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A compound bow is a modern bow that uses a levering system, usually of cables and pulleys, to bend the limbs. Image File history File linksMetadata Download high resolution version (713x1812, 80 KB) Summary I, Ewok Slayer, Created this Image. ...
Image File history File linksMetadata Download high resolution version (713x1812, 80 KB) Summary I, Ewok Slayer, Created this Image. ...
Look up Browning and browning in Wiktionary, the free dictionary. ...
This article is about the projectile weapon bow. ...
For the band, see Pulley (band). ...
The limbs of a compound bow are usually much stiffer than those of a recurve bow or longbow. This limb stiffness makes the compound bow more energy efficient than other bows, but the limbs are too stiff to be drawn comfortably with a string attached directly to them. The compound bow has the string attached to the pulleys, one or both of which has one or more cables attached to the opposite limb. When the string is drawn back, the string causes the pulleys to turn. This causes the pulleys to pull the cables, which in turn causes the limbs to bend and thus store energy. Modern recurve bow // A recurve bow is a form of bow defined by the side-view profile; in contrast to the simple longbow, a recurve bow has tips that curve away from the archer when the bow is aimed. ...
Lemonwood, purpleheart and hickory longbow, 45 lbf / 200 N draw force. ...
The use of this levering system gives the compound bow a characteristic draw-force curve which rises to a peak weight and then "lets off" to a lower holding weight.
The compound bow is little-affected by changes of temperature and humidity and gives superior accuracy, velocity, and distance in comparison to other bows. The compound bow was first developed and patented by Holless Wilbur Allen in Missouri in 1967 and has become increasingly popular. In the United States, the compound is the dominant form of bow. Holless Wilbur Allen was the inventor of the compound bow. ...
This article is about the U.S. state. ...
Year 1967 (MCMLXVII) was a common year starting on Sunday (link will display full calendar) of the 1967 Gregorian calendar. ...
In literature of the early 20th century, composite bows have been described as "compound". A composite bow is a bow made from disparate materials laminated together, usually applied under tension. ...
Construction of compound bow
 Browning Compound Bow Pulley System Closeup The central riser of a compound bow is usually made of aluminium or magnesium. Many risers are made of the aircraft-grade 6061 aluminum alloy. Risers are designed to be as rigid as possible. The riser is the central mount for other components such as the limbs, sights, stabilizers and quivers. Image File history File linksMetadata Download high resolution version (1023x471, 33 KB) Summary I, Ewok Slayer, took this Image. ...
Image File history File linksMetadata Download high resolution version (1023x471, 33 KB) Summary I, Ewok Slayer, took this Image. ...
Aluminum redirects here. ...
General Name, symbol, number magnesium, Mg, 12 Chemical series alkaline earth metals Group, period, block 2, 3, s Appearance silvery white solid at room temp Standard atomic weight 24. ...
6061 is an aluminum alloy, with magnesium and silicon as the alloying elements. ...
Limbs are made of composite materials and are capable of taking high tensile and compressive forces. The limbs store all the energy of the bow - no energy is stored in the pulleys and cables. A cloth of woven carbon fiber filaments, a common element in composite materials Composite materials (or composites for short) are engineered materials made from two or more constituent materials with significantly different physical or chemical properties and which remain separate and distinct on a macroscopic level within the finished structure. ...
In the most common configuration, there is a cam or wheel at the end of each limb. The shape of the cam may vary somewhat between different bow designs. There are several different concepts of utilizing the cams to store energy in the limbs, and these all fall under a category called bow eccentrics. The four most common types of bow eccentrics are Single Cam, Hybrid Cam, Dual Cam and Binary Cam. However, there are also other less common designs, like the Quad Cam and Hinged. For other uses, see CAM. Animation showing rotating cams and cam followers producing reciprocating motion. ...
For other uses, see Wheel (disambiguation). ...
// The Binary Cam system is a relatively new development in the world of compound bows. ...
