is negligible — perhaps 5–15 days per machinist for structured interviews and demonstrations, with minimal disruption to productive work.

The one genuine tension is between using experienced machinists for production (fixing the immediate equipment backlog) and using them for teaching (preserving the long-term capability). This tension cannot be entirely resolved — it must be managed, with an explicit allocation target. A reasonable starting point: every machinist aged 60+ should be allocated at least 20% of their working time to formal teaching, regardless of production pressure. At 65, this rises to 40%. At 70, teaching becomes the primary role and production secondary. This progression captures knowledge before capacity declines while maintaining production in the critical early years.

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1. WHY MACHINE SHOPS ARE FOUNDATIONAL

1.1 The meta-capability

Manufacturing is a chain of capabilities, each depending on the others. At the base of that chain sits the ability to shape metal to specified dimensions. Consider what happens when any piece of essential equipment breaks:

• A hydro station gate valve needs a new shaft seal seat. Someone must turn that seat on a lathe to within 0.05 mm of the specified dimension, or it leaks.
• A wood gasifier needs a new air inlet nozzle. Someone must machine that nozzle from steel bar stock.
• A wire drawing operation needs new dies. Someone must machine and finish those dies to precise internal profiles (Doc #105).
• A tractor’s hydraulic pump fails. The replacement pump does not exist — it must be rebuilt, which means machining new pistons, bores, or valve seats.

In each case, the chain leads back to a machine shop: a lathe, a milling machine, a grinder, and a person who knows how to use them. Without that capability, broken equipment stays broken. And in a world without imports, every piece of equipment will eventually need repair.

1.2 The “just” problem

Recovery planning documents — including earlier drafts of documents in this library — sometimes say things like “just machine a replacement part.” This phrase conceals an enormous amount of implicit capability. Making a replacement hydraulic pump piston, for example, actually requires:

1. Material: A suitable piece of steel or bronze bar stock of the right alloy, diameter, and length. Where does this come from? NZ Steel (Doc #89) produces structural steel, not precision bar stock. Existing stocks of bar, rod, and plate are finite.
2. Measurement: The old part must be measured accurately. If it is worn, the original dimensions must be inferred or found in documentation that may not exist. This requires micrometers, calipers, bore gauges — precision instruments that are themselves imported and irreplaceable.
3. Tooling: Cutting tools (lathe tools, drills, reamers) of the right geometry and material. These wear out with use and must be sharpened or replaced.
4. Machine capability: A lathe large enough to hold the workpiece, rigid enough to cut accurately, and in good enough condition to hold tolerance. Not every lathe can make every part.
5. Skill: A machinist who knows how to set up the work, select the right cutting speed and feed, achieve the required surface finish, and measure the result. This is not a weekend skill. Basic competence takes months; genuine proficiency takes years.
6. Heat treatment: If the part needs to be hardened (a pump piston might), someone must heat-treat it — requiring knowledge of the steel’s composition, a suitable furnace, and quenching capability.

Every time this library says “machine a replacement part,” all six of these requirements are implied. This document exists to ensure they are met.

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2. NZ’S CURRENT MACHINE SHOP LANDSCAPE

2.1 Types of shops

NZ’s machine shop capability exists across several distinct categories:

Precision engineering firms: Companies with modern CNC and manual equipment capable of tight-tolerance work (±0.01 mm or better). Concentrated in Auckland, Christchurch, and Hamilton. Examples include firms in the Onehunga–Penrose industrial area of Auckland, the Woolston–Bromley area of Christchurch, and the Te Rapa–Frankton area of Hamilton. These shops serve the dairy industry, marine sector, oil and gas, and general manufacturing. Typical equipment includes CNC lathes and mills, surface grinders, cylindrical grinders, CMMs (coordinate measuring machines), EDM (electrical discharge machining), and precision measurement labs.⁶

General jobbing shops: Smaller operations serving local industry with a mix of manual and CNC machines. Found in most NZ towns with any industrial base. Typically a few lathes, a mill or two, a drill press, welding equipment, and a surface plate. These shops do repair work, one-off parts, and small production runs. They are the backbone of NZ’s local manufacturing capability.

Agricultural repair workshops: Found throughout rural NZ, often associated with farm machinery dealerships or independent rural engineers. Focused on keeping farm equipment running — welding, basic machining, fabrication. Equipment tends toward robustness rather than precision: older lathes, large drills, heavy welding gear. The machinists in these shops often have decades of experience making things work with limited resources — exactly the skill set needed under recovery conditions.

Automotive machine shops: Specialising in engine reconditioning — boring cylinders, grinding crankshafts, resurfacing heads. NZ had a significant engine reconditioning industry that has contracted as replacement engines became cheaper to import than rebuild.⁷ The remaining shops have specialised equipment (boring bars, crankshaft grinders, valve seat cutters) that is directly relevant to keeping internal combustion engines running.

Industrial maintenance workshops: Operated within major industrial facilities — Fonterra dairy plants, NZ Steel at Glenbrook, Methanex at Motunui, meat processing plants. These workshops maintain the plant’s own equipment and have equipment and skills matched to that plant’s needs. They may not be visible in business directory searches but represent significant capability.

Educational workshops: Te Pūkenga polytechnics (formerly ITPs — Institutes of Technology and Polytechnics), universities, and some secondary schools have training workshops with machine tools.⁸ These are primarily teaching facilities but represent equipment and, critically, people who know how to teach machining.

2.2 Geographic distribution

Machine shop capability correlates with population and industrial activity. Auckland, Christchurch, and Hamilton have the greatest concentration. But most NZ towns of any size — from Whangārei to Invercargill — have at least one general engineering shop. The rural distribution matters because agricultural equipment fails on farms, not in cities, and transport of broken equipment to distant workshops is costly in fuel and time.

The actual distribution is unknown without the census (Doc #8). The census should capture: location, equipment list, condition, capability (what can this shop make?), and — most importantly — the skills and age of the machinists.

2.3 Scale of the sector

NZ’s manufacturing sector employed approximately 230,000 people in 2023, of which metal product manufacturing accounted for a significant portion.⁹ The number of people who can actually operate a lathe or milling machine — as distinct from those who work in manufacturing more broadly — is much smaller and is not captured in standard employment statistics. Engineering NZ (formerly IPENZ) has approximately 22,000 members across all engineering disciplines, but this includes civil, software, and other engineers who have never touched a machine tool.¹⁰

The Motor Trade Association (MTA) represents approximately 3,800 member businesses including automotive workshops, some of which have machining capability.¹¹ The Maintenance, Engineering and Manufacturing Association (MEMA — a NZ industry body, not to be confused with similarly named overseas associations) represents industrial maintenance and engineering firms operating in NZ.¹²

Honest assessment: We do not know how many machinists NZ has, how many machine shops exist, or what their combined capability is. The census must establish this. Estimates in this document are necessarily rough.

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3. CRITICAL EQUIPMENT

3.1 The lathe

The lathe is the most fundamental machine tool. It rotates the workpiece against a fixed cutting tool, producing cylindrical shapes — shafts, bushings, pistons, threads, tapers. A competent machinist with a good lathe and appropriate tooling can make an extraordinary range of parts.¹³

What lathes do: Turning (reducing diameter), facing (making flat ends), boring (enlarging holes), threading (cutting screw threads), taper turning, knurling, parting off. With accessories: gear cutting, grinding, milling (to a limited extent).

What matters in a lathe: Bed length and swing (determines maximum workpiece size), spindle bore (limits bar stock diameter for through-work), rigidity (determines accuracy under load), condition (worn ways and bearings degrade accuracy). A worn lathe can still make parts, but not precise ones. The distinction between “rough machining” (±0.5 mm) and “precision work” (±0.01 mm) depends heavily on machine condition.

