The Home Bow Mechanic
May 04, 2011
I remember when setting up new bows meant no more than adding a stick-on rubber rest, installing a brass nocking point a bit above square, assuring both limb bolts were tightened evenly and consulting an Easton aluminum arrow chart. More raw speed, especially precise, highly adjustable arrow rest designs, quickly changed that. Today, all but the most mechanically inclined head to the local pro shop when equipment needs set-up and/or tuning.
That's too bad. Tuning even the most sophisticated set-up isn't rocket science. Relying on pro-shop experts leaves you vulnerable to troublesome in-field breakdowns with little idea how to get back into the game. Too, learning to set up and tune your own gear instills confidence, knowing equipment can be tweaked no finer.
TOOLS OF THE TRADE
Start-up costs are determined by how often you intend to tinker with gear and available space. This monetary discrepancy is largely a factor of choosing between "professional" opposed to portable tools. Consider bringing partners into the fold, splitting the cost of top-drawer gear between several friends for all to use.
The bow press, used to relax bowstring and buss-cable tension while replacing strings, installing peeps, or making adjustments, includes many options. Professional-grade, bench-mounted presses make work faster and safer but cost from $350 to $1,500 and require a sturdy mounting bench. Models made to accommodate today's parallel-limbed bows generally cost more than "standard" designs for conventional compound-bow limbs. By contrast, the portable bow press costs from $50 to $100, takes up little room and is easily transported and stored, but it's generally slower to operate.
Prime examples of bench-style presses come from Apple Archery, Sure-Loc Archery, C.W. Erikson's Manufacturing and Last Chance Archery. Portable bow presses of note include options from Prototech (BowMaster and Split Limb Adaptor) and RAM Archery (RatchetLok Portable).
A bench-mounted bow vise provides an extra hand to hold equipment securely and level when needed. The best are infinitely adjustable and non-marring, such as models offered by Apple Archery, HTM Precision and R.S. Archery Products.
Center-shot tools make rest set-up precise and simple. The idea's to perfectly align string, rest cradle and arrow, allowing a bow's energy to be transferred straight down the shaft for precise launch. The most precision is afforded by laser guides, Easy-Eye Archery's EZE-Center for instance. Attached to sight taps, adjusted to correlate to the string center, they sight down a nocked arrow to provide perfect rest alignment front to rear.
To round out your home shop, you'll need a handful of hand tools: Bow square, nock crimper, string splitter, Allen wrenches, string server and small torch. Later you might also add a chronograph to measure arrow speed and grain scale to weigh arrows and points.
A bow square snaps onto the string to show nocking-point location in relation to arrow rest height. There are plenty of options, including those from Saunders Archery and Eastman Outdoors. Nock-crimping pliers help install and remove standard brass nocking points without damaging either the serving or nocking point. They come in basic options -- Eastman Outfitters or Easton Technical Products -- or those with added options like added screwdriver and hex bits (Saunders Archery) or more innovative nock removers (Tru-Fire).
For more advanced nock installation, look to R.S. Archery Products' R.S. Level Combo or HTM's Set-Up Master Set, bowstring and arrow leveling devices allowing more precise nock location.
String splitters help while installing peeps or string silencers, separating string strands, sometimes without a bow press (take extra care to avoid damage on tightly-wound strings). Look to Bohning Archery and Neet Products for viable options. Hex-wrench sets, like those from Western Recreation/Vista, Pine Ridge or Easton, or the Fletcher Field Tool from Jim Fletcher Archery, with open-end adjustable wrench and flat- and Phillips-head screwdriver heads, are used for a wide variety of tasks from installing accessories to adjusting draw weight.
Finally, quality string-serving tools make quick work of replacing worn center or buss-cable end-loop serving. The best come from Bohning (Serve-Tite) and AAE/Cavalier Archery (Pro String Server). A high-temp torch, like Muzzy Products' Butane Micro
Torch, is perfect for use with hot-melt glues, cooking out old inserts and tasks such as mushrooming the ends of string loops to prevent slippage after installation.
Basic set-up involves installing an arrow rest and adjusting it properly, installing a nocking point or string loop, positioning a peep and/or kisser button, and adding string accessories as necessary. Other accessories -- sights, stabilizer, wrist sling and quivers -- rarely introduce tuning problems.
Properly setting up arrow rests is most important to accuracy. To begin, study installation instructions for better understanding. Bolt the rest into place, leveling it to the riser shelf before anchoring. Carefully adjust rest-arm height to correlate with sight window mounting holes, engaging activation cords to raise drop-away cradles when necessary.
Install your nocking point (finger shooters or release attached directly to serving) or loop (release shooters) using a standard bow square; just tight enough to hold it in place while allowing it to move on the string.
