UK 09Other British Machine Tools

Boring machines: the first large machine tools, which made the steam engine work

Boring is the operation of enlarging an existing hole by cutting its inside with a tool, finishing it round, straight and to a set size. In 18th-century Britain the most pressing need for it was the steam engine cylinder. If the clearance between cylinder and piston is large, steam leaks and the engine loses power. Watt at first complained that in an 18-inch cylinder the long and short diameters differed, at the worst place, by as much as three-eighths of an inch (about 9.5 mm)^[2].

Smeaton's overhung boring bar

The best machine until then was the boring machine John Smeaton built in 1769 at the Carron ironworks in Scotland. A head with cutters around it was fixed to the end of a long bar supported at one side only, and the cylinder, on a carriage, was drawn toward the cutters by chain and winch. But since the end of the bar was unsupported, the weight of the cutter head made it cut mostly the lower side of the cylinder, and the bore was dragged along by the shape of the casting and came out crooked. At Smeaton's works the cylinder was turned 90 degrees at a time and bored in four stages to make it at least a little rounder^[1][2].

Wilkinson: passing the bar through and supporting both ends

The man who solved this problem was the ironmaster John Wilkinson. He began with cannon. His British Patent No. 1063 of January 27, 1774, "a new method of casting and boring iron guns," cast the gun solid without a core and, by waterwheel or steam engine, turned the gun itself, drilling a hole and then finishing it with a boring bar fitted with cutters^[3].

For cylinders, Wilkinson passed a thick boring bar through the cylinder and supported both ends of the bar in bearings. The cutter head turned with the bar while sliding along it, advanced little by little by a feed rod and rack running through the bar. The cylinder was chained to a wooden cradle. Because the bar was supported at both ends, the bar itself became a straightedge, and even if the casting was crooked, as long as there was enough stock the bore came out straight and round^[1][2][4]. At his works at Bersham near Wrexham he bored the first cylinder for Boulton & Watt in 1775, and in 1776 Boulton wrote that even a 50-inch (about 1.27 m) cylinder was not out by the thickness of an old silver shilling^[2]. From 1776 to 1795, Watt's cylinders were cast and bored at Bersham^[1]. Roe rates this boring machine as "probably the first metal-working machine tool that could do large work with something near today's accuracy"^[2].

Feed screws and vertical boring machines

Later improvements were in "feed" and "orientation." Boulton & Watt built the new Soho Foundry in 1795, and in 1798 bored a 64-inch cylinder on a horizontal boring machine designed by William Murdock^[1]. Around 1800, in place of weights and racks, a method in which a screw inside the boring bar fed the cutter head is said to have come into use at Soho. The boring bar that survived at Bersham had also later been modified with a feed screw added inside, so that the cutter head advanced a set amount for each revolution of the bar^[1].

The cylinders of large marine engines distort under their own weight when laid on their side. So the idea of boring the cylinder upright led to the vertical boring machine. At Soho Peter Ewart designed one in 1795 (not built), and in 1802 Michael Billingsley patented and built one. The vertical boring machine that Nasmyth, Gaskell & Co. installed at Woolwich Dockyard in 1838 fixed a 6-foot diameter cylinder to the floor and lowered the cutters by slowly turning a screw inside a 16-inch diameter boring bar through planetary gearing. Set vertically, neither the cylinder nor the bar sagged, chips fell away without tangling with the cutters, and less floor space was needed^[1].

Toward the horizontal boring machine

From the end of the 19th century the boring machine became a machine for "boring holes at several places in a large box-shaped part without moving it." The universal machine of George Richards of Broadheath, near Manchester, was basically a boring machine, but could also drill and mill in a single setup, with 48 spindle speeds^[20]. In 1961 Asquith of Halifax was building ram-type horizontal boring and milling machines weighing over 270 tons, with electronically controlled spindle and feeds^[18]. For toolrooms, Kearns sold horizontal boring machines with optical coordinate reading^[34].

What changed on the shop floor. Up to Smeaton, "the hole follows the path of the cutter"; from Wilkinson on, "the hole follows the guide (the boring bar)." In boring today, too, the basics for long holes are to keep tool overhang short and to support the far side as well (line boring or rear support): the idea is the same as 250 years ago.