NZ context: NZ’s machine shop fleet includes lathes ranging from small bench lathes (150 mm swing) to large industrial lathes (1,000 mm+ swing). The most common and useful size range for general recovery work is centre lathes with 300–500 mm swing and 1,000–2,000 mm between centres. Many NZ shops have older manual lathes — British-made Colchester and Harrison machines were widely imported into NZ through the 1960s–1980s, as were American South Bend machines; Dean Smith & Grace (DSG, UK) was a prestige brand found in higher-precision NZ shops — that are precisely the machines needed, being robust, well-understood, and independent of electronic controls. The actual make/model distribution in NZ shops is unknown without the census (Doc #8).¹⁴

3.2 The milling machine

Milling machines use a rotating cutter against a workpiece that moves on a table in multiple axes. They produce flat surfaces, slots, keyways, pockets, and complex shapes.

What mills do: Face milling (flat surfaces), end milling (slots, pockets, profiles), drilling, boring, gear cutting (with dividing head). Vertical mills (Bridgeport-type) are the most common in NZ shops and the most versatile for general work.

NZ context: The Bridgeport-style vertical mill is ubiquitous in NZ machine shops and is one of the most useful machines for recovery manufacturing. A competent operator with a Bridgeport can machine a wide range of flat-surfaced parts within the machine’s working envelope (typically up to approximately 300 mm × 200 mm table travel for a standard knee mill, though larger variants exist) — covering most agricultural and general repair work. Parts requiring larger flat surfaces need a horizontal mill or bed-type machine, which are less common in NZ shops. Horizontal mills are less common but important for heavy production work.

3.3 Drilling machines

Dedicated drilling machines — pedestal drills, radial arm drills — make holes. While lathes and mills can also drill, dedicated drill presses are faster and more practical for drilling operations, and every NZ workshop has at least one.

3.4 Grinders

Grinding machines use abrasive wheels to produce precision surfaces. Surface grinders produce flat surfaces to very tight tolerances (±0.005 mm). Cylindrical grinders finish round parts. Tool and cutter grinders sharpen cutting tools.

Why grinders matter for recovery: Grinders are the machines that produce the highest precision. When a part must be accurate to a few thousandths of a millimetre — bearing journals, valve seats, gauge surfaces — grinding is how it gets there. Grinders are also essential for resharpening cutting tools (Section 4.1), which becomes critical as carbide insert stocks deplete and NZ reverts to HSS (high-speed steel) tooling that requires regular resharpening.

3.5 Sheet metal equipment

Brakes (for bending), rollers (for curving), shears (for cutting), and folders handle sheet metal work. Much of the fabrication in recovery manufacturing — gasifier bodies, tanks, ductwork, guards — involves sheet metal. NZ has sheet metal shops and equipment throughout the country, often associated with roofing and HVAC businesses.

3.6 Welding equipment

Welding joins metal parts and is covered in detail in Doc #94 (Welding Electrodes). In the machine shop context, welding is used for fabrication (building structures and assemblies), repair (building up worn surfaces for re-machining), and hard-facing (applying wear-resistant material to surfaces). MIG, TIG, and arc welding equipment is widespread in NZ workshops.

3.7 Measuring instruments

This is the most critical and least appreciated category. Measuring instruments are the reference standards that make precision manufacturing possible. Without accurate measurement, a machinist cannot verify that a part meets specification. The part may look right but be 0.1 mm oversize — and 0.1 mm matters when it is a bearing journal or a hydraulic seal seat.

Essential instruments:

• Micrometers: Outside (measure external dimensions), inside (measure bore diameters), depth (measure hole depths). Accuracy typically ±0.01 mm. These are the workhorse instruments of the machine shop.
• Vernier and dial calipers: Less precise than micrometers (±0.02–0.05 mm) but more versatile and faster for routine measurement.
• Dial indicators and test indicators: Measure small displacements — used for aligning workpieces, checking runout, and verifying machine accuracy.
• Gauge blocks (slip gauges): Precision-ground steel blocks of known dimensions, used to calibrate other instruments and to set up machines. A set of gauge blocks is the dimensional reference standard of a machine shop. These are the “reference library” of manufacturing.¹⁵
• Surface plates: Flat granite or cast iron surfaces used as reference planes for measurement and layout. Essential for any precision work.
• Thread gauges, plug gauges, ring gauges: Verify that threads and holes meet standard dimensions.

The measurement problem under recovery conditions: All of these instruments are imported. NZ does not manufacture micrometers, gauge blocks, or dial indicators. When instruments are damaged, lost, or worn beyond calibration, they cannot be replaced. The existing stock of precision instruments in NZ is finite. Preserving, maintaining, and carefully allocating these instruments is as important as preserving the machine tools themselves — arguably more so, because a lathe without measuring instruments produces parts of unknown dimension, which is nearly useless for precision work.

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4. CONSUMABLES AND THEIR DEPLETION

Machine shops consume materials that are steadily used up during operations. Under normal conditions, these are routinely reordered from suppliers. Under recovery conditions, they are finite stocks that must be managed.

4.1 Cutting tools

Carbide inserts: Modern machining predominantly uses indexable carbide inserts — small, precisely shaped pieces of tungsten carbide that are clamped into a tool holder. When one cutting edge is worn, the insert is rotated to present a fresh edge; when all edges are used, the insert is discarded. NZ imports all carbide inserts. The total NZ stock (in distributor warehouses, at tooling suppliers like Sutton Tools, Sandvik, Kennametal distributors, and in individual shop drawers) is unknown but finite.¹⁶

Depletion timeline: Depends entirely on machining volume and the type of work being done. Heavy rough machining consumes inserts faster than light finishing. Insert life varies widely by application: rough-turning hardened steel may consume an edge in 5–20 minutes; finish-turning aluminium may yield several hours per edge.¹⁷ Under recovery conditions, machining volume in most NZ shops will likely be in the range of 20–50% of pre-disruption industrial production (driven by repair demand rather than production runs), but every repair job still consumes tooling. Without an inventory audit, the months of stock remaining cannot be estimated with confidence.

The HSS reversion: As carbide stocks deplete, NZ must revert to high-speed steel (HSS) tools — the standard cutting tool material before carbide became dominant in the 1960s–1970s. HSS tools are slower (lower cutting speeds), require more frequent sharpening, and wear faster on hard materials. But they have a critical advantage: they can be resharpened on a bench grinder or tool and cutter grinder, indefinitely, by a skilled machinist. NZ has substantial stocks of HSS tool blanks and existing HSS tools. The skill of grinding HSS lathe tools and drill bits to the correct geometry is exactly the kind of knowledge held by older machinists and not routinely taught to modern CNC operators.¹⁸

Carbon steel tools: Before HSS, cutting tools were carbon steel — which loses its hardness above approximately 250°C, limiting cutting speeds to roughly 5–15 m/min on mild steel compared to 25–40 m/min for HSS and 100–300 m/min for carbide.¹⁹ Carbon steel tools can potentially be made from NZ-produced steel (Doc #89) but the dependency chain involves several steps that must be verified: NZ Steel (Glenbrook) currently produces structural steels; producing a high-carbon tool steel grade (0.8–1.2% carbon) would require either adjusting the Glenbrook process or using existing imported high-carbon steel bar stock, which is a finite resource. Hardening and tempering then requires a furnace or forge capable of reaching 780–820°C with reasonable temperature control (±20°C), a quenching tank with water or oil, and a machinist trained in hand-hardening technique — skills that are part of the Phase C curriculum (Section 7.2) but not currently widespread. The resulting tools cut at roughly one-fifth to one-tenth the speed of carbide and wear significantly faster, but they work, and once NZ has high-carbon steel production and heat treatment capability, production is indefinitely renewable. This is the ultimate fallback, but it depends on resolving the steel grade and heat treatment prerequisites first.

