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    ASTM F1880 - 09(2013)

    Standard Test Method for the Determination of Percent of Let-Off for Archery Bows

    Active Standard ASTM F1880 | Developed by Subcommittee: F08.16

    Book of Standards Volume: 15.07

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    This test method covers procedure to determine the percent of let-off for archery bows. Percent of let-off shall be determined from formula using force-draw curve. Other factors for percent of let-off determination include hysteresis effect and rating conditions.

    This abstract is a brief summary of the referenced standard. It is informational only and not an official part of the standard; the full text of the standard itself must be referred to for its use and application. ASTM does not give any warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date.

    Significance and Use

    4.1 It is recognized that certain designs of the cams used in the compounding systems of archery bows cause variation in the percent of let-off with change in draw length, draw weight, or both. This is true particularly with the style of cam that achieves draw length adjustment by effectively altering the length of the shooting string by any of several methods. In this case, the mid-draw length and the maximum draw weight obtainable (but not to exceed the maximum rated weight of the bow) shall be used to determine the official percent of let-off for the bow in question.

    4.2 Historically, two methods have been in use to establish the percent of let-off for archery bows. The most common method uses the peak draw force and the minimum holding force read from the force-draw curve to calculate the percent of let-off. The second method uses the peak draw force from the force-draw curve and the minimum holding force from the let-down curve for this calculation. This test method defines the two methods and distinguishes between them.

    1. Scope

    1.1 This test method covers the procedure to be used to determine the percent of let-off for archery bows.

    1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

    2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

    ASTM Standards

    F1832 Test Method for Determining the Force-Draw and Let-Down Curves for Archery Bows

    ICS Code

    ICS Number Code 97.220.40 (Outdoor and water sports equipment)

    UNSPSC Code

    UNSPSC Code 49181602(Archery bows)

    Referencing This Standard
    Link Here
    Link to Active (This link will always route to the current Active version of the standard.)

    DOI: 10.1520/F1880-09R13

    Citation Format

    ASTM F1880-09(2013), Standard Test Method for the Determination of Percent of Let-Off for Archery Bows, ASTM International, West Conshohocken, PA, 2013, www.astm.org

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