What is bow and arrow?

Since the invention of bows and arrows by humans, from the initial hunting tools to war weapons, and then to the current sports events, the content given by them has become increasingly rich and professional.

With the advancement of technology, the material of the bow has also changed from early wood, bamboo, etc. to today's composite materials (glass fiber, carbon fiber, aluminum-magnesium alloy); it is more stable and accurate to use, the structural design is also increasingly innovative, it is more labor-saving to use, and the arrow speed is faster.

The development of arrows is also constantly improving with the development of bows. The straightness, toughness, deflection, and durability have been greatly improved, the wind resistance is better, and the flight is more stable.

According to the form of the bow, it can be roughly divided into:

Straight-pull bow

Traditional recurve bow (personally think that Mongolian bows and Qing bows can be classified as this category)

Competitive recurve bows (mainly used in split modern composite material sports events)

Compound bows (mainly modern technology bows with pulleys)

This is further subdivided into single bow pieces, double bow pieces, single pulleys, double pulleys, compound wheels, etc. according to structural characteristics.

Here we mainly introduce the knowledge about compound bows.

I. How to choose a bow that suits you

Beginners can refer to the following suggestions when choosing a bow;

Draw length: the distance of the bowstring. That is, the straight-line length of the bowstring from static to displacement and then to the full bow from the push point, usually in inches. Our arm length, shoulder width and the ratio of the big and small arms will determine how long we should choose the bow. Generally, we can refer to the arm span length (cm) divided by two, and then divided by 2.54 (conversion unit) to get the approximate draw length. Beginners are advised to use a bow with adjustable draw length. After practicing for a period of time, adjust the fixed draw length according to their own situation and action characteristics.

Draw force: the force exerted to draw the bowstring. Although compound bows have the ability to save effort, it is recommended to choose the poundage of the bow according to their own strength base and purpose, and do not blindly pursue a bow with high power.

Bowstring height: the vertical distance from the bow handle to the main string in the initial state, also called the bow height. Beginners are advised to choose a bow with a slightly larger parameter, which is easier to master and convenient for practice.

Axlebase: refers to the length of the bow when the bowstring is fixed at both ends of the pulley. Generally speaking, competitive target bows should use bows with a regular axis distance (more than 38 inches, the current mainstream is about 41 inches). 3D competition or hunting bows have relatively shorter axis distances.

Bow weight: refers to the weight of the bare bow at the factory. Due to different structures, materials, and sizes, the weight varies. Generally speaking, it is slightly heavier for competition.

Initial velocity: refers to the arrow speed measured when the arrow is released from the taut bowstring and is about 3~5m away from the shooter. The IBO standard arrow speed is generally used, that is, the parameters measured with 70 pounds of tension, 30 inches of draw length, and an arrow weight of not less than 5 grains per pound. Generally speaking, the speed of hunting bows of the same level is higher than that of competitive bows.

Effort saving ratio: refers to the force required to pull the pulley to fully pull the bow. The higher the effort saving ratio, the less force is required after pulling past the effort saving point. Generally speaking, competitive bows have fixed win ratios and are relatively small, while hunting bows have adjustable effort ratios, which are different and relatively high.

Pulley type: There are round wheels, oval wheels, water drop wheels, etc. Generally speaking, the larger the cam, the faster the speed, the greater the vibration, the sharper the peak force, and the harder it is to pull.

Bow limbs: The width, thickness, and curve are different. Generally speaking, they are divided into single limbs and double limbs. Some models of bows can be equipped with limbs of different models (usually competitive bows), but generally single and double limbs cannot be interchanged.

For traditional bows and recurve bows, the draw length is 28 inches and the draw force is 40 pounds. When the draw length is pulled to 28 inches, 40 pounds of pull force must be paid, which is effort-saving, and the longer the draw length, the heavier the pull force. The compound bow uses the principle of mechanical force to convert potential energy from potential energy. Depending on the shape and structure of the cam, the force required when pulling the bow from the top of the cam to the full bow is less than before. Generally speaking, the labor saving percentage of the compound bow is about 65~85%, so the compound bow is more labor-saving and easier to control when drawing the bow and aiming. If the same 40 pounds of force is 85% of the labor saving ratio, then only (40x0.15) 6 pounds of force is required.

The draw length of the compound bow is fixed, and each draw length corresponds to a stop point. It is just that due to the different pulley group structures, it is divided into adjustable and non-adjustable. The adjustable one is generally adjusted by the upper and lower wheels corresponding to different limit screw mounting holes between 2.5 inches (now there are bows with a larger adjustment range, but if other parameters such as bowstring length remain unchanged, the larger adjustment range will affect the performance of the bow). When the draw length needs to be changed, the corresponding pulley group needs to be replaced. There is also an adjustment method in the adjustable one that does not require the pulley to be replaced but the corresponding draw length adjustment module needs to be replaced.

Usually the string height of a compound bow is smaller than that of a recurve bow and a traditional bow. The reason is that the lower the bowstring height, the faster the arrow speed. You can imagine that in simple terms, the displacement torque is longer and the energy of the conversion is higher under a fixed draw distance. However, the smaller the string height of a compound bow, the harder it is to draw, and it is easier to hit the forearm if the action is incorrect.

