Machine tool

Thus, the relative movement between the workpiece and the cutting tool (which is called the toolpath) is controlled or constrained by the machine to at least some extent, rather than being entirely "offhand" or "freehand".

Today machine tools are typically powered other than by the human muscle (e.g., electrically, hydraulically, or via line shaft), used to make manufactured parts (components) in various ways that include cutting or certain other kinds of deformation.

Many historians of technology consider that true machine tools were born when the toolpath first became guided by the machine itself in some way, at least to some extent, so that direct, freehand human guidance of the toolpath (with hands, feet, or mouth) was no longer the only guidance used in the cutting or forming process.

Since what these vectors describe our instant moments of degrees of freedom the vector structure is capable of expressing the changing mode of a machine tool as well as expressing its fundamental structure in the following way: imagine a lathe spending a cylinder on a horizontal axis with a tool ready to cut a face on that cylinder in some preparatory moment.

Then the operator would unlock the y-axis on the cross slide of the lathe, assuming that our examples were equipped with that, and then the operator would apply some method of traversing the facing tool across the face of the cylinder being cut and a depth combined with the rotational speed selected which engages cutting ability within the power of range of the motor powering the lathe.

The value that machine tools added to these human talents is in the areas of rigidity (constraining the toolpath despite thousands of newtons (pounds) of force fighting against the constraint), accuracy and precision, efficiency, and productivity.

With a machine tool, toolpaths that no human muscle could constrain can be constrained; and toolpaths that are technically possible with freehand methods, but would require tremendous time and skill to execute, can instead be executed quickly and easily, even by people with little freehand talent (because the machine takes care of it).

Many reports on machine tool export and import and similar economic topics use this broader definition.

The colloquial sense implying [conventional] metal cutting is also growing obsolete because of changing technology over the decades.

Clockmakers of the Middle Ages and renaissance men such as Leonardo da Vinci helped expand humans' technological milieu toward the preconditions for industrial machine tools.

During the 18th and 19th centuries, and even in many cases in the 20th, the builders of machine tools tended to be the same people who would then use them to produce the end products (manufactured goods).

In order of historical emergence, they have been firearms (small arms and artillery); clocks; textile machinery; steam engines (stationary, marine, rail, and otherwise) (the story of how Watt's need for an accurate cylinder spurred Boulton's boring machine is discussed by Roe[8]); sewing machines; bicycles; automobiles; and aircraft.

Machine tools filled a need created by textile machinery during the Industrial Revolution in England in the middle to late 1700s.

[8][9] The advance in the accuracy of machine tools can be traced to Henry Maudslay and refined by Joseph Whitworth.

The process by which the master plane gages were produced dates back to antiquity but was refined to an unprecedented degree in the Maudslay shop.

The first step is to rub plates 1 and 2 together with a marking medium (called bluing today) revealing the high spots which would be removed by hand scraping with a steel scraper, until no irregularities were visible.

Repeating this process of comparing and scraping the three plates could produce plane surfaces accurate to within millionths of an inch (the thickness of the marking medium).

The traditional method of producing the surface gages used an abrasive powder rubbed between the plates to remove the high spots, but it was Whitworth who contributed the refinement of replacing the grinding with hand scraping.

[8] The first machine tools offered for sale (i.e., commercially available) were constructed by Matthew Murray in England around 1800.

[11] Others, such as Henry Maudslay, James Nasmyth, and Joseph Whitworth, soon followed the path of expanding their entrepreneurship from manufactured end products and millwright work into the realm of building machine tools for sale.

American production of machine tools was a critical factor in the Allies' victory in World War II.

[14][15] The production of machine tools is concentrated in about 10 countries worldwide: China, Japan, Germany, Italy, South Korea, Taiwan, Switzerland, US, Austria, Spain and a few others.

NC and CNC machines could precisely repeat sequences over and over, and could produce much more complex pieces than even the most skilled tool operators.

[citation needed] Before long, the machines could automatically change the specific cutting and shaping tools that were being used.

[citation needed] Examples of machine tools are: When fabricating or shaping parts, several techniques are used to remove unwanted metal.

Devices that fabricate components by selective addition of material are called rapid prototyping machines.