A bow drill is a simple hand-operated type of tool, consisting of a rod (the spindle or drill shaft) that is set in rapid rotary motion by means of a cord wrapped around it, kept taut by a bow which is pushed back and forth with one hand. This tool of prehistoric origin has been used both as a drill, to make holes on solid materials such as wood, stone, bone, or teeth, and as a fire drill to start a fire. [1] [2] [3]
The spindle can be held into a fixed frame, or by a hand-held block (the hand piece or thimble) with a hole into which the top of the shaft is inserted. Some lubricant should be used to reduce friction between these two parts, otherwise, it could lead to some trouble when doing it too fast. A popular campcraft book of 1920 attributed this invention to the Inuit. [4] In Mehrgarh (Pakistan) it has been dated between the 4th-5th millennium BCE. [5]
The string of the bow is wrapped once around the spindle, so that it is tight enough not to slip during operation. In a variation called the Egyptian bow drill, the cord is wound around the shaft multiple times, or is fixed to it by a knot or a hole.[ citation needed ]
The strap drill is a simpler version, where the bow is absent and the cord is kept taut by pulling the ends with both hands, while moving them left and right at the same time. In the absence of a frame, the thimble is shaped so that it can be held with the chin or the mouth.[ citation needed ]
The bow lathe used for traditional woodturning uses the same principle as the bow drill.
Bow drills with green jasper bits were used in Mehrgarh between the 4th and 5th millennium BC to drill holes into lapis lazuli and carnelian. Similar drills were found in other parts of the Indus Valley civilization and Iran one millennium later. [6]
For use as a fire drill, the shaft should have a blunt end, which is placed into a small cavity of a stationary piece of wood (the fireboard). Turning the shaft with high speed and downward pressure generates heat, which eventually creates powdered charcoal and ignites it forming a small ember. [4]
For drilling, the lower end of the spindle may be fitted with a hard drill bit that creates the hole by abrasion or cutting.[ citation needed ]
Mehrgarh is a Neolithic archaeological site situated on the Kacchi Plain of Balochistan in Pakistan. It is located near the Bolan Pass, to the west of the Indus River and between the modern-day Pakistani cities of Quetta, Kalat and Sibi. The site was discovered in 1974 by the French Archaeological Mission led by the French archaeologists Jean-François Jarrige and Catherine Jarrige. Mehrgarh was excavated continuously between 1974 and 1986, and again from 1997 to 2000. Archaeological material has been found in six mounds, and about 32,000 artifacts have been collected from the site. The earliest settlement at Mehrgarh, located in the northeast corner of the 495-acre (2.00 km2) site, was a small farming village dated between 7000 BCE and 5500 BCE.
Carnelian is a brownish-red mineral commonly used as a semiprecious stone. Similar to carnelian is sard, which is generally harder and darker; the difference is not rigidly defined, and the two names are often used interchangeably. Both carnelian and sard are varieties of the silica mineral chalcedony colored by impurities of iron oxide. The color can vary greatly, ranging from pale orange to an intense almost-black coloration. Significant localities include Yanacodo (Peru); Ratnapura ; and Thailand. It has been found in Indonesia, Brazil, India, Russia (Siberia), and Germany. In the United States, the official State Gem of Maryland is also a variety of carnelian called Patuxent River stone.
The router is a power tool with a flat base and a rotating blade extending past the base. The spindle may be driven by an electric motor or by a pneumatic motor. It routs an area in hard material, such as wood or plastic. Routers are used most often in woodworking, especially cabinetry. They may be handheld or affixed to router tables. Some woodworkers consider the router one of the most versatile power tools.
A lathe is a machine tool that rotates a workpiece about an axis of rotation to perform various operations such as cutting, sanding, knurling, drilling, deformation, facing, threading and turning, with tools that are applied to the workpiece to create an object with symmetry about that axis.
A drill is a tool used for making round holes or driving fasteners. It is fitted with a bit, either a drill or driver chuck. Hand-operated types are dramatically decreasing in popularity and cordless battery-powered ones proliferating due to increased efficiency and ease of use.