The advantages and disadvantages of high and low arrow speeds. The advantages of high arrow speeds are: the arrow has a short air time, which avoids the accuracy of the arrow being affected by external factors such as wind and rain; the arrow flies straighter and has a higher hit rate under normal circumstances. Especially for hunting purposes, the straight arrow path and fast flight are still obvious advantages in avoiding the blocking of arrows by branches and leaves of shrubs and trees, and reducing the hit rate and lethality due to the rapid reaction of animals. Of course, the speed of the arrow is also a double-edged sword. Too high an arrow speed makes it easier to reach the target before the arrow's flight posture is stable, thus affecting the hit rate; the higher the arrow speed, the higher the consistency of your movements in order to ensure accuracy. A change in a little movement will reflect a higher error in the landing point, plus a higher peak value, which is a disadvantage for competitive games with a fixed distance, a large amount of firing, and the pursuit of density, so we must first understand our purpose.

The weight of a bare compound bow is generally between 3-5 pounds. The heavier the bow, the stronger the force the archer needs to use to stabilize the bow, but the relative reaction force of the bow will also be slower, that is, a heavier bow is less likely to feel the vibration after the energy is released, which is beneficial for continuous and repeated use over a period of time to improve accuracy.

In terms of wheelbase, in simple terms, a bow with a long wheelbase will be more comfortable, more stable, and more tolerant when opening, leaning, and aiming, and a bow with a short wheelbase is easier to carry.

2. How to choose the right arrow

The choice of arrow needs to match the draw distance and tension of the bow, so that the arrow can fly steadily. An arrow that is too light is like an empty bowstring, which is very harmful to both the bow and the arrow. On the contrary, an arrow that is too heavy will shorten its effective flight distance and fail to play the role of the bow.

We need to know that an arrow includes four main parts: arrowhead, shaft, feathers and tail; each part will affect the flight quality of the arrow.

Arrowhead:

It mainly depends on the weight and type. The weight of the arrowhead should match the shaft. If the arrowhead is too heavy, the shaft will become relatively soft (or hard as a whole). The reason is that the arrow will swing up and down and left and right when flying. If the arrowhead is too heavy, the work of correcting the swing of the shaft will fall on the shaft itself, and the arrowhead will still fly forward in slow motion, so the time and distance required for the shaft correction will also increase. Therefore, the matching of the arrowhead and the shaft is very important. As for the type, it refers to the external shape of the arrow, which affects the wind resistance of the arrow during flight. Some blade arrows used for hunting have the same weight as ordinary arrows, but they will have left and right deviations (commonly known as "wind deviation"), because the blade arrow will eat wind when flying, which means that the blade arrow will deviate due to the feathers plus the rotation angle of the blade arrow, so it is best to use hidden blade arrows. But sometimes in order to pursue lethality, when using fixed blade arrows, it is necessary to carefully adjust the arrow shaft and feathers.

Arrow shaft:

Due to different materials, it is roughly divided into wooden arrows, aluminum arrows, fiberglass arrows, carbon fiber arrows and carbon aluminum. Now most hunting arrows use aluminum arrows, while indoor and outdoor competitive arrows are basically carbon arrows or aluminum arrows for indoor use, and carbon aluminum arrows for outdoor use. When choosing an arrow shaft, the first thing to consider is your pulling force and pulling distance, and make a decision based on the manufacturer's arrow selection table. As for which arrow shaft is good, in fact, it is enough to follow one principle according to your own use, which is economical, stable and durable.

Arrow feathers:

There are many types of arrow feathers. The materials are mainly real feathers and plastic feathers. The number of feathers is two, three, four, and wavy. The shapes are straight, spiral, and circular. In terms of length, there are 1.5-inch feathers, 2-inch feathers, 3-inch feathers, 4-inch feathers, and 5-inch feathers. I won’t list them one by one, but their purpose is to correct the stability of the arrow during flight. How to choose the right arrow feathers?

Generally speaking, the heavier the arrow, the larger the feathers are needed. The arrow feathers used for competition are generally three-piece feathers. Large feathers are used indoors, and small feathers are used outdoors. Spiral feathers are more common for recurve bows, and straight feathers are more common for compound bows. As for how many degrees should be attached to make the arrow fly most stably? Generally, the feathers used for competition are about 0.5~1.5 degrees. If the angle is too large, it will increase the resistance to the long-distance flight of the arrow, shorten the effective flight distance and increase the flight time. It is easy to be affected by external factors such as wind and affect the accuracy of the arrow.

As for whether the arrow feathers rotate clockwise or counterclockwise, it mainly depends on whether the user is a right-handed bow or a left-handed bow. Generally speaking, for a right-handed bow (left hand holding the bow, right hand pulling the bow), the arrow feathers should be clockwise, and for a left-handed bow, the arrow feathers should be counterclockwise. The direction is from the tail to the arrow head. If real feathers are used as arrow feathers (generally for indoor competitive players or hunting arrows), you should also pay attention when choosing arrow feathers. For a right-handed bow, it is best to use feathers from the right wing, and for a left-handed bow, it is best to use feathers from the left wing.

