Primitive Archer

Main Discussion Area => Bows => Topic started by: IndianKid on January 03, 2015, 11:41:43 pm

Title: Best Bow wood, mathematically speaking
Post by: IndianKid on January 03, 2015, 11:41:43 pm
It's amazing what can be found on the net...

I couldn't find reference to the link below, my apologies if it's been covered already...

I'm posting the url as long as all who read accept the fact
that I don't want to piss any one off ! It may contain imformation akin to fighting words for someone
who knows way more....

But all of that aside I am kinda impressed with the findings,
Kinda jives with what I have been reading.. do you think it's
Reasonably accurate?

http://www.wood-database.com/wood-articles/bow-woods/

Title: Re: Best Bow wood, mathematically speaking
Post by: JackCrafty on January 03, 2015, 11:48:01 pm
All that proves is that there are types of wood that are "mathematically" ideal for bow making.

Your results may vary.  :)
Title: Re: Best Bow wood, mathematically speaking
Post by: Jim Davis on January 04, 2015, 12:19:28 am
The data on that website has been gleaned from the Forest Products Laboratories and a few other places.  The original testing was done in the 1930s. It's just a rehash with commentary.

One horrible omission are the figures for dry Osage orange. Either the testing was not done, or the results were not included in the 1930s reports. To this day, no one has done the necessary tests on what is certainly one of the best bow woods.

As far as the value of the mechanical properties is concerned, it is true that little can be concluded from the numbers that has not been observed for centuries about how certain woods behave in bending. But, not everyone has learned those things by experience. And, if one knows what to look for in the numbers, a lot of time can be saved by not  bothering with questionable woods.

Then again, if you like to see a mystery in every tree you look at and like to prove you can make a bow from weak wood, don't try to learn from the numbers. It will take away the mystery.
Title: Re: Best Bow wood, mathematically speaking
Post by: okie64 on January 04, 2015, 12:23:43 am
Osage is best, thats really all you need to know ;D
Title: Re: Best Bow wood, mathematically speaking
Post by: wizardgoat on January 04, 2015, 12:33:54 am
our ancestors already figured out all the best bow woods.
i thought there was some kind of bow wood formula someone made with those data base numbers where yew and osage ranked almost identical?
Title: Re: Best Bow wood, mathematically speaking
Post by: huisme on January 04, 2015, 12:53:48 am
Yep, it was something like a low ratio between elasticity and MOR, which seems kinda counterintuitive for purely performance bows because a stiff wood like locust would be deemed mediocre wood rather than one of the speed demons.

I doubt there's one equation for good bow wood to be had. Osage will outlast all the other bows. Locust snaps back faster than osage. Yew is like a natural laminate. HHB bends like rubber. Maple makes perfect backings. Elm is extremely versatile. Ipe and bamboo make crazy skinny bows.
Title: Re: Best Bow wood, mathematically speaking
Post by: paulsemp on January 04, 2015, 01:35:50 am
Osage is best, thats really all you need to know ;D


YUP
Title: Re: Best Bow wood, mathematically speaking
Post by: huisme on January 04, 2015, 01:45:18 am
Nah >:D
Title: Re: Best Bow wood, mathematically speaking
Post by: H Rhodes on January 04, 2015, 01:47:53 am
Oh yeah. OSAGE IS KING. 
Title: Re: Best Bow wood, mathematically speaking
Post by: huisme on January 04, 2015, 01:50:13 am
I elect my wood based on individual characteristics  O:)
Title: Re: Best Bow wood, mathematically speaking
Post by: H Rhodes on January 04, 2015, 02:11:43 am
 ;D I was just stirring the pot....  Actually, I am no purist.  I have spent as much time in the woods this season with my buckthorn bow as I have with any of the others.  A good bow is a good bow and there are lots of good bow woods that I have yet to try.   
Title: Re: Best Bow wood, mathematically speaking
Post by: DavidV on January 04, 2015, 10:42:58 am
https://docs.google.com/file/d/0B5GmFhNj7jLNQmNMWk52TWFSakk/edit?usp=docslist_api

That article isn't very useful but the numbers can be. Make a ratio for compression strength over MOR and you get a number that tells you if it is a tension or compression wood. Tension woods are on top and compression woods are on bottom, notice most woods are 2 to 3 times stronger in tension. You can design bows around this ratio keeping individual factors such as ring ratio in mind.

Edit: sorry, the column to look at is the second to last, I was playing around with it and accidentally saved. The last column is MOR/compression so it would be the same thing just a number not a decimal, with 1.0 being equal forces
Title: Re: Best Bow wood, mathematically speaking
Post by: willie on January 04, 2015, 11:13:01 am


are you guys ignoring the thousands of excellent rosewood bows that have been built since those wood tests were made 80 years ago?


has any one seen one rosewood bow?
Title: Re: Best Bow wood, mathematically speaking
Post by: PatM on January 04, 2015, 12:05:21 pm
Rosewood is a broad term and the Dalbergia family is huge.
 I know a guy who  made a tulipwood bow and he said the wood was quite Osage-like.
 The price and rarity of Rosewood make it an unlikely candidate for frequent use but there are some out there.
Title: Re: Best Bow wood, mathematically speaking
Post by: Badger on January 04, 2015, 12:48:03 pm
     I used brazilian rosewood with a maple back on the first bow I ever built. It came out great and I had no clue what I was doing.
I could never make heads or tails of the wood sheets or how to read them.