BOW TYPE YOUR DRAW   SPINE-O-METER
      BOW
  BOW MAKE STRIKE PLATE POSITION    
       
  BOW MODEL STRIKE PLATE THICKNESS    ARROW  
       
  WEIGHT             INCHES  STRING MATERIAL/TYPE    
       
SHAFT MATERIAL POINT WEIGHT    
       
  SHAFT MANUFACTURER  INSERT WEIGHT      SETUP RESULTS  
       
 SHAFT TYPE NOCK END WEIGHT    
SHAFT SIZE  FLETCHING TYPE    
   
  BOP LENGHT   OTHER FLETCHING WEIGHT    
   
  AMO STATIC SPINE   FOOTING    
   
           GPI                DIAMETER  TAPERED   FORM FACTOR  
       

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  Bow Type

Click on the cell and then select from the dropdown list (small arrow to the right) the specific bow type that you are shooting.

The following bow types are available:
 

 - Deflex / Reflex Longbow

 - Horsebow

 - Longbow

- Performance Recurve

 - Recurve
 

NOTE: If the "All Types" selection is made then all bow manufactures will be shown regardless of bow type.
 


Bow Make

Select from the dropdown list the specific maker of your bow. If your bowyer is not listed then select the "Generic" option.

NOTE: Only the manufactures that make the type of bows selected previously will be shown.


  Bow Model

Select from the dropdown list the specific model of your bow. If your model is not listed then you must go back to the Bow Make selection and choose the "Generic" option.

NOTE: Only bows matching the selected "Bow Type" and "Bow Make" will be shown in the dropdown list.


  Weight (#)

Type into this cell, the rated draw weight of your bow.

NOTE: It is always recommended to measure the actual draw weight of your specific bow. It is not uncommon for a bow to draw
3~4# different that what is marked.


 @ Inches

Type into this cell, the AMO draw length that your bow's weight was measured.

NOTE: This distance is measured from the string at full draw to 1.75" past the deepest part of the bows grip. Draw weight is most
often measured at 28".


  Your Draw

Type into this cell, your own personal draw length on the specific bow.


  Strike Plate Position

This field will be blank unless one of the "generic" bow types is selected.
In that case, type into this cell, the location of your strike plate (the side surface where the arrow touches).

Measure your actual bow's strike plate position relative to the string when centered on the limbs. There
are many techniques to do this and here are a few:

Definition of position numbers (Reference the attached sketch to the right)
Looking at the bow from the belly side with the string lined up directly in the center of the limbs.

If the surface of the strike where the arrow lies directly in line with the string then that is considered at true center position and is = 0. A plate surface outside of center would be POSSITIVE numbers as shown to the left in the picture.

A NEGATIVE number would be used when the strike surface is
past center, or to the right in the picture.

Most recurves are center cut or past, most long bows are center cut or even slightly outside of center.


 

Below, see an example of measurement techniques:

  Strike Plate Thickness
 

Type into this cell, the actual thickness of the strike plate you are using. This cell will only be visible if a specific bow model is selected.

NOTE: Make sure that you include any adhesive tape that adds thickness. Also, if there is any "buildout" under the strike plate
(such as a small strip of leather or match stick) then make sure to also include it in this thickness number.


  String Material / Type

Click on this cell and then select from the dropdown list the specific type and strand count of your string.


  Shaft Material

Click on the cell and then select from the dropdown list the specific material type of the arrow shaft.

The following bow types are available:
- Aluminum
- Carbon
- Fiberglass
- Hybrid (a combination of different material like the Easton A/C/C)
- Wood Shaft

NOTE: If the "All Materials" selection is made then all shaft manufactures will be shown regardless of material type.


  Shaft Manufacturer or Wood Type

If any selection of material other than "Wood Shaft" was made then select from the dropdown list the specific manufacturer of the arrow shaft.

If "Wood Shaft" was selected for the shaft material then the dropdown list will show a list of popular shaft woods. The selected wood species will be used to determine an average GPI based that is included in the information section shown to the right.


 Shaft Type

Click on the cell and then select from the dropdown list the specific shaft type produced by the manufacturer selected.

NOTE: This field will be blank if "Wood Shaft" has been selected.


  Shaft Size

Click on the cell and then select from the dropdown list the specific shaft size that is offered for the specific shaft type selected.

NOTE: This field will be blank if "Wood Shaft" has been selected.


  BOP Cut Length

Type into this cell, the BOP length of the shaft.

NOTE: BOP stands for Back Of Point. This length is the measurement from the bottom of the nock groove (where the string touches)
to the back of the point.


  AMO Static Spine

Type into this cell, the static spine of the shaft used. Make sure to use the AMO static spine which is measured with a 2# weight applied in the middle of a 26" span.

NOTE: This field will remain blank unless "Wood Shaft" or "Other" has been selected.

Most carbon and aluminum arrow manufactures report spine using the ASTM method of 1.94# ON A 28" span. If only the
ASTM spine is available then you can use the converter located directly below the DSC


GPI

Type into this cell, the Grains Per Inch of the shaft used.

NOTE: This field will remain blank unless "Wood Shaft" or "Other" has been selected.

