The rose (something new under the sun)

[zuma]

Dear friends


The rose

New geometries in splitcane building we see not often. Most of it is already invented. The most used geometry is traditionally the hexagon. Other shapes, like Quads, Pentas and Oktas are known since long time.

In addition to the blank forms are also the hollow builts in recent years more and more established in splitcane building
A hollowbuilt, regardless of the selected geometry is lighter and livelier in action. However, one finds both the hollowbuilt, as well as for the massive construction arguments for their respective properties. A massively built rod is probably heavier, but this weight may be just a very positive impact on the casting characteristics of a rod. When the mass of the blank weight is set in motion, the fly line casts almost independently.

But for Rose:
The rose is a new formed blank construction, very interesting for two-handed rods, and there especially for Speycaster.
The result is the rose as an advancement of our 13-strip split cane, which we construct since 2003. On the occasion of the rodbuildersmeeting 2006 in Sarnen (Switzerland), we presented the geometry of the 13-strip split cane in a 6 sided hollow construction:



This blank form that we developed is now being implemented by several rods builders all over the world successfully. The blanks are characterized by a silky smooth, but allways lively action and are a real asset in the blank geometry.
This has motivated us to experiment further and thereby meet the demands of modern Speycasting needs. The resulting blank geometry we call a rose:



In this design are 36 splices installed in hollow construction.
The manufacturing work is correspondingly high, must still be made for a 3-piece rod not less than 108 splices and processed for the blank. For making the hand and the middle part it is reasonably comfortable. In the top part, the diameter of each splice is only 0.30 mm.


Following some impressions from one of two finished rods:







Thanks for your interest!

Many greetings from Switzerland
Kurt

ps: Sorry for my bad english!

[jan96]

Kurt, this is not "normal"!! How did you get the idea of such a complicated construction? Just to make something different or are there any significant advantages over "normal" construction? Are the tips made in the same way?

r

[RyanAK]

Something new under the sun indeed! Impressive Kurt! I, for one, would be interested in any information you could share with the forum.

R

[Isonychia]

I would guess, since the "rose" arrangement essentially creates a fluted rod, it would have the effect of stiffening the blank considerably. Manufacturers of match-grade rifle barrels cut flutes into them to reduce weight while retaining stiffness.

It looks as if you're really onto something, Kurt!

John

[Turkish]

I think if the fluting does in fact increase the rigidity of the rod it would make sense to use this construction for much longer 2 handed rods. Interesting.

[paramiyuki]

It is a wonderful idea.

[skipscratch]

This "Rose" geometry seems to have alot going for it at first glance. In comparing the standard hex it has many small strips all made from the very outer area of the cane wall - so very high power fiber concentration configured in many dimensions throughout a cross section.

First guess would be that a rod built to around the same dimensions as a hex would be alot stiffer.
Kurt can you comment?

Would I be correct in saying that because of some of the very small tip strips required it would not be possible to make this Rose configuration in say a 7 foot 5 weight for instance?

wow kurt, bravo!

[CaneCaster]

What is the lightest line you have designed these spey rods to cast successfully? 34 grams or so? (scnadinavian shooting head style)

What glue are you using for these rods? I would imagine that the glue used has a significant effect on the rods feel since there is a greater ratio of glue to cane that other composite cane geometries (24 separate gluing surfaces?).

What is the smallest effective tip diameter you can successfully build with this geometry?
I am understanding you correctly here "In the top part, the diameter of each splice is only 0.30 mm" 0.30mm is equal to about .012"..... is that the wall thickness of the bamboo in the tip section?

Very interesting design, very labor intensive too. I would love to cast one!

Can you give some specifics about the 2 handed rod pictured above? such as Length, Line Wt, Static weight of the rod itself?

Where's Lee Koch when you need him? I am sure he could speak to this design as well.

[Lee Koch]

WOW! The only thing I could add is that Kurt must be crazy (in a good way)!

I learned about tri-hex construction (or EVO 2 as Kurt and Philippe call it) after seeing Kurt's drawing of the original 13-strip geometry. It's more trouble to make a tri-hex than it is making a regular hex rod, and the Rose design uses 6 tri-hexes. Jeez! Glue-up must occur in 2 phases: build each of the 6 tri-hexes, then glue 6 tri-hexes into the rose.