Planers: making "flat surfaces" by machine

A planer moves a table carrying the work back and forth under a stationary tool, cutting one stroke at a time and stepping the tool sideways to finish a flat surface. Machine guideways, the faces of steam engine slide valves, the bars of textile machinery: flat surfaces were needed everywhere, yet until the early 19th century they were made by hand, cut with chisel and file and fitted by scraping.

Who came first: Murray, Fox, Roberts

The "inventor" of the planer cannot be pinned down to one person. Matthew Murray of Leeds was using a planer to machine the faces of steam engine D slide valves by 1814, and people who worked there at the time testified that he hid it, unpatented, in a locked room. James Fox of Derby also built a planer around 1814, with automatic feed of the toolholder and an automatic reversing gear that switched direction with three bevel gears. This machine is said to have been in use until 1859^[2][1].

The oldest planer that survives today is the one Richard Roberts of Manchester built in 1817. The table (52 inches long, 11 inches wide) rests on a flat way on one side and an inverted-V guide on the other, and is moved back and forth by turning a chain and drum by hand. The crossrail sits on two columns, the toolholder can be set at an angle, and the tool was mounted in a hinged clapper that lifted on the return stroke. The bed still shows marks of chisel and file, which shows that the planer itself was made without a planer^[1][7][2]. The form of table, crossrail and toolholder is already that of today's planer.

Clement's large planer: 18 shillings per square foot

In 1825 Joseph Clement of London built a large planer that could take work up to 6 feet square. The table ran on rollers, it had two tools to cut on both the forward and return strokes, and it was hand-operated. For more than ten years there was no other machine this size, and Clement took on planing at 18 shillings per square foot, which became his main income^[1][2]. Planing a flat surface had itself become a business. By 1829 Fox's price list showed planers in five sizes^[1].

Whitworth's "Jim Crow" and quick return

The weakness of reciprocating machines is the idle return stroke. In a planer patented in 1835, Joseph Whitworth of Manchester devised a mechanism in which the toolholder swings around at the end of the stroke and cuts on the return as well. In the shops it was called "Jim Crow," after the popular song "Jump Jim Crow," whose dancer spins around. On the 1842 machine, a screw in the middle of the bed moved the table, and each time a dog on the table pushed a rack bar, a belt reversed the toolholder and advanced the cross feed one step^[1][12].

This reversing mechanism did not catch on, however. The Science and Industry Museum explains that it was probably too complicated and not robust enough for heavy work^[44]. By about 1860 it became usual to cut in one direction only and return the table quickly (quick return) instead^[1]. Nasmyth's works built quick-return planers driven by rack, and, for small machines, quiet, fast planers of the "mangle wheel" type (a pinion travels around the inside and outside of a pin wheel to reverse the motion)^[1].

The cost of a flat surface falls to 1/100

In 1856, in his presidential address to the Institution of Mechanical Engineers, Whitworth said that 30 years earlier the labor cost of finishing a cast-iron surface true by hand had been 12 shillings per square foot, but that now, with the planer, it was less than a penny. Since a shilling is 12 pence, the labor cost had fallen to less than 1/100. In exchange, whereas a craftsman's tools had cost only a few shillings, the planer required more than £500 of capital per worker, and he said that shift work had begun so that expensive machines would not stand idle^[10]. These figures show clearly how machine tools replaced "human skill" with "machines and capital." In the 20th century, large flat surfaces moved to the plano-miller, which mounts rotating milling heads on the same bridge frame and long table as the planer. The machine Asquith built for its own use in 1920 had four milling heads on a 30-foot table and was still in use in 1961 for heavy roughing with carbide milling cutters^[18]. The history of the milling machine is covered in Chapter 6.

What changed on the shop floor. Even after the planer appeared, the final finish was by scraping. Whitworth argued that grinding surfaces together with abrasive powder made the removal uncontrollable, and that three surfaces should be matched against one another and finished by scraping^[10]. The scraping patterns seen on the guideways of today's machine tools continue this tradition of "machining, then fitting by scraping."

