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Multimachine
The multimachine is an all-purpose open source machine tool that can be built inexpensively by a semi-skilled mechanic with common hand tools, from discarded car and truck parts, using only commonly available hand tools and no electricity. Its size can range from being small enough to fit in a closet to one hundred times that size. The multimachine can accurately perform all the functions of an entire machine shop by itself. The multimachine was first developed as a personal project by Pat Delaney, then grew into an open source project organized via a Yahoo! group. The 2,600 member support group that has grown up around its creation is made up of engineers, machinists, and experimenters who have proven that the machine works. As an open-source machine tool that can be built cheaply on-site, the Multimachine could have many uses in developing countries. The multimachine group is currently focused on the humanitarian aspects of the multimachine, and on promulgating the concept of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MultiMachine
The multimachine is an all-purpose open source machine tool that can be built inexpensively by a semi-skilled mechanic with common hand tools, from discarded car and truck parts, using only commonly available hand tools and no electricity. Its size can range from being small enough to fit in a closet to one hundred times that size. The multimachine can accurately perform all the functions of an entire machine shop by itself. The multimachine was first developed as a personal project by Pat Delaney, then grew into an open source project organized via a Yahoo! group. The 2,600 member support group that has grown up around its creation is made up of engineers, machinists, and experimenters who have proven that the machine works. As an open-source machine tool that can be built cheaply on-site, the Multimachine could have many uses in developing countries. The multimachine group is currently focused on the humanitarian aspects of the multimachine, and on promulgating the concept of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Machine Tools
A machine tool is a machine for handling or machining metal or other rigid materials, usually by cutting, boring, grinding, shearing, or other forms of deformations. Machine tools employ some sort of tool that does the cutting or shaping. All machine tools have some means of constraining the work piece and provide a guided movement of the parts of the machine. 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". It is a power-driven metal cutting machine which assists in managing the needed relative motion between cutting tool and the job that changes the size and shape of the job material. The precise definition of the term ''machine tool'' varies among users, as discussed below. While all machine tools are "machines that help people to make things", not all factory machines are machine tools. Today machine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Machine Tool
A machine tool is a machine for handling or machining metal or other rigid materials, usually by cutting, boring, grinding, shearing, or other forms of deformations. Machine tools employ some sort of tool that does the cutting or shaping. All machine tools have some means of constraining the work piece and provide a guided movement of the parts of the machine. 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". It is a power-driven metal cutting machine which assists in managing the needed relative motion between cutting tool and the job that changes the size and shape of the job material. The precise definition of the term ''machine tool'' varies among users, as discussed below. While all machine tools are "machines that help people to make things", not all factory machines are machine tools. Today machine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bore (engine)
In a piston engine, the bore (or cylinder bore) is the diameter of each cylinder. Engine displacement is calculated based on bore, stroke length and the number of cylinders: displacement = The stroke ratio, determined by dividing the bore by the stroke, traditionally indicated whether an engine was designed for power at high engine speeds (rpm) or torque at lower engine speeds. The term "bore" can also be applied to the bore of a locomotive cylinder or steam engine pistons. Steam locomotive The term bore also applies to the cylinder of a steam locomotive or steam engine. See also * Bore pitch * Compression ratio * Engine displacement Engine displacement is the measure of the cylinder volume swept by all of the pistons of a piston engine, excluding the combustion chambers. It is commonly used as an expression of an engine's size, and by extension as a loose indicator of the ... References {{Steam engine configurations Engine technology ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
First World War
World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fighting occurring throughout Europe, the Middle East, Africa, the Pacific, and parts of Asia. An estimated 9 million soldiers were killed in combat, plus another 23 million wounded, while 5 million civilians died as a result of military action, hunger, and disease. Millions more died in genocides within the Ottoman Empire and in the 1918 influenza pandemic, which was exacerbated by the movement of combatants during the war. Prior to 1914, the European great powers were divided between the Triple Entente (comprising France, Russia, and Britain) and the Triple Alliance (containing Germany, Austria-Hungary, and Italy). Tensions in the Balkans came to a head on 28 June 1914, following the assassination of Archduke Franz Ferdina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Concrete
Concrete is a composite material composed of fine and coarse aggregate bonded together with a fluid cement (cement paste) that hardens (cures) over time. Concrete is the second-most-used substance in the world after water, and is the most widely used building material. Its usage worldwide, ton for ton, is twice that of steel, wood, plastics, and aluminum combined. Globally, the ready-mix concrete industry, the largest segment of the concrete market, is projected to exceed $600 billion in revenue by 2025. This widespread use results in a number of environmental impacts. Most notably, the production process for cement produces large volumes of greenhouse gas emissions, leading to net 8% of global emissions. Other environmental concerns include widespread illegal sand mining, impacts on the surrounding environment such as increased surface runoff or urban heat island effect, and potential public health implications from toxic ingredients. Significant research and development is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zinc Aluminum
