Exact Quilt Fill Quantity
 Display Avatars Sort By: Date (Chronological) Date (Reverse Chronological)
 Peter McDonough (crazypete) - F Locale: Above the Divided Line Exact Quilt Fill Quantity on 11/13/2006 16:11:40 MST Here is a way to find out the exact quantity of down needed to fill a quilt. The formulation shown below is good for a 2 inch thick layer revolved around a 2 foot radius.The basic idea is to determine the area between the two lines I used to construct a basic quilt shape and revolve that area halfway around the x-axis.QUILT EQUATIONSFoot:y=x^(.5)+1y=x^(.5)+1.167Body:y=0.0283x+1.83y=0.283x+2Area/Volume Calcuation(S will be used as integral sign)Volume ==(3.14/2) { S (x^(.5)+1.167)^2-(x^(.5)+1)^2 + S (0.283x+2)^2-(0.0283x+1.83)^2}The first integral is evaluated from 0 to 0.723 and the second is from 0.723 to 6.Volume = (3.14/2)(0.3985 + 3.60654) = 6.29109 ft^2Fill Calculation6.29109(12^3) = 10871 cubic inches10871 / 800 = 13.6 ozIt should be simple to replace thickness layer with another thickness(like 1 inch or 1.5 inches), or to make the sleeping bag longer or shorter than 6 feet(just change the linear slope so that it intersects that point).I hope this is useful for you guys. Edited by crazypete on 11/13/2006 16:15:03 MST.