Redneck testing

[kennym]

I talked to a good bowyer this morning and he got me thinking....   :D    

So tonite I cut some .060 parallel lams exactly the same length, checking thickness on each one and adjusting as needed to get as close to .060 as possible. Also cut all to 1.5" width with table saw set for all so as close as possible to exact.

The deflection was checked by hanging over end of bench 6" and clamping it and a straight board down to bench. Then measuring deflection to straight board, and flipping over to check and average result.  

Here are the results so far, most of these would be core woods, and are edge grain.

Wood -- weight in grains --   deflection in "

R. elm ------- 32.4 -------- 1  1/16
A-wood ------- 44.2 -------- 7/8
Amber boo ---- 37.4 -------- 1  1/4
Nat boo ------ 41.0 -------- 1  3/16
Ash ---------- 34.8 -------- 1  5/16
Walnut ------- 32.4 -------- 1
H locust ----- 39.5 -------- 1  3/8
Hickory ------ 39.6 -------- 7/8+
Osage -------- 49.1 -------- 7/8+
Maple -------- 41.1 -------- 7/8-

See why a lot of old bows were maple core? LOL

Hope these numbers can help you decide on cores, but the numbers are pretty much controlled by the individual tree they came from. YMMV    

[Mad Max]

I have been using hard rock maple rift sawn for some time now.
good stuff

Nice project.

[kennym]

I know Roy's gonna crucify me for being technical on simple bows, but I bet he picks good stuff for his tri lams too...        JK Roy!

Actually this would help on any kind of bow or bendy thing.

I like maple,  amberboo and walnut in that order.

The best hunting  bow I've made was walnut, just a sweet shooting bow.

[goobersan]

[Dale in Pa]

Very interesting Kenny. I'm surprised walnut isn't more popular as core material.

[Roy from Pa]

Thanks Ole Boy.
Ya have me thinking now cause I use red elm for cores a lot. Also surprised that Osage is heavier than hickory. But what happened to the .025 etc stuff?  

[kennym]

Remember these were just from one sample, next board or tree may be whole different story.

The .025 stuff was just veneers for known heavier woods.  

[Roy from Pa]

You need to test some poplar and Mongolian tulip wood next..  

But yup the next trees could be different. That's why I like using sister billets when making bows.

[Mad Max]

I did this test for myself on static tips.

 http://tradgang.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=125;t=012157#000000

[kennym]

Mtw is the very best but I can't source it. Some guy in PA bought it up.

[kennym]

Walnut is real good but it came in a bit light when I built the test bows a few years back. This board might have been better.

[Wolftrail]

I use mostly Maple exclusively, I like working with it and the dust impact is on the lower end of the scale compared to woods like, yew and black walnut.
I wonder how White Oak compares..?

Good stuff Kenny...  What is the total length of the laminations you cut???  I would like to cut a piece of Sheoak and compare to the other woods...  Have you thought about putting a small weight weight on the end also???  Your results may vary...

  Thanks for sharing...

[kennym]

I forgot to say I put a 2" spring clamp on the last 1/8" of the lam to deflect it. I intended to weigh it too but haven't gotten it done.

[kennym]

Originally posted by kennym:
I talked to a good bowyer this morning and he got me thinking....    :D        

So tonite I cut some .060 parallel lams exactly the same length, checking thickness on each one and adjusting as needed to get as close to .060 as possible. Also cut all to 1.5" width with table saw set for all so as close as possible to exact.

The deflection was checked by hanging over end of bench 6" and clamping it and a straight board down to bench. Then measuring deflection to straight board, and flipping over to check and average result.   I used a 2" spring clamp square on the lam end 1/8" onto the end of lam , was gonna weigh it but didn't yet.

Here are the results so far, most of these would be core woods, and are edge grain.

Wood -- weight in grains --   deflection in "

R. elm ------- 32.4 -------- 1  1/16
A-wood ------- 44.2 -------- 7/8
Amber boo ---- 37.4 -------- 1  1/4
Nat boo ------ 41.0 -------- 1  3/16
Ash ---------- 34.8 -------- 1  5/16
Walnut ------- 32.4 -------- 1
H locust ----- 39.5 -------- 1  3/8
Hickory ------ 39.6 -------- 7/8+
Osage -------- 49.1 -------- 7/8+
Maple -------- 41.1 -------- 7/8-

See why a lot of old bows were maple core? LOL

Hope these numbers can help you decide on cores, but the numbers are pretty much controlled by the individual tree they came from. YMMV      

[kennym]

Not sure how I did that!! The lams are exactly 36" , deflection checked with 6" over end of  bench with straight board clamped on top to hold down, 2" spring clamp for weight 1/8" from lam end.

[Roy from Pa]

What was the weight of the spring clamp?
This flaw throws a curve ball into your testing.
Ya some kind of Missouri redneck...
AH NEVER MIND.

[goobersan]

[monterey]

I saw something similar done comparing wood lams to foam.  The foam hung like a wet noodle.

[Bvas]

If Im interpreting this correctly, then the hickory did slightly better than the maple.  As they both had the same deflection but the hickory is lighter. (Assuming that is a typo, and the maple didn't elevate 7/8 for a negative reading  :D  )