Primitive Archer

Main Discussion Area => Bows => Topic started by: Siyah Later on July 09, 2016, 05:05:35 pm

Title: Simple Yellow Birch Flatbow
Post by: Siyah Later on July 09, 2016, 05:05:35 pm
A year ago I cut down a yellow birch tree thinking it was the best wood option I had (now I've discovered that I have access to sugar maple).  Yellow birch grows really straight and quite clean, so I got some nice staves out of the tree.  Since this is my first bow not built from a board, and I didn't know what to expect from yellow birch, I decided to make a nice safe bow.  It's 66" long, 2" wide at the fades and 1/2" at the nocks.  It is parallel to about mid-limb.  It pulls 40# at 28".  I decided to keep this bow really simple; no tip overlays, no handle lamination, no backing, not even an arrow shelf.  I also didn't do any heat bending, so the bow is a little twisted, but the string lines up through handle so it works fine.  As it turns out yellow birch bends real easy with dry heat, but I'll save that for when I post my other bows.  After putting some fancy finishes on a few bows it was kind of nice to make a bow that was just a single piece of wood.  The bow has 2-2.5" of string follow, but the stave was deflexed at least an inch to begin with, so it really didn't take too much set.  I've yet to have a yellow birch bow break on me, and I get the impression that it's more likely to take set than explode.  All things considered I think it's a fairly decent bow wood.  I'm going to try to make a yellow birch bow in the 50lb range next (all of my others have been 40# or less) so we'll see how it handles that.

Extra information and pictures are available here: diydudes.com/a-simple-yellow-birch-flatbow-bow-4/

(https://www.dropbox.com/s/skoj91dc9ci3wuu/Yellow%20Birch%201-2.jpg?dl=1)

(https://www.dropbox.com/s/kbow7h7cqdcbw0m/Yellow%20Birch%201-4.jpg?dl=1)

(https://www.dropbox.com/s/svw4sngrw2rshtu/Yellow%20Birch%201-6.jpg?dl=1)

(https://www.dropbox.com/s/blkykhx31sggerq/Yellow%20Birch%201-7.jpg?dl=1)

(https://www.dropbox.com/s/ncmookw6dvodsek/Yellow%20Birch%201-9.jpg?dl=1)

(https://www.dropbox.com/s/ewmg18uz00h9m6q/Yellow%20Birch%201.jpg?dl=1)

And here's a quick video of the bow in action:


https://www.youtube.com/watch?v=4wPaxUKCykM
Title: Re: Simple Yellow Birch Flatbow
Post by: bjrogg on July 09, 2016, 05:12:35 pm
Nice looking bow you got a beautiful bend out of her.
Title: Re: Simple Yellow Birch Flatbow
Post by: Stixnstones on July 09, 2016, 05:32:05 pm
good lookin bow and cool vid. nice and simple.
Title: Re: Simple Yellow Birch Flatbow
Post by: bradsmith2010 on July 09, 2016, 05:37:08 pm
nice bow,, contrats
Title: Re: Simple Yellow Birch Flatbow
Post by: Knotty on July 09, 2016, 05:40:11 pm
Looks very nice! Well done. 😉
Title: Re: Simple Yellow Birch Flatbow
Post by: wizardgoat on July 09, 2016, 05:48:14 pm
Nice bow, I hear yellow birch is the best of the birches. You'd probably get good results with heat treating the next one. Cheers
Title: Re: Simple Yellow Birch Flatbow
Post by: loon on July 09, 2016, 06:28:08 pm
Nice! Looks pretty

If you are not getting cut by fletching, I'd say it's proof enough that a shelf is really not necessary except to make it more center shot, but then could just make the handle narrower as well

would birch somehow be better at tension than maple? (since those reaction pine bows were backed with birch..)
Title: Re: Simple Yellow Birch Flatbow
Post by: GB on July 10, 2016, 12:47:30 am
Good looking bow!  Nicely done.
Title: Re: Simple Yellow Birch Flatbow
Post by: mikekeswick on July 10, 2016, 02:28:27 am
Nice! Looks pretty

If you are not getting cut by fletching, I'd say it's proof enough that a shelf is really not necessary except to make it more center shot, but then could just make the handle narrower as well

would birch somehow be better at tension than maple? (since those reaction pine bows were backed with birch..)

If you get cut by your fletches then your nocking point is too low. Simply raise it 1/8th at a time until you don't feel anything.

You got a loverly bend going on there. Well done. I'd also try heat treating it.
Title: Re: Simple Yellow Birch Flatbow
Post by: Del the cat on July 10, 2016, 02:59:08 am
Yup, single piece of wood, that's what I like  :)
Sweet
Del
Title: Re: Simple Yellow Birch Flatbow
Post by: Marc St Louis on July 10, 2016, 07:02:21 am
Very nice.  Keeping the bow long and wide was a good idea.  I made several Yellow Birch bows many years ago and most chrysalled over time which suggests that it is a bit low in elasticity and heat-treating won't help that
Title: Re: Simple Yellow Birch Flatbow
Post by: Siyah Later on July 10, 2016, 06:20:44 pm
Thanks for all the kind comments.  I'd definitely be interested in trying some heat treating on my next bow, especially since heat bending works so well with yellow birch.  However, like Marc St. Louis said it might negatively affect the longevity of the bow.  Only one way to find out!
Title: Re: Simple Yellow Birch Flatbow
Post by: scp on July 10, 2016, 06:47:12 pm
Nice work. I never had much luck with birch. Too many knots in my staves. I would have left the tips ticker, so that I have the option to flip the tips, if not making a proper recurve. I would definitely try heat treating the belly. How fast does it shoot?
Title: Re: Simple Yellow Birch Flatbow
Post by: Siyah Later on July 10, 2016, 09:24:03 pm
Nice work. I never had much luck with birch. Too many knots in my staves. I would have left the tips ticker, so that I have the option to flip the tips, if not making a proper recurve. I would definitely try heat treating the belly. How fast does it shoot?

I have no quantitative way of measuring speed at the moment, so I'm not really sure.  I've already made another bow with flipped tips since this one, so I'm not too worried about making this one faster.  I've got one ready for tillering that has about 3.5" of reflex, so I guess that one could be considered a proper recurve.  It's a really clean and straight stave so I'll see if I can hit 50# with it.
Title: Re: Simple Yellow Birch Flatbow
Post by: PlanB on July 10, 2016, 09:49:47 pm
I like your bow very much Siyah. I've had good luck with black birch bows so far, and I have yellow birch growing here which I'd like to try. I think you made good conservative design choices for the wood and a first trial at it. Good work!  :)
Title: Re: Simple Yellow Birch Flatbow
Post by: Siyah Later on July 11, 2016, 06:35:42 am
Thanks Planb!  Good to hear that you've had success with birch.