Henry Maudslay: Machine Tools
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Note: This is a sub-section of Henry Maudslay.
Henry Maudslay was the most influential machine tool maker at the end of the 18th and start of the 19th centuries.
It is intended in this section to identify as many of his machine tools as possible. He became famous for making the blockmaking machinery at Portsmouth, and for his lathes, which spearheaded the industrial application of slide lathes and machine screwcutting. See Portsmouth Block Mills for more information on the blockmaking machinery.
His first known machine tools were produced for lockmaking, during his employment with Joseph Bramah from 1790 to 1797.
Maudslay's Lambeth workshop became a 'nursery' for many men who would become famous engineers in their own right, and who would advance machine tool technology to its next phase, with machines of heavier construction and greater versatility.
Maudslay's best-known lathes featured triangular bar beds. The earliest known example of a lathe with a triangular bar bed was made by Henry Hindley before 1758, and early lathes of somewhat similar design by other makers are not uncommon. Very few by Maudslay are known to exist. Maudslay's have certain distinctive design features, and display fine workmanship.
Examples of Maudslay lathes can be seen in a number of museums. The London Science Museum has on display an early screwcutting lathe. Some historians put the date at c.1797-8. Maudslay left Joseph Bramah's employment and set up on his own in 1797, and it is likely that he would have devoted early attention to screwcutting developments. Also, his reputation as a machine tool maker was well-established by 1800, when Marc Brunel sought him out to build models of his blockmaking machines for Portsmouth Block Mills. This 'pre-1800' lathe was powered by hand, and generations of apprentices were required to produce screws on it. This is said to explain why it is 'opposite handed', with the headstock on the operator's right hand side: presumably most apprentices came, and left, with stronger right arms.[1] The model screwcutting lathe is similarly handed and hand-powered.
The Science Museum has on display a model of a hand-powered screwcutting lathe (see photos). It represents an advance on the 'pre-1800' lathe in a number of respects.
The Science Museum's complete Maudslay treadle lathe is currently not on display. Photo here and here.
This c.1805 example in Australia, originally owned by Sir John Barton, is ascribed to Maudslay, Sons & Field. However, while the slide rest is fully consistent with Maudslay's design and construction, some other keys aspects, primarily the headstock and tailstock, are not Maudslay-like.
The Henry Ford Museum in the USA has two examples. One is a treadle lathe similar to that in the Science Museum's collection, but with the addition of a form of 'back gear' - an important development. The other lathe ascribed to Maudslay is larger. See 'c.1804' lathe photos. Like the smaller well-known screwcutting lathe in the Science Museum, it has a two-bar bed and a central leadscrew, and has a close family resemblance to that lathe, particularly in the detail of the carriage and the toolholders. Unusually, though, the carriage is held down by rollers pressing on the underside of the slideways. Another unusual feature shared with the Science Museum lathe is that it is 'opposite handed', i.e. the headstock is to the right of operator, contrary to later universal practice. This lathe was gifted to the Ford Museum by Sir W. G. Armstrong, Whitworth and Co. Photographs here.
Confusion arises over the lathe donated to the Henry Ford Museum by Sir W. G. Armstrong, Whitworth and Co. A 1936 article in 'The Engineer'[2] included a photograph of the larger lathe, i.e. that identified as 'c.1804' in photographs here. The article states that 'At the time the machine tool department of Sir W. G. Armstrong, Whitworth was merged with Craven Brothers, an interesting photograph came into the latter's possession. It shows an early Whitworth lathe, made about 1828 at tho works of Henry Maudslay, Lambeth, London, the birthplace of the world's machine tool industry. At the time Josoph Whitworth was engaged there. An inscription upon tho machine states that a number of these lathes were used in the Lambeth works up to 1885; also that this particular lathe was presented by the directors of Sir W. G. Armstrong, Whitworth and Co., Ltd., to Mr. Henry Ford, of Dearborn, Michigan, U.S.A., for exhibition in the Ford Technical Museum. A reproduction of this photograph is given in Fig. 5. This early Whitworth lathe is of interest as an exhibit, and as showing the conception of a lathe by the best tool makers of that period - more than a century ago. But from the nature of the design it appears to have been made for a specific purpose - possibly the generation of lead screws.' 'Fig. 5' in that article shows the'c.1804' lathe, and not the lathe shown in the 'American Machinist' in 1908. The caption to Fig. 5 states 'Lathe made by Whitworth, 1828.' It has the clear hallmarks of Maudslay, so whether there is a Joseph Whitworth connection, we may never know.
