Why opt for a penta or quad?

Re: Why opt for a penta or quad?

feeds@yuku.com (senior) — Sat, 16 Aug 2008 15:47:10 GMT

I remember one major penta manufacturer as stating that their cane was harvested only from hilltop locations , where it was normal for the wind to blow in from different directions every day,thus developing the power fibers in a uniform way. I.E. the fibers were both stretched and compressed equally in incremental time and stress frames . Is this an engineering factor ,(or quality control ) rather than a marketing ploy ?

Re: Why opt for a penta or quad?

feeds@yuku.com (czkid) — Thu, 14 Aug 2008 10:45:55 GMT

From the purely sensual aspect of fishing vs. figuring out how to correctly build a rod, I must say there is quite a difference between the three x-sections characteristics.

I've got experience in many hex rods; quads by Edwards, Nunley, Mallucci, and others; and pentas by Wire, Uslan, and Beasley. And most fortunately, most of them were in the same length, line weight rating.

Firstly, I'd have to say that I've enjoyed the vast majority of all of them...

Re: Why opt for a penta or quad?

feeds@yuku.com (fishbum) — Thu, 14 Aug 2008 09:47:24 GMT

David

Like I said, there are trade-offs. You have chosen the ones you like and that is fine. I hope you enjoy your new rod from Jerry.

I am going fishing!

fishbum

Re: Why opt for a penta or quad?

feeds@yuku.com (David Dornblaser) — Thu, 14 Aug 2008 09:40:08 GMT

rdsphoto wrote:
f

David Dornblazer - I have not had the pleasure of a Bob Clay rod but you should be quite happy with your Kustich he definitely seems to understand the design.

rdsphoto - I am really happy with my current Kustich penta. The one that Jerry is working on is a new taper based on our conversations, he calls it the Dornblaser-4, probably to...

Re: Why opt for a penta or quad?

feeds@yuku.com (fishbum) — Thu, 14 Aug 2008 08:31:56 GMT

Thank you Ralph.

Great example of a dynamic system and the challange of dealing with the many variables that go along with analysing a dynamic system.

Rob
I have pointed you to the tools to understand and to prove to yourself what these stresses are. Stress is as relevent to a fly rod as it is to a bridge or a building. Fly rod design is a bunch of trade-offs. You have to decide for yourself what to trade. In the penta vs hex debate there is a small gain in stiffness...

Re: Why opt for a penta or quad?

feeds@yuku.com (czkid) — Thu, 14 Aug 2008 07:52:58 GMT

Folks, as an ageing Aerospace Engineer (read Rocket Scientist), I must remind you that most of the work done on fly rod loading was calculated as a static load. Dynamic loads are FAR, FAR different and generally worse. Dynamic loading considers the object under discussion in what would be a more realistic situation, and takes into consideration things such as rate of load application, frequency of the the applied load, etc. etc. Dynamic calculations are exceedingly complex, even for...

Re: Why opt for a penta or quad?

feeds@yuku.com (rdsphoto) — Thu, 14 Aug 2008 01:24:32 GMT

fishbum- Do you consider a flexed rod in motion and under the effect of the line while casing to be a static load? Wouldn't 220,000 lbs per sq inch be relative to the section points volume of fibre?? and is there any test data supporting this quantitative summation??? - from my experiences it seems totally irrelevant to the actual loads or stress values that a well designed bamboo fly rod performs under. I do agree with your comment that "Both the Proportional Limit and the Modulus...

Re: Why opt for a penta or quad?

feeds@yuku.com (fishbum) — Wed, 13 Aug 2008 23:35:24 GMT

David:

We should be designing our fly rods with some safety factor so the operating range is well below a level where failure will occur. It matters not what the rod geometry is if you exceed the maximum stress that your rod can withstand it is going to suffer damage. It don't matter how that level is exceeded whether by the tail gate of the truck, by trying to horse a big fish or the ceiling fan in the hotel room if you exceed that level you have a damaged rod. The narrower the...

Re: Why opt for a penta or quad?

feeds@yuku.com (David Dornblaser) — Wed, 13 Aug 2008 21:28:04 GMT

fishbum,

Interesting post, it does raise a question - are the stresses that would break a penta, hex, or, quad anywhere near normal fly fishing stresses? I have not heard of anyone having a problem with a quad/penta configured rod. If Bob Clay can make a hollow-built penta endure the powerful torque generated with a spey rod doing a spey cast, I am not going to worry about my 4 & 5 wts. I really have enjoyed my current penta and I look forward to the one Jerry Kustich is working...

Re: Why opt for a penta or quad?

feeds@yuku.com (fishbum) — Wed, 13 Aug 2008 11:20:17 GMT

Sorry about the messed up font in my reply above. It all looked so good when I put it together. It looks like I am yelling and I am not. I tried to fix it but it still looks like crap.

fishbum

Re: Why opt for a penta or quad?

feeds@yuku.com (gooseberryrods) — Wed, 13 Aug 2008 11:01:40 GMT

So if Garrison and Fishbum are correct, wouldn't it stand to reason that rods with an unequal number of strips would weaken or become soft over time? There are those on this board who have been looking for anecdotal evidence of broken pentas, but is the real issue that these rods could be more prone to becoming soft rather than breaking? Anyone have this experience with pentas?

Re: Why opt for a penta or quad?

feeds@yuku.com (fishbum) — Wed, 13 Aug 2008 10:21:34 GMT

Rob:

A few short answers to your questions. We have already sorta hijacked Bob's thread by moving towards a technical discussion of beams.

Re: Why opt for a penta or quad?

feeds@yuku.com (rdsphoto) — Wed, 13 Aug 2008 00:37:41 GMT

fishbum - What is the maximum stress that the bamboo can withstand then? Are you referring to shear strength of the joint?? Please explain. Furthermore please define the neutral center of the flexed rod and how you quantify it - thanks!
Best Regards, Rob

Re: Why opt for a penta or quad?

feeds@yuku.com (fishbum) — Tue, 12 Aug 2008 23:56:56 GMT

The glue isn't the weakness in the penta design or any design using an odd number of strips. It is the apex oppisite the guide flat being so far from the neutral center. This has the effect of reducing the safety margin in the stress department. By operating closer to the maximum stress the bamboo can withstand you run a greater risk of exceeding that maximum stress.

fishbum

Re: Why opt for a penta or quad?

feeds@yuku.com (Piglegs) — Tue, 12 Aug 2008 17:08:56 GMT

One thing that has occured to me since I first mentioned the Garrison article in this thread is that the glue which he used might not have been so good as our modern ones - perhaps with the passage of time his findings on the Penta design have been made redundant by new glue? After all, the practical findings of the forum members so far don't appear to bear out his theoretical findings on the penta design.

Re: Why opt for a penta or quad?

feeds@yuku.com (David Dornblaser) — Tue, 12 Aug 2008 13:35:45 GMT

I have a friend who has one of Bob Clay's cane spey rods. I spoke with Bob today about his River series Spey rods, http://www.riverwatchrods.com/rods.html , which he makes in both hex and penta configurations, both hollow-built. I asked him about the strength of the penta rods and he said that he has not had one break and that is with big BC steelhead and having a spey rod load the rod faster than the single-handed rod....

Re: Why opt for a penta or quad?

feeds@yuku.com (rdsphoto) — Sat, 09 Aug 2008 13:45:