We won't pretend that I'm an expert in physics. I only know a little about the micro aspects of building a good arrow. We all have our own skills. If I were to tell you exactly how an arrow flies and why it matters, it would be like a patient's family member telling me why my nursing license excludes me from knowing the important details they found on WebMD.
Let's pretend you're getting ready for a hard winter and use wood to heat your home. You've been busy at work all summer, but it's early fall, and you've barely had time to chop wood. You don't have a machine splitter, so you must chop wood by hand. Time is not on your side.
What tools will you choose to get the job done? I only chop wood if I'm camping, but my guess is that you would choose a sledge hammer and an iron wedge. They are the right tools for the job at hand. However, we aren't talking about how size and shape matter to your bow setup. We're talking about the performance of the tools you've chosen.
Truly, I'm a simple guy who loves to be in the woods and hunt. But, with that said, I have some skills to help you learn some basics of why good arrow flight matters.
Arrow Recovery: Why Does it Matter?
To start the conversation around arrow recovery we need to first define what arrow recovery is. When an arrow is launched from a compound bow it experiences extreme forces that cause the arrow to not only flex linearly but experience gyroscopic rotation, oscillation, torsion, and non linear flex. To keep this simple the longer the arrow experiences these factors at the extreme levels the more energy (KE and P) it loses during flight. The faster the arrow at flight comes into equilibrium, a point in which these factors are minimized, the less energy it loses. Now that we understand arrow recovery is how fast an arrow in flight can reach equilibrium and the impact it has on the down range efficiency we can move on.
We need to address energy at this point to help understand the basic concept of arrow flight. The first thing I will mention is potential energy. This is when you hold the sledge with the head of the hammer resting on the ground. It's just like an undrawn bow. Raising the hammer above your head is like drawing a bow with a nocked arrow. At that time, the potential energy increases. In this stage, the bow's string wants to get back to its normal state, as the sledge wants to return to the ground.
When you pull the trigger on your release, work is applied to the arrow, like putting muscle into hitting that wedge with the hammer. The potential energy now turns into what we know as kinetic energy. Shortly after your arrow leaves the bow, KE and P, are at their peak. As the arrow continues down range, KE and P deprivation happens impacting trajectory, penetration, and lethality.
KE and P deprivation is somewhat a constant. There will always be some loss of energy in the form of KE and P as your arrow is in flight. However, the rate of deprivation is a variable impacted by mass, velocity, and arrow recovery. It's great to know your KE and P at your bow but it's even more important to know what you have downrange when your arrow impacts your target.
Addressing the Impacts
In archery, there is something called "the archer's paradox." When your arrow is released it experiences forces previous mentioned, flexing, rotating, and bending back and forth as it flies. It gets more in-depth than one paragraph can explain, so this is what you will want to know.
Imagine you raised your hammer above your head and are about to drive that wedge home. Right then, someone bumps your back as you bring the hammer down. The hammer makes contact with the wedge, but does it split the log all the way in half? Probably not! The wedge likely only made it partway into that log, and now you'll have to take another whack at it.
What does that mean to your arrow flight? Well, if there weren't outside influences, potential and kinetic energy would stay the same. That means maximum lethality would be delivered to a downrange animal with every arrow regardless of the circumstances with the best possible trajectory.
Outside influences are always part of hunting. Wind, brush, buck fever, and many more things affect arrow flight. Very much like a shove or tired muscles can impact how many logs we can split in one hit.
An arrow that recovers faster carries more energy in both KE and P, which in turn make the arrow more lethal. Because of the fast correction, it will perform better in windy conditions due to the smaller footprint or crosswind signature it carries. Thus the arrow has a higher chance of good penetration. If my eight-year-old daughter pushed me, there would be a better chance of the wedge still going through the log because I have a higher likelihood of self correcting my swing back into equilibrium. But if someone my size pushed me while I was swinging the hammer, not so much.
Check things that can change your arrow's flight. These could be things that contact your arrow before leaving the bow, like fletchings making contact with your bow's cable. Or it might be your form, such as putting too much pressure on the string with your face.
Consider stability. A big fixed blade broadhead will change the flight of an arrow. It may need to be corrected with how many fletchings you're using. Understanding that the relation between center of gravity and center of pressure will impact flight characteristics is important when looking a broadheads and vane configurations. A general rule of thumb is that the further COG is from COP the more stable flight becomes. Adding weight at the front of your arrow movings the COG forward, while COP is manipulated by your vane configuration (number of vanes, location, amount of friction induced, etc)
The build of your arrow is most important. Making certain the static spine of the arrow properly serves your setup is paramount. An underspined arrow will have to work harder to recovery. In addition to static spine, having every arrow built from the shaft's first dynamic bend also ensures arrow to arrow consistency with the way each arrow reacts off the bow. Poorly placed fletchings, ill-fitting nocks, or lack of attention to the overall design will greatly impact how fast your arrow will return to an accurate flight path.
Without getting too technical, there is a way to force your hunting arrow to recover faster. Meet AeroConcept by Firenock, an inner carbon tube in the front of the arrow shaft to elongate the front node of the arrow. Every arrow has 2 nodes, a point where all vibration and movement is centralized. Moving a node from a point into an area, theoretically shorts the distance vibration and movement travels through the arrow shaft, thus force the arrow to recovery and come into equilibrium faster.
Wrap it Up Professor
You don't need a math lesson to understand some basics of arrow flight, but you should care about your accuracy. After all, the more you can stack things in your favor, the more confident you'll be when you're about to take a shot at the trophy of a lifetime.
AUTHOR: Aaron Hepler, Exodus Black Hat Team Member