The Rose has to be incredibly strong for its weight. The observations about being all power fibers, and a high proportion of glue in the rod, are surely both correct. The challenge surely is in the tip, where measurements get VERY small. It looks like the flat-to-flat dimension of the rose is 8 times the thickness of each strip. If the smallest strip is 12 thou, then the tip must be about .100 across.

Think about planing strips down to 12 thou. I can't do it; can't get anywhere near that. Even if I could, imagine gluing up those tiny strips, and holding the geometry in place as you glue up. If you were planning to make a trout rod with this geometry, say with a 60 thou tip, each strip would have to be around 8 thou. No wonder Kurt says it's a geometry for spey, etc!

Lastly, the outside flutes must create some interesting challenges as a person wraps guides onto the rod.

Kudos to kurt!

Lee

[CaneCaster]

8 tho is a bamboo fart

Thanx for posting Lee, I never even thought about wrapping guides on the rod. I do plan on one of these days attempting the Evo 2/Tri-Hex construction on a spey rod.... I may want to pick your brain about things a bit when the time comes Lee. I cannot even image the tiny strips you are planing for trout rods now.

[Jaimec]

Kurt,

That's awesome. Does it work/cast well?

PM sent.

[zuma]

Gentlemen

Thank you for your kind words!
I try to answer on the questions, but i have a lot of problems to find the correct words in English (I learned my bad english not in the school, no i learned it by my clients as a flyfishing guide):

The tips are made in the same geometry and the way to make this construction is perfect explained from Lee Koch – thanks Lee!
I use a 2-K Epoxy glue from the aviation technology. This glue is liquid like water. To make a tip section of this geometry you need a glue like water.
The hand and the middle section are hollow all over the blank. I used a cord inside of every of the 6 Evo/Tri-hex strips and remove the cord at the end of the gluing process. Unfortunately it was not possible to draw out a thread from the top parts. So, the tip section is only hollow in the middle.

You are right, the features are the combination of lightness, stiffness, and the properties of the glue
It is possible to make a rod in 7, to 8 foot 5 weight – but gluing up the tip section is no fun. So I think it is better to make more heavier rods.
My self, I am not a two hand caster. Normally I use rods in 6 foot 3 weight. I have only a 7 wt one hand line to test the lighter of the two rods. I arrived to cast from 5 meters line outside of the tip ring, in one cast to 15 – 20 meters without problems. I am sure that a real two hand caster make 30 meters in one cast. The basic taper comes from Hoergaard and the rod load deep – no tip action!

To make the guide wraps, it is no problem. The problem is more the varnish. I have not varnished this rods my self. The varnish is a sprayed 2-K PU, made by a body shop.

The Grip is made from birch bark and so the weight of the rod is a little bit heavier to a cork handle. But the weight is into the hand section and the rods feel good in hand.

I think the lighter rod is for line class 6/7 and the heavier is for line class 9/10.
Will try to make more photos this weekend.

Thanks a lot for your comments and your interest.

Best regards
Kurt

[RyanAK]

Kurt - your English is excellent! Thanks for the explanation! A few follow up questions:

1. When designing the taper, is there any conversion needed for the Rose geometry? Or is the flat-to-flat dimension the same for a rod with conventional construction?

2. For trout rods, I would imagine that a Rose butt and mid could be combined with a 'normal' hollowbuilt tip. Ever try this?

3. Uh, guides would be low on my worry list. How about ferrules?

Again, very impressive.

(Am I missing something, or is there no spellcheck on this editor?)

Best,
Ryan

[bamann345]

That is one impressive rod. Glue up in one of the steps I hate, so I can’t image gluing 6 tri-hexs together and then gluing these into the Rose! Man, I would give up. However, I am very interested in how the tapers are designed, etc.

Again, I echo what everyone else has state, WOW!

William

[Idahoan]

WOW! I think I just peed a little. I'm going to have visions of grandiousity now.

I WANT ONE!

[Larry Swearingen]

It would seem to me that you are giving up outside powerfibers
at the extreme corners of the glued up blank and moving those
powerfibers to the interior of the section where they don't contribute
as much to the stiffness of the section. In essence you are defeating
the purpose of Hollow building.
I don't see the purpose of the labor.
I could be wrong but I don't think so.

Larry Swearingen
Fort Wayne, IN
http://planingforms.webs.com

[skipscratch]

larry wrote: "giving up outside powerfibers
at the extreme corners of the glued up blank and moving those
powerfibers to the interior of the section where they don't contribute
as much to the stiffness of the section. In essence you are defeating
the purpose of Hollow building"

if you look at the profile of the cross section in post number 1 you see that extreme corner that is being given up is a really a very little piece of corner.

