Core Manufacturing Principles
Everything in the man-made world from the food we eat to the clothes we wear, even the air we breathe has been processed by machine tools. These machines tools, in turn, are manufactured by a small sector of industry commonly known as the Toolroom. Where standards and precision are at their highest, rivalled and exceeded only by extreme tolerance laboratory work.
Nothing escapes the process of being tooled into existence via this methodical, easy to understand basic engineering practice.
To be schooled well in precision Toolroom engineering bestows upon the maker limitless insight for product manufacture in almost any material.
Lee J Rowland
From Gargantuan to the micro. The lathe is an indispensable tool that has been with us for centuries. Though the machines can look complex, their purpose and modus operandi is simple and constant.
They are used to produce ''cylindrical'' objects or anything that has radial symmetry. A spherical object could me made on a lathe, for example, a cube though not impossible, would not lend itself well to being turned on a lathe.
Huge Lathes are used to make items such as ship drive shafts or spindles for wind turbines. The chosen material for these components is rotated and consequently reduced in size as a hardened tool is ploughed through the surface in a procedure known as ''turning'' Anyone skilled with operating a lathe would be commonly known as a turner by trade.
Jewellers will occasionally use the lathe to manufacture their tiny items and watch components, often in precious metals. Cutting the material at this scale is such a light procedure it can be done using hand-held tools.
Beautiful surface finishes can be achieved when turning by using cutting tools made from ultra hard materials to radially sculpt metals. The example to the left is an aluminium chess piece being cut by a ceramic or tungsten carbide tool seen buried in the top half of the work as it spins.
This lathe operator begins with a huge, flat disc of redwood. The process though labour intensive is very easy to undertake. Whilst spinning, the wood's surface is removed using sharp chisel-like tools and the profile will gradually take form as the operator moves across the radius of the work. After ''Roughing out'' the wood to within 1 % of the finished size. Abrasive cloths can be used to finely finish the now sculpted surface.
Left: the hobbyist wood lathe is still a popular machine tool for craftsman worldwide.
The zeus book is an essential pocket sized reference for the Toolroom engineer. It's a handy 28 page compilation providing precise information on everything from imperial/metric dimension equivalents to material hardnesses and cutting tool geometry.
The perspective on precision dimensions used in industry
Standard kitchen foil is just 1/40th of a millimetre thick, or 1/1000th of an inch. The lathe operator can just about remove this amount of material accurately. This limit is commonly known in industry as the ''THOU''
The ''THOU'' is small but signifies nothing more than the beginning for ultra precision engineering. The MICRON breaks down the THOU into 25/ths. There are 25 microns to the thickness of standard kitchen foil and between 50 and 70 MICRONS to a human hair thickness. A human red blood cell is just 7 MICRONS across, seen above perched atop of a dining needle tip. The aids virus is just 1/10th of a MICRON across, 70 times smaller than the red blood cell it assimilates.
Gold plate or plating is considered thick at anything over two microns, around a 1/10th the thickness of foil. So the term ''Plate'' can be misleading.
Believe it or not, it is actually quite easy working to these extremely small limits. Whenever we use T-cut on car paintwork, for example, we remove a layer of paint which would be measured by the MICRON
The MICRON can be broken down into portions still workable by modern engineering. The NANOMETER is made up of 1000 microns! And we can still work with them when cutting materials to size. The latest telescope mirrors are cut and polished to within 25 NANOMETRES or 1/50th of a micron or approximately 1/2000th the thickness of kitchen foil.
The results at this level of precision need no introduction. A piece of glass shaped and polished to within NANOMETRES allows us to see solar systems billions of miles away with stunning clarity.