INSIDE TUNING 2.50 0 PAGE nary Bow Setup . . . . . . . . . . . . .... ....... .... . . . . . . . . . . . . . 14 MAINTENANCE AND ASSEMBLY . . . . . 15 A A C C . . . . . 27 2 Arrow Tuning and Maintenance Guide INTRODUCTION Successful tuning can only be achieved by using a properly spined arrow shaft. Start with a shaft recommended on Easton's Arrow Shaft Selection Chart, available on the Easton web site at www.eastonarchery.com, in the Easton Target and Bowhunting catalogs, and on the Easton Shaft Selector "Plus" software program. Final verification is achieved during the tuning process. Problems caused by an improperly spined shaft will become evident during tuning. Before tuning, be sure that shafts are straight, properly fletched, and have perfectly aligned nocks. Find the Limb Centers In order to have a reference point from which to adjust the arrow's left/right position on the bow, it is necessary to find and mark the exact center of the limbs on a recurve bow, or what is termed the "balanced limb center" on a compound bow, as defined below. Recurve Bows To find the limb center for recurve bows, place a piece of masking tape across the inside of each limb near the riser. Measure the width of the limbs, and make a small vertical mark on the tape in the exact center of each limb. Choose Your Shooting Style. Tuning procedures for the three most popular shooting setups are described and abbreviated throughout this guide as follows: x recurve bows, using finger release (RF) x compound bows, using finger release (CF) x compound bows, using a release aid (CR) Some of the techniques of bow tuning apply to all types of bow setups and others apply to just one or two types. When separate tuning procedures are required for specific setups, find your setup within the topic and follow those specialized instructions. Compound Bows To find the balanced limb center location for the preliminary setup of your compound bow, place a piece of masking tape across the inside of each limb near the riser. Measure the width of the limbs, and make a small vertical mark on the tape in the exact center of each limb. Next, measure 3/16" (4.8 mm) to the left of the mark (for right-handed archers) and make a larger vertical mark on the tape. (Left-handed archers place a larger mark 3 /16" (4.8 mm) to the right of the limb center mark.) This second mark will be used for arrow centering. (See Fig. 2.) This procedure is done to compensate for the amount the eccentric wheel or cam is offset from the actual center of Install All Accessories Before starting any bow tuning, be sure to install on your bow all the items you intend to use when shooting. This includes the correct bowstring, bow sight, stabilizers, arrow rest, cushion plunger, bow quiver, etc. Any adjustments made to the bow or changes in bow components can affect the tune of your equipment. Remember, when tuning, it is very important to change only one variable at a time! Fig. 2 Compound Bow Balanced Limb Center Location Wheel Bow limb Tape Actual limb center (right mark) Balanced limb center (left mark) Measured 3/16" from actual center Tape Bow limb Wheel The first phase in achieving well tuned equipment is good preliminary equipment setup. If the initial setup is done correctly, bow tuning can be an easy process. By following the bow setup guidelines in the initial preparation of your equipment, you can eliminate most or all of the possible disturbances that cause tuning problems, including false tuning indicators. An example of a false tuning indicator would be having a high nocking point indication when the problem is actually poor clearance. Install the Nocking Point Install a moveable nocking point on the bowstring. Clampon types are ideal. Initially, position the nocking point on the bowstring about 1/2" (1.3 cm) above square for RF and CF and approximately 1/4" above square (0.63 cm) for CR. See Fig. 1. the limb. The 3/16" (4.8 mm) measurement is an average "offset" difference for most compound bows and does not need to be a precise measurement in the preliminary setup stage, as you will locate the true balanced limb center when performing the fine-tuning procedures. "Centering" the Arrow The objective of arrow centering is to have the arrow leave the "theoretical" or "balanced" limb center of the bow. In actuality, it is the two nodes (Fig. 3) of the arrow shaft that should leave the center of the bow in direct alignment to the target. Releasing the string with fingers creates a horizontal bending motion within the arrow. Releasing the string with a release aid causes a slight up/down bending motion. Because of this, the arrows must be positioned differently for each style of release. Adjust the horizontal (in/out) position of the cushion plunger or arrow rest assembly so that the tip (center) of the arrow point is correctly aligned with the type of equipment you shoot. (See Node Alignment diagram to the right). Fig. 1 1 1 /2" RF, CF /4" CR 90° Nocking Point Position Tuning--Bow Setup Adjust the Arrow's Left/Right Position 3 Aligning the Nodes Fig. 3 Nodes Arrow Nodes - As the arrow oscillates, the nodes remain in direct alignment to the target. This diagram clearly illustrates the front and rear node positions of the arrow. The front node is usually closer to the front end of the arrow than the rear node is to the nock end. This is due to the mass weight of the point--nodes will always be located closer to the heavier mass. Rear Node Front Node Direct Line to Target Top View of Arrow Adjust the horizontal (in/out) position of the cushion plunger or arrow rest assembly, so that the tip (center) of the arrow point is correctly aligned with the type of equipment you shoot, as described below. Finger Release (RF,CF) Align the "tip" of the arrow point 1/16" to 1/8" (1.63.2 mm) or less outside the bowstring with the bowstring properly centered according to Fig. 7. The arrow tip is placed slightly outside the string to provide compensation for the amount the cushion plunger or side loading device compresses into the bow when the arrow is released. See Fig. 4. With a finger release, the arrow bends horizontally, first bending in toward the bow, then bending away from the bow, which causes the arrow shaft to leave the arrow rest. In the next bending sequence, the arrow nock disengages from the bowstring. The arrow is then on its way, freely oscillating all the way to the target. The amount of oscillation decreases