Primitive Archer

Main Discussion Area => Bows => Topic started by: OTDEAN on December 14, 2014, 09:17:19 am

Title: I know I have learned something but I don't know what? Need your brains
Post by: OTDEAN on December 14, 2014, 09:17:19 am
Sooooo, I got this lovely piece of ash that I am tillering, now at 12" on a string when nocked that is the same length as the bow, so not braced yet!  Anyhow! So this sucker was pulling about 20lb at 12" and I have been putting it on and off the tiller stick removing me flat spots, I weigh it again after 1hr working on it at 12" and the sucker has gained 5lb!!! wtf is going on?  My scales are working fine, is this some kind of magic trick?

Dean
Title: Re: I know I have learned something but I don't know what? Need your brains
Post by: bushboy on December 14, 2014, 09:33:45 am
Maybe you are not exercising it enough between wood removal? The wood will try to go back to the original profile. It has a bend memory.might mind your dirty fingers even in abbreviated form also.
Title: Re: I know I have learned something but I don't know what? Need your brains
Post by: OTDEAN on December 14, 2014, 09:37:08 am
I am exercising it 30 times each time I remove a little wood with my scraper.  So I can't see it being that?
Title: Re: I know I have learned something but I don't know what? Need your brains
Post by: bushboy on December 14, 2014, 09:57:07 am
Could be a physics,friction thing?dose it go back the preset draw weight after a bit of exercise?kinda like warming up a rubber band.i don't weigh my bows very much so i'm just guessing here.
Title: Re: I know I have learned something but I don't know what? Need your brains
Post by: burchett.donald on December 14, 2014, 10:32:46 am
  Temperature could play a part...If the bow was inside and you went out to a really cold shop it could gain some weight as it cools...
                                                                                                      Don
Title: Re: I know I have learned something but I don't know what? Need your brains
Post by: Stringman on December 14, 2014, 11:15:30 am
Might mind your dirty fingers even in abbreviated form also.

2x
Title: Re: I know I have learned something but I don't know what? Need your brains
Post by: missilemaster on December 14, 2014, 11:24:11 am
Is it well seasoned?
Title: Re: I know I have learned something but I don't know what? Need your brains
Post by: OTDEAN on December 14, 2014, 11:38:01 am
Yeah its well seasoned.  My shed is heated so its not that I am guessing.  I have no idea.  Oh well tillering is coming on, I will just keep weighing as I go.
Title: Re: I know I have learned something but I don't know what? Need your brains
Post by: Carson (CMB) on December 14, 2014, 11:59:27 am
If the stave is coming from the side of the tree with strong tension wood. Sometimes early belly wood removal results in the stave pulling in more reflex. Similar to when you split or bandsaw certain woods in half along their length and the two halves pull away from eachother, the tension side into reflex and the compression into a little deflex.

Has the amount of reflex changed since you started on the stave?
Title: Re: I know I have learned something but I don't know what? Need your brains
Post by: Badger on December 14, 2014, 12:37:36 pm
    I am thinking like Carson, not real unusual for a bow to start going into more reflex once wood is removed from the belly. If it is not this I got nothing!
Title: Re: I know I have learned something but I don't know what? Need your brains
Post by: DC on December 14, 2014, 12:50:52 pm
Did your string stretch and did you tighten it up. If your string stretched the first time you weighed it and then you took the stretch out I think you would get a higher weight at the "same" draw length.
Title: Re: I know I have learned something but I don't know what? Need your brains
Post by: OTDEAN on December 14, 2014, 02:47:39 pm
I like the string theory best.  Think I may switch to a strong linen instead of the bouncy b50 I have at the moment.  At least with the linen the string wont stretch as much.