Mulberry core question?
Hello, this is my second attempt at asiatic compoite bows. I am starting on two bows, one has a hickory core and I'm thinking about use mulberry for the core on the other one. My question is can the core have more than one growth ring in it or does it need to be one unviolated growth ring in the bending section? I would like some opinions on how good mulberry is for a core wood in a highly reflexed bow, what have your experiences been with it? Riley
For Chinese bows, mulberry is the classic core material (note: not for the siyahs, though). Mulberry was a valuable crop tree so I speculate that they were only cut down for lumber when they were quite mature. I don't know the answer on the number of growth rings; the main concern should be the absence of knots and evenness of the grain along the working limbs.
All dependence how part of your mulberry you use- radial or horizontal. And how thick was rings. If you use horizontal rings(like selfbow) and if rings was very thick(0,5-0,7 cm) one ring is good. Anyway your started working thick is about 1 cm .
just out of curiosity, is Osage close enough to Chinese Mulberry to be used in its place?
Osage is certainly widely used for self and sinew-backed bows. I don't know if anyone is using it for horn bow cores. Jack Farrell will know.
Some people do it. But i think that Osage is too haevy wod for composite. Mulberry and Osage is close in botanic sense , but very dificult in machanical characteristic.
I used osage once and it worked fine, although I had some sinew separations, probably because the wood is oily or resinous and shoud be well prepared for the glue (like yew).
As to the "too heavy" wood: if you plan a flight bow, perhaps then this may become a consideration. For a normal bow you will not see any differences in cast, unless the siyahs are made too big with the heavy woods. Although the wood grain should be paraller for the best characteristics (shear and tensile/compressive) there is no need to have one growth ring in the bending section. Note the grain of core is severely violated on the back of the composites at the grip and elsewhere with no ill effects.
Adam
As to the "too heavy" wood: if you plan a flight bow, perhaps then this may become a consideration. For a normal bow you will not see any differences in cast, unless the siyahs are made too big with the heavy woods. Although the wood grain should be paraller for the best characteristics (shear and tensile/compressive) there is no need to have one growth ring in the bending section. Note the grain of core is severely violated on the back of the composites at the grip and elsewhere with no ill effects.
Adam
Adam ,I learn too much from your book.and thank you very much. I have uesd banboo(cut in winter),mulberry(cut the tree by myself ) and maples(buy end product).
I feel banboo is better ,tough , light and good recover. maples is lighter than mulberry . hornbow made of wood is more distort than bamboo.
if same lengh，same shape and same pull weight ,I feel wood bow will thicker than banboo.
I feel banboo is better ,tough , light and good recover. maples is lighter than mulberry . hornbow made of wood is more distort than bamboo.
if same lengh，same shape and same pull weight ,I feel wood bow will thicker than banboo.
Yes bluesky, you are right about the wood: sal's core material with a greater modulus (stiffness) will make the bow a little heavier in weight. However, since most stresses are taken up by sinew and horn, the differences in draw weight will be very small - I would be surprised to see more than 5%, given the relatively small differences in stiffness for the woods and bamboo. Even then, for such a test to be meaningful, one would have to make both bows absolutely exactly the same (down to 0.1 mm) everywhere along the length and measure all components like that. In practice this would be nearly impossible to do. At the same time the properties of horn and sinew would have to be identical etc.
One will see more diffences if the core and horn thicknesses are varied. Thicker horn = more resilient/less string follow, thicker core wood/bamboo = more stability. I suppose if the core is exceptionally resilient, one can have both the resiliency and the stability in the same bow.
So, again, I would not worry about the choice of wood in the bending section too much, only about the mass of the siyahs for an average bowyer, who rarly makes more than a few bows. The mass of siyahs is the overriding factor for the cast.
Adam
One will see more diffences if the core and horn thicknesses are varied. Thicker horn = more resilient/less string follow, thicker core wood/bamboo = more stability. I suppose if the core is exceptionally resilient, one can have both the resiliency and the stability in the same bow.
So, again, I would not worry about the choice of wood in the bending section too much, only about the mass of the siyahs for an average bowyer, who rarly makes more than a few bows. The mass of siyahs is the overriding factor for the cast.
Adam
learn a lot of again :P
I'll try to decrease the mass of bow .I have used orange's wood for siyahs,it's very good ,light and hard .
Natural material is so unstable , sinew wood bamboo horn all have good and bad .must choose carefuly :? .
I'll try to decrease the mass of bow .I have used orange's wood for siyahs,it's very good ,light and hard .
Natural material is so unstable , sinew wood bamboo horn all have good and bad .must choose carefuly :? .
Thanks eveyone for the replies. The growth rings in the mulberry are about 1/8 of an inch thick. I'm thinking about using hickory for the bow core instead of mulberry. I've got some straight grained hickory and a piece of red maple (soft maple) has anyone used either of these two woods? I'll probably have more questions and I'll post some pics.
i know bluesky79 spend more than 1500$ buy the stuff in many years,buy stuff like gambling and arms race, if you has no experience you need pray good luck and you can know don't choose like this, a way of money spread it !
the tree growth very fast in warm and demp south china, the result is wood is very soft , you can your nail make a indentation on wood, or very easy cut or you can draw the wood fiber more easy than sinew strings, but lost wood in south china is very straight no like some north china wood has twist grain, i see some Russia wood ring very average on each year growth, but south china tree not like that,
i agree adam if add some condition that 5% differences of wood as a core x%differences of glue give the effect of speed will be right ,i am not ask what condition need but i want ask how much money adam spend for buy the stuff in years
the tree growth very fast in warm and demp south china, the result is wood is very soft , you can your nail make a indentation on wood, or very easy cut or you can draw the wood fiber more easy than sinew strings, but lost wood in south china is very straight no like some north china wood has twist grain, i see some Russia wood ring very average on each year growth, but south china tree not like that,
i agree adam if add some condition that 5% differences of wood as a core x%differences of glue give the effect of speed will be right ,i am not ask what condition need but i want ask how much money adam spend for buy the stuff in years
"how much money adam spend for buy the stuff in years" - too much! Mostly on horn, glue and the decorations. I live in the country and have wood and sinew for free.
As to the wood: I have not used red maple, but it may be ok for sub-60lb bows. I know of one bowyer who used hickory with good success.
Adam
As to the wood: I have not used red maple, but it may be ok for sub-60lb bows. I know of one bowyer who used hickory with good success.
Adam
Adam, I'm very glad you spent all that money, that enabled you to write your book, now myself and many others can save lots of money experimenting- thank you
the comrade Adam has greet contribute for Comintern :)
in canada cut a tree can be free and legal cut ?
in canada cut a tree can be free and legal cut ?