Shapers and slotting machines: small surfaces and keyways

From the block mill mortiser to the slotting machine

To fix a gear or wheel to a shaft, a keyway is cut inside the bore. In the old days this was heavy work with chisel and file. According to Nasmyth's autobiography, the wooden mortising machine Maudslay built for the Portsmouth block mills (see a later section) had all the principles needed for use on metal, and Richard Roberts improved it so that it could cut keyways in metal wheels^[8]. Gilbert (1966) says Roberts began this slotting machine (slotter) in 1830^[1].

Manchester's Science and Industry Museum has a slotting machine built by Sharp, Roberts & Co. in 1835. It is related to the machines that cut keyways in the wagon wheels of the Liverpool & Manchester Railway; the vertical tool bar is moved up and down by a crank on the flywheel shaft, and the stroke can be varied up to 6 inches by the position of the crankpin. The table rotates and moves in and out and side to side, and when tilted it could also cut tapered slots^[1][9]. But a machine of this form cannot take work whose radius is larger than the distance from the tool bar to the column. Nasmyth writes that he designed his own keyway machine that could be used on wheels of any diameter, had no parts that sprang like a spring, and took one-third of the space and cost^[8].

Nasmyth's "Steam Arm"

The planer was convenient for large work, but the small parts of machines were still cut with chisel and file. In 1836 Nasmyth built the shaper, a planer scaled down for small parts. According to his autobiography, this machine was called "Nasmyth's Steam Arm," and with a single careful boy to tend it, it could cut parts cheaply that were as good as a skilled man's handwork^[8]. The mechanism: a crankpin set in a slot in a rotating disk pushed against a vertical slot in the ram (arm) carrying the toolholder, moving it back and forth, and the stroke was varied by the position of the pin. The work table moved sideways a little at a time by hand or by pawl feed^[1]. By 1856 Nasmyth, Gaskell & Co. had built 236 shapers^[17].

To this shaper Whitworth added a quick-return mechanism, so that it cut slowly on the forward stroke and returned quickly. This mechanism is still called the "Whitworth quick-return mechanism"^[2][1]. For large work Whitworth also built shapers in which the tool head ran along a lathe-like bed, with the tool working out beyond the end of the bed^[19].

What changed on the shop floor. With shapers and slotting machines, "small flat surfaces" such as the hexagon flats of nuts and keyways could be machined, and part dimensions began to be consistent. Today keyways are often cut by milling, broaching or wire EDM, but for a single slot inside a bore, tools based on the slotting idea (slotter tools) are still used.

⚓The Portsmouth block mills: mass production begins with a line of special-purpose machines

Sailing ships need huge numbers of wooden pulley blocks to carry their ropes. According to Roe, the Royal Navy was then buying about 100,000 handmade blocks a year, and a single frigate used about 1,500^[2]. In 1802 Marc Isambard Brunel proposed making the blocks by machine, and on the recommendation of Samuel Bentham, Inspector General of Naval Works, the Admiralty adopted the plan. Brunel designed the machines and Henry Maudslay built them^[1][2].

A special-purpose machine for each operation

What was new about this factory was that it assigned one type of machine to each operation and passed the work from machine to machine in sequence. Elm logs were cut with a pendulum circular saw and squared on circular saw benches, and a boring machine drilled two holes at right angles: the hole for the sheave's pin and the pilot hole for the mortise. Next, a mortising machine cut the mortise for the sheave, starting from the pilot hole, a shaping machine shaped the outside, and a scoring machine cut the groove for the rope. For the sheaves, hard wood was sliced into discs, rounded and bored at the center, and a seat for the metal bearing bush (coak) was milled^[1].

The mechanisms, too, already had parts of later machine tools. The mortising machine was among the first to have a cone clutch and brake between the flywheel and the shaft; with each stroke of the chisel a feed screw and ratchet advanced the block shell, and the feed stopped automatically at a set length^[1][2]. The shaping machine held 10 shells between two rings and rotated them, moving the cutter along a template to shape the outside, and gears indexed all 10 at once, 90 degrees at a time^[1][2]. Roe writes that it clearly shows the idea of fixing a reference point for machining and keeping to it through every operation^[2].

