Primitive Archer

Main Discussion Area => Bows => Topic started by: Jefficus on February 26, 2016, 05:22:05 pm

Title: Question about grain
Post by: Jefficus on February 26, 2016, 05:22:05 pm
I've got some real straight quartersawn boards I'm planning to make bows from.  I've only made flatsawn before, and a question occurred to me:

If grain is basically everything when dealing with something like 1/4 sawn wood for a bow, doesn't tapering to the tips compromise the bow? After all it's basically creating runouts along the slope of the taper.  Yet everybody does it, and it's fine.  Why is that/ why isn't that more of a problem?

It's just got me scratching my head haha.  Thanks all!
Title: Re: Question about grain
Post by: Stick Bender on February 26, 2016, 05:38:30 pm
I'm a newer Bower but since your not geting  a lot of response I will  try it's my understanding that as you move farther out to the last third of the limb in most designs  it's doing less of the work & is less stressed  there for grain violations are less of a problem that's why you see in most designs guys will make them as light as possible with out becoming whip ended I think it's TBB 1 design section it's exsplaned in detail  hope that helped maybe some one with more exsperience will chim in.
Title: Re: Question about grain
Post by: bubby on February 26, 2016, 06:16:08 pm
To tell you the truth I don't know why, I do know i have used quarter and riftsawn selfbows, used both for backings and belly and core and never had that issue
Title: Re: Question about grain
Post by: Dances with squirrels on February 26, 2016, 06:49:39 pm
It doesn't have to be ZERO runout to be usable, and durable, but it should be minimal. Cutting across straight 'grain'/growth rings to effect width taper is a minimal violation and shouldn't concern you.

It's a matter of degree, and relativity. The more highly stressed any area of the limb is, the less runout we should allow.
Title: Re: Question about grain
Post by: Jefficus on February 26, 2016, 06:53:45 pm
Thanks all!
Title: Re: Question about grain
Post by: Springbuck on March 03, 2016, 05:05:01 pm
  No, but on QS boards, look very carefully about how the wood grain runs back to front. It's hadrer to see on a QS board, but it'll kill you if it runs back to front and you didn't see it.
Title: Re: Question about grain
Post by: George Tsoukalas on March 04, 2016, 08:13:57 am
On a 1/4 sawn board, you have to look at the edge grain and it has to be straight tip to tip.
No violations occur when doing a width taper because the fibers are only cut on the end.
Jawge
Title: Re: Question about grain
Post by: Jefficus on March 16, 2016, 01:05:05 am
Thanks George, that makes perfect sense!