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Dovetail
A dovetail joint or simply dovetail is a joinery technique most commonly used in woodworking joinery (carpentry), including furniture, cabinets, log buildings, and traditional timber framing. Noted for its resistance to being pulled apart, also known as tensile strength, the dovetail joint is commonly used to join the sides of a drawer to the front. A series of pins cut to extend from the end of one board interlock with a series of 'tails' cut into the end of another board. The pins and tails have a trapezoidal shape. Once glued, a wooden dovetail joint requires no mechanical fasteners. History The dovetail joint technique probably pre-dates written history. Some of the earliest known examples of the dovetail joint are in ancient Egyptian furniture entombed with mummies dating from First Dynasty, the tombs of Chinese emperors, and a stone pillar at the Vazhappally Maha Siva Temple in India. The dovetail design is an important method of distinguishing various periods of furni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linear-motion Bearing
A linear-motion bearing or linear slide is a bearing designed to provide free motion in one direction. There are many different types of linear motion bearings. Motorized linear slides such as machine slides, X-Y tables, roller tables and some dovetail slides are bearings moved by drive mechanisms. Not all linear slides are motorized, and non-motorized dovetail slides, ball bearing slides and roller slides provide low-friction linear movement for equipment powered by inertia or by hand. All linear slides provide linear motion based on bearings, whether they are ball bearings, dovetail bearings, linear roller bearings, magnetic or fluid bearings. X-Y tables, linear stages, machine slides and other advanced slides use linear motion bearings to provide movement along both X and Y multiple axis. Rolling-element bearing A rolling-element bearing is generally composed of a sleeve-like outer ring and several rows of balls retained by cages. The cages were originally machined fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telescopic Sight
A telescopic sight, commonly called a scope informally, is an optical sighting device based on a refracting telescope. It is equipped with some form of a referencing pattern – known as a ''reticle'' – mounted in a focally appropriate position in its optical system to provide an accurate point of aim. Telescopic sights are used with all types of systems that require magnification in addition to reliable visual aiming, as opposed to non-magnifying iron sights, reflector (reflex) sights, holographic sights or laser sights, and are most commonly found on long-barrel firearms, particularly rifles, usually via a scope mount. Similar devices are also found on other platforms such as artillery, tanks and even aircraft. The optical components may be combined with optoelectronics to add night vision or smart device features. History The first experiments directed to give shooters optical aiming aids go back to the early 17th century. For centuries, different optical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Woodworking Joints
Joinery is a part of woodworking that involves joining pieces of wood, engineered lumber, or synthetic substitutes (such as laminate), to produce more complex items. Some woodworking joints employ mechanical fasteners, bindings, or adhesives, while others use only wood elements (such as dowels or plain mortise and tenon fittings). The characteristics of wooden joints—strength, flexibility, toughness, appearance, etc.—derive from the properties of the materials involved and the purpose of the joint. Therefore, different joinery techniques are used to meet differing requirements. For example, the joinery used to construct a house can be different from that used to make cabinetry or furniture, although some concepts overlap. In British English joinery is distinguished from carpentry, which is considered to be a form of structural timber work; in other locales joinery is considered a form of carpentry. History Many traditional wood joinery techniques use the distinctive mate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eddystone Lighthouse
The Eddystone Lighthouse is a lighthouse on the Eddystone Rocks, south of Rame Head in Cornwall, England. The rocks are submerged below the surface of the sea and are composed of Precambrian gneiss. View at 1:50000 scale The current structure is the fourth to be built on the site. The first lighthouse (Winstanley's) was swept away in a powerful storm, killing its architect and five other men in the process. The second (Rudyard's) stood for fifty years before it burned down. The third (Smeaton's) is renowned because of its influence on Lighthouse, lighthouse design and its importance in the development of concrete for building; its upper portions were re-erected in Plymouth as a monument. The first lighthouse, completed in 1699, was the world's first open ocean lighthouse, although the Cordouan Lighthouse off the western French coast preceded it as the first offshore lighthouse. The need for a light The Eddystone Rocks are an extensive reef approximately SSW off Plymouth S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miter Joint
A miter joint (mitre in British English) is a joint made by cutting each of two parts to be joined, across the main surface, usually at a 45° angle, to form a corner, usually to form a 90° angle, though it can comprise any angle greater than 0 degrees. It is called beveling when the angled cut is done on the side, although the resulting joint is still a miter joint. For woodworking, a disadvantage of a miter joint is its weakness, but it can be strengthened with a spline (a thin wafer of wood inserted into a slot, usually arranged with the long grain of the spline across the short grain of the frame timber). There are two common variations of a splined miter joint, one where the spline is long and runs the length of the mating surfaces and another where the spline is perpendicular to the joined edges. Common applications include picture frames, pipes, and molding. Non-perpendicular joints For miter joints occurring at angles other than 90°, for materials of the same ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iron Sights