Arrow tail:

The tightness of the arrow tail on the string not only affects the accuracy of the arrow, but also poses a safety hazard. If it is too loose, it will easily come loose when you pull the bow, or there will be a gap, causing the arrow to fly in error, affecting the accuracy. In severe cases, the arrow will fall before or during the release, causing the bow to be released empty, or because the gap between the arrow tail and the string is too large, causing excessive energy to act on the arrow shaft at the moment of release, causing the arrow to break, which is dangerous to the equipment and the personal safety of the shooter. But if it is too tight, the arrow will be affected by the vibration of the bowstring at the moment of release due to unclean release, causing the arrow to fall off the string.

So what is the appropriate tightness? Generally, the arrow is placed vertically downward on the bowstring point, and the bowstring is tapped downward with a finger at a height of about 15cm above the string. The arrow will fall off the string with a little force. If it is too loose or too tight, it is necessary to replace the appropriate arrow tail or rewind the string guard.

Generally speaking, the length of the arrow shaft should be combined with the hardness and purpose of the arrow shaft. If the hardness of the arrow has been configured, shortening the arrow shaft will make the arrow shaft harder, so the length of the arrow should be determined in advance when choosing an arrow.

Simply speaking from the length, the competitive indoor arrow shaft can be longer, because there is no influence of external weather factors, the distance is shorter, and a longer arrow shaft is conducive to stability and accuracy. The length of the outdoor arrow is preferably about one inch beyond the arrow rest point; the length of the hunting arrow is best considered based on the selected arrow and feathers, and determined by multiple tests. I have no experience in this regard.

3. Bow Adjustment

A new bow does not have practical conditions when it leaves the factory. We need to configure the corresponding accessories and make preliminary adjustments according to our own parameters, including installing a peephole on the bowstring and determining the arrow point. In China, most of the time, equipment is purchased from equipment dealers (or other users). Responsible dealers will do the most basic installation and debugging according to the parameters provided by the buyer to make the equipment usable. However, in order to achieve good performance of the equipment, it is still necessary to fine-tune it according to the user's own situation. As information for beginners, only a brief introduction is given here.

The adjustment of compound bows is relatively complicated, mainly because there are many types and functional accessories of compound bows. Different bows have different adjustment methods, but the most basic adjustment is still universal.

The draw length adjustment of compound bows has been briefly introduced above, so I will not go into details here. The pulling force can be simply completed by adjusting the poundage screw.

Here we mainly introduce the arrow point position of the bowstring. Compound bows have different cam types, so their nocking points and arrow rest positions are also slightly different. The nocking point of a double cam bow is 1/8 inch upward from the arrow rest at a right angle to the main string, and the arrow rest position is generally on the plane where the bowstring projection coincides with the centerline of the bow body. However, not all bows are compound bows, so the arrow rest is also fixed by the distance that the cam main string deviates from the centerline of the bow body, which is generally 1/8 inch toward the bow hand.

Single cam bows are slightly different from double cams because they are driven by the lower cam. The nocking point is generally 3/8 inch upward from the vertical position of the arrow rest and the main string. Since the arrow rest only has a single cam that deviates from the centerline of the bow body, and the round wheel on it is at the center of the bow body, it only needs to be offset about 1/16 inch toward the bow hand.

After making the above simple adjustments, the arrow flight may not be adjusted to the best, so it is still necessary to do a paper tuning test. Since this test requires the user to either have equipment such as a bow bed or have a certain consistency of movement, I will briefly explain it. Friends who are interested can refer to the relevant articles separately.

First, prepare a frame, fix a piece of newspaper in the center of the frame, clamp it on all four sides, place it 2 to 3 meters in front of your shooting position, and place the target at the back more than 1 and a half distance from the target stand. Then pull the bow to the normal position, keep the up and down and left and right directions of the arrow shaft as perpendicular to the paper as possible (you can ask another friend to remind and confirm), shoot the arrow through the newspaper, and observe the traces left by the arrow after passing through. If there is only the trace of the arrow feathers, the hole in the middle of the arrow shaft is in the middle, and the positions of the three feathers are very uniform, it means that the arrow point and the arrow stand are relatively suitable. Then you increase the shooting distance with the test stand and repeat the above steps, observe the flying posture of the arrow and the posture of the arrow hitting the target, whether each arrow is very straight, and there is no problem until 30 meters, which means that the arrow adjustment of this bow is relatively perfect (if there is no condition to do a long-distance test, you can just test it at a close distance). But if the arrow hole on the newspaper is not in the middle, and the tear marks of the arrow feathers are uneven, it needs to be adjusted accordingly. Generally speaking, adjust the arrow stand first, and then adjust the bowstring arrow point if it is not satisfied. Simply put, the arrow rest should be adjusted in the opposite direction to which the arrow hole is tilted, or the bowstring nock point should be adjusted in the same direction.