Cutting tool progression:

1. Carbide inserts (existing stock — best performance, finite)
2. HSS tools (existing stock + resharpened — good performance, long-lasting with skill)
3. Carbon steel tools (NZ-producible — limited performance, indefinitely renewable)

4.2 Cutting fluids

Cutting fluids cool and lubricate the cutting zone, extending tool life and improving surface finish. Modern cutting fluids are petroleum-based emulsions or synthetic formulations, all imported.

Substitutes:

• Tallow (rendered animal fat): Effective as a cutting lubricant for many operations. NZ produces abundant tallow from its livestock industry. Used historically for machining before petroleum-based fluids.²⁰
• Plant oils (rapeseed/canola, linseed): Feasible for some applications. NZ grows rapeseed.
• Dry machining: Many operations can be performed dry, particularly with carbide tools. Tool life is reduced but the work gets done.
• Water with soap (tallow-based): Provides cooling if not lubrication. Better than nothing for flood-cooling applications.

Cutting fluid substitution is feasible because animal fat is locally abundant, though tallow and plant oils provide lower cooling capacity and poorer chip evacuation than modern synthetic or semi-synthetic formulations, and they degrade more quickly in recirculating systems (rancidity within days to weeks in warm conditions). For many individual operations — particularly threading, tapping, and light turning where lubrication matters more than cooling — tallow performs comparably to petroleum-based fluids. For heavy flood-cooling applications, the performance gap is significant.²¹

4.3 Abrasives

Grinding wheels, sanding discs, sandpaper, and lapping compounds are consumed during use. NZ imports virtually all abrasive products.

NZ abrasive minerals: NZ has deposits of garnet (an abrasive mineral) in Westland and other locations, and some emery-bearing rocks have been reported, though their commercial extent is unverified.²² Converting these deposits into usable abrasive products requires a dependency chain that NZ does not currently have in place: geological assessment to confirm grade and quantity; mining or alluvial extraction; crushing, grading, and size-classification of particles (requiring screens, ball mills, and water separation); bonding into grinding wheels using vitrified ceramic bonds (requiring clay, feldspar, and kiln firing at 1,000–1,300°C) or resin bonds (requiring phenolic resins, currently imported); and wheel balancing and testing before use. Each of these steps requires infrastructure and skill not currently operating at production scale in NZ — this is a Phase 3–5 development project, not an immediate substitute. Silicon carbide and aluminium oxide — the primary modern abrasive materials — require industrial chemistry (carbothermal reduction in electric arc furnaces, or the Bayer process for aluminium oxide) that NZ does not currently have and would take many years to develop.²³

Depletion management: Grinding wheel stocks should be inventoried and allocated carefully. Wheels should be used to their minimum safe diameter (not discarded with substantial abrasive remaining, as sometimes happens in commercial practice). Natural sharpening stones (Arkansas, India stones — existing stocks) can substitute for powered grinding in some tool-sharpening applications.

4.4 V-belts and bearings

Machine tools themselves use V-belts (to transmit power from motors to spindles) and bearings (in spindles, slides, and feed mechanisms). These are consumed by wear and cannot be produced in NZ.

V-belts: NZ has stocks across automotive, agricultural, and industrial suppliers. Total stock is unknown. When belts fail, the affected machine is inoperable unless a matching belt is found. Standardisation helps — common belt sizes (A, B, C section) can be cross-matched across many applications. Flat belts (leather or fabric) can sometimes substitute and can potentially be made locally, though flat belts transmit roughly 20–40% less power than V-belts for a given belt width due to lower wedging friction, require more frequent tensioning, and slip more under variable loads — meaning machines may need to run at reduced speed or load.²⁴

Bearings: Anti-friction bearings (ball and roller bearings) are precision manufactured items that NZ cannot produce. Bearing failure in a machine tool spindle is a serious problem. Bearing stocks (held by NZ bearing distributors including CBC Bearings NZ, Motion NZ, and agents for manufacturers such as SKF, NSK, and NTN) should be inventoried and allocated as part of the national consumables strategy (Doc #1).²⁵ For some applications, plain bearings (bronze bushes) can substitute for ball bearings — these can be cast (Doc #93) and machined in NZ, though plain bearings generate 5–10 times the friction of ball bearings at comparable speeds, require continuous lubrication, have shorter service life under high-speed rotation, and cannot match the speed ratings of anti-friction bearings. For machine tool spindles running at moderate speeds (below 500–1,000 RPM), plain bearings are adequate; for high-speed spindles they are not a viable substitute.²⁶

4.5 Depletion summary

Consumable	Current source	NZ stock depth	Local substitute	Timeline to substitute
Carbide inserts	Imported	Months to years (est.)	None — revert to HSS	Immediate reversion as stocks deplete
HSS tool blanks	Imported	Years (est.)	Carbon steel tools (NZ-producible)	Years to establish
Cutting fluids	Imported	Months	Tallow, plant oil	Available immediately
Grinding wheels	Imported	Years (est.)	NZ garnet — unproven	Years to develop
V-belts	Imported	Years (est.)	Flat belts (leather/fabric)	Months to establish
Bearings	Imported	Years (est.)	Plain bronze bearings	Months to establish
Micrometers/calipers	Imported	Existing stock only	None in foreseeable future	N/A — preserve existing

“Est.” appears throughout because NZ has not inventoried these stocks. The census (Doc #8) must include machine shop consumables as a Category A item.

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5. MANUAL MACHINING SKILLS: WHAT IS BEING LOST AND WHY IT MATTERS

5.1 What is being lost

NZ’s most experienced machinists learned their trade through apprenticeships in the 1970s, 1980s, and 1990s — a period when manual machining was the primary method and CNC was either nonexistent or supplementary. These machinists know:

• How to grind a lathe tool from a blank piece of HSS to the correct geometry for a specific operation — rake angles, clearance angles, nose radius — by eye and feel on a bench grinder
• How to read the behaviour of a cutting tool by the sound it makes, the colour and shape of the chips it produces, and the surface finish it leaves
• How to set up a workpiece on a faceplate or in a four-jaw chuck, indicating it true with a dial indicator to within 0.02 mm
• How to cut a thread on a manual lathe by engaging the half-nut at the correct point on the threading dial — a coordination of hand and eye that must be practised to be learned
• How to hand-scrape a surface flat using a surface plate and marking blue — the technique that produces the precision reference surfaces on which all other precision depends
• How to select cutting speeds, feeds, and depths of cut for different materials without consulting a computer

This knowledge is not in any textbook. Much of it is tacit — embedded in the hands and judgement of the practitioner, difficult to articulate, impossible to learn without practice under supervision.²⁷

5.2 The age profile

NZ’s engineering trades workforce is aging. Data from the Tertiary Education Commission and Industry Training Organisation reports indicate that the median age of qualified engineering tradespeople has been rising, with fewer young people entering traditional machining apprenticeships relative to the existing workforce.²⁸ The shift to CNC has meant that many younger machinists are primarily CNC operators — skilled at programming and operating computerised machines but with limited manual machining experience.

This is not a criticism of younger machinists. They are skilled in CNC operation, which was the appropriate skill for a world with functioning electronics supply chains. But under recovery conditions, CNC controllers will progressively fail (Section 6), and the skill that matters is manual operation.

Honest uncertainty: The exact age distribution of NZ’s manual machinists is not known from publicly available data. The claim that experienced manual machinists are predominantly 50–70 years old is based on industry observation and anecdotal evidence from NZ engineering employers, not a systematic survey. The census (Doc #8) must establish this.