Zinc-aluminium (ZA) alloys are alloys whose main constituents are zinc and aluminium. Other alloying elements include magnesium and copper. This type of alloy was originally developed for gravity casting. Noranda, New Jersey Zinc Co. Ltd., St. Joe Mineral Co. and the International Lead Zinc Research Organization (ILZRO) were the main companies that pioneered the ZA alloys between the 1950s and the 1970s. They were designed to compete with bronze, cast iron and aluminium using sand and permanent mold casting methods. Distinguishing features of ZA alloys include high as-cast strength, excellent bearing properties, as well as low energy requirements (for melting). ZA alloys make good bearings because their final composition includes hard eutectic zinc-aluminium-copper particles embedded in a softer zinc-aluminium matrix. The hard particles provide a low-friction bearing surface, while the softer material wears back to provide space for lubricant to flow, similar to Babbitt metal. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Head Gasket
In an internal combustion engine, a head gasket provides the seal between the engine block and cylinder head(s). Its purpose is to seal the combustion gases within the cylinders and to avoid coolant or engine oil leaking into the cylinders. Leaks in the head gasket can cause poor engine running and/or overheating. Purpose Within a water-cooled internal combustion engine, there are three fluids which travel between the engine block and the cylinder head: # Combustion gases (unburned air/fuel mixture and exhaust gases) in each cylinder # Water-based coolant in the coolant passages # Lubricating oil in the oil galleries Correct operation of the engine requires that each of these circuits do not leak or lose pressure at the junction of the engine block and the cylinder head. The head gasket is the seal that prevents these leaks and pressure losses. Types * Multi-Layer Steel (MLS): Most modern engines are produced with MLS gaskets. These consist of two to five (typically three) th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cylinder Head
In an internal combustion engine, the cylinder head (often abbreviated to simply "head") sits above the cylinders and forms the roof of the combustion chamber. In sidevalve engines, the head is a simple sheet of metal; whereas in more modern overhead valve and overhead camshaft engines, the cylinder head is a more complicated block often containing inlet and exhaust passages, coolant passages, valves, camshafts, spark plugs and fuel injectors. Most straight engines have a single cylinder head shared by all of the cylinders and most V engines have two cylinder heads (one per bank of cylinders). Design A summary of engine designs is shown below, in chronological order for automobile usage. Sidevalve engines In a flathead (''sidevalve'') engine, all of the valvetrain components are contained within the block, therefore the head is usually a simple sheet of metal bolted to the top of the engine block. Sidevalve engines were once universal in automobiles but are now lar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Engine Block
In an internal combustion engine, the engine block is the structure which contains the cylinders and other components. In an early automotive engine, the engine block consisted of just the cylinder block, to which a separate crankcase was attached. Modern engine blocks typically have the crankcase integrated with the cylinder block as a single component. Engine blocks often also include elements such as coolant passages and oil galleries. The term "cylinder block" is often used interchangeably with "engine block", although technically, the block of a modern engine (i.e. multiple cylinders integrated with another component) would be classified as a monobloc. __TOC__ Construction The main structure of an engine typically consists of the cylinders, coolant passages, oil galleries, crankcase, and cylinder head(s). The first production engines of the 1880s to 1920s usually used separate components for each of these elements, which were bolted together during engine assembly. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LEGO
Lego ( , ; stylized as LEGO) is a line of plastic construction toys that are manufactured by The Lego Group, a privately held company based in Billund, Denmark. The company's flagship product, Lego, consists of variously colored interlocking plastic bricks accompanying an array of gears, figurines called minifigures, and various other parts. Lego pieces can be assembled and connected in many ways to construct objects, including vehicles, buildings, and working robots. Anything constructed can be taken apart again, and the pieces reused to make new things. The Lego Group began manufacturing the interlocking toy bricks in 1949. Movies, games, competitions and eight Legoland amusement parks have been developed under the brand. , 600 billion Lego parts had been produced. History The Lego Group began in the workshop of Ole Kirk Christiansen (1891–1958), a carpenter from Billund, Denmark, who began making wooden toys in 1932. In 1934, his company came to be called ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yahoo! Group
Yahoo! Groups was a free-to-use system of electronic mailing lists offered by Yahoo!. Prior to February 2020, Yahoo! Groups was one of the world's largest collections of online discussion boards. It allowed members to subscribe to various groups, read subscribed discussions online, view and share photos, files and bookmarks within a group, access a group calendar, create polls for group members, and receive email notifications of new discussion topics. Some groups were simply announcement boards, to which only the group moderators could post, while others were discussion forums. Depending on each group's settings, membership could be open to everyone or only to invited and/or approved people. On February 1, 2020, Yahoo! removed online access to discussions and all other features except simple membership management, essentially turning all groups into mailing lists, and on October 13, 2020, it announced that Yahoo Groups would shut down completely on December 15, 2020. History ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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