Bamboo shafts
All,(Particularly Jack Farrell)
I previously inquired in the Technique section,with ultimately not an answer I could use in it's current form. the discussion was derailed by Orda's assertion that bamboo shafts are not splined. the seller on Ebay lists a spline,so presumably he splines them(Orda's experience is clearly different from mine) the range is rather large,and he seems to imply that it isn't as important as with wooden shafts,which you corroborated. You listed an appropriate weight. can you hazard a guess as to what difference the length will make? (35")also I would be using plastic nocks, and 125g field points.(I can see that will be a heavier tip than one of those light-weight crimp on tips) I would appreciate any advice, from yourself or others.
Boghadair
I previously inquired in the Technique section,with ultimately not an answer I could use in it's current form. the discussion was derailed by Orda's assertion that bamboo shafts are not splined. the seller on Ebay lists a spline,so presumably he splines them(Orda's experience is clearly different from mine) the range is rather large,and he seems to imply that it isn't as important as with wooden shafts,which you corroborated. You listed an appropriate weight. can you hazard a guess as to what difference the length will make? (35")also I would be using plastic nocks, and 125g field points.(I can see that will be a heavier tip than one of those light-weight crimp on tips) I would appreciate any advice, from yourself or others.
Boghadair
You can easily spine test bamboo shafts. I have some old bamboo shafts from Japan that despite their small diameter are very stiff (suitable for a ninety pound bow at 28 inches with a three finger draw). The arrow shaft is 38 inches long and would make 36 inch arrows.
If a seller decides to do this, you have to translate his stiffness measurement to your style of shooting and draw length. this is not necessarily easy.
Spine is the combination of the effects of stiffness, draw length and bow weight. It is a measure of the compatibility of an arrow with a bow. In the days when all bows were the same, it was a more valuable measurement than it is now. Its relevance depends on how you shoot and what your bow performs like. Knowing the stiffness of a shaft and how your bow shoots an arrow of that stiffness is helpful.
If a seller decides to do this, you have to translate his stiffness measurement to your style of shooting and draw length. this is not necessarily easy.
Spine is the combination of the effects of stiffness, draw length and bow weight. It is a measure of the compatibility of an arrow with a bow. In the days when all bows were the same, it was a more valuable measurement than it is now. Its relevance depends on how you shoot and what your bow performs like. Knowing the stiffness of a shaft and how your bow shoots an arrow of that stiffness is helpful.
Ok back to bamboo shafts. There are several factors in play.
The species of bamboo takes some experience to determine. Japanese and Korean fletchers use species of Pseudosasa which have an eye above the node (sheath scar). A long tapering groove like the tail of a comet usually extends upward from the eye. Grooves do not disrupt the roundness of the shaft. The overall shaft tapers neatly through the nodes. Some rare and coveted shafts have no taper over the shaft length.
These bamboos are excellent quality in select diameters and can be made to pass the spin test. The relative weight indicates accurately the spine, spine which is the stiffness of the shaft. SHAFTS ARE MATCHED BY WEIGHT AND NODE PLACEMENT.
By moving the orientation of the eyes and placement of the nodes around on a spine tester many different spine readings can be produced. Therefore spine testing is not such a good indicator.
You might use gardening bamboos which might be described as Mountain bamboos from China. These bamboos taper greatly to the node and again increase in diameter and taper to the next. They have eyes but minimal to non existent grooves. This is the correct species for Mughal arrows. If the internode tapering is extreme, they are not good. The overall shafts may be smaller diameter than Pseudosasas of the same weight. Arrows of this species will only spin test at certain places along the shaft.
Arundinarias are also very stout but have grooves so prominent that they can disrupt the roundness of the shaft.
An important thing to remember is that the strongest wood lays nearest to the surface so removing wood to attain straightness is dangerous. Selecting for ideal shafting is the solution.
Because of long processing time, these arrows are ideal for target shooting. Sorry for the long post. Jack
The species of bamboo takes some experience to determine. Japanese and Korean fletchers use species of Pseudosasa which have an eye above the node (sheath scar). A long tapering groove like the tail of a comet usually extends upward from the eye. Grooves do not disrupt the roundness of the shaft. The overall shaft tapers neatly through the nodes. Some rare and coveted shafts have no taper over the shaft length.
These bamboos are excellent quality in select diameters and can be made to pass the spin test. The relative weight indicates accurately the spine, spine which is the stiffness of the shaft. SHAFTS ARE MATCHED BY WEIGHT AND NODE PLACEMENT.
By moving the orientation of the eyes and placement of the nodes around on a spine tester many different spine readings can be produced. Therefore spine testing is not such a good indicator.
You might use gardening bamboos which might be described as Mountain bamboos from China. These bamboos taper greatly to the node and again increase in diameter and taper to the next. They have eyes but minimal to non existent grooves. This is the correct species for Mughal arrows. If the internode tapering is extreme, they are not good. The overall shafts may be smaller diameter than Pseudosasas of the same weight. Arrows of this species will only spin test at certain places along the shaft.
Arundinarias are also very stout but have grooves so prominent that they can disrupt the roundness of the shaft.
An important thing to remember is that the strongest wood lays nearest to the surface so removing wood to attain straightness is dangerous. Selecting for ideal shafting is the solution.
Because of long processing time, these arrows are ideal for target shooting. Sorry for the long post. Jack
Thanks Jack for the informative post. Now I am tempted to try the bamboo shafting more seriously. My experience in making arrows is limited.
Historically, the wooden shafts (not bamboo) were also selected by weight however. A heavier shaft would be used with a heavier bow. If the material is homogenous enough and the shaft is matched by length, then the greater weight means the greater thickness and the higher spine. Unless the bamboo shafts are more consistent material-wise, then I think the custom of weight-matching for bamboo is just the tradition, not related to any special properties of bamboo vs wood. Does it make sense? Has anyone actually tested how consistent is bamboo in the diameter vs spine?