Metalworking is the process of shaping and reshaping metals in order to create useful objects, parts, assemblies, and large scale structures. As a term, it covers a wide and diverse range of processes, skills, and tools for producing objects on every scale: from huge ships, buildings, and bridges, down to precise engine parts and delicate jewelry.
A drill bit is a cutting tool used in a drill to remove material to create holes, almost always of circular cross-section. Drill bits come in many sizes and shapes and can create different kinds of holes in many different materials. In order to create holes drill bits are usually attached to a drill, which powers them to cut through the workpiece, typically by rotation. The drill will grasp the upper end of a bit called the shank in the chuck.
Drilling is a cutting process where a drill bit is spun to cut a hole of circular cross-section in solid materials. The drill bit is usually a rotary cutting tool, often multi-point. The bit is pressed against the work-piece and rotated at rates from hundreds to thousands of revolutions per minute. This forces the cutting edge against the work-piece, cutting off chips (swarf) from the hole as it is drilled.
Woodturning is the craft of using a wood lathe with hand-held tools to cut a shape that is symmetrical around the axis of rotation. Like the potter's wheel, the wood lathe is a mechanism that can generate a variety of forms. The operator is known as a turner, and the skills needed to use the tools were traditionally known as turnery. In pre-industrial England, these skills were sufficiently difficult to be known as "the mysteries of the turners' guild." The skills to use the tools by hand, without a fixed point of contact with the wood, distinguish woodturning and the wood lathe from the machinist's lathe, or metal-working lathe.
In archaeology, a perforated baton, bâton de commandement or bâton percé is a type of artefact from prehistoric Europe made from antler, which probably served many functions such as being used as a spear-thrower, in rope-making, and ceremonial and other uses.
Fire making, fire lighting or fire craft is the process of artificially starting a fire. It requires completing the fire triangle, usually by heating tinder above its autoignition temperature.
Turning is a machining process in which a cutting tool, typically a non-rotary tool bit, describes a helix toolpath by moving more or less linearly while the workpiece rotates.
A brace is a hand tool used with a bit to drill holes, usually in wood. Pressure is applied to the top while the handle is rotated. If the bit's lead and cutting spurs are both in good working order, the user should not have to apply any pressure other than for balance: the lead will pull the bit through the wood. Bits used to come in a variety of types but the more commonly used Ridgeway and Irwin-pattern bits also rely on a tip called a snail, which is a tapered threaded screw that pulls the bit forward.
A hand drill is the simplest primitive method to produce rapid rotary motion of a rod. It consists in holding the rod vertically between both hands and moving these back and forth, in opposite directions, as in rubbing them. The rod typically is one or two feet long and half an inch in diameter.
Dietmar Otto Ernst Rothermund was a German historian and professor of the history of South Asia at the Ruprecht-Karls University in Heidelberg. He is considered an important representative of modern German historical scholarship. Although he began his academic career as an Americanist, he eventually became a notable figure in the German historiography of South Asia. He helped to lay the foundations for South Asian Studies in Germany and Europe.
A pump drill is a simple hand-powered device used to impart a rapid rotating motion to a rod. It can be used for fire making or as a drill to make holes in various materials. It consists of: the drill shaft, a narrow board with a hole through the center, a weight acting as a flywheel, and a length of cord. The weight is attached to the shaft, near the bottom end, and the hole board is slipped over the top. The cord is run through a hole or slot near the top of the shaft and attached to both ends of the hole board. The length of the cord is such that, at its lowest position, the board lies just above the weight.
String is a long flexible structure made from fibers twisted together into a single strand, or from multiple such strands which are in turn twisted together. String is used to tie, bind, or hang other objects. It is also used as a material to make things, such as textiles, and in arts and crafts. String is a simple tool, and its use by humans is known to have been developed tens of thousands of years ago. In Mesoamerica, for example, string was invented some 20,000 to 30,000 years ago, and was made by twisting plant fibers together. String may also be a component in other tools, and in devices as diverse as weapons, musical instruments, and toys.
A fire drill, sometimes called fire-stick, is a device to start a fire by friction between a rapidly rotating wooden rod and a cavity on a stationary wood piece .