The rod is still hollow but instead of having internal walls composed of weak pith the internal walls are right to the core made of much stronger power fibers and some glue. I wish I could do the math to analyize this structure strength, but me thinks with all the bracing with power fibered walls between hollowed areas and assuming the glue does not introduce a weakness it would be signficantly stronger/stiffer than a "equivalent" hollowed hex rod.

[HexaMaineiac]

We're not worthy, we're not worthy...

Kurt that is an amazing feat of patience and engineering. Hat's off to you sir.

Henry.

[Lee Koch]

Larry, I suspect you are wrong. I can't prove it, and I'm not sure anyone will until someone makes a couple test rods to see for sure. But here's something to think about:

I accept the engineering idea that more bamboo farther away from the center line will make a rod stiffer. Thus, moving bamboo from the outside to the inside must decrease stiffness. But how much? The "missing corner bamboo" in each of the outside flutes that you mention represents the area of 2 of the little triangles. The Rose design has the same cross-sectional area as 72 of the little triangles. So the "missing bamboo" (or more specifically, the bamboo that you say was moved from the outside to the inside, represents 17% of the mass (12/72). How much stiffness is lost if 17% of the mass is moved from the outside to 2/3 of the way in to the center? I have no idea, but I have to think that it isn't a 100% loss of that 17%. Maybe half? Let's go with that for now. A loss of 8.5% stiffness for having moved that bamboo "inside".

On the other hand, I'm pretty sure there are some things about the rose design that add stiffness. As Skipscratch notes, the internal bracing, or buttressing, has to increase stiffness. The Rose design makes me think of flying buttresses, which created that same web pattern in order to increase stiffness per weight. How much? I look to the engineers to answer. In particular, the 6 double-wide radii which are in fact 2 trapezoidal strips glued back to back have to increase the stiffness as compared to a hollow rod, or even a star-cut hollowed rod. I can tell you, from having made several tri-hexes now, that those large trapezoidal strips are TOUGH - they do not want to flex left to right. ( It's the same principal as bending a 2X2, compared to a 2X4 (along the 2-inch axis).) And 4 of the 6 radii are being asked to flex left-to-right (at a 60 degree angle) as the rod is cast. They resist that.

Overall, the Rose has a very high proportion of dense power fibers. How much stronger are the top 30 or 40 thou of bamboo power fibers as compared to the fibers 100 thou into the culm? I don't know, but from the strips I've broken, I believe that they are noticeably stronger.

Glue: comparing the Rose to a hollow hex of the same flat-to-flat dimensions, where, let's say, half the height of each triangle is removed to hollow the hex, and, for simplicity, let's say there are no dams. The simple hollow hex has the advantage you cited of having more bamboo out on the corners, to aid in stiffness. But I think the Rose design has 4 times the glued surface, compared to the simple hollowed hex. Even if you figure that the regular hollow hex has dams that have glued surface for 25% of the interior cavity, the ratio is still 3:1. I don't know Kurt's glue, but most 2-part glues make rods stiffer than do air-cured glues like Titebond. I think it's pretty well accepted, for example, that URAC and Resorcinol make for stiffer rods, all things being equal, than does Titebond. So I'll guess that the glue he uses is a stiffening glue. Having 4 times the glued surface area will make a rod noticeably stiffer.

OK, so will the added effects of more glued surface, more power fibers, and buttressing, outweigh the loss of "outside corner" power fibers, which I assumed above to be maybe 8.5%? My answer is Yes. Someone else will have to "prove" it.

What remains to be shown is that building 6 tri-hexes and gluing them into a Rose design is "worth the effort." Commercially, I have my doubts, even if a person had access to a CNC mill. But just in terms of inventing stuff, seeing if it can be done, and seeing what it turns out to be, well my hat is off to Kurt.

Lee

[fishbum]

Larry is correct.

Everything removed reduces the stiffness of the section. Using the Parallel Axis theorem those portions removed are a negative term. The stiffness of the portions removed are (d^2A +I)where d is the distance from the neutral axis of the section(large enclosing hex) A is the area of the part removed from the outside corner and I is the the second moment of area of the part that is removed. In other words the change in stiffness is proportional to the square of the distance from the neutral axis to the centroid multiplied by the area of the part removed plus the local second moment of area of the par removed.

Just my humble opinion for what it is worth.