Arrows Series – Part 6: Fletching and Indexing

Now that you have cut your arrows you need to fletch them. Fletchings are found at the back of the arrow, traditionally made from bird feathers and are used to stabilize the arrow by creating a small amount of drag.

Wikipedia: Fletching (also known as a flight) is the aerodynamic stabilization of arrows or darts with materials such as feathers, each piece of which is referred to as a fletch. The word is related to the French word “fleche”, meaning “arrow,” via Old French; the ultimate root is Frankish fliukka. A fletcher is a maker of arrows.

Nowadays, there are two types of fletchings, real or synthetic feathers and plastic vanes. Some target archers have them attached to the arrow with a slight twist to increase arrow spin because a spinning projectile is more stable and helps reduce the effects of Archer’s Paradox (We will discuss Archer’s Paradox in more detail in the Part 7 of the series).

The most conventional style of indexing is a three-feather fletching where feathers or vanes are mounted to the arrow, evenly distributed around the spine of the arrow. One feather, called the “cock”, is set at a right angle to the string and pointed at the archer and the other two fletchings on the riser side are angled up and down away from the bow. This is done so the fletchings/vanes will not contact the bow when the arrow is shot. For compound archers the cock feather’s indexing depends on the type of arrow rest.

Quick Tip: Choose a different colour for the “cock” feather. It is great reminder to always point it towards you and away from the riser for proper nocking of the arrow.

Fletching an arrow is a time consuming and tedious task to do accurately by hand. In modern times, most people use a fletching jig, especially to fletch arrows with a slight twist. Check out my earlier blog about fletching jigs.

It is important to understand that once an arrow is released it starts to bend and if the arrow is not correctly indexed the feathers or vanes will make contact with the riser. This will cause the arrow to react differently than expected, distort your feathers and possibly cause damage to you or your equipment.

Arrows Series – Part 3: Draw Weight

Obviously, force is required to move the arrow forward off the bow and it is generated from the tension of the limbs through the bowstring. Therefore, when purchasing arrows you need to know your draw weight so you can purchase the correct corresponding spine size for best performance. Limbs stiffness is determined by the amount of force, measured in pounds, required to draw the bow to a 28” draw length as outlined in the following Archery Trade Association (ATA) standard.

AMO BOW WEIGHT STANDARD

For Conventional Bows

Bow weight is the force required to draw the nocking point of the bow string a given distance from the pivot point of the bow grip (or the theoretical vertical projection of a tangency line to the pivot point parallel to the string). Draw length from pivot point shall be designated as DLPP and shall be referred to as TRUE

DRAW LENGTH.

For the purpose of uniform bow weight designation, bow weight is the force required to draw the bow string 26 1/4” from the pivot point. This weight will be marked on bow as being taken at 28” draw (26 1/4” plus 1 3/4” = 28”) See DRAW LENGTH STANDARD.

EXAMPLE: Weight Adjustment Range: 45/55 lbs. Weight Set At: 50 lbs.; Hold 32 lbs. Draw Length Range: 29” – 30”

EXPLANATION: The pivot point is a more realistic measuring point (when compared to the variations of profile of the back of bows at the handle section) for establishing bow weight since the pivot point is a constant in all bows as well as the contact point of the bow hand from which the true draw length is generated.

The 26 1/4” DLPP is the approximate equivalent of the 28” draw used previously on the more massive wooden handle bows.

Therefore, your draw weight is a combination of your draw length (See Arrow Series – Part 2 Measurements) and the combination of your riser (23” or 25”) and your limb stiffness (15#-50#).

For example, a 25” riser with a 34# long limb produces a 70” bow with a draw weight of 34 pounds at a 28” draw length.  If these same limbs were used on a 23” riser, the combination would produce a 68” bow with a draw weight of 36 pounds at a 28” draw length.

However, not everyone has 28” draw length, especially young archers whose draw length will change progressively with growth. So as a rule of thumb you can add or subtract approximately two pounds for each inch your draw length is over or under the 28” standard.

Using the previous example, if an archer has a 26” draw length and uses a 25” riser with 34# long limbs it will produce 30# of force at full draw OR uses the 23” riser with 34# long limbs it will produce 32#.

This is very important to select limbs that enable you to develop and compete however do not cause long-term physical damage. When purchasing limbs you need to determine if the limbs are too heavy, you can try this simple 7-second challenge.

7-second challenge

  1. Draw the bow to the anchor
  2. Hold seven seconds
  3. Let down without lowering your hands, stay in set-up position to take a 2 sec brake,
  4. Repeat several times.

If you cannot do it properly then the limbs are too heavy for you. If you find this challenge extremely easy, you can look at heavier poundage limbs, if you choose.

Now you understand draw weight and used in combination with your draw length you can see the arrows that match your equipment using a manufacturers arrow selection chart. In the up coming blogs we will try to examine the arrow spine, flex and stiffness.