Gallery Video Directory Hammock Articles Donate Hammock Forums Store Today's Posts Mark Forums Read
 Hammock Forums - Elevate Your Perspective How much Gross Grain is left on the roll
 Home Forums Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

 12-02-2010, 19:52 #1 nacra533 Senior Member     Join Date: May 2009 Location: Hartwell, GA Hammock: DIY dbl 1.1 Tarp: DIY hex Insulation: DIY 3 season tq+uq Suspension: webbing, again View my gallery 26 Posts: 620 Images: 26 How much Gross Grain is left on the roll For the DIY or gear maker, it's nice to know how much gross grain, or tape, or whatever else is left on a roll, without unwinding it. I found these two formulas online and they agree with each other. I have not measured them, but they agreed with what was printed on one of my rolls of grossgrain. L=pi*(r2^2 - r1^2)/t where L= length of tape remaining in inches pi=3.14 r2 = outer radius of roll in inches r1 = radius of the cardboard core in inches (typically about .072") t = thickness of the grossgrain in inches (typically about .0165") Another one using diameters is: L=pi*N*(D+d)/2 where pi=3.14 N=(D-d)/2*t D= outer diameter of roll in inches d= diameter of cardboard core in inches (typically 1.45") I use the formula in excel and enter the diameters and thickness and let Excel do the rest. I convert the the total length measurement to feet and yards. Actually having the measurement in feet is more beneficial to me making gear.
12-02-2010, 20:27   #2

Join Date: Apr 2007
Location: Illinois
Hammock: DIY Bridge, v0.n, where n is large
Tarp: depends on season
Insulation: DIY UQ
View my gallery 564
Posts: 4,684
Images: 564
Quote:
 Originally Posted by nacra533 For the DIY or gear maker, it's nice to know how much gross grain, or tape, or whatever else is left on a roll, without unwinding it. I found these two formulas online and they agree with each other. I have not measured them, but they agreed with what was printed on one of my rolls of grossgrain. L=pi*(r2^2 - r1^2)/t where L= length of tape remaining in inches pi=3.14 r2 = outer radius of roll in inches r1 = radius of the cardboard core in inches (typically about .072") t = thickness of the grossgrain in inches (typically about .0165") Another one using diameters is: L=pi*N*(D+d)/2 where pi=3.14 N=(D-d)/2*t D= outer diameter of roll in inches d= diameter of cardboard core in inches (typically 1.45") I use the formula in excel and enter the diameters and thickness and let Excel do the rest. I convert the the total length measurement to feet and yards. Actually having the measurement in feet is more beneficial to me making gear.
The first is intuitive---the area of a ring with given inner and outer radii, divided by the thickness. An approximation to what happens when the tape wraps around itself, but seemingly fine if t is small relative to (r2-r1). The second says exactly the same thing, but it seems odd to me to create D^2 - d^2 by the product (D-d)*(D+d) and then get rid of the extra 2 from D^2 = (2r)^2 with two separate divisions by 2. Huh.
__________________
Grizz

 12-02-2010, 20:49 #3 Shug Whoooo Buddy))))     Join Date: Oct 2007 Location: Minnesota Hammock: DIY GreenBeanHammock Tarp: DIY Tarps/HG Cuben Insulation: Frankenquilt/Pod Suspension: Whoopie Slings View my gallery 62 Posts: 14,448 Images: 62 I love when ya'll talk and type like that!!!!! Shug.... Math Dolt __________________ Whoooo Buddy)))) I Love Onions, Grits, Greens, Livermush, NC Style BBQ, Potted Meat, Anchovies, 'Naner Puddin", Peanut Butter Pie, Red Velvet Cake and Cocoa and Straaaaaawwwwberrrry Milk and Coffee Crisps.... I Hope Heaven has a Bakery!!!! Shug's YouTube Videos Hammock How-To Videos ..... Essentials For Noobs Shug and Friends Jammin'
 12-02-2010, 20:51 #4 Old River Rat Senior Member     Join Date: Jul 2010 Location: Deville, La. Hammock: GrizzBridge Rhino Tarp: Speer Winter Tarp Insulation: HammockGear TQ/UQ Suspension: Whoopie Slings Posts: 755 I would just have to keep track of how much I have used from the roll. Or unroll it and measure.
 12-02-2010, 21:04 #5 Syb     Join Date: Nov 2010 Location: Trenton, NJ Hammock: WBBB 1.1 DL/DIY Tarp: OES/WB Superfly Insulation: Incubator/Burrow Suspension: WB Straps View my gallery 41 Posts: 1,835 Images: 41 I have absolutely no idea what Nacra and Grizz are talking about Syb
 12-02-2010, 21:07 #6 lonetracker     Join Date: Oct 2009 Location: iron mountain mi Hammock: diy fiddle factor Tarp: diy cat cut hex Insulation: whatever Suspension: openable whoopies View my gallery 28 Posts: 462 Images: 28 not enough __________________ diyin to hang
 12-02-2010, 21:09 #7 rjcress Senior Member     Join Date: Oct 2010 Location: Central NC Hammock: DIY FrankenBird + 5 other DIYs Tarp: DIY Sil Ogee, etc. Insulation: IX UQ & TQ +fleece Suspension: DIY whoopies View my gallery 19 Posts: 874 Images: 19 Uh... was any of that in English? It must be, I recognized the word DIY. __________________ "I keep telling myself that if I make perfect seams, nobody will believe that I made it... " -JohnSawyer My outdoor gear review site http://gear-report.com Gear reviews, DIY / MYOG projects, Outdoor gear discounts, sales and coupons updated daily
12-02-2010, 21:13   #8
nacra533
Senior Member