5.3 Knowledge capture urgency

If the average experienced manual machinist is 60 years old at the time of the event, NZ has roughly 10–20 productive years to transfer their knowledge to the next generation. This sounds like plenty of time, but:

• Some machinists are older and may have fewer years of active capability
• Health problems, injury, or death reduce the pool without warning
• Knowledge transfer is slow — it takes years of supervised practice, not a weekend workshop
• Every experienced machinist who is not actively teaching represents knowledge that is aging in place, at risk of being lost

Knowledge capture is not the same as knowledge transfer. Capturing (documenting, filming, recording) is a first step that preserves information. Transfer (actually teaching people to do it) requires the master machinist to work alongside the learner for extended periods. Both are needed.

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6. CNC VS MANUAL: THE CONTROLLER PROBLEM

6.1 What CNC depends on

CNC (Computer Numerical Control) machine tools are controlled by electronic controllers — essentially industrial computers — that interpret programmed instructions and drive servo motors to move the cutting tool along precise paths. Modern CNC machines are remarkable: they can produce complex shapes to tight tolerances at high speed, with minimal operator intervention.

They depend on:

• Controllers: Circuit boards, processors, memory, displays, and software. These are manufactured in East Asia (primarily Taiwan, Japan, China) and are not producible in NZ or anywhere in the Southern Hemisphere. Major CNC controller manufacturers include Fanuc, Siemens, Haas, Mitsubishi, and Heidenhain.²⁹
• Servo motors and drives: Precision electric motors that position the machine axes. Also imported.
• Linear encoders and resolvers: Feedback devices that tell the controller where the machine axes actually are. Precision devices, imported.
• Power supply stability: CNC controllers are sensitive to power quality. Voltage spikes, sags, and frequency variation can cause faults or damage.
• Environmental conditions: Controllers are sensitive to dust, moisture, and temperature extremes.

6.2 What happens as controllers fail

Electronic components have finite life. Electrolytic capacitors in power supplies typically have a design life of 5,000–20,000 hours at rated temperature (varying by manufacturer and grade), and degrade faster in adverse conditions — capacitor life roughly halves for every 10°C above the rated temperature.³⁰ Relay contacts wear. Display screens fail. Memory chips degrade. Software may become corrupted.

Under normal conditions, failed controllers are repaired by replacing circuit boards or components, supplied by the manufacturer or specialist repair companies. Under recovery conditions, replacement boards do not exist.

Projected timeline: The existing stock of CNC controllers will progressively fail over years to decades. Some machines will fail early (poor-quality controllers, adverse environments). Some will last for many years (well-made controllers, good conditions). As each CNC machine’s controller fails, the machine becomes inoperable — unless it can be converted to manual operation.

6.3 CNC-to-manual conversion

Some CNC machines retain manual handwheels and can be operated manually if the controller fails. The handwheels were either part of the original design (common on older CNC lathes and mills, particularly conversions from manual machines) or were included as a setup convenience.

Other CNC machines — particularly modern purpose-built CNC machining centres — have no manual controls at all. The axes are moved only by servo motors under controller command. If the controller fails, these machines cannot be operated. They become sources of spare parts (spindle bearings, chucks, toolholding) but not functional machine tools.

The census must assess each CNC machine for manual operability. This is a specific question: “If the controller dies, can this machine be cranked by hand?” The answer determines which CNC machines have a future beyond their controllers.

6.4 Implications for the machine fleet

NZ’s machine tool fleet falls into three categories under recovery conditions:

1. Manual machines: Fully operational, no electronics dependency. These are the most valuable machines in the fleet and should be maintained as top priority. Includes older lathes, manual mills, pedestal drills, manual grinders.
2. CNC machines convertible to manual: Operational on CNC now, with a future as manual machines after controller failure. Valuable in both roles.
3. CNC machines not convertible: Operational on CNC until controller failure, then scrap for parts. Useful now but with a finite operational life that cannot be extended.

The strategic response is clear: maximise the life of CNC controllers (environmental control, power conditioning, careful operation), identify and protect all manual machines, assess all CNC machines for manual convertibility, and begin converting where practical before controller failure forces the issue.

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7. TRAINING PROGRAM DESIGN

7.1 Who to train

Priority 1 — Existing tradespeople with adjacent skills: Welders, fitters, boilermakers, automotive mechanics, and other metalworking tradespeople already understand materials, measurement, and workshop practice. Teaching them to operate a lathe is building on a strong foundation. They can reach useful competence fastest.

Priority 2 — CNC machinists with limited manual experience: They understand machining principles, G-code, tooling, and measurement. They need to develop hand skills — manual feed control, tool grinding, setup without CNC assistance. This is a targeted skill gap that can be addressed with 3–6 months of structured daily practice on manual machines, though developing the hand-feel for manual threading and freehand tool grinding typically takes longer — 6–12 months for competent independent work.

Priority 3 — New entrants with no metalworking background: Younger people, career changers, anyone with mechanical aptitude and willingness to learn. These take longest to train but are the long-term workforce.

7.2 Training curriculum

A phased curriculum, progressing from basic to advanced:

Phase A — Basic lathe operations (first 3 months):

• Machine safety, workshop practice, housekeeping
• Lathe nomenclature and controls
• Workholding: three-jaw chuck, four-jaw chuck, between centres
• Basic turning: facing, parallel turning, shoulder turning
• Drilling and boring on the lathe
• Basic measurement: calipers, micrometers, steel rules
• Cutting tool selection and basic tool grinding (HSS)
• Surface finish and its relationship to speed, feed, and tool geometry

Phase B — Intermediate skills (months 3–6):

• Thread cutting on the manual lathe (single-point threading — the skill most CNC machinists lack)
• Taper turning (compound slide, offset tailstock)
• Basic milling: squaring stock, slotting, drilling on the vertical mill
• Workholding on the mill: vise, clamps, fixtures
• Tolerance interpretation: reading engineering drawings
• Introduction to grinding: surface grinder basics
• Intermediate measurement: dial indicators, bore gauges, gauge blocks
• Tool and cutter grinding: sharpening drills, end mills, lathe tools

Phase C — Advanced skills (months 6–18):

• Precision fitting: making mating parts to specified clearances
• Gear cutting basics (dividing head on the mill)
• Heat treatment: hardening, tempering, annealing of carbon and alloy steels
• Precision grinding: surface and cylindrical
• Advanced measurement: using gauge blocks as standards, checking machine accuracy
• Repair machining: building up worn parts by welding and re-machining
• Introduction to scraping: hand-finishing precision surfaces

Phase D — Mastery (years 2–5+):

• Machine tool maintenance and repair
• Making jigs, fixtures, and tooling
• Complex workholding and setups
• Machine tool alignment and accuracy testing
• Training others (the multiplier skill)
• Making parts for new machine tools (Section 9)

7.3 Training infrastructure

Training requires machines dedicated to teaching (learners make mistakes that can damage machines and consume material), raw material for practice (mild steel bar stock is the standard training material), cutting tools, measuring instruments, and — above all — experienced machinists willing and able to teach.

NZ’s existing training infrastructure: Te Pūkenga (the national network of polytechnics and institutes of technology) delivers engineering trades training through institutions including Unitec (Auckland), Waikato Institute of Technology (Wintec, Hamilton), Western Institute of Technology at Taranaki (WITT, New Plymouth), Universal College of Learning (UCOL, Palmerston North), WelTec (Wellington), Ara Institute of Canterbury (Christchurch), and Otago Polytechnic (Dunedin).³¹ These institutions have workshop facilities and teaching staff, though their focus has shifted increasingly toward CNC and away from manual machining in recent decades.

