Bow Modeling Overview

Site Tape Overview


Archer's Advantage provides accurate sight settings for any archer using a sliding (Freestyle) sight. After entering setup information that characterizes your equipment, Archer's Advantage will accurately calculate Arrow Speed from any two Sight Settings and print out Sight Tapes calibrated in Yards or Meters. These Sight Tapes provide you with exact sight settings in one yard or one meter increments.

Even if two bows have the same arrow speed, sight settings will differ depending on the type of arrow you are shooting and the way you set up your bow. So, how does Archer's Advantage provide you with accurate marks for any setup? Archer's Advantage uses Setup information you provide the program to calculate Arrow Drag and Parallax Error for your equipment.

Arrow Drag causes your arrow to slow down on the way to the target. Accurately characterizing arrow drag requires the following setup information: Arrow Diameter, Arrow Length, Arrow Weight, Fletch Length and Fletch Type. This information allows Archer's Advantage to calculate initial arrow speed from two sight settings. With initial arrow speed and arrow drag, Archer's Advantage can accurately determine arrow drop at any distance.

When you reach anchor, your aiming eye is several inches above the plane of the arrow. This introduces a parallax error when you aim. It is this parallax error that causes your sight to go backwards (down the sight) as you start shooting distances shorter than 10 to 12 yards. Parallax error increases the closer you get to the target. The rate of change in parallax error is relatively small at longer ranges but increases dramatically as you approach ranges under 15 yards. As part of the setup information, you enter Peep Sight Height (at full draw) and Peep Sight-to-Sight Distance (at full draw). Since FITA shooters have no Peep Sight, they should use their Aiming Eye as a reference point in place of the Peep. These measurements allow Archer's Advantage to accurately determine the parallax error for any range.

When Archer's Advantage calculates a sight setting it uses the range to target to calculate Arrow Drop and Parallax Error. It then combines Arrow Drop with Parallax Error to provide the correct sight setting for the selected range.
 

Shaft Selection Overview

Archer's Advantage provides you with the ability to select the proper shaft from a variety of manufacturers. Most shaft selection tools select shafts for only one manufacturer making it difficult to effectively compare competing shafts in performance. These tools are inflexible and provide minimal support for tailoring the results to your specific equipment & shooting style. As shown in the introduction, Archer’s Advantage supports a wide variety of shafts and will continue to be updated as new shafts are introduced. Archer’s Advantage adjusts its shaft selection based on the following criteria:

  • Applied Force, incorporating user defined parameters for the following:

  • Type of Bow

  • Type Of Cam

  • Peak Weight

  • Holding Weight or Percentage of Let-Off

  • Brace Height

  • Draw Length

  • Bow Length

  • Custom Force Draw Data or Pre-Defined Force Draw Data

  • Length Of Shaft

  • Point Weight

  • Overdraw Length

  • Release Type

  • String Material

When you select a particular shaft, the software indicates how close to the "Sweet Spot" the shaft comes on a custom built control that goes from Red-to-Yellow-to-Green-to-Yellow-to-Red, ranging from Too Weak to Too Stiff. You can adjust point weight, shaft length, peak weight, etc. and immediately see how much these changes affect the tune of the arrow by observing the custom control.

Bow Modeling Overview

Shaft selection tools attempt to select the proper shaft based on the total energy transferred to the shaft during a shot and the dynamic response of the shaft to this transfer of energy. Most shaft selection tools attempt to simplify this selection process by limiting the variables that the tool adjusts for. There are a number of factors in proper shaft selection that are simply not addressed by most shaft selection tools on the market. Just compare the list of variables above to any of the shaft selection charts available from arrow shaft manufacturers, and it becomes clear that these charts offer a rough approximation for the needs for any particular setup.

Archer’s Advantage provides you with the ability to calculate total stored energy by adjusting for a wide variety of variables from a Pre-Defined set of Force Draw Data, or the ability to enter your own Force Draw Data to obtain the most accurate results possible. Once you have defined the characteristics of your bow, Archer’s Advantage will automatically calculate estimated IBO and AMO Speed Ratings and the speed of any previously selected shaft.

These Speed Ratings are derived from calculated Total Stored Energy and the Estimated Bow Efficiency. Archer’s Advantage allows you to adjust the program’s estimated bow efficiency based on manufacturer’s published IBO & AMO Speed Ratings or by using user supplied chronograph speeds along with a known arrow weight.

This level of customization provides you with the most accurate model of your bow & arrow’s performance possible, enabling you to select the proper shaft for your bow with the greatest degree of precision. At this point, it is important to point out that the spring scales utilized by most archers and pro-shops are not particularly accurate. I have found errors as high as 3 pounds in peak weight for bows in the 50 to 55 pound range. Errors of this magnitude will result in significant uncertainty when attempting to select the proper shaft to use with your bow.

This is where calibrating the Bow’s Efficiency using a known Arrow Weight & Arrow Speed comes in handy. This Calibration Routine provides a precise measure of how much energy your bow transfers to an arrow shaft. This significantly reduces the uncertainty in Shaft Selection and allows Archer’s Advantage to perform shaft selection with unmatched precision.

You can also use the Manufacturer’s IBO or AMO rating to calibrate Archer’s Advantage’s Bow Efficiency Rating. However, this will not produce as accurate a result as calibrating to your own arrow weight and speed. Due to the number of variables involved, it is impossible to perfectly match both Archer’s Advantage’s IBO & AMO speed ratings to Manufacturer’s published data. If the manufacturer supplies both IBO and AMO ratings, use the rating that most closely matches your setup to calibrate the Bow Efficiency Rating.