To aid in peep installation, bolt on your sight, rough adjusting so it appears ballpark reasonable. Sighting will be conducted only after tuning. If your sight has 3rd-axis capabilities, use a carpenter's bubble level to first square the bow in your vise, then the sight head on the leveled bow.
Next, release string/cable tension in your bow press and install your peep between equal strands of string. Determine rough vertical location, pushing it up and down the string to locate a comfortable location, drawing the bow between adjustments until it lines up with your sight aperture while anchored. When that location's determined, mark it and coax the peep to set square to the sight at full draw, swapping single strands from one side of the peep to the other if necessary. This also applies to peeps equipped with rubber alignment tubing. When your peep's turning reliably, shoot about 10 arrows to assure it stays put -- only then securing it permanently with thin serving material and sparse superglue.
While your bow's in the press, it's also a good time to add string silencers (slipped between string strands or over the string via hairpin and pliers) and eliminator buttons (small rubber buttons situated between nock and release jaws preventing pinch and dislodging the arrow during let-down).
Secure your bow, top limb up, in your bow vise, attaching a string level to the serving and establishing vertical/horizontal plumb. Your rest should be adjusted to height and a nocking point loosely installed. Snap your preferred arrow on the string, install an arrow level and establish a 90-degree orientation to the string, adjusting your nocking point or string loop accordingly before locking it securely -- 1/8- to 1/4-inch above zero for fingers, slightly high or even for release. (It's generally accepted that a bit of upward nock pressure during launch creates greater accuracy. When hooking up directly to the string, this pressure is provided automatically by the pressure of release jaws. With a string loop replicate this effect by adding a nocking point at the bottom and inside the string loop below the arrow nock).
With an arrow nocked and across the rest arm(s), step a few feet behind the bow, sighting along the bow string and cam flats. Adjust the rest so the string sights down the shaft center from rear to tip. Confirm this assessment with a laser center-shot tool.
The laser is also used to detect cam lean, which complicates tuning by creating irregular nock travel. Lay your bow on a flat surface and direct the laser over a cam flat, across to the opposite. The laser should shoot across both cam flats evenly. If it shows on one part of a cam, without touching the remaining cam flat, the cam requires lean adjustment. Relax cable tension with your press, removing the longer yolk half (the one the cam leans away from) and twisting to shorten. Reinstalled the cam should pull straight when tension's restored. This can involve careful trial and error. Binary cams, cables riding along cam sides instead of slaved to the limb tips, have eliminated this issue.
If initial shooting reveals obvious arrow kicks, fletching contact (with arrow rests, buss cables or cable slides) is likely the problem. Improper fletching orientation in relation to arrow-rest arms or an incorrectly adjusted drop-away rest are the most likely culprits. Twist nocks to allow clean passage or adjust drop-away spring tension or activation-cord length to promote proper clearance.
Paper tuning is an archery mainstay, consisting of first tightly stretching and stapling butcher paper across a wooden frame, or through use of commercial paper tuners like those from Specialty Archery or Saunders Archery. Stand about 10 feet behind and 90 degrees to the paper face and carefully shoot through the blank face (arrows captured by a safe butt behind). Vertical and/or horizontal tears reveal how arrows behave while passing. Vertical tears are a function of nocking point and/or rest-arm height; horizontal tears reflect center-shot and/or arrow spine. Angled tears indicate a combination of these factors.
What you're seeking are perfect bullet holes (with clean cuts for fletchings). Upward tears show an arrow coming off the rest tail high, meaning the nocking point is high or rest arms are adjusted too low. Move the nocking point down, or rest arm(s) up. A downward tear indicates the opposite fixes.
Solutions for horizontal tears are more complex. A left tear (for right-hand shooters; reverse for left-hand) indicates an arrow rest adjusted left of center-shot, an arrow not stiff enough for draw weight and/or draw length and tip weight. Move the arrow rest-arm toward the riser (inward), decrease draw weight, choose stiffer-spine arrows, shorten the arrow (when feasible) or choose lighter tips to decrease arrow flex after release. Right tears mean the arrow's too stiff or the rest adjusted right of center. Move your rest arm out (away from riser), increase draw weight, choose a lighter-spined arrow, shoot a longer arrow or install a heavier tip. When confronted by a combination of factors, tackle one plane at a time, with the vertical plane normally the easiest place to start.
Be patient, experiment, tinker. You're well on your way to tuning independence.
(Editor's Note: Patrick Meitin is the author of the new book "The Bowhunter's Guide To Better Shooting -- Expert Advice For Making Every Shot Count," available soon from Intermedia Outdoors.)