By 1805 the block mills were making all the blocks the navy needed, saving about £17,000 a year. The work of 110 skilled men is said to have been done by 10 unskilled ones^[1]. Roe puts production, once the mills were in full operation in 1808, at more than 130,000 blocks a year^[2]. The machines were so well made that some were used for nearly 150 years^[1]. In London, the boring machine and the coaking machine can be seen in the Science Museum's Making the Modern World gallery^[6][42].

The museum's text, however, calls it a puzzle that such a success remained a “one-off” and did not spread to other industries, and notes that it was more than 50 years before British factories and the government turned to American-style mass production^[6]. The story 50 years later (the Enfield rifle factory and American machines) is told in Chapter 2.

The steam hammer: a machine that changed the scale and control of forging

The steam hammer does not cut, but as a forging machine that hammered out blanks for large shafts and cranks, it supported the machine shop. The earlier “tilt hammers,” lifted by water wheel or steam, were levers with a head on the end of an arm; their stroke was small and they could not forge thick work^[2].

In 1839 the designer of the steamship Great Britain came to Nasmyth with a problem: no hammer existed that could forge its 30-inch-diameter paddle shaft. On November 24 Nasmyth drew in his notebook a heavy weight that steam would lift and then drop straight down along guides — the sketch of a new hammer^[8][1]. The ship changed from paddle wheels to a screw propeller, and the shaft was never made. Later, at the Le Creusot works in France, Nasmyth found a hammer built to his idea already in use, and on June 9, 1842 he took out British Patent No. 9382^[2]. The Science Museum explains that Nasmyth was neither the first to conceive it nor the first to build it, and that there was a dispute over priority with Bourdon, an engineer at Le Creusot^[13].

The first type raised the piston with steam, released the steam at a set height and let the head fall under its own weight. In 1843 his partner Robert Wilson devised an automatic valve gear that switched the valve to drop the head when it reached a set height and went back to lifting after the blow. Eventually it became “double-acting,” with steam also admitted from above on the down stroke to add force^[1]. Its control was almost too fine: Nasmyth is said to have shown that a 2.5-ton hammer could crack just the shell of an egg set in a wine glass^[8]. The model steam hammer Nasmyth gave to the new South Kensington Museum in 1857 became the start of the Science Museum's machine tool collection^[1].

Drilling machines: from automatic feed to the radial drill

Drilling has long been work that is easy to hand over to a machine. The 1801 inventory of the Soho Foundry's equipment already lists three drilling machines^[1]. Progress in 19th-century British drilling machines came in two areas: automating the feed and locating hole positions.

Automatic feed by Nasmyth and Whitworth

Around 1840 the Nasmyth, Gaskell & Co. drilling machine carried its spindle on a crossbeam spanning two columns and drove it through bevel gears. Besides a hand-turned feed screw, it had an automatic feed that advanced the spindle little by little with an eccentric and a pawl^[1][11]. The automatic feed Whitworth patented in the late 1830s was cleverer. Two worm gears meshed with a thread cut on the upper part of the spindle and normally just turned idly with it. When a brake on the gear shaft slowed them, the gears acted as a nut and the spindle moved down; the strength of the brake set the rate of feed^[1].

Locating holes with a template

To drill many holes in the same pattern, marking out every position each time is far too slow. In 1848 Roberts patented a machine that drilled the holes in clock plates while a guide pin was inserted into the holes of an enlarged template. The ratio between template and work could be changed by their positions on the arm^[1]. Sharp and Furnival's 1855 patent was a machine that cut slots by reciprocating a rotating cutter, with elliptical gears to even out the reciprocating speed^[1]. The idea of locating positions with a template led to the later jig and the jig borer.

Radial drills from Halifax

Large, heavy work cannot be moved to line up each hole. On a machine whose spindle head rides on an arm projecting from a column, with the arm swinging and the head moving along it — a radial drilling machine — the tool goes to the hole instead. In Britain the center for these machines was Halifax in Yorkshire. The Science Museum has a Kitchen & Wade radial drill from about 1914^[21]. Kitchen & Wade went public in 1936 and was bought in 1959 by Asquith, whose works stood next to its own^[23][30].