When using wood shafts, the GPI can vary greatly within a given wood type and spine range. Always measure your specific
shafts to determine the GPI. If the shaft are not yet available to be weighed then the average GPI number shown in the
information table can be used.

Make sure that the shaft GPI entered includes the weight of the finished applied. This extra weight should be added to the
measured bare wood GPI or to the recommended average GPI listed above. As an example, a 5/16" shaft will increase
approx. 0.2 GPI with multiple polyurethane seal and top coats. A 11/32" shaft typically increases by about 0.3 GPI.


  Diameter

Type into this cell, the outside diameter of the shaft used. The diameter should be measured near the front (directly behind the point if possible) to avoid a false measurement from a tapered shaft.

NOTE: This field will remain blank unless "Wood Shaft" or "Other" has been selected.


  Point Weight

Type into this cell, the weight (in grains) of the point used.


  Insert Weight

Type into this cell, the weight (in grains) of the specific insert being used.

If you are not sure about the type and weight of the insert then check the factory data / recommendation in the
information table. There is also additional data on other inserts available listed in the Comment section if available.


  Nock End Weight

Type into this cell, the weight (in grains) of the nock being used.
Be sure to include the weight of any arrow wrap (if used)


  Fletching Type

Select from the dropdown list the specific fletching configuration that you are using. If your type is not listed then select the "Other" option.

NOTE: 3 x 4" Feathers means three 4" feathers, 4 x 5" Feathers means a four fletch using 5" feathers, etc

The calculation for feathers assumes the average weight of Trueflight feathers. The "Generic Vanes" option assumes an
average three 4" vane fletch of 32 grains total.

There is also a "bare shaft" option that can be selected. This removes all the affect of fletching on dynamic spine.


  "Other" Fletching Weight

If "Other" was selected above then enter the total fletching weight (gr) used in this cell.


  Footing  

(TO USE Enter Applicable Values)
(IF UNUSED
Enter ZERO)

If an internal OR external footing is being used, enter the footing length and weight.
If none used, make sure values are set to 0 (ZERO)

NOTE: An example of an internal footing would be any insert with a length greater than 0.9" (std. insert length) or the extends into the
shaft more than 0.9" An example is the HIT insert as shown in the diagram below.

An example of an external footing would include be an aluminum shaft glued over the outside of a carbon shaft. In the case of
an external footing enter the total length of the footing minus 0.9" as indicated by X.XX" in the diagram below.

The diagram below shows the correct interpretation of a standard insert, an internal footing, and an external footing.

 

 
  Tapered

(To USE Enter Applicable Values)

(If UNUSED Enter ZERO)

If a tapered wood shaft is being used, enter the taper length and tapered nock diameter.
If none used, make sure values are set to 0 (ZERO)

NOTE: Generally wood shafts are tapered over the last 10" of the nock end of the shaft. The taper is gradual and generally reduce
the nock end diameter by 1/32". (Ex: 11/13" shaft with a 10" taper to a nock end diameter of 5/16")


  Bow / Arrow

These two boxes simply show which specific bow and arrow have been selected.

NOTE: A red error message apears whenever there is a selection made that is not allowed. In that case, please go back to the input
cells and correct the one(s) that are red.


  Setup Results

Total Weight = The total finished weight of the arrow setup is displayed in grains.

Specific Weight (GPP) = The total finished weight of the arrow relative to the bows weight at draw. A good
general rule of thumb is 8~9 GPP for a target/3D arrow and around 10+ GPP for a
hunting arrow.

FOC (%) = The balance point of the shaft is shown here as a percentage of the amount forward of the center point.
A minimum amount of approximately 5% is necessary to ensure stable arrow flight. Too much F.O.C.
will result in an increase in arrow drag and will limit effective cast.

Speed (FPS) = The speed displayed is estimated based on shooting from the fingers and takes into account all
aspects of the bow and arrows inputs.

Energy (ft-lbs) = The kinetic energy of the arrow, based on its initial velocity.


  Personal Form Factor (PFF)

The personal form factor is a way to calibrate the DSC to your own personal shooting style. To use it simply enter accurate info about an arrow setup that has been proven to work well for you and then enter you bows info as usual. I recommend bare shaft testing for point-of-impact relative to fletched shafts for final confirmation of correct flight. With that done you now simply enter a number (ranging from -15 to +15) until the bow required dynamic matches your good shooting arrow's dynamic spine. Now that you have found your Personal Form Factor you simply leave it in place when changing to new arrows or bow. If you are new to trad archery, your form and style will change over the first years. The PFF will provide a way for the DSC to change right along with you.

For the vast majority of archers using a default "0" setting will remain accurate and the results will be the exact same as the previous version.


  Spine-O-Meter

The Spine-O-Meter is a graphical output that shows the specific bow's spine requirement value, and the arrow's dynamic spine.

NOTE: Each bows setup indicates it's spine requirement with the Green(Average), RED(Maximum), and Orange(Minmum) vertical bars.

Each arrow setup also gives a dynamic spine output, which is shown by the
DARK BLUE vertical bar.
An arrow is considered
"tuned" when it's indicator falls between the Maximum & Minimum bow output values.

The closer the Arrow Bar is to being matched with the Bow Average Bar,
the better the tune.


Once a shaft is selected, modify the length and point weight to move the bar indicator into the desired position.


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