Trad Gang

Main Boards => PowWow => Topic started by: huntin_sparty on March 01, 2010, 10:19:00 PM

Title: Measuring a recurve
Post by: huntin_sparty on March 01, 2010, 10:19:00 PM
I was measuring my bow with a tape just to see how much shorter a 48 would be in comparison.  I noticed anyway I measured it it was not 58 like it is supposed to be.  It comes up as 56 tip to tip.  Am I measuring incorrectly?
Thanks,    (http://[img]http://i742.photobucket.com/albums/xx69/sparty44/IMG_2590.jpg)[/IMG]
Title: Re: Measuring a recurve
Post by: huntin_sparty on March 01, 2010, 10:24:00 PM
photos   (http://i742.photobucket.com/albums/xx69/sparty44/IMG_2591.jpg)
 (http://i742.photobucket.com/albums/xx69/sparty44/IMG_2590.jpg)
Title: Re: Measuring a recurve
Post by: MJB on March 01, 2010, 10:31:00 PM
huntin_sparty
Take the tape and measure the belly side tip to tip. Follow the contour of the limbs.
Title: Re: Measuring a recurve
Post by: huntin_sparty on March 01, 2010, 10:34:00 PM
QuoteOriginally posted by MJB:
huntin_sparty
Take the tape and measure the belly side tip to tip.
Bingo, thanks sorry for the newbie stupid ?  Im sure Black widow knows what they are shipping!
Title: Re: Measuring a recurve
Post by: MJB on March 01, 2010, 10:35:00 PM
huntin_sparty
No such thing as stupid question here .    :thumbsup:
Title: Re: Measuring a recurve
Post by: Pete W on March 02, 2010, 12:25:00 AM
http://peteward.com/AMOStandards.pdf
AMO CONVENTIONAL
BOW LENGTH STANDARD
AMO Bow Length Standard is designated to be three inches longer than AMO
Bow String Master that braces bow at proper String or Brace Height. Bow String
Master will carry only the bow length designation. Example: A Bow String
Master designated as AMO 66" (bow length) will have an actual length under
tension of 63".
Cable length is determined by placing loops over 1/4" diameter steel pins and
stretching under 100 pound load and measuring from outside of pin to outside of
pin. Tolerance is +-1/16". End loops of cable will be 1 1/4" long and plastic
coated.
Bow String Master shall have the following material specifications or equivalent:
1/16" 7 x 7 galvanized (Mil-C-1511) or stainless (Mil-C-5424) steel aircraft cable
of 480 lb. test.
A Bow String Master Set shall consist of twenty-five Bow String Masters to
measure bow lengths in one inch increments ranging from 48" to 72"; (i.e. actual
string lengths 45" to 69").
The AMO prefix to bow lengths in inches means that the bow has been manufactured
to a length that properly uses a bow string designated with the identical
AMO marking. (i.e. A bow marked "AMO 60", 50 lb. will brace to the proper
string height with a string marked "AMO 60", 45 lb. to 55 lb.)
Title: Re: Measuring a recurve
Post by: yaderehey on March 02, 2010, 09:51:00 AM
QuoteOriginally posted by Pete W:
 http://peteward.com/AMOStandards.pdf  
AMO CONVENTIONAL
BOW LENGTH STANDARD
AMO Bow Length Standard is designated to be three inches longer than AMO
Bow String Master that braces bow at proper String or Brace Height. Bow String
Master will carry only the bow length designation. Example: A Bow String
Master designated as AMO 66" (bow length) will have an actual length under
tension of 63".
Cable length is determined by placing loops over 1/4" diameter steel pins and
stretching under 100 pound load and measuring from outside of pin to outside of
pin. Tolerance is +-1/16". End loops of cable will be 1 1/4" long and plastic
coated.
Bow String Master shall have the following material specifications or equivalent:
1/16" 7 x 7 galvanized (Mil-C-1511) or stainless (Mil-C-5424) steel aircraft cable
of 480 lb. test.
A Bow String Master Set shall consist of twenty-five Bow String Masters to
measure bow lengths in one inch increments ranging from 48" to 72"; (i.e. actual
string lengths 45" to 69").
The AMO prefix to bow lengths in inches means that the bow has been manufactured
to a length that properly uses a bow string designated with the identical
AMO marking. (i.e. A bow marked "AMO 60", 50 lb. will brace to the proper
string height with a string marked "AMO 60", 45 lb. to 55 lb.)
Sounds like the gooberment was involved in this one!  Wonder if it had any trouble getting through the senate and the house.
Title: Re: Measuring a recurve
Post by: bowfiend on March 02, 2010, 10:21:00 AM
QuoteSounds like the gooberment was involved in this one!  Wonder if it had any trouble getting through the senate and the house. [/QB]
Seriously - they must have had a congressional panel investigate the matter.

I can accept the Master String Man measurement system for AMO, but is that standard for both longbows and recurves? I'm asking becasue I have a 58" longbow that's longer than my 60" recurve. The AMO definition above makes me think that the type of bow is irrelevant.
Title: Re: Measuring a recurve
Post by: Jeremy on March 02, 2010, 10:33:00 AM
The AMO convention for bow length is for recurves and longbows.  Many, many bowyers are incorrectly marking their bows "AMO" when they aren't.  It's become a big pet peeve of mine!
Title: Re: Measuring a recurve
Post by: Buckwheaties on March 02, 2010, 10:34:00 AM
Is that belly side tip to tip or string groove to string groove?
Title: Re: Measuring a recurve
Post by: Pete W on March 03, 2010, 12:16:00 AM
Here is an example of why AMO standards are needed.
62" bow 56" string

  (http://peteward.com/internet%20pictures/herters.string.jpg)

Or how about the guy that wanted to try a shorter bow, spent $700.00 and discovered his new 58" marked bow is the same as his old 60" bow. Both take a 57" string.  :banghead:  

Pete
Title: Re: Measuring a recurve
Post by: bowfiend on March 03, 2010, 11:02:00 AM
OK. So what I'm taking away from this thread is that I should be asking string length and not bow length. Now that I think about it, it makes a lot of sense  :knothead:  It is somewhat frustrating though that something with the illusion of being standardized (bow length) is really somewhat arbitrary and dependent upon the bowyer's chosen scale. Lesson learned.