Training model under recovery conditions: A combination of:

• Formal courses at polytechnic workshops (for new entrants)
• On-the-job apprenticeship in working machine shops (the traditional and most effective model)
• Short courses for existing tradespeople adding machining skills (targeted upskilling)
• Master-apprentice pairing: experienced manual machinists each take on 2–4 learners for intensive, hands-on training

7.4 Realistic timelines

There is no shortcut. Machining skill is developed through practice — cutting metal, making mistakes, learning to feel when a tool is cutting correctly, building hand-eye coordination for manual feed control.

• Useful for supervised basic work: 3–6 months
• Competent for routine jobs with minimal supervision: 1–2 years
• Genuinely skilled — can tackle unfamiliar problems, achieve tight tolerances, train others: 3–5 years
• Master machinist — can make anything the machine is capable of, diagnose problems by sound and feel, design and make tooling: 5–10+ years

The traditional NZ engineering apprenticeship was 4 years for good reason.³²

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8. PRIORITY MANUFACTURING TASKS

8.1 What machine shops will actually be making

Under recovery conditions, machine shops will not be running production lines of consumer goods. They will be making and repairing the specific parts that keep essential systems running. The priority list, roughly in order of urgency:

Agricultural equipment repair (immediate and ongoing): Shafts, bushings, hydraulic components, sprocket hubs, PTO adapters, bearing housings. NZ’s farming depends on machinery — tractors, milking equipment, feed-out wagons, fencing gear — all of which will break and cannot be replaced. Machine shops keep farms running. This is the highest-volume ongoing demand.

Hydro station maintenance (ongoing): Valve components, bearing journals, gate mechanism parts, shaft sleeves. See Doc #65. The hydro system is NZ’s most important single piece of infrastructure, and its maintenance generates steady machining demand.

Wood gasifier production (Phase 1–2): Air inlet nozzles, grate components, gas mixer fittings, flanges. Gasifier construction (Doc #56) is primarily fabrication (welding and cutting) but requires machined components for gas-tight joints and critical dimensions.

Boatbuilding fittings (Phase 2–3): Winch drums, rudder fittings, mast hardware, through-hull fittings, propeller shaft components. See Doc #138. NZ’s maritime recovery depends on building and maintaining vessels.

Wire drawing dies (Phase 2–3): Precisely shaped dies through which wire is drawn to reduce its diameter. See Doc #105. Wire is needed for fencing, electrical applications, and dozens of other uses. The dies are precision-machined parts that wear out with use.

General repair of everything: Pump shafts, valve seats, gear pins, linkage components, hinge pins, lock mechanisms, pipe fittings, brackets, adaptors. The miscellaneous repair demand will be enormous and continuous. Every piece of mechanical equipment in NZ will eventually need a machined part.

Blacksmithing tooling (Phase 1–2): Hardy tools, swages, fullers, mandrels — the tooling that blacksmiths (Doc #92) use to shape hot metal. Some of this tooling is best made on a lathe or mill.

Foundry patterns and tooling (Phase 2–3): Pattern plates, core boxes, and moulding tools for the foundry (Doc #93). Casting and machining are complementary — castings often require machining to achieve final dimensions.

8.2 What machine shops will NOT be making

Machine shops are not factories. They make individual parts and small batches, not mass-produced consumer goods. NZ will not be machining thousands of identical parts on manual lathes — that was possible in WWII because of dedicated production setups, but it requires a scale of organisation and tooling that takes years to establish. The near-term role of machine shops is repair, replacement, and one-off fabrication.

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9. THE MACHINE TOOL BOOTSTRAP

9.1 The challenge

Machine tools wear out. Ways (the sliding surfaces that guide the cutting tool) wear with use, reducing accuracy. Spindle bearings develop play. Lead screws develop backlash. Over decades of use without replacement, machine tools degrade from precision instruments to rough-work-only machines.

Under normal conditions, worn machine tools are replaced with new ones imported from manufacturers in Taiwan, Japan, Germany, China, and elsewhere. NZ does not manufacture machine tools.

Under recovery conditions, the existing stock of machine tools is all there is. When they wear out, NZ must either accept degraded precision or learn to make new machine tools — using the old machine tools as the production equipment. This is the machine tool bootstrap: using machines to make machines.

9.2 Why it is possible

The machine tool bootstrap is how industrialisation actually happened. Every machine tool in the world was ultimately made by another machine tool, and the first machine tools were made by hand. The chain is traceable: hand-scraped surfaces begat the first accurate lathes, which made parts for better lathes, which made parts for milling machines, which made parts for grinders, and so on.³³

A lathe can make most of the cylindrical parts for another lathe — spindles, shafts, chuck bodies. A milling machine can make the flat parts — beds, saddles, cross-slides. A grinder can finish the precision surfaces. The combination of lathe, mill, and grinder — plus casting capability (Doc #93) for the large structural parts — can, in principle, reproduce the entire suite of machine tools. Lead screws are a special case (see Section 9.3).

9.3 Why it is extremely difficult

The principle is tractable in theory. The execution involves compounding difficulties at every step.

The precision problem: A machine tool must be more precise than the parts it produces. A lathe with 0.1 mm of spindle runout cannot make a spindle with 0.01 mm of runout for a new lathe. The bootstrap must either start from machines that are still in good condition (before they are worn out) or use hand-scraping techniques to establish precision independently of machine accuracy.

Hand scraping: The traditional method of producing precision flat surfaces — and therefore the foundation of machine tool accuracy — is hand scraping. A skilled scraper uses a surface plate and marking blue (Prussian blue) to identify high spots on a surface, then removes them with a hand scraper, iterating until the surface is flat to within a few thousandths of a millimetre over its entire area. This technique is independent of machine tool accuracy — it references only the surface plate, which is itself produced by scraping three plates against each other (the three-plate method).³⁴ Hand scraping is the ultimate bootstrap technique, and it is nearly a lost art. If any NZ machinists still practise it, their knowledge is exceptionally valuable.

Casting capability: Machine tool beds, headstocks, and other large structural parts are traditionally made from cast iron, which must be cast in a foundry (Doc #93). NZ’s foundry capability determines whether large machine tool components can be produced locally. Cast iron’s vibration-damping properties make it superior to fabricated steel for machine tool structures, though steel weldments are a feasible if inferior substitute.³⁵

Lead screws: The lead screw is the component that converts rotation into precise linear motion — it is what makes a lathe capable of cutting accurate threads and what moves a milling machine table precisely. Making an accurate lead screw requires either an accurate lead screw to copy from (circular dependency) or a precision-ground screw, or the use of calibration techniques (split nut compensation, thread grinding from first principles). This is one of the hardest problems in the machine tool bootstrap.

9.4 The Gingery approach — and its limits

David Gingery’s series of books, beginning with The Charcoal Foundry (1983), describe building a complete machine shop from raw materials, starting with a charcoal-fired foundry and progressively making a lathe, drill press, milling machine, and other tools.³⁶ This series is widely cited in self-sufficiency circles and provides genuinely useful information.

What the Gingery approach offers: A documented path from minimal equipment to a functioning (if basic) machine shop. Proof of concept that the bootstrap is possible. Practical designs for small machine tools built from aluminium castings.

What it does not offer: Precision. Gingery machines are small, light, and limited in accuracy and rigidity. They can make small parts to modest tolerances. They cannot make the heavy, precise parts needed to maintain industrial equipment, nor can they replace a worn 2-tonne centre lathe. The Gingery series is a starting point for the bootstrap, not an endpoint.