1806 Some machines were observed at Maudslay's works in Margaret Street, Cavendish Square, and described in Olinthus Gregory 's Treatise of Mechanics, published in 1806[3]. Drawings were produced by John Farey and may be seen here . One of the machines described was a treadle lathe with four-speed pulleys. The large lathes in the works were turned by men cranking large wheels. A strap from the large wheel turned pulleys fixed to the ceiling, from which the lathe was driven by a catgut belt. The ceiling pulleys were mounted in a weighted frame which maintained belt tension. The operator had control of the drive by fast and loose pulleys, rather than stopping the men turning the great wheel. The text also describes how gears were cut using the large lathes. The workpiece was held in the chuck or on the faceplate, and the angular positions set using the index holes in the largest pulley (17 concentric circles of holes). The rotating cutter had four teeth and its spindle was held in a frame held by the toolholders on the compound slide. The power was taken from the great wheel, and speed was stepped up by pulleys to a remarkable 7300 rpm. The spindle was set loose in its conical bearings such that it when it expanded it would would have a satisfactory running fit. The cutter spindle could be angled for cutting wormwheels. The text includes a non-too lucid description, and a drawing which looks like the work of M. C. Escher, of an arrangement involving oblique slots which appears to serve to adjust the height of the compound slide.
Advertisements
1825 A 'good second-hand Turning Lathe, by Maudsley' was advertised for sale, along with a braiding machine,at 44 Chandos Street, Covent Garden[4]
1832 Advert: 'TURNING LATHE.- To be SOLD, a Gentleman's TURNING LATHE, made by Mr. Maudsley, London, at the Cost of £220; to be Sold for £100. Particulars may be known on Application to Mr. Donkin, Land Agent, Bootham, York, or by Letter, Post-paid.'[5]
Screwcutting
Maudslay devoted considerable time and effort to the production of increasingly accurate screws. At one end of the scale they would be used for interchangeable fasteners, while at the higher end they would be leadscrews for machine tools, and, in their most accurate form, for measuring instruments, scientific instruments, dividing engines, etc.
He adopted various methods to generate screw threads. One way is frequently described in histories of engineering in terms which convey the impression of a primitive method. In fact nothing could be further from the truth. Even the noted machine tool historian K. R. Gilbert might have inadvertently conveyed this impression, when writing: 'In the method finally adopted a hard-wood cylinder was rotated in a suitable holder against a crescent shaped knife held obliquely to its axis. The knife in cutting into the cylinder caused it to traverse, thus generating a screw which could be copied in steel.'[6] In fact Maudslay produced a very sophisticated device to accurately guide the wooden or soft metal cylinder. The device is on display in the Science Museum, and the quality and sophistication will be apparent from the first two photographs above.
Charles Holtzapffel described Maudslay's progressive improvements in screwcutting[7]. Having produced accurate screws by a variety of methods, he selected the most suitable. Then 'it was employed as a guide-screw, in a simple apparatus which consisted of two triangular bars fixed level, parallel, and about one foot asunder, in appropriate standards with two apertures; the one bar carried the mandrel and popit heads as in the ordinary bar lathe. The slide rest embraced both bars, and was traversed thereupon by the guide-screw placed about midway between the bars; the guide-screw and mandrel were generally connected by three wheels, or else by two or four, when the guide and copy were required to have the reverse direction. The mandrel was not usually driven by a pulley and cord; but on the extremity of the mandrel was fixed a light wheel, with one arm serving as a winch handle for rapid motion in running back; and six or eight radial arms, (after the manner of the steering wheels of large vessels,) by which the mandrel and the screw were slowly handed round during the cut.'
Holtzapffel continued: 'In a subsequent and stronger machine, the bar carrying the mandrel stood lower than the other, to admit of larger change wheels upon it, and the same driving gear was retained.' This description is consistent with the large lathe at the Henry Ford Museum, although of course other examples have been made.