William Asquith, also of Halifax, opened his works in 1865 and at first built everything from lathes to planers and shapers, but after the founder died in 1901 the firm concentrated from 1903 on radial, upright and horizontal drilling machines and heavy horizontal boring and milling machines. A trade journal of 1961 says it later supplied all the drilling machines used to build the Sydney Harbour Bridge. That year the works covered 12 acres with about 1,000 employees, building about 30 type OD radial drills a month, and its range went up to machines with a 12-foot arm that drilled 5-inch holes from the solid. With Kitchen & Wade, Drummond, the shaper maker Ormerod and others it formed a group, the Asquith Machine Tool Corporation, which claimed to be the world's largest works making only drilling and boring machines^[18].

What changed on the shop floor. Radial drills made it possible to drill holes in large castings and welded structures without moving them by crane. Radial drills were long a standard machine in Japanese shops too; their story is in the timeline of Japanese Archive Chapter 5.

Jig borers: the first one went to Enfield

Drilling in mass production needs jigs, with bushings set in exact positions to guide the drill. The machine that bores the holes in those jigs is the jig borer. The Science Museum has a machine built in 1921 by the Swiss firm SIP (Société Genevoise d'Instruments de Physique), the first industrial jig borer, made for the Royal Small Arms Factory at Enfield in Britain. SIP had built a positioning machine for marking out clock plates in 1912, and it grew into the industrial jig borer. In the meantime, Pratt & Whitney in the United States had also brought out a jig borer, in 1917^[22][1].

Like a planer, this machine had a crossrail spanning two columns; the spindle head moved left and right along the crossrail and the table moved back and forth (capacity 18 × 24 inches, weight about 2 tons). Two features gave it its accuracy. One was compensation for lead-screw error: for each screw, a metal template was made recording the error at every centimeter against a precision scale read by microscope, and a 200:1 lever turned the vernier of the dial to cancel the error. The other was that, allowing for the bed to deflect under the weight of the table, the guideways had been machined very slightly convex. The Science Museum explains that the jig borer is a precision machine that should be kept in a room at constant temperature^[22][1].

British makers also built toolroom jig borers after the war. In 1958 Newall advertised its Model 1520, with a 15 × 20-inch table and spindle speeds of 67–3,000 rpm, as the fruit of 20 years spent developing jig borers^[29].

What changed on the shop floor. Jig borers made it possible to locate holes in jigs and dies to within a few thousandths of a millimeter. SIP machines also came to Japan in the 1930s and served as models for Japanese jig borers (Japanese Archive Chapter 5). For today's thinking on positioning accuracy, see the Machining center guide.

Broaching machines: machining in a single pass

A broach is a long tool with dozens of teeth, each slightly higher than the last; push or pull it through a hole, and by the time the last tooth has passed, a keyway, spline or gear form is finished. The Science Museum catalogue explains that the teeth have staggered nicks so that chips do not clog, and that the last few teeth have the exact finished form, and it traces the idea back to drawings by Leonardo da Vinci and to Polhem's clock-gear making in Sweden in 1729. In the mid-19th century, tools called “drifts” were hammered or pushed through. Because the tools were expensive and complex, broaching became practical only at the end of the 19th century, when high-speed steel and tool grinders were available, and the catalogue dates modern broaching from Lapointe's opening of a factory in the United States in 1902^[1].

In Britain too, the Lapointe Machine Tool Co. Ltd of Watford (whose advertisements also named the American company of the same name in Hudson) advertised in 1960 horizontal hydraulic broaching machines with pulls of 24–50 tons and strokes of 30–78 inches, together with sharpening machines for broaches up to 80 inches long^[34]. Broaches are resharpened and used many times, so they were sold as a set with sharpening machines. The beginnings of the broaching machine in the U.S. are covered in Other American Machine Tools.