Join Date: May 2009
Location: Hartwell, GA
Hammock: DIY dbl 1.1
Tarp: DIY hex
Insulation: DIY 3 season tq+uq
Suspension: webbing, again
View my gallery 26
Posts: 620
Images: 26
Quote:
 Originally Posted by GrizzlyAdams The first is intuitive---the area of a ring with given inner and outer radii, divided by the thickness. An approximation to what happens when the tape wraps around itself, but seemingly fine if t is small relative to (r2-r1). The second says exactly the same thing, but it seems odd to me to create D^2 - d^2 by the product (D-d)*(D+d) and then get rid of the extra 2 from D^2 = (2r)^2 with two separate divisions by 2. Huh.
I thought the second one was more clutzy as well, although they give exactly the same result. When I punched it in to Ecxel, I used the fmla with the radius, then immediately miscalculated because I entered diameter. I changed my input to diamter and divided it by 2.

Here is one

Here is the other.

12-02-2010, 21:35   #9

Join Date: Apr 2007
Location: Illinois
Hammock: DIY Bridge, v0.n, where n is large
Tarp: depends on season
Insulation: DIY UQ
View my gallery 564
Posts: 4,684
Images: 564
Quote:
 Originally Posted by nacra533 I thought the second one was more clutzy as well, although they give exactly the same result. When I punched it in to Ecxel, I used the fmla with the radius, then immediately miscalculated because I entered diameter. I changed my input to diamter and divided it by 2. Here is one http://answers.yahoo.com/question/in...9131009AALIEzO Here is the other. http://www.newton.dep.anl.gov/askasc.../math99015.htm
yeah. The intuitive one comes from the hoi polli on the Internet, and the clutzy one from Argonne National Laboratories. Your tax dollars at work
__________________
Grizz

 12-02-2010, 22:08 #10 WV     Join Date: Feb 2008 Location: southeast WV Hammock: DIY View my gallery 202 Posts: 3,718 Images: 202 Dutch and I divided a large amount of amsteel by weighing it. (I weighed it and gave Dutch half; he hasn't complained yet.) You could do the same thing with gross grain. Might even be easier, since it's probably not wound on a core.

 Bookmarks

 Tags grosgrain, gross grain, grossgain, grossgrain, roll

 Thread Tools Display Modes Linear Mode

 Posting Rules You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is On HTML code is Off Forum Rules
 Forum Jump User Control Panel Private Messages Subscriptions Who's Online Search Forums Forums Home Site Topics     Introduce Yourself     Announcements     Feedback and suggestions     Articles Hammock Camping     General Hammock Talk         Long distance travel with a hammock     Suspension Systems, Ridgelines, & Bug Nets     Top Insulation     Bottom Insulation         Pads         Under Quilts     Weather Protection     Do-It-Yourself (DIY)         Fabrics         DIY Stickies Outings     Hangouts, Campouts, and Trip Planning         Northeast         Southeast         Midwest         Southwest         West         All Others     Trip Reports Marketplace     For Sale         Group Buys         Pay it Forward         [SOLD] items no longer available     For Trade         [TRADED] Items no longer available     Want to Buy Hammock Gear - Manufacturers and Services     Reviews     Other Vendors and Services     Arrowhead Equipment (Home of Kick Ass Quilts)     Butt in a Sling Hammock Gear     Clark Jungle Hammocks     Claytor Hammocks     DD Hammocks     Dream Hammock     Dutchware     Eagles Nest Hammocks     Grand Trunk     Hammock Gear     Hennessy Hammocks     2QZQ Hammock Specialties (Hennessy Bugnet Zipper Mods)     Jacks-R-Better     Molly Mac Gear     OES Tarps     Tree to Tree Trail Gear         Speer Hammocks     Trek Light Gear     UGQ Outdoor Equipment     Warbonnet Hammocks     Whoopie Slings     Wilderness Logics

All times are GMT -5. The time now is 18:06.