Compound bow strings and cables are normally made of high-modulus polyethylene and are designed to have great tensile strength and minimal stretchability, in order that the bow transfers its energy to the arrow as efficiently and durably as possible. In earlier models of compound bows, the cables were often made of plastic-coated steel. For the bowstring bridge, see tied arch bridge. ...
Ultra high molecular weight polyethylene (UHMWPE), also known as high modulus polyethylene (HMPE) or high performance polyethylene (HPPE), is a thermoplastic. ...
Advantages over traditional bows
Technical advantages - As the bow is drawn, the draw weight increases to a peak and then "lets off". The let-off is usually between 65% and 80% of the peak weight, and one manufacturer (Concept Archery) produces a compound bow with 99% let-off. The "let off" is a term that describes what happens as the cam rolls all the way over. If you look at the photo to the right you can see that the axle attaching the limb to cam is mounted at the edge of the cam as opposed to the center. As the string is drawn the cam turns and imparts force to compress the limb. Once the cam turns all the way around the least amount of force needs to be applied to the string to keep the limbs bent. This is known as "let off". This enables the archer to hold the bow fully drawn and take more time to aim.
- This let-off enables the archer to accurately shoot a bow with a much higher peak draw weight than they could manage with a longbow or recurve.
- The bow is resilient to temperature and humidity changes giving the bow superior accuracy, velocity, and distance in comparison to bows made of natural materials.
- The pulley system usually will include some rubber-covered blocks that act as draw-stops. These provide a solid "wall" that the archer can draw against. These draw stops can be adjusted to suit the archer's optimum draw-length. This helps the archer achieve a consistent anchor point and a consistent amount of force imparted to the arrow on every shot, further increasing accuracy.
- The design of the pulleys (cams) directly controls the acceleration of the arrow. What is termed a "soft cam" will accelerate the arrow more gently than a "harder" cam. Novice archers will typically shoot a soft cam whereas a more advanced archer may choose to use a harder cam to gain speed. Bows can be had with a variety of cams, in a full spectrum from soft to hard.
- Some pulley systems use a single cam at the bottom of the bow and a balanced wheel at the top of the bow instead of two identical cams. This design eliminates the need for buss cables and instead uses a single string that begins at the cam on the bottom of the bow, travels over the wheel on top, around the bottom cam again, and ends attaching to the top limb. Single cam bows are generally faster than other compounds, reaching speeds close to 315 fps.[1] Single cam bows are less adjustable than twin cam bows, so to change the draw length of a single cam bow, the cam and string must usually be replaced.
Circumstantial advantages - Compound archers usually use a mechanical release aid to hold and release the string. This attaches to the bowstring near the point where the arrow attaches, and permits the archer to release the string with a squeeze of a trigger or a slight increase of tension. The use of a release aid gives a more consistent release than the use of fingers on the string.
- In tournaments, compound archers are usually allowed the use of a magnifying sight. This is not allowed for other bow classes.
- Stabilizers and dampeners are particularly well-developed for the compound bow. They allow the archer to shoot even more accurately, by reducing the movement of the bow when the string is released.
Circumstantial disadvantages - The relatively low holding weight of a compound bow compared to a recurve bow makes the compound more sensitive to certain form faults when the archer is at full draw. In particular, it's easier for the archer to torque the bow around the vertical axis, leading to left-right errors.
Quantities describing compound bows AMO standard draw length is the distance from the string at full draw to the lowest point on the grip plus 1.75 inches (4.45 cm).[2] Because the draw force may increase more or less rapidly, and again drop off more or less rapidly when approaching peak draw, bows of the same peak draw force can store different amounts of energy. Norbert Mullaney has defined the ratio of stored energy to peak draw force (S.E./P.D.F.). This is usually around one foot-pound-force per pound (3 joules per kilogram) but can reach 1.4 ft·lbf/lb (4.2 J/kg). In physics, a foot-pound force (symbol ft·lbf or ft·lbf), usually abbreviated to foot-pound, is an Imperial and U.S. customary unit of mechanical work, or energy, although in scientific fields one commonly uses the equivalent metric unit of the joule (J). ...
