Trad Gang
Main Boards => The Bowyer's Bench => Topic started by: kennym on April 20, 2017, 08:37:00 PM
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I talked to a good bowyer this morning and he got me thinking.... :D :scared:
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 :)
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I have been using hard rock maple rift sawn for some time now.
good stuff
Nice project.
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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... :laughing: 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.
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:archer2:
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Very interesting Kenny. I'm surprised walnut isn't more popular as core material.
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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? :)
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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. :)
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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.
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I did this test for myself on static tips.
http://tradgang.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=125;t=012157#000000
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Mtw is the very best but I can't source it. Some guy in PA bought it up.
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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.
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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..?
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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...
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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.
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Originally posted by kennym:
I talked to a good bowyer this morning and he got me thinking.... :D :scared:
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 :)
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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.
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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.
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:knothead:
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I saw something similar done comparing wood lams to foam. The foam hung like a wet noodle.
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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 )
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I talked to a good bowyer this morning and he got me thinking....
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
>>>>>--------------------->
The yardstick I was using was in 1/16" inc. so I added a plus or minus if above or below the 1/16" measure. So the maple bent less and the hickory was lighter . Maybe it should have been -7/8".
Or maybe should have done in 1/1000 " I have a dial indicator but it is an inch job.
Seems to be a correlation in weight vs stiffness of lams in general but some just seem to fail in both and need to be veneers.....
Should have done a bocote lam and some glass for fun...
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Also, I took and relisted from lightest to heaviest.
Now, delete any woods that are both heavier and deflect same amount or more than any previous wood.
This leaves only two woods.....walnut and hickory.
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I get it now!!!
So hickory was 29/32 and maple was 27/32.
That means maple would be back on the list lol
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I'd say maple and hickory are real close, the hickory bent roughly a 1/16 more than maple and the maple is 1.5 grains heavier. (now let the hickory lay around a week cut in lams and draw moisture and the maple would be in front :D )
Do the math on the weight / deflection and tell me!! :laughing:
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For now, Im sticking with walnut. Seems smooth and quiet. :)
But I also haven't finished Avery's maple cored bow. ;)
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I like walnut, in this test it is less than an 1/8 more deflection and 7.2 grains lighter.
It seems to make a quiet bow too. Don't know how it would but to me it does. Let me know what you think when you get hers done!
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Maple is a proven core wood... I have heard that even though hickory can make a fast bow it does not fare as well as maple in the long run... What say Yee'all???
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I think walnut would be ok in edge grain. I know that it soaks a lot of glue.
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Hard Rock Maple Rift sawn.
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Bamboo...............
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Mongolian tulip wood... :laughing:
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Hey Kenny,
Been doin a little research on bow woods. I noticed you used honey locust in your test, but black locust seems to have a much better weight to flex ratio.
Can you source black locust?
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Actually I have some real nice black locust in the back of shop, been there for 4 years !
And some sassafrass I think!!
Forgot about it and never got it on my site yet!
Thanks for the reminder.... :)
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Originally posted by kennym:
Actually I have some real nice black locust in the back of shop, been there for 4 years !
And some sassafrass I think!!
Forgot about it and never got it on my site yet!
Thanks for the reminder.... :)
Uhhhhh.......You're welcome :readit:
And by not selling it all before I can convince the wife that I need another bow. Lol
Who knows, they may even beat out MTW???
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I have a bunch of Mongolian Tulip wood.
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Originally posted by Roy from Pa:
I have a bunch of Mongolian Tulip wood.
I figured you used all your stash for making thumping sticks.
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Hey Kenny, if you do update this list with black locust and possibly sassafrass (and maybe Mongolian Tulip wood? =D ), would you care to run some black cherry through the test? I'd be very interested to see how cherry does.