Measuring machines and probes: Britain and the “power of measurement”

Whitworth's measuring machine: measuring by touch

In an 1856 lecture Whitworth argued that the two great elements of machine making are the “true plane” and the “power of measurement.” A true plane is made by fitting three surfaces against one another and finishing them by scraping (published in 1840). On measurement, he recommended measuring that is confirmed by the touch of the hand rather than by reading a scale by eye. If an object is held between two parallel planes and adjusted until it can barely be felt by hand, bringing the planes 1/50,000 inch closer makes it distinctly tight. Whitworth's measuring machine placed a thin plate called a “gravity piece” between a standard inch bar and the measuring face, and was set at the point where the plate just fell under its own weight. Bringing the faces 1/1,000,000 inch closer from there, he said, was enough for friction to keep the plate from falling. With a one-yard bar, the expansion caused by the warmth of a brief touch of a finger was said to stop the plate^[10].

Whitworth said that in the workshop it was easier to work to 1/10,000 inch with standards that measure between end faces (end measures) than to 1/100 inch with the lines of a 2-foot rule, and that all fitting work should use end measures^[10][2]. At the Great Exhibition in London in 1851 he showed a measuring machine and gauges alongside his machine tools^[1]. The Science Museum, however, says of the 1855 measuring machine (displayed in Making the Modern World) that the claim of one millionth of an inch was an exaggeration given changes in room temperature, and that it was later refuted by the National Physical Laboratory (NPL)^[15]. Even if the figures were exaggerated, the ideas of “measuring between end faces” and “length changes with temperature” became the basis of today's gauge blocks and micrometers.

The Talysurf surface roughness instrument

In the 20th century, people began to measure not only size but also surface roughness. The Talysurf of Taylor, Taylor & Hobson of Leicester is a stylus instrument that traces a surface with a fine stylus, magnifies its rise and fall electrically and records it with a pen. The April 1943 journal of the Institution of Production Engineers describes a wartime factory carrying the Talysurf pickup to a 1.2-ton roll, fixing it to the work on a three-point stand and making the measurement in 5 minutes^[24]. The Science Museum has a Talysurf from 1946^[25].

Ferranti's coordinate measuring machine (1959)

Inspection in machining long meant laborious work on a surface plate, combining dial gauges, gauge blocks and height gauges. In 1959 Ferranti, a maker of NC equipment, announced a co-ordinate inspection machine. With the work on the table, the operator touched a probe hanging from a cantilever beam to the center of a hole or other feature, and its X (24 in.) and Y (15 in.) position was displayed as numbers. Position was detected by photocells counting the moiré fringes of diffraction gratings fitted to each axis, reading to 0.001 inch (about 0.025 mm). The probe moved 10 inches up and down^[32]. Mechanical World that year introduced it as the first machine of its kind in the world and gave its price as about £2,200^[33]. The moiré-fringe scale was the same technology the company used for NC positioning; it could build a measuring machine precisely because it built NC machines. The 500th machine was installed in 1965^[35].

Renishaw's touch-trigger probe (1972)

Probes on early CMMs had a hard tip that was pressed into a hole while the position was set by hand. In 1972, to inspect parts of the Olympus engine for the supersonic airliner Concorde, a probe that sends a signal the instant it touches was devised by Rolls-Royce engineer David McMurtry^[39]. According to the patent (U.S. Patent 4,153,998, claiming priority from a British application of September 21, 1972), the stylus is held by a spring in a position defined by three balls, and the balls and contacts form an electrical circuit. When the stylus touches the work and tilts slightly, the circuit opens and the coordinates at that instant are read. Pushed in any direction, the stylus returns to the same position when released^[38].

In 1973 McMurtry and his colleague John Deer registered Renishaw Electrical and began selling the TP1 probe for CMMs. In 1977 they brought out a probe for machine tools, so that setting up the work and inspecting it after machining could be done automatically on the machine^[39].

What changed on the shop floor. The CMM turned inspection, once the “craft of the surface plate and gauges,” into coordinate numbers, and the touch probe made it automatic. Centering the work and checking dimensions after machining on today's machining centers carries on from these two British inventions. For how to think about measurement error, see also the articles “Measurement Errors” and Gauges. The story of Ferranti's NC and of Renishaw as a company is in Chapter 4.