9.5 Realistic timeline

NZ should not plan to need the machine tool bootstrap in the near term. The existing stock of machine tools, if properly maintained, will last decades. The bootstrap is a 10–20 year horizon project — beginning with skills development (hand scraping, precision metrology, foundry capability) and progressing to actual machine tool production as existing machines wear out.

The critical near-term action is not building new machine tools but maintaining existing ones — keeping them lubricated, aligned, protected from damage, and operated within their capabilities.

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10. MEASUREMENT STANDARDS AND PRECISION PRESERVATION

10.1 Why measurement is the real foundation

A machine shop’s capability is ultimately limited by its ability to measure. A lathe can cut to whatever dimension the machinist can verify. If the measuring instruments are inaccurate, every part made in the shop is uncertain. If the instruments are lost, the shop produces parts of unknown dimension — usable only where fit is approximate.

10.2 The calibration chain

Under normal conditions, measurement accuracy is maintained through a calibration chain:

1. National measurement standards (held by MSL — Measurement Standards Laboratory of New Zealand, a division of Callaghan Innovation, based in Lower Hutt)³⁷
2. Calibration laboratories that reference their standards to MSL
3. Workshop instruments calibrated against laboratory standards

Each level references the one above it, and the whole chain ultimately traces back to the SI definition of the metre.

Under recovery conditions, the calibration chain may break. If MSL is unable to function (unlikely — it is a robust institution in a building in Lower Hutt, and the grid is expected to continue — but possible), the national reference standards are unavailable.

10.3 Preserving precision locally

Even without the national calibration chain, precision can be maintained at the workshop level through:

Gauge blocks: A good set of gauge blocks (Johansson blocks) is accurate to within 0.001 mm or better and remains stable for decades if properly stored (dry, temperature-stable, protected from corrosion). Gauge blocks are the local reference standard. Every machine shop that has a set should treat it as irreplaceable — because it is.

Master screws and thread gauges: Reference-grade lead screws and thread gauges establish thread accuracy. A single accurate lead screw can calibrate all thread cutting in a shop.

Surface plates: Granite surface plates are extremely stable dimensionally. They define “flat” for an entire workshop. As long as they are not cracked or damaged, they provide an indefinite reference.

The three-plate method: If no reference flat surface exists, three cast iron or granite plates can be scraped against each other in a three-way rotation until all three are flat — this is a self-referencing method that produces flatness from nothing. It requires only a scraper, marking blue, and patience.³⁸

Ring and plug gauges: If these exist in the shop, they provide fixed-dimension references (e.g., a 25.000 mm ring gauge checks that a turned diameter is exactly 25.000 mm). They don’t wear quickly if used properly.

10.4 Actions for precision preservation

1. Inventory all gauge blocks, master gauges, and surface plates in NZ as part of the census (Doc #8). These are among the most valuable items in any machine shop.
2. Centralise backup standards. MSL’s standards should be duplicated — high-grade gauge block sets distributed to regional centres (Auckland, Hamilton, Wellington, Christchurch) so that no single event can destroy NZ’s entire dimensional reference.
3. Train machinists in calibration techniques. Many working machinists use instruments without understanding calibration. Under recovery conditions, every skilled machinist should understand how to check and adjust their own instruments against gauge blocks.
4. Protect instruments. Store precision instruments in cases, in stable-temperature environments, away from grinding dust and coolant. This is standard workshop practice but is not always followed — enforcement becomes important when instruments are irreplaceable.

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11. WORKSHOP POWER AND INFRASTRUCTURE

11.1 Electrical power

Machine tools are overwhelmingly electric. Lathes, mills, grinders, and drills are driven by electric motors, typically 1–15 kW for workshop-size machines. Under the baseline scenario, NZ’s grid continues operating (85%+ renewable hydro, geothermal, and wind — see Doc #65). Machine shops that are connected to the grid can continue operating.

Backup power: Shops not connected to the grid, or in areas with unreliable supply, need alternative power. Options:

• Wood gas generators (Doc #56) driving workshop motors
• Water power — a small water turbine can drive a workshop via line shaft (this was historically common in NZ — Christchurch’s early industry ran on water power from the Avon and Heathcote rivers)³⁹
• Line shaft systems — a single motor or engine driving multiple machines through an overhead shaft and belt system, as was standard practice before individual electric motors became cheap. This reduces the number of motors needed but requires workshop reconfiguration.

11.2 Three-phase power

Many industrial machine tools require three-phase electrical power. Residential and some rural areas only have single-phase supply. Phase converters (rotary or electronic) convert single-phase to three-phase, but electronic converters depend on imported electronics. Rotary phase converters (essentially a three-phase motor run as a generator) can be built or maintained locally.⁴⁰

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CRITICAL UNCERTAINTIES

Uncertainty	Impact if Wrong	Resolution Method
Number and distribution of NZ machine shops	Cannot plan allocation or training if unknown	National census (Doc #8)
Age profile of manual machinists	Knowledge capture may be more or less urgent than assumed	Census skills survey
CNC machine convertibility to manual	Overestimating convertibility means machines lost when controllers fail	Physical assessment of each machine
Consumable stock depths (carbide, HSS, abrasives, bearings)	Depletion timelines may be much shorter or longer than estimated	Distributor inventory audit (Doc #1)
NZ’s gauge block and precision instrument inventory	If less than assumed, precision manufacturing capability is at risk sooner	Census — include metrology equipment
Foundry capability for machine tool castings	Limits the machine tool bootstrap if inadequate	Assess foundry capacity (Doc #93)
NZ Steel product range expansion	Determines whether bar stock and tool steel can be produced locally	NZ Steel assessment (Doc #89)
Manual machining knowledge actually held by “experienced” machinists	Some may have less manual skill than assumed	Skills assessment, not just age

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CROSS-REFERENCES

• Doc #1 — National Emergency Stockpile Strategy (consumable requisition framework)
• Doc #8 — National Skills and Asset Census (must include machine shops as specific category)
• Doc #33 — Tires (machine shops needed for retreading equipment maintenance)
• Doc #52 — Wire (wire production requires machined components)
• Doc #56 — Wood Gasification (gasifier construction requires machined parts)
• Doc #65 — Hydroelectric Station Maintenance (ongoing machining demand for parts)
• Doc #89 — NZ Steel (local steel production — raw material for machining)
• Doc #92 — Blacksmithing (complementary metalworking capability)
• Doc #93 — Foundry Operations (casting + machining = complete parts)
• Doc #94 — Welding Electrode Fabrication (welding as complementary joining process)
• Doc #105 — Wire Drawing (dies require precision machining)
• Doc #138 — Sailing Vessel Design (fittings and hardware require machining)
• Doc #157 — Trade Training Priorities (machining as core trade skill)
• Doc #160 — Heritage Skills Preservation and Transmission (hand scraping, manual techniques, wānanga-based training models, te reo Māori technical vocabulary)

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1. Tertiary Education Commission (TEC) and Workforce Development Council reporting on engineering trades training. https://www.tec.govt.nz/ — Specific age-profile data for machining trades is not aggregated in publicly available sources. Industry observation from NZ engineering employers consistently notes an aging manual machining workforce. The Hanga-Aro-Rau (Manufacturing, Engineering and Logistics) Workforce Development Council may hold more specific data.↩︎

2. Estimated machinist counts are rough order-of-magnitude figures derived from Stats NZ manufacturing sector employment data (approximately 230,000 total manufacturing workers), the known proportion of metal product manufacturing within that total, and industry observation that a minority of manufacturing workers in NZ can operate a manual lathe or mill. No public data source enumerates machinists as a specific occupation separately from broader manufacturing employment categories. The Hanga-Aro-Rau Workforce Development Council and the Tertiary Education Commission hold some trade-specific data; the national census (Doc #8) is the appropriate mechanism to establish verified counts.↩︎

