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      email: tony@lathes.co.uk
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      NASMYTH'S Shaper


      Although well known for self-aggrandisement and false claims, it is possible that the shaping machine was invented (or at least developed into a practical working form) by the English engineer James Nasmyth at some point before 1836. He took as his inspiration the early and crude form of the planing machine, a machine tool invented independently circa 1814/17 by Matthew Murray and Richard Roberts and intended for the economical machining of large components. The planer was arranged very simply: a bridge, carrying one or more toolholders and able to be elevated and moved from side to side was carried on uprights bolted to a heavy cast iron base plate upon which slide a table that carried the workpiece or workpieces. 
      In 1836 Nasmyth was in the middle of moving his small, general-engineering business from the centre of Manchester to a new, larger factory at Patricroft, to the west of the city on a site that occupied a corner of the ground where the Bridgewater Canal and Manchester to Liverpool railway crossed. It must be considered a remarkable achievement that, in the middle of such an upheaval, with new buildings to erect and machine tools to install, he found time to sketch out in his "Scheme Book" plans for a compact, self-acting machine able to be worked by semi or unskilled labour and suited to the manufacture of smaller components. His words on the subject, from his autobiography of  1883, explain his thinking:
      "Although the introduction of the planing machine into the workshops of mechanical engineers yielded results of the highest importance in perfecting and economising the production of machinery generally, yet, as the employment of these valuable machine tools was chiefly intended to assist in the execution of the larger parts of machine manufacture, a very considerable proportion of the detail parts still continue to be executed by hand labour, in which the chisel and file were the chief instruments employed. The results were consequently very unsatisfactory both as regards inaccuracy and costliness.
      With the desire of rendering the valuable services of the Planing Machine applicable to the smallest detail parts of machine manufacture, I designed a simple and compact modification of it, such as should enable any attentive lad to execute all the detail parts of machines in so unerring and perfect a manner as not only to rival the hand work of the most skilled mechanic, but also at such reduced cost as to place the most active hand workman far into the background. The contrivance I refer to is usually known as "Nasmyth's Steam Arm.
      None but those who have had ample opportunity of watching the process of executing the detail parts of machines, can form a correct idea of the great amount of time that is practically wasted  and unproductive, even when highly-skilled and careful workmen are employed. They have so frequently to stop working, in order to examine the work in hand, to use the straight edge, the square, or the calipers, to ascertain whether they are "working correctly." During that interval, the work is making no progress; and the loss of time on this account is not less then one-sixth of the working hours, and sometimes much more; though all this lost time is paid for in wages.
      By the employment of such a machine as I describe, even when placed under the superintendence of a well-selected intelligent lads, in whom the facility of good sight and nicety of handling is naturally in a high state of perfection, and deficiency in their physical strength is amply compensated by these self-acting machines.
      The factory engine supplies the labour or the element of Force, while the machines perform their work with practical perfection. The details of machinery are thus turned out with geometrical accuracy, and are in the highest sense fitted to perform their intended purpose.".

      James Nasmyth's  "steam-arm" shaper of 1836

      A cam, concentric with the crankshaft axle, operated an arm, pivoted in its middle, which transferred the motion to a ratchet wheel.

      Table cross-feed ratchet.


      email: tony@lathes.co.uk
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      NASMYTH'S Shaper
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