EDM, ultrasonics, transfer machines and additive manufacturing

EDM. In July 1954 the British technical journals The Engineer and Automobile Engineer described Sparcatron electrical discharge machining. The process blasts away particles of metal with electric sparks and can sink holes and die shapes into cemented carbide, which cutting tools cannot cut and which is hard even to grind, and into steel in the hardened state. Each spark lasts only an instant and the work is cooled by the fluid flowing in the gap, so, it was explained, the hardness from quenching is not lost either. The equipment was made by Impregnated Diamond Products under a Sparcatron license, and at the time it was used first of all for sinking holes and die shapes with the work held stationary^[26][27].

Ultrasonic and electrochemical machining. The Science Museum has an ultrasonic drilling machine from 1957. The tool vibrates 20,000 times a second and cuts little by little with an abrasive slurry; because the tool does not rotate, it can make square and irregular holes, and it was used on glass and ceramics^[1]. The 1966 catalogue lists, as new processes born in the mid-20th century, ultrasonic machining, electrochemical machining (the reverse of electroplating) and electrical discharge machining, which cuts with sparks^[1].

Transfer machines. On lines of machines that pass the work automatically to the next operation (transfer machines), Gilbert (1966) writes that the first was built in 1923–24 for Morris's engine factory in Coventry^[1]. It takes the Portsmouth block mills' idea of “lining up special-purpose machines operation by operation” and links them with automatic transfer. How this developed in American car plants is covered in the chapter on American mass production.

Additive manufacturing. Renishaw, which began with the touch probe, launched a range of additive manufacturing (3D printing) products in 2011; a measuring company had expanded into machines that build shapes by adding material^[39].

Links with Japan

Coordinate measuring machines. In October 1971 Ferranti and Tokyo Seimitsu (TSK) signed a seven-year cross-license. Tokyo Seimitsu gained the right to make and sell Ferranti's CMMs and digital readouts for lathes and other machine tools in Japan, mainland China and the Soviet Union. Ferranti, for its part, would make and sell Tokyo Seimitsu's electronic gauges and roundness and flatness measuring instruments in Europe and Africa. The royalty was 4% of sales^[36][37]. It is an example of British-born CMM technology passing to a Japanese measuring instrument maker. Japanese CMMs later spread around the world, and in 1983 the Science Museum in London acquired a complete Mitutoyo FN-403 CMM^[40].

Jig borers. The first SIP jig borer was delivered in 1921 to the Royal Small Arms Factory at Enfield in Britain^[22]. SIP machines came to Japan too, around 1937 and in 1939, and served as models for Japanese jig borers (see the timeline of Japanese Archive Chapter 5).

EDM. The Japanese archive's Chapter 6 timeline, citing Seimitsu Shiage-ho (Precision Finishing Methods, 1955), puts the launch of EDM machines as commercial products in Britain at about 1952. The Sparcatron articles (1953–54) confirmed in this chapter describe British EDM of that period^[26].

FAQ

What was new about Wilkinson's boring machine?

He passed a thick boring bar right through the cylinder and supported both ends of the bar in bearings. On Smeaton's earlier machine the bar was cantilevered, so the weight of the cutter made the bore drift downward and follow the crookedness of the casting. On Wilkinson's machine the bar acted as a straightedge and the cutter head was fed along it, so the bore came out round and straight even if the casting was crooked. From 1775 it bored the cylinders of Watt's steam engines and helped make the steam engine practical.

What is Whitworth's “Jim Crow”?

It is the nickname of the planer Whitworth patented in 1835. At the end of each stroke the tool box swivels around so that it cuts on both the forward and return strokes of the table; in the shop it was named after the words of a popular song. The mechanism was complicated, however, and did not catch on; later the usual arrangement was to cut in one direction and return the table quickly (quick return).

Who invented the shaper?

In 1836 James Nasmyth of Britain built the shaper, a planer scaled down for small parts. In his autobiography it is called “Nasmyth's Steam Arm.” A crank reciprocates a ram carrying the tool while the work is fed sideways little by little; Whitworth later added a quick-return mechanism.

Where were the coordinate measuring machine and the touch probe born?

Both in Britain. In 1959 Ferranti announced a coordinate inspection machine (CMM) that counted position with the moiré fringes of diffraction gratings. In 1972 David McMurtry of Rolls-Royce conceived the touch-trigger probe, which sends a signal the instant it touches, to inspect parts for Concorde's engines, and in 1973 he founded Renishaw to make it a product.