Iron sights are a system of physical alignment markers used as a sighting device to assist the accurate aiming of ranged weapons such as firearms, airguns, crossbows, and bows, or less commonly as a primitive finder sight for optical telescopes. Iron sights, which are typically made of metal, are the earliest and simplest type of sighting device. Since iron sights neither magnify nor illuminate the target, they rely completely on the viewer's naked eye and the available light by which the target is visible. In this respect, iron sights are distinctly different from optical sight designs that employ optical manipulation or active illumination, such as telescopic sights, reflector (reflex) sights, holographic sights, and laser sights. Iron sights are typically composed of two components mounted perpendicularly above the weapon's bore axis: a 'rear sight' nearer (or 'proximal') to the shooter's eye, and a 'front sight' farther forward (or 'distal') near the muzzle. During ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Web Frame
In cabinet making, a web frame is the term for the internal structural frame of a cabinet which provides the support for drawers. The web frame forms a divider between drawers and provides a mounting point for the drawer runners. In some cabinets, a thin sheet of plywood is inserted into a groove in the web frame to serve as a dust cover between drawers. A basic web frame consists of a front rail which is usually visible from the front of the cabinet and two side rails which extend from the front to the rear of the cabinet. In many web frames, these side rails also serve as the drawer runners, on which the drawer itself slides. An optional rear rail may also be included. In fine cabinet work, the front rail is connected to the sides of the cabinet, or to vertical frame members, using sliding dovetails. In solid timber carcases, the side rails are housed in a dado in the cabinet sides and fixed only at the front to allow for seasonal movement. A screw in an elongated hole is used ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Milling Machine
Milling is the process of machining using rotary cutters to remove material by advancing a cutter into a workpiece. This may be done by varying directions on one or several axes, cutter head speed, and pressure. Milling covers a wide variety of different operations and machines, on scales from small individual parts to large, heavy-duty gang milling operations. It is one of the most commonly used processes for machining custom parts to precise tolerances. Milling can be done with a wide range of machine tools. The original class of machine tools for milling was the milling machine (often called a mill). After the advent of computer numerical control (CNC) in the 1960s, milling machines evolved into ''machining centers'': milling machines augmented by automatic tool changers, tool magazines or carousels, CNC capability, coolant systems, and enclosures. Milling centers are generally classified as vertical machining centers (VMCs) or horizontal machining centers (HMCs). The integr ... [...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 workpiece 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. While all machine tools are "machines that help people to make things", not all factory machines are machine tools. Today machine tools are typically ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perumthachan Pillarവാഴപ്പള്ളി
Perumthachan (പെരുന്തച്ചന്), also spelled as ''"Perunthchan"'' (പെരു - Peru/big, തച്ചന് - thachan/craftsman), meaning ''the master carpenter'' or ''the master craftsman'', is an honorific title that is used to refer to an ancient legendary carpenter (ആശാരി Aashari), architect, woodcarver and sculptor (stone/wood) from Kerala, India. However Perumthachan is an important figure in the folklore of Kerala and many a wondrous structure and architecture that still stand are attributed to him. History and legend Birth and related legends Many legends of Perumthachan are seen in Aithihyamala, the compilation of legends and folklore of Kerala written by Kottarathil Sankunni. Given that Perumthachan was a Vishwakarma his biological parents were not craftsman, his biological father, vararuchi,was a scholar in the palace of vikramadhitya . He married a woman whom he beloved that she belonged to his cast but later he understood ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fastnet Lighthouse
Fastnet Lighthouse is a lighthouse situated on the remote Fastnet Rock in the Atlantic Ocean. It is the most southerly point of Ireland and lies southwest of Cape Clear Island and from County Cork on the Irish mainland. The current lighthouse is the second to be built on the rock and is the tallest in Ireland. First lighthouse Construction of the first lighthouse began in 1853, and it first produced a light on 1 January 1854. The lighthouse replaced an early one built on Cape Clear Island in 1818, partly motivated by the loss of an American sailing packet, ''Stephen Whitney'', in thick fog during November 1847 on nearby West Calf Island causing the death of 92 of her 110 passengers and crew. The new lighthouse was constructed of cast iron with an inner lining of brick and was designed by George Halpin. Costing £17,390, the tower was tall with an lantern structure on top, giving a total height of around . It had an oil-burning lamp of 38 kilocandelas; in contrast, moder ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
