Author Topic: bamboo/cane spine questions  (Read 5608 times)

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Offline osage outlaw

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bamboo/cane spine questions
« on: March 06, 2011, 01:32:31 pm »
I recently made a spine tester and have been testing all of the rivercane and lowes' bamboo I have collected during the last year and I have a few questions.

1.  When I collected the rivercane, I collected some of the immature shoots thinking they were closer to the size that I needed.  I let them dry and cut them 3/8" at the bottom and 31" long.  Almost all of them spined really weak, 30-40 lbs or so.  I only had one spine over 50 lbs.  If I would have collected mature plants, would they have spined higher?  And is there a certain time of year that is better for cutting it?

2.  The bamboo that I bought at Lowes seems to be much better than the cane that I have.  It spines higher and is a lot smaller diameter.  It also has fewer and smaller nodes.  I should be able to make arrows with only 2 nodes on them.  Is this common?  Besides being free and collecting it yourself, is there any reason to use rivercane over the bamboo?

3.  Spine testers are set up for 26" apart.  What if I want to cut arrows down to 25"?  Lets say I spine an arrow out at 50 lbs and I cut it down to 25",   what would the spine be then?

4.  If an arrow spines higher on one side than the other, which side do you put towards the bow?

5.  Is there any way to reduce the spine of a cane or bamboo shaft?

Thanks for any help
I started out with nothin' and I still got most of it left

Offline Pat B

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Re: bamboo/cane spine questions
« Reply #1 on: March 06, 2011, 02:59:10 pm »
Mature cane(2nd year growth or older) have thicker walls thus are more rigid.
You want your cane shafts to spine heavier than your bow. You can reduce the effective spine weight by up to 10# because of the natural taper of the cane. Also for each inch over 28" you can reduce the spine by 5# per inch and the reverse for each inch under 28". You can reduce the spine weight of a cane arrow by sanding the shaft but the easiest way is to cut them long.  I draw 26" but cut my cane and hardwood shoots 29" so for a 60# spined arrow 75# cane arrows work well for me...but I very rarely spine test cane or hardwood shoot arrows except to find the stiff side.
  You will want to place the stiffest spined side against the bow.
  Cane is great for arrows. No matter if they are Martha's store bought garden cane or river cane, hill cane switch cane, Tonkin cane, Jap arrow cane or whatever you can get. They all make great arrows. I personally like to collect everything I can. Money is harder for me to come by than arrow making materials.
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline CherokeeKC

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Re: bamboo/cane spine questions
« Reply #2 on: March 06, 2011, 03:03:08 pm »
1.  Yes you want to get at least second year growth.  To test if its first year I just grab the plant and test its "flimsiness" by bending a little.  You can feel if its stiff second year or flimsy first year.
2.  Im not sure.  lol
3.  I think you add 5 pounds per inch for every inch under?  But let someone else confirm.
4.  You want the stiff side towards the bow riser.
5.  I have never done this but have heard that people scrape the middle of the shaft just like with shoot shafts to decrease spine.
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Offline CherokeeKC

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Re: bamboo/cane spine questions
« Reply #3 on: March 06, 2011, 03:04:22 pm »
Oh sorry if there are repeats.  Pat B replied while I was typing mine.  :)
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Offline NTD

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Re: bamboo/cane spine questions
« Reply #4 on: March 06, 2011, 03:05:34 pm »
Yep, Pat covered most of it. 

The stuff you get at lowes is Tonkin Cane. 

You can also reduce weight by adding heavier points.  You will effectively reduce the spine by 5# for every 25grains over 125 gr.  I like Pat's mention about longer arrows to reduce spine but found myself getting into trouble having other people (Newbs) shoot my bows.  They would attempt to draw the whole length of those longer arrows.  So I try to keep my arrows as close to the intended draw length as possible. 

Here is a Thread where Chris Cade, Cane Arrow making extraordinaire, explains spine in cane arrows.
http://www.primitivearcher.com/smf/index.php/topic,18488.0.html
Nate Danforth

Offline osage outlaw

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Re: bamboo/cane spine questions
« Reply #5 on: March 06, 2011, 08:20:38 pm »
Thanks for the help.  I bought a pack of bamboo from Home Depot last night for $3.  I cut them and spined them today and ended up with 69, 59, 52, 46, 37, 37, and 27.  Now if I can figure out how to straighten them.  I've been working on it, I can get them close, but not perfectly straight.  Any tips on that?
I started out with nothin' and I still got most of it left

Offline Pat B

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Re: bamboo/cane spine questions
« Reply #6 on: March 06, 2011, 08:52:44 pm »
I don't know if your spine values will be accurate after straightening. The heat will temper the cand and should stiffen it.
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline osage outlaw

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Re: bamboo/cane spine questions
« Reply #7 on: March 06, 2011, 09:24:57 pm »
I was planning on spining them again after they were straight and then cutting them to the proper length.  I spined them now so I coule sort out some that are near my target weight. 
I started out with nothin' and I still got most of it left

Offline hillbilly61

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Re: bamboo/cane spine questions
« Reply #8 on: March 06, 2011, 11:50:35 pm »
 I'd like to know also about the straightness. I can get mine very close, but never perfectly straight. Heating and rolling the nodes help me the best to get them that close.
I will say of the Lord,"He is my refuge and my fortress;
  My God, in Him I will trust."  Psalm 91:2

Offline Pat B

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Re: bamboo/cane spine questions
« Reply #9 on: March 07, 2011, 01:13:00 am »
I never get my cane arrows perfectly straight. Once I straighten them I add the point(field point, trade or stone point or commercial points) and if I can get the arrow to spin true it is good to go. I spin the arrow on my finger tip or the palm of my hand. If I feel a wobble I readjust the point until it spins true. If I can't get it to spin true I go back to the heat and straighten a bit more.
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline hillbilly61

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Re: bamboo/cane spine questions
« Reply #10 on: March 07, 2011, 08:51:49 am »
Thanks Pat. I've been spinning mine ( just like I did alum ones) That makes me feel better ;D
I will say of the Lord,"He is my refuge and my fortress;
  My God, in Him I will trust."  Psalm 91:2