The rose (something new under the sun)

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skipscratch
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Re: The rose (something new under the sun)

#21

Post by skipscratch »

what happens to stiffness when you remove a weak material (pith) and replace it with a strong material (power fiber & glue) ?

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Lee Koch
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Re: The rose (something new under the sun)

#22

Post by Lee Koch »

I have to admit Jerry that I am uneducated enough not to understand 80% of what you wrote. But among the 20% I understood, I didn't see anything that addressed the countervaling effects of increased glued surface, powerfiber density and buttressing. Are they non-issues?

Lee

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fishbum
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Re: The rose (something new under the sun)

#23

Post by fishbum »

Lee Koch wrote:I have to admit Jerry that I am uneducated enough not to understand 80% of what you wrote. But among the 20% I understood, I didn't see anything that addressed the countervaling effects of increased glued surface, powerfiber density and buttressing. Are they non-issues?

Lee
Yep, pretty much a non-issue.

Stiffness is a function of the second moment of area (area moment of inertia) I, a property of the geometry and Modulus of Elasticity E, a property of the material.

Variation in Modulus of Elasticity is somewhat constant to a depth of about 0.080" on a culm. We can only guess what it is in the sections shown since it varies from culm to culm, position around the culm and from end to end on a culm. Since we are talking about the geometry of the section in this post it is probably best to ignore the Modulus of Elasticity and concentrate on the second Moment of Area to describe the changes to stiffness caused by the hollow parts.

The glue is only important if we know the sheer properties as it effects creep between the individual pieces of bamboo. If you laminate a few pieces of bamboo and then measure the resulting Modulus of Elasticity of the resultant beam the sheer properties of the glue will be part of the MOE. Stiffer glue (Urac) will result in the MOE being greater than if a softer glue (Titebond) is used.

So, in a nutshell, a non-issue.

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TimM
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Re: The rose (something new under the sun)

#24

Post by TimM »

Hi Kurt,

First off thanks for posting your design. It is something different and the shape is really quite beautiful. It reminds me of cookies.

A few questions - I see you've built each strip from the outer layer of the culm to maximize the power fiber usage. Have you considered other orientations?

The strips at the center of the rod will be quite heavy but (due to their proximity to the neutral axis) will not add significantly to the stiffness. The same goes for the inside of the 12 "spoke" pieces. Here is what I would try:

1. Inside "small" 6 strips - Make with the lightest pith you feel comfortable using and turn the strip upside down so the "better" fibers are to the outside of the rod.
2. Middle 12 "big" spoke strips - Cut the bamboo perpendicular to the culm surface and assemble with power fibers to the outside of the rod.
3. Outer 18 strips - Keep "as is" with maximum power fiber usage and best fibers to the outside.

You would have to modify the taper to increase the tip size (give the number of strips I'm guessing that is a good thing) but with the reduced mass I think the mid section dimensions would be roughly equal and the butt would be reduced for an overall reduction in rod mass.

Does this make sense? If not please let me know and I will create a diagram.

-Tim

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Lee Koch
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Re: The rose (something new under the sun)

#25

Post by Lee Koch »

Thanks for the reply, Jerry! (I understood it!)

Lee

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Moucheur
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Re: The rose (something new under the sun)

#26

Post by Moucheur »

New, and a thing of beauty.

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Paul B
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Re: The rose (something new under the sun)

#27

Post by Paul B »

Marvellous workmanship Zuma but I really think you should be seeking help ;)

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zuma
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Re: The rose (something new under the sun)

#28

Post by zuma »

Gentlemen,

Thanks for your kind replies. There are a lot of good ideas to try - and the result is much more work. In the following some technical informations and a few more photos:

Image

1. Rod (the upper one on the picture)

Lenght: 387 cm
Lineclass: 11/12
Weight: 787 Gramm
(The handle is from Birch bark and the endcap from massiv NS)

2. Rod

Lenght: 373 cm
Lineclass: 8/9
Weight: 480 Gramm
(The handle is also from Birch bark)

Image

Image

Image

Image

Image

All the best and many greetings from switzerland
Kurt

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jhcoffeebum
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Re: The rose (something new under the sun)

#29

Post by jhcoffeebum »

zuma wrote:Gentlemen,

Thanks for your kind replies. There are a lot of good ideas to try - and the result is much more work. In the following some technical informations and a few more photos:

Image

1. Rod (the upper one on the picture)

Lenght: 387 cm
Lineclass: 11/12
Weight: 787 Gramm
(The handle is from Birch bark and the endcap from massiv NS)

2. Rod

Lenght: 373 cm
Lineclass: 8/9
Weight: 480 Gramm
(The handle is also from Birch bark)

Image

Image

Image

Image

Image

All the best and many greetings from switzerland
Kurt
Wow! er ah, wow! I have to agree We are not worthy, We are not worthy! Great workmanship, your rods will be apart of bamboo rod history for sure.
Jack

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PaducahMichael
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Re: The rose (something new under the sun)

#30

Post by PaducahMichael »

I'm not smart enough to understand - much less spell - the geometry involved in this unique rod. All I can say is that it is VERY cool and while I may not understand it I certainly recognize amount of thought, care and talent that goes into making this rod.

Other than that, I just don't have the words to express my admiration for this lovely design. Makes me wish I needed a spey rod.

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RWHoffhines
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Re: The rose (something new under the sun)

#31

Post by RWHoffhines »

the splendid engineering aside:


MMMMM...Belgian waffles...

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piscator
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Re: The rose (something new under the sun)

#32

Post by piscator »

Hi Kurt et al., despite the extravagant design and the wonderful craftmanship I have one concern with the wraps. On all other rod-profiles the curvature of the blank-surface is the same; here, it chances sign and there must be hollow tubes underneath the wraps. These may be filled with varnish, but will eventually lead to cracks in the wraps -- just my feeling. Juergen

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Re: The rose (something new under the sun)

#33

Post by macknnc »

Not a scientist, nor do I play one on the internet..(nor o TV) and very defintely not a mathematician..my algebra one teacher in high school thought so highly of me that she had me back the next year in the same class...but I do have, I think, a valid question..

up in the 'fishing with bamboo' forum, I put up a thread dealing with the length of the rod, bemoaning the modern preference (or so it seemed to me) for the shorter rods..it accomplished nothing,nor did I expect it to since it is largely a matter of personal likes and dislikes.. but some of those who prefer shorter rods did mention the lighter weight

These 'rose' rods would seem, even hollow built, to be much heavier than a hex...though I accept your arguements about the usefulness in the spey rod and their stiffness..(heavy lines, and salt water anybody?)

And they seem like they would be a real pain to build...though if I could afford a new rod or two, I'd be asking you to build me spey...14 ft for number 10 line and a nine footer for 6 or 7...

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