3. Estimated machinist counts are rough order-of-magnitude figures derived from Stats NZ manufacturing sector employment data (approximately 230,000 total manufacturing workers), the known proportion of metal product manufacturing within that total, and industry observation that a minority of manufacturing workers in NZ can operate a manual lathe or mill. No public data source enumerates machinists as a specific occupation separately from broader manufacturing employment categories. The Hanga-Aro-Rau Workforce Development Council and the Tertiary Education Commission hold some trade-specific data; the national census (Doc #8) is the appropriate mechanism to establish verified counts.↩︎

4. NZ farm count data from Stats NZ agricultural production surveys and MBIE agricultural sector statistics. https://www.stats.govt.nz/ — The 65,000 farms figure is approximate and includes all farms of commercial scale; the number with significant mechanical equipment (tractors, milking machines) that would generate machining demand is a subset. The figure is used here for order-of-magnitude illustration of aggregate demand, not as a precise count.↩︎

5. NZ hydro generation statistics: MBIE, “New Zealand Energy Quarterly,” available at https://www.mbie.govt.nz/building-and-energy/energy-and-n... — Hydro generation varies year to year with rainfall (the “hydro year”) and typically contributes 55–65% of NZ’s total electricity generation. In low-rainfall years this can fall to the low 50s; in high-rainfall years it can exceed 65%.↩︎

6. NZ precision engineering firms are represented by the Maintenance, Engineering and Manufacturing Association (MEMA) and the Employers and Manufacturers Association (EMA). Industry directories (e.g., NZ Manufacturer, Yellow Pages commercial listings) provide partial coverage but no comprehensive national database exists. The geographic concentration in Auckland’s Onehunga–Penrose area, Christchurch’s industrial suburbs, and Hamilton’s Te Rapa–Frankton area reflects NZ’s broader industrial geography.↩︎

7. The decline of NZ’s automotive engine reconditioning industry mirrors global trends. The Engine Reconditioners Association of New Zealand (ERANZ) has documented the contraction as imported replacement engines became cheaper than reconditioning. Remaining shops hold specialised equipment (boring bars, crankshaft grinders) that is directly relevant to recovery manufacturing.↩︎

8. Te Pūkenga was established in 2020 as a merger of NZ’s 16 Institutes of Technology and Polytechnics (ITPs). Engineering trades training programs at these institutions deliver NZ Certificate in Mechanical Engineering and related qualifications. See Te Pūkenga programme listings: https://www.tepukenga.ac.nz/ — Note: Te Pūkenga’s structure and programme delivery may have changed since its establishment; the training facilities and equipment at constituent institutions remain relevant regardless of institutional structure.↩︎

9. Stats NZ, “Business demography statistics,” and MBIE, “Manufacturing sector factsheet.” https://www.stats.govt.nz/ — The 230,000 figure is approximate and includes all manufacturing subsectors. Metal product manufacturing is a significant component but detailed breakdowns by specific skill (e.g., machining vs. assembly vs. management) are not readily available from standard statistical sources.↩︎

10. Engineering New Zealand (formerly IPENZ) membership data: https://www.engineeringnz.org/ — Membership is broadly defined and includes all engineering disciplines. The subset with practical machining skills is a small fraction of total membership.↩︎

11. Motor Trade Association membership data: https://www.mta.org.nz/ — MTA represents automotive businesses, some of which include machining capability (engine reconditioning, brake drum/rotor machining). The 3,800 figure is approximate and subject to change.↩︎

12. Maintenance, Engineering and Manufacturing Association of New Zealand (MEMA NZ): https://www.mema.org.nz/ — MEMA represents approximately 300 member companies in NZ’s industrial maintenance, engineering, and manufacturing sectors. Membership data is current as of 2024; the association’s membership and structure may have changed. MEMA NZ is distinct from similarly named bodies in Australia, the UK, and the USA.↩︎

13. The lathe’s foundational role in manufacturing is well-documented. See Woodbury, R.S., “History of the Lathe to 1850,” MIT Press, 1961. The lathe is sometimes called “the mother of machine tools” because other machine tools were historically made on lathes.↩︎

14. NZ machine tool import history: the UK was NZ’s primary source of machine tools through the post-war period, reflected in the prevalence of British brands (Colchester, Harrison, DSG, Myford) in NZ shops. American machines (South Bend, LeBlond, Clausing) were also imported. Taiwanese and Chinese brands became more common from the 1990s. This history is documented in NZ Manufacturer trade journals (various issues) and machinery dealer histories; no systematic national census of machine tool makes and models has been published. The census (Doc #8) should capture this data as part of the machine tool condition assessment.↩︎

15. Gauge blocks (Johansson blocks, named after their inventor Carl Edvard Johansson) are described in standard metrology texts. See Busch, T., “Fundamentals of Dimensional Metrology,” Delmar, various editions. A typical workshop set contains 81 or 112 blocks that can be combined to produce any dimension in 0.001 mm increments.↩︎

16. Cutting tool distributors in NZ include agents for major manufacturers: Sandvik Coromant, Kennametal, Iscar, Seco, Mitsubishi Materials, and others. Sutton Tools (Australian manufacturer) has significant NZ distribution. Total NZ stockholding of carbide inserts is commercially sensitive data not publicly available — it would need to be established through the distributor inventory audit.↩︎

17. Carbide insert life data is application-specific and varies widely. Tool manufacturer application guides (e.g., Sandvik Coromant “Turning application guide,” Kennametal “Tooling handbook”) provide typical cutting data and expected tool life for specific insert grades and workpiece materials. As a general guide: roughing hard steel (Brinell hardness 250+) with uncoated carbide may yield 10–20 minutes per edge; finishing aluminium alloy with polished carbide may yield 2–4 hours per edge. These figures are reference ranges only; actual life depends on cutting parameters, coolant, and setup rigidity.↩︎

18. HSS tool grinding is covered in standard workshop texts. See: South, D., “Workshop Technology Part 1 & 2,” Longman, various editions — a text widely used in NZ apprenticeship training through the 1970s–1990s. Also: Oberg, E. et al., “Machinery’s Handbook,” Industrial Press — contains comprehensive tool geometry data for HSS tools.↩︎

19. Cutting speed data for carbon steel, HSS, and carbide tools from: Oberg, E. et al., “Machinery’s Handbook,” Industrial Press (multiple editions) — see tables on cutting speeds for various tool materials and workpiece materials. Carbon steel tools are limited to approximately 5–15 m/min on mild steel by their low red-hardness (~250°C); HSS tools (with red-hardness to ~600°C) operate at 20–40 m/min; carbide tools (red-hardness >800°C) at 100–300+ m/min depending on grade and application.↩︎

20. Tallow and lard as cutting fluids have a long history predating petroleum-based fluids. See: Shaw, M.C., “Metal Cutting Principles,” Oxford University Press, 2005, Chapter 13 (Cutting Fluids). Tallow is particularly effective for threading and tapping operations due to its high film strength.↩︎

21. Cutting fluid performance comparisons between tallow/vegetable oil and modern petroleum-based or synthetic fluids are discussed in: Shaw, M.C., “Metal Cutting Principles,” Oxford University Press, 2005, Chapter 13. The primary limitations of bio-based fluids in recirculating systems are bacterial degradation (rancidity) and poorer heat capacity compared to water-based synthetic fluids. For single-application (drip or brush) use, the performance gap narrows considerably.↩︎

22. NZ mineral resources are documented in GNS Science (Institute of Geological and Nuclear Sciences) publications. https://www.gns.cri.nz/ — NZ’s garnet deposits are known but not commercially exploited at scale for abrasive applications. Whether these deposits are suitable for grinding wheel production would require geological and materials science assessment.↩︎

