ASTM F1832-97

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

SCOPE
1.1 This test method covers the procedure to be used to determine the force-draw and let-down curves for archery bows.

General Information

• Status: Historical
• Publication Date: 09-Nov-1997
• Technical Committee: F08 - Sports Equipment, Playing Surfaces, and Facilities
• Drafting Committee: F08.16 - Archery Products

Relations

• Replaced By: ASTM F1832-97(2002) - Standard Test Method for Determining the Force-Draw and Let-Down Curves for Archery Bows
• Effective Date: 10-Nov-1997

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or
withdrawn. Contact ASTM International (www.astm.org) for the latest information.
Designation: F 1832 – 97
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Test Method for
Determining the Force-Draw and Let-Down Curves for
1
Archery Bows
This standard is issued under the fixed designation F 1832; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope height to the full draw position corresponds to the draw stroke
of a bow.
1.1 This test method covers the procedure to be used to
2.1.5 draw cycle—the combination of the draw-stoke and
determine the force-draw and let-down curves for archery
the power-stoke, resulting in a full cycle from brace height to
bows.
full draw and return to brace height.
1.2 The values stated in inch-pound units are to be regarded
2.1.6 draw-stroke—the distance in inches (millimeters)
as the standard. The SI units given in parentheses are for
from brace height to full draw.
information only.
2.1.7 force-draw curve—the curve that is plotted using the
1.3 This standard does not purport all of the safety con-
force readings, taken at incremental values of draw length
cerns, if any, associated with its use. It is the responsibility of
when drawing the bow, as the ordinate and the corresponding
the user of this standard to establish appropriate safety and
draw length as abscissa.
health practices, and determine the applicability of regulatory
2.1.8 full draw—the position assumed by the bowstring
limitations prior to use.
when the bow is drawn to a draw length corresponding to that
2. Terminology from which it will be released for the shot. For most standard
test purposes full draw is specified as 30 in. (762 mm) AMO
2.1 Definitions of Terms Specific to This Standard:
draw length for compound bows, and 28 in. (711.2 mm) AMO
2.1.1 AMO (archery manufacturers and merchants organi-
draw length for noncompound bows, but it can take any
zation) draw length—the perpendicular distance from the point
assigned value.
where the shooting string of the bow contacts bottom of the
2.1.9 let-down curve—curve that is plotted using the force
nock slot of the arrow, to a vertical line through the pivot or
readings, taken at incremental values of draw length when
low point of the hand grip (draw length pivot point), plus a
relaxing the bow, as the ordinate and the corresponding draw
standard dimension of 1 3/4 in. (44.5 mm).
length as abscissa.
2.1.2 brace height—the dimension in inches (millimetres),
2.1.10 let-off—the difference between the peak or maximum
from the grip pivot point (low point) of the grip to the nearest
draw force reached during the draw stroke of a bow, and the
side of the bowstring, measured perpendicular to the bow-
lowest level of draw force reached subsequent to that peak.
string, with the bow strung and in the undrawn condition.
Quantitatively, it is most frequently expressed as a percentage
2.1.3 compound bow—a type of bow that imposes a sec-
of the peak force and is then referred to as percent of let-off.
ondary system of control of the force-draw characteristic on the
2.1.11 non-compound bow—a bow constructed in the tradi-
usual limb geometry control system of the conventional bow.
tional manner, having two flexing limbs extending outwardly
This secondary control system can be composed of cam, levers,
in opposite directions from a handle. A single shooting string of
cables, or other elements, and combinations thereof. The dual
a length shorter than the bow, connects the extreme ends of the
control system permits great versatility in the design of the
limbs causing them to assume a pre-stressed flexed condition.
force-draw characteristic, and simplifies the inclusion of let-
Drawing the bow causes additional bending and stressing of
off. In general, it is normal for compound bows to have greater
the limbs, storing the energy necessary to propel the arrow.
stored energy than conventional bows for a given level of peak
Control of the force-draw characteristic of the bow is exercised
or maximum draw weight.
entirely by the static and dynamic geometry of the flexing
2.1.4 draw—to move the shooting string of a bow from the
limbs and the bowstring.
rest or braced position toward the full drawn position by
2.1.12 peak draw force—the maximum force reached when
applying force to said string. Such action causes the limbs of
drawing a bow. For conventional bows, the peak draw force is
the bow to bend and store energy. Moving the string from brace
usually reached at the full draw condition. For compound
bows, the peak draw force is reached part way throug
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