Look up pound in Wiktionary, the free dictionary. ...
Efficiency of the bows also varies. Normally between 70-85% of the stored energy is transferred to the arrow. This stored energy is referred to as potential energy. When transferred to the arrow it is referred to as kinetic energy. The product of S.E./P.D.F. and efficiency can be called power factor. There are two measurement standards of this quantity, AMO and IBO speed. AMO is defined as the initial velocity of a 540 grain (35 g) arrow when shot from a bow with a peak draw weight of 60 lbf (270 N) and draw length 30 inches (76 cm). IBO speed is defined as the initial velocity of a 350 grain (22.7 g) arrow shot from a bow with a peak draw weight of 70 lbf (300 N) and a draw length of 30 inches (76 cm). Potential energy can be thought of as energy stored within a physical system. ...
The cars of a roller coaster reach their maximum kinetic energy when at the bottom of their path. ...
Brace height is the distance from the deepest point of the grip to the string at rest. Typically a shorter brace height will result in an increased power stroke.
Arrows used - See also: Arrow
Arrows used with compound bows differ very little from arrows shot by recurve archers. Shafts of arrows used with compound bows are usually made of an aluminum alloy, or carbon fiber, or a combination of these. Due to the greater forces that a compound bow places on the arrow, wooden arrows may break when shot from a compound bow, possibly driving the broken shaft into the archer's arm, or the arrow may shatter because of the changes in force applied to it during release. Manufacturers produce shafts with different stiffnesses and lengths in the same model of shaft to accommodate to different draw weights and draw lengths. Arrow stiffness (spine) is an important parameter in finding arrows that shoot accurately out of a particular bow (see Archer's paradox). This article is about the weapon. ...
Aluminum is a soft and lightweight metal with a dull silvery appearance, due to a thin layer of oxidation that forms quickly when it is exposed to air. ...
Carbon fiber composite is a strong, light and very expensive material. ...
Diagram of the archers paradox, showing what happens when arrows are incorrectly spined The term archers paradox refers to the flexing of an arrow shaft that occurs when it is shot from a non-centershot bow. ...
See also This article is about the projectile weapon bow. ...
This article is about the weapon. ...
Self-yew English longbow, 6 ft 6 in (2 m) long, 470 N (105 lbf) draw force. ...
Lemonwood, purpleheart and hickory longbow, 45 lbf / 200 N draw force. ...
An American Flat bow, similar to the longbow but based on native American bows A flatbow is a bow with non-recurved, flat, relatively wide limbs that are rectangular in cross-section. ...
Archery is the practice of using a bow to shoot arrows. ...
A horse archer (or horsed archer, mounted archer) is a cavalryman armed with a bow. ...
// The Binary Cam system is a relatively new development in the world of compound bows. ...
Bow construction techniques Self bow A self bow is a bow made from a single piece of wood. ...
// Laminated bow is a description applied to a method of construction of bows in which different materials are laminated together to form the bow stave itself. ...
A composite bow is a bow made from disparate materials laminated together, usually applied under tension. ...
Bow forms Modern recurve bow // A recurve bow is a form of bow defined by the side-view profile; in contrast to the simple longbow, a recurve bow has tips that curve away from the archer when the bow is aimed. ...
A decurve bow is a bow that has arms curved or curled at the ends to turn towards the archer. ...
A deflex bow is a bow that has arms curved or curled at the base or throughout their length, to turn towards the archer. ...
A reflex bow is a bow (often made entirely of wood) that has curved or curled arms. ...
References - General references
- (1992) The Traditional Bowyers Bible Volume 1. The Lyons Press. ISBN 1-58574-085-3
- (1992) The Traditional Bowyers Bible Volume 2. The Lyons Press. ISBN 1-58574-086-1
- (1994) The Traditional Bowyers Bible Volume 3. The Lyons Press. ISBN 1-58574-087-X
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