23. Silicon carbide production requires carbothermal reduction of silica (SiO₂) with petroleum coke or coal coke in a resistance furnace (the Acheson process) at approximately 2,000–2,500°C — an industrial process requiring purpose-built electric arc furnaces and substantial electrical power. Aluminium oxide (corundum) abrasives are produced either by mining natural corundum/emery and processing it, or via the Bayer process from bauxite (electrolytic alumina reduction) followed by fusion and crystallisation — neither process is currently available in NZ. These are Phase 6–7 industrial development targets, not near-term substitutes.↩︎

24. Flat belt vs. V-belt power transmission comparison: see Shigley, J.E. and Mischke, C.R., “Mechanical Engineering Design,” McGraw-Hill (multiple editions), Chapter on belt drives. V-belts achieve higher power transmission efficiency per unit of belt width due to the wedging action in the groove (friction coefficient effectively multiplied by the groove geometry). Flat belts rely on surface friction alone and require higher tension for equivalent power, increasing bearing loads. The 20–40% power transmission disadvantage of flat belts is a rough estimate for equivalent belt widths operating at similar speeds; the actual gap depends on the specific belt materials, groove geometry, and pulley sizes involved.↩︎

25. NZ bearing distributors: CBC Bearings operates multiple NZ branches (Auckland, Hamilton, Wellington, Christchurch, Dunedin and others). Motion NZ (formerly BSC Industrial) similarly has national coverage. These distributors hold inventory across all major bearing types and sizes. Total NZ bearing stockholding is commercially sensitive and not publicly available; it must be established through the distributor inventory audit (Doc #1). SKF, NSK, NTN, FAG, and Timken are among the major bearing manufacturers whose products are distributed in NZ.↩︎

26. Plain (journal) bearing design using bronze alloys is well-established engineering practice. Bronze bushes can be cast (from NZ copper and tin stocks — tin is imported, copper is mined in small quantities in NZ, primarily as a byproduct) and machined to specification. Performance is adequate for many applications where ball bearings were used as a convenience rather than a necessity, though friction is higher and lubrication requirements are more demanding.↩︎

27. The concept of tacit knowledge in skilled trades is well-documented. See: Polanyi, M., “The Tacit Dimension,” University of Chicago Press, 1966. For machining specifically, much practical knowledge is transmitted through apprenticeship rather than textbooks — the “feel” of a cutting tool, the sound of a correct cut, the visual assessment of surface finish.↩︎

28. Tertiary Education Commission (TEC) and Workforce Development Council reporting on engineering trades training. https://www.tec.govt.nz/ — Specific age-profile data for machining trades is not aggregated in publicly available sources. Industry observation from NZ engineering employers consistently notes an aging manual machining workforce. The Hanga-Aro-Rau (Manufacturing, Engineering and Logistics) Workforce Development Council may hold more specific data.↩︎

29. CNC controller manufacturers: Fanuc (Japan), Siemens (Germany), Haas (USA — integrated machine/controller), Mitsubishi (Japan), Heidenhain (Germany). All manufacturing and primary support is Northern Hemisphere. NZ has service agents but no component-level manufacturing or repair capability for controllers.↩︎

30. Electrolytic capacitor life ratings and degradation behaviour are described in manufacturer datasheets and standard electronics engineering references. See: Nichicon Corporation, “Technical Notes: Lifetime Estimation of Aluminum Electrolytic Capacitors,” available from major component distributors. The 5,000–20,000 hour design life range reflects the wide variation between low-grade general-purpose capacitors and long-life industrial-grade types. The rule that capacitor life roughly halves for every 10°C rise above rated temperature is a standard application of the Arrhenius equation to electrolytic failure mechanisms — see also Chemelli, R., “Electrolytic Capacitor Life,” Proceedings of the Annual Reliability and Maintainability Symposium. This has direct implications for CNC controllers operating in unconditioned machine shop environments, where summer temperatures may exceed controller design ratings.↩︎

31. Te Pūkenga was established in 2020 as a merger of NZ’s 16 Institutes of Technology and Polytechnics (ITPs). Engineering trades training programs at these institutions deliver NZ Certificate in Mechanical Engineering and related qualifications. See Te Pūkenga programme listings: https://www.tepukenga.ac.nz/ — Note: Te Pūkenga’s structure and programme delivery may have changed since its establishment; the training facilities and equipment at constituent institutions remain relevant regardless of institutional structure.↩︎

32. NZ engineering apprenticeships were historically 4 years (10,000+ hours of on-job training plus block courses at polytechnics), governed by the Apprenticeship Act 1983 and subsequent legislation. The modern NZ Apprenticeship programme continues this general framework, though structure and duration have varied under different policy settings. See: https://www.apprenticeships.govt.nz/↩︎

33. The history of the machine tool bootstrap is documented in: Rolt, L.T.C., “Tools for the Job: A History of Machine Tools to 1950,” HMSO, 1986; Woodbury, R.S., “Studies in the History of Machine Tools,” MIT Press, 1972. The progression from hand-scraped surfaces to precision machine tools is one of the foundational stories of industrialisation.↩︎

34. The three-plate method for producing flatness and the technique of hand scraping are described in: Connelly, R., “The Whitworth Three Plates Method,” and more accessibly in: King, R.J., “Machine Tool Reconditioning and Applications of Hand Scraping,” various editions. Also: Moore, W.R., “Foundations of Mechanical Accuracy,” Moore Special Tool Company, 1970 — a classic reference on achieving precision from first principles.↩︎

35. Cast iron is preferred for machine tool structures because of its superior vibration damping — grey cast iron has a specific damping capacity roughly 5–25 times that of steel, depending on grade and measurement method (see Balachandran, P., “Engineering Materials,” PHI Learning, and standard materials engineering references). This results in better surface finish and tool life. However, fabricated steel structures can work, particularly for lower-precision applications. Many modern machine tool manufacturers use steel weldments with added damping material for smaller machines.↩︎

36. Gingery, D.J., “The Charcoal Foundry” (Build Your Own Metal Working Shop from Scrap, Vol. 1), David J. Gingery Publishing, 1983. The series continues through lathe, drill press, milling machine, and other tools. While limited in the precision and capability of the resulting machines, the series provides a documented bootstrap path that has been followed by many home shop machinists worldwide.↩︎

37. Measurement Standards Laboratory of New Zealand (MSL), part of Callaghan Innovation, Lower Hutt. https://www.measurement.govt.nz/ — MSL maintains NZ’s national measurement standards and provides calibration services. It is NZ’s link to the international measurement system.↩︎

38. The three-plate method for producing flatness and the technique of hand scraping are described in: Connelly, R., “The Whitworth Three Plates Method,” and more accessibly in: King, R.J., “Machine Tool Reconditioning and Applications of Hand Scraping,” various editions. Also: Moore, W.R., “Foundations of Mechanical Accuracy,” Moore Special Tool Company, 1970 — a classic reference on achieving precision from first principles.↩︎

39. Christchurch’s early industrial use of water power is documented in local histories. See: Wilson, J., “Canterbury: A Regional History,” Canterbury University Press. The principle of water-powered workshops via millraces and line shafts was standard industrial practice through the 19th century and remains technically viable where water flow is available.↩︎

40. Rotary phase converters are well-established technology. A large three-phase motor, started on single-phase (via capacitor starting), generates a third phase that, combined with the two incoming phases, approximates three-phase power. The output is not perfectly balanced but is adequate for most machine tool motors. Construction and sizing guidance is available in standard electrical engineering references.↩︎