as the arrow travels farther from the bow. Fig. 4 Finger Release (RF, CF) Line to target When there is no pressure on the cushion plunger, the fingerreleased arrow nodes are aligned slightly outside the center of the bowstring. Line to target As the cushion plunger compresses, the nodes of the arrow come in direct alignment to the target. Mechanical Release (CR) Align the "tip" of the arrow point down the center of the bowstring. See Fig. 5. The center line (axis) of the arrow must start out in a direct line with the bowstring when the bowstring is aligned to the balanced limb center. See Fig. 7. When using a release, the arrow most often bends vertically, rather than horizontally. Therefore, there is no need for an inward compression device such as a cushion plunger. Follow the bow tuning methods in the Fine Tuning and Micro Tuning sections on pages 12-14 to find the best in/out position for your arrow shaft, which allows the arrow nodes to be in direct alignment to the target. The diagrams in Fig. 7 indicate the correct in/out arrow position for your shooting style. Fig. 5 Compound Mechanical Release (CR) Fig. 6 Misaligned Arrow RF, CF, CR (Incorrect Arrow Rest Position) Bowstring to target alignment Rear node position Front node position Line to target Fig. 7 Arrow Centering Compound Bow Finger Release Arrow Tip Out 1 /16"-1/8" Compound Bow Mechanical Release Aid Arrow Tip in line with bowstring Nock Recurve Bow Finger Release Arrow Tip Out 1 /16"-1/8" The arrow tip is aligned down the center of the bowstring. Nodes of the arrow are in alignment to the target. (Since the arrow bends vertically when using a release, the nodes stay in alignment with the center of the bowstring.) The arrow is not positioned to leave the center of the bow--it is out too far. Nodes are not in alignment to the target. Nock Nock Bowstring aligned with limb center Bowstring aligned with balanced limb center 4 Arrow Tuning and Maintenance Guide Adjusting for Outsert Components (CR) When using carbon arrow shafts with externally fitted nocks, it may be necessary to adjust your nocking point up slightly to allow the nock to clear the arrow rest. (The nock diameter is larger than the shaft diameter.) A slightly higher nocking point lifts the arrow off of the arrow rest and keeps the nock from contacting it, eliminating a potential clearance problem. Internal-fit nock systems do not have this problem. Adjust the Arrow Rest (Recurve and Compound) The arrow rest support arm position is critical to achieving good arrow clearance. Finger Release (RF, CF) Most flipper/rest setups have an adjustable arm for the arrow rest. If this adjustment is available on the rest you're using, the arrow rest support arm should be adjusted so that it is not visible past the outside of the arrow shaft when observed from an overhead view. See Fig. 8. Mechanical Release (CR) On launcher type rests, commonly used on compound bows with release aids, be sure that the arrow support arm is narrow enough to allow the two lower vanes to pass over the rest without making contact. (See the Fig. 9.) This is very important for archers using release aids because the arrow is most often supported on the rest for its full length of forward travel. For the smaller diameter aluminum/carbon or carbon shafts with less space between vanes, it may be necessary to significantly reduce the width of the launcher blade. RISER-MOUNTED CLICKERS (RF, CF) For shooters using a clicker, be sure that the arrow is well supported on the rest and not held in place only by the tension of the clicker. Draw the bow a few times without the clicker to make sure the arrow can be drawn and let down without the arrow falling off the arrow rest. ALIGN THE BOW-SIGHT PIN Initially, set the sight pin on your bow sight over the centerline of the arrow shaft. SET CUSHION PLUNGER Not every type of bow setup uses a cushion plunger. For example, many archers use a SpringyTM rest, and some traditional archers use other styles of arrow rests that do not have side pressure tension adjustments. If your setup incorporates a cushion plunger, start with the spring tension set at medium. Fig. 8 Arrow Rest - Overhead View (RF, CF) Correct Position Incorrect Position (out too far) Set Brace Height (Recurve bows) Start with the brace height at the lower end of the manufacturer's recommendation or use the following chart. To locate the optimum brace height for your particular bow, "twist up" the bowstring to make it shorter. This raises the brace height. BOW LENGTH 64" 66" 68" 70" 8 8 8 8 BEGINNING BRACE HEIGHT 1 3 BOW Arrow rest NOTE: Be sure enough of the flipper arm is extended to safely hold the arrow on the rest. NOTE: Be sure that the arrow rest has enough height above the arrow shelf to allow for vane clearance. BOW Arrow rest /4" /8" 1 /2" 5 /8" - 8 8 8 8 1 5 /2" /8" 3 /4" 7 /8" (21.0 (21.3 (21.6 (21.7 cm cm cm cm - 21.6 21.9 22.2 22.5 cm) cm) cm) cm) Fig. 9 Arrow Rest - Back View, Vane Clearance (CR) Correct Incorrect Good Vane Clearance Poor Vane Clearance All bows are different, even bows of the same make and model can have small variations. Therefore, it is important to locate a brace height that fits your particular bow and shooting style. Shoot a few arrows at the suggested beginning brace height, then unstring the bow, add 3-4 twists to the bowstring and shoot again. Continue this process until the bow feels smoothest and quietest when shooting. If the bowstring is too short to allow a brace height at the lower setting, use a slightly longer string. If the string is too long to allow a higher brace height (and starts to knot-up from too many twists), try a slightly shorter bowstring. There are many custom bowstring makers who produce strings to your exact specifications including length, type of material, type and color of serving, etc. Standard Tuning--Bare Shaft Planing Test The brace height determines the specific point at which the arrow separates from the bowstring and the amount of bend the arrow has when the separation occurs. The best brace height for your recurve or compound bow is one that allows the most compatible launch position for the arrow at the end of the bow's "power stroke." Locating the best brace height for your bow can significantly improve arrow grouping and shooting consistency. 5 Arrows that do not fly well and do not group tightly are usually affected by one or more of the following problems: 1. They may POR ...