Adam
Historically, the wooden shafts (not bamboo) were also selected by weight however. A heavier shaft would be used with a heavier bow. If the material is homogenous enough and the shaft is matched by length, then the greater weight means the greater thickness and the higher spine. Unless the bamboo shafts are more consistent material-wise, then I think the custom of weight-matching for bamboo is just the tradition, not related to any special properties of bamboo vs wood. Does it make sense? Has anyone actually tested how consistent is bamboo in the diameter vs spine?
Adam
There is not a exact linear relationship between diameter and spine. Some special shafts (within one group of species, in a garden for instance) will be thinner but stouter than larger shafts.
One comes to think of how compact the material is.
For instance, when one handles dry shafts and one comes to a one year old shaft. This shaft is the same size, diameter, taper and quite like three year old shafts. But it is immediately apparent that the shaft weighs only half that of a mature shaft.
The variation within groups of mature shafts is also quite amazing. A gram/grain scale is a necessary tool.
It is also true that a bamboo arrow perfect for a fifty pound bow will also work for a sixty pound bow though maybe not be ideal.
Bows over forty pounds; align the fletch node to the axis of the string. -j-
One comes to think of how compact the material is.
For instance, when one handles dry shafts and one comes to a one year old shaft. This shaft is the same size, diameter, taper and quite like three year old shafts. But it is immediately apparent that the shaft weighs only half that of a mature shaft.
The variation within groups of mature shafts is also quite amazing. A gram/grain scale is a necessary tool.
It is also true that a bamboo arrow perfect for a fifty pound bow will also work for a sixty pound bow though maybe not be ideal.
Bows over forty pounds; align the fletch node to the axis of the string. -j-
Fletch node?
Lucas; My arrow lay out starts with a node 7-8 inches from the nock. Koreans and Japanese call this the fletch node.
Adair; 125 grain point is excessive and spine will suffer especially with an excessive length of 35". Why degrade a piece of art with plastic nocks? Go Asian traditional.
Make one arrow and see how it works. There is not just one answer. -j-
Adair; 125 grain point is excessive and spine will suffer especially with an excessive length of 35". Why degrade a piece of art with plastic nocks? Go Asian traditional.
Make one arrow and see how it works. There is not just one answer. -j-
Buy horn nocks from jaap koppedrayer, they are durable and beautiful!!! I love horn nocks because I always used to break my previous wood nocks from my other arrows, so I switched to horn nocks.
But what do you mean by aligning the node with the string?
If you were to hold your bow vertically, the fletch node would point straight up or straight down, ie. aligned with the axis of the string.
Jack,
35" excessive length? maybe I can do 34" but 33" has the tip resting on my thumb knuckle,which just makes me nervous, and my shoulders will let me draw a bit farther,in the Khalka style.
I know plastic nocks are lazy, but I do not have a big workshop,living in an apartment, 14th floor.
what points/type would you recommend instead of 125grain field tips?
Thanks for all the in-put
Boghadair
35" excessive length? maybe I can do 34" but 33" has the tip resting on my thumb knuckle,which just makes me nervous, and my shoulders will let me draw a bit farther,in the Khalka style.
I know plastic nocks are lazy, but I do not have a big workshop,living in an apartment, 14th floor.
what points/type would you recommend instead of 125grain field tips?
Thanks for all the in-put
Boghadair
By excessive length, Jack is referring to the arrow length/point weight, not your draw length. The heavier the point, the more the arrow flexes and a long arrow will flex more than a short one. I would be inclined to try something around 60 grains.
Rather than use plastic nocks, why don't you cut self nocks? (It would probably be easier anyway unless you have insert type nocks.) Just use some twine to lash the area in front of the nock.
Rather than use plastic nocks, why don't you cut self nocks? (It would probably be easier anyway unless you have insert type nocks.) Just use some twine to lash the area in front of the nock.
Buy some horn nocks, or make some dogwood nock inserts, it doesnt take any fancy equipment, just a steady hand and some files, and sandpaper, and a knife to wittle the wood.
Jack,orda,Lucas,Adam,Bede,Everybody :-)
thanks for the insights. I'm looking at the shafts on Ebay, all from the same seller.
As I mentioned, my current shafts are Port Orford Cedar, 32", 55-60#(at 28"-I know that's standard) spine. my bows are all about 40# at 32". the arrows all tend to stick with the nocks angled a bit to the right side. 125gr. field points. the bow handles are about 1-1.25" wide.
I know it's not exact science,but would you all care to hazard a guess as to whether my current arrows might be over or under-spined? I hate to bother anyone,but I can't just get 1 shaft from that supplier to try them out. He is listing some 100cm shafts 80-85#, I'm wondering if they would work well,or be too stiff,at 35" or so.(the ebay post says they are 8-11mm. dia
Thanks,
Boghadair
thanks for the insights. I'm looking at the shafts on Ebay, all from the same seller.
As I mentioned, my current shafts are Port Orford Cedar, 32", 55-60#(at 28"-I know that's standard) spine. my bows are all about 40# at 32". the arrows all tend to stick with the nocks angled a bit to the right side. 125gr. field points. the bow handles are about 1-1.25" wide.
I know it's not exact science,but would you all care to hazard a guess as to whether my current arrows might be over or under-spined? I hate to bother anyone,but I can't just get 1 shaft from that supplier to try them out. He is listing some 100cm shafts 80-85#, I'm wondering if they would work well,or be too stiff,at 35" or so.(the ebay post says they are 8-11mm. dia
Thanks,
Boghadair