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Arrow Tuning and Maintenance Guide
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.
Recurve Bows To find the limb center for recurve bows, place a piece of masking tape across the inside of each limb a few inches from the riser. With an ink pen, make a small vertical mark on the tape in the exact center of each limb. 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 a few inches from the riser. Accurately measure the width of the limb (at the tape) and place a very small pen (or pencil) 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 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.
Center Location Actual limb center (right mark) Balanced limb center (left mark) Measured 3/16" from actual center
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
Compound Bows
Fig. Compound Bow Balanced Limb 2
Aligning the Nodes
Wheel Bow limb Tape
Fig. 4 Finger Release (RF, CF) Line to target
When there is no pressure on the cushion plunger, the finger-released arrow is 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.
Fig. 5
Fig. 6
Compound Mechanical Release (CR)
Misaligned Arrow RF, CF, CR (Incorrect Arrow Rest Position)
Bow limb
Bowstring to target alignment Rear node position
Wheel
Front node position
Tape
“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's the two nodes 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 instead. Because of this, the arrows must be positioned differently for each style of release. (See Node Alignment diagram to the right). A description of these position adjustments follows.
Line to target
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 down 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.