Holtzapffel then described an intriguing development, for which no details appear to have survived: 'And in another structure of the screw-cutting lathe, Mr. Maudslay placed the triangular bar for the lathe heads in the center, whilst a large and wide slide-plate, moving between chamfer bars attached to the framing, carried the sliding rest for the tool: in this last machine, the mandrel was driven by steam power, and the retrograde motion had about double the velocity of that used in cutting the screw. Indeed these machines may be fairly considered to be the precursors of the present screwing lathes, in which the detached triangular bars or slides have been exchanged for one strong bearer with two ridges or fillets, upon which the slide plate moves for guiding the traverse of the tool.'
In response to a brief article in 1843 about a method developed by Shanks of Johnstone for cutting screws in a lathe, Joshua Field wrote that while the machine was ingenious, he could not perceive, from the drawing presented, any novelty in it, 'A similar machine, made by the late Mr. Maudslay, had been in use in Maudslay and Field's manufactory for the last fifteen years.' [i.e. since c.1828]. He also mentioned that the screwing dies invented by Joseph Whitworth 'cut out the threads of screws as clearly as if done by a chasing tool, and entirely without compression'.[8]
Machines Photographed Following Closure of Lambeth Works in 1900
Staff from 'Engineering' magazine visited the works when its contents were about to be sold off, and reported on their findings[9]. Many of the machine tool photographs are reproduced here. Their inclusion does not necessarily imply that Henry Maudslay was involved in their design, although all the machines illustrated do have some Maudslayian features.
A characteristic of Maudslay's designs was the elegance of their details, with well-shaped, slender castings and forgings, all made with an insistence on very high standards of fit and finish. Massive construction was not a hallmark, though, and his typical structures obtained their stiffness using slender ligaments and extensive cross bracing. This concept was not followed by his successors, who moved towards a more rational approach, with weight not being seen as such an adversary. The likes of Fox, Roberts, and Whitworth would adopt box-like bed castings, but we must also recognise that Maudslay did use shallow box beds with dovetail slides on some of his machines, namely the model screwcutting lathe in the Science Museum and the Portsmouth pin-turning lathes and facing lathes.
The typical frame castings, with their classical columns and slender bracing, may well reflect Marc Brunel's input to the Portsmouth blockmaking machinery designs.
The shaping machine is unimpressive. It appears that the coarse setting of the cutter height demands the adjustment of the nuts on four threaded columns. The bedplate supports clearly point to Henry Maudslay's era. It is a pity that we do not have a photograph of the other side, to see whether the machine had automatic traverse. According to J. G. Moon, the stroke could be adjusted by moving the crankpin in a slot.[10] It was able to cut in both directions, using a rotating tool holder later revived by Joseph Whitworth. A point of interest is that James Nasmyth claimed to have invented the shaping machine or 'steam arm' in 1836. Maudslay's machine surely predated this. As W. Steeds points out, it is unlikely that Maudslay's works would have built their machine if something much better had been available from Nasmyth at the time.
Another interesting machine, with many typical Maudslay characteristics, is the boring and facing machine. In one mode it could be used with a boring bar supported by the tailstock. Aleration of the centre height required the work piece to be raised on packers, or for the auxiliary table to be raised on its jacking screws. The machine could also undertake facing (the article called it milling, but flycutting might have been more likely). The headstock could be traversed manually or automatically.
The bevel gear cutting machines may well be out of place here. One has what may be a recycled bed, while the other, for larger diameter gears, has a more modern-looking box frame. In fact the only typical Maudslay influences are in the design of the pulleys on the latter machine.
See also 1902 article in the American Machinist, here.
See Also
Sources of Information
- ↑ 'English & American Tool Builders' by Joseph Wickham Roe, 1916, quoting the recollections of James George Moon
- ↑ [1] The Engineer, 12 June 1936
- ↑ [2]
- ↑ Morning Advertiser - Monday 19 September 1825
- ↑ Leeds Intelligencer - Thursday 23 February 1832
- ↑ 'A History of Technology': Vol IV, Oxford University Press, 1958
- ↑ 'Turning And Mechanical Manipulation' by Charles Holtzapffel.
- ↑ [3] W. Newton's 'The London Journal of Arts, Sciences and Manufactures, and Repertory of Patent Inventions', Vol XXIII, 1843
- ↑ 'Engineering' 18 January 1901
- ↑ 'English & American Tool Builders' by Joseph Wickham Roe, 1916, quoting the recollections of J. G. Moon