Tune Up: A Step-by-Step Guide to Assembling an Accurate Bow
Skip the bow shop and try your own hand at rigging your compound
Whether you’ve upgraded to a new bow, are just starting out, or simply need to give your hunting bow a once-over before the season, this guide is designed to get your bow shooting bull’s-eyes. I’ve fine-tuned these steps over the years to develop a simple formula for setting up a bow. For more in-depth advice, go to www.eastonarchery.com and download a free copy of Easton’s Arrow Tuning & Maintenance Guide.
1. Attach the Nock Point
The first decision is whether to use a string loop or a brass nock set. I spent the last two seasons experimenting with string loops while using a variety of release aids, but I never got comfortable with them. To their credit, however, string loops lengthen the serving life of bowstrings, position the release aid (and the apex of the bowstring at full draw) directly in line with the arrow and equalize pressure above and below the nock so the arrow remains straight as the bow is drawn and aimed.
Regardless of which system you decide to use, you’ll need a T-square to find the point on the string that is parallel to the riser’s cushion-plunger hole. Next, attach the nock set or the string loop’s top knot 1/8 to 1/4 inch above the point parallel to the cushion-plunger hole. (You’ll need a pair of nocking pliers to attach the nock set.) If your bow is producing perfectly level nock travel, this placement should be good enough. However, it might need to be readjusted later. You’ll know whether it needs to be moved when you paper-tune the bow in step 7.
2. Attach the Rest
You have to decide if you want to use a drop-away rest or a fixed-position rest. If you plan to shoot carbon shafts, I recommend a drop-away; the aggressive helical fletching needed to stabilize small-diameter carbon arrows makes fletching contact with the rest common. Larger-diameter aluminum shafts allow you to use either style of rest.
Move the rest so that the arrow will cross directly over the center of the cushion-plunger hole. Then move the rest so that it is in line with the string. The best way to achieve this position is to install a stabilizer, nock an arrow and look down on the bow to see if the shaft is parallel with the stabilizer. You may need to tweak the rest one way or the other later, but this is an excellent starting point.
If you are using a drop-away rest, you will still need to adjust the timing of the rest’s rise and fall. Ideally, the rest will reach its full upright position when the string is still about 6 inches short of full draw. This will allow the rest to stay up a little longer during the forward travel of the arrow, which will provide some guidance before falling out of the way of the fletching.
3. Install the Peep Sight
You wouldn’t shoot a rifle without a rear sight, so don’t shoot a compound bow without a peep sight. A bow press is needed to install most peep sights. If you don’t have one, you’ll need to go to a pro shop. If you’d rather do it yourself, you can buy a portable bow press. There are inexpensive models available from catalog outlets such as Cabela’s for less than $40. I used one exclusively for six years before I broke down and bought a full-sized model.
The key to properly installing a peep sight is finding the center of the string. If the string on your bow has two different colored strands twisted together, you can just separate them. If not, you’ll have to count the strands and divide by two. This is an important step; if the peep sight isn’t in the string’s center it can spin too much when you draw back the bow.
After putting the peep sight in, install string silencers. Also, if you are using brass nock sets, you should install “eliminator buttons”–these are little rubber donuts that slide onto the string to cushion the arrow’s nock from the release aid’s jaws.
Now take the bow out of the press, put an arrow on the string and draw it back. Look through the peep sight to see if it needs further alignment. The peep sight should line up perfectly with your eye and the center of the sight window when you’re at your anchor point. Normally, you can slide the peep sight up and down without putting the bow back in the press, but not always.
Once you have the peep sight at the proper height, follow its directions to secure it in place. Next, shoot the bow several times to set the string before worrying about how the peep sight is rotating in the string. If the peep sight is not turning over to the desired level, detach one end of the string from the bow (using the bow press again) and twist the string. Continue this process until the peep sight comes back square to your eye every time. This process should take place over a week of shooting so that the string can reach its fully stretched length.
4. Attach the Sight
Choose a solidly constructed bow sight with fiber-optic pins that are easy to adjust. Before purchasing a sight, determine how many pins you need. In my opinion, you should use as few as possible to limit confusion. Most whitetail hunters do fine with two or three pins set for 20 and 30 yards, 25 and 35 yards or 20, 30 and 40 yards. Western hunters normally will have opportunities for longer shots and so should set four or five pins for 20 through 50 yards or 20 through 60 yards. Follow the instructions that come with your sight to install.
5. Silence the Rest
Your bow should be quiet while being drawn and fired. I use a thin layer of adhesive-backed foam rubber or fleece on the riser so that, if an arrow should fall off the rest, it won’t clatter when it hits the riser’s shelf. Dr. Scholl’s moleskin works great on the rest’s launchers. It stays in place better than any other product I’ve tried and does a great job silencing the draw.
6. Reserve Your String
After shooting your bow a few hundred times you need to perform two maintenance steps:
1. If the string has stretched, twist it back down to its original length. Twist the string in the direction of the existing spiral. If a string stretches, the bow’s draw length will increase, forcing you to make a deeper, more uncomfortable anchor point.
2. At this point, I recommend replacing the serving on your string. Your best bet is to pay to have it done the first time. Watch a professional and learn, and you’ll be able to do it yourself the next time. While you’re there, pick up a spool of serving material and a good serving jig.
7. Paper Tuning
Cut a square hole in the bottom of a cardboard box. Tape a sheet of paper across the opening and place a target more than an arrow length behind the sheet of paper. Now stand about 6 feet away from the box and shoot through the paper to the target. If the arrow cuts a clean, shaft-sized hole with tiny tears that are the same width as the fletching, the bow is tuned. If there is a tear wider than the arrow’s fletching to any side of the hole, some tuning is required. (See the chart on this page to diagnose and correct any tuning problem.)
Most modern bows tune easily, but some have string-travel problems that result from cam lean during the draw and release. If you absolutely can’t get your bow to tune, take the bow to a pro shop for help. The bow itself just might be at fault.
8. Sighting In
When sighting in the bow, space the pins close together in the middle of the sight body (position them lower if your anchor point is above the corner of your mouth). To make sighting in simpler, move the sight body left or right until the pins and string line up with an arrow placed on the bow’s rest. Next, move the entire sight up and down while sighting in the top pin (the pin for the closest yardage). Move all of the other pins independently while sighting them in.
If your arrows are hitting the target above the intended spot, move the pin up. If your arrows are hitting to the left of the spot, move the pin to the left–and so on. Plan on sighting in your bow over the course of several days or even weeks. Because shooting form can change slightly from one day to the next, you need to average the effect over time to get the best results. It takes me at least five days to get a bow sighted in perfectly.
Diagnosing Paper Tears
After shooting through paper, use the following chart to determine the best course of action to properly tune your bow. Wheel timing is a consideration only when shooting a two-cam bow.
PAPER-TEAR RELEASE STYLE: HOW TO FIX IT
TAIL HIGH Fingers or release aid –Check the bow’s wheel timing. –Move the nock point down. –Check the rest’s fletching clearance.
TAIL LOW Fingers or release aid –Check the bow’s wheel timing. –Move the nock point up.
TAIL LEFT Fingers or release aid Fingers –Use a stiffer shaft. Release aid –Move the rest from side to side. Fingers and release –Check the rest’s fletching aid clearance. –Have a pro shop check the bow cam for lean.
TAIL RIGHT Fingers –Use a weaker shaft. Release aid –Move the rest from side to side.