Howdy kylos,
Great question.
I just did the research on this a few weeks ago. (My tillering board is
nearly complete. But, now it's gotten really cold outside, and so I'm keeping busy inside.)
Here's a link that I looked at....
http://www.geocities.com/salampsio/oak6.htmIn this link, the author refers to the term,
AMO, which is has to do with industry standards, and a set, standard way of measuring draw length.
So, according to AMO, we set the zero mark by measuring 1.75 in
above the bottom notch on our tillering stick.
eg. So, what I did was measured 4-1/4" down from the bottom of the handle notch to my first string groove. I then marked that first string groove as 6" (of drew length).
I hope that explains your question. (And,
please correct me if I'm wrong.)
All the best,
Canoe
Copied from
AMO Standards Publication 2000yr...
AMO DRAW LENGTH STANDARD
For Manufacturers
Draw length is a specified distance, or the distance at the archer’s full draw, from
the nocking point on the string to the pivot point of the bow grip (or the theoretical
vertical projection of a tangency line to the pivot point parallel to the string)
plus 1 3/4”. Draw length from pivot point shall be designed at DLPP and shall be
called TRUE DRAW LENGTH.
EXAMPLE: 26 1/4” DLPP plus 1 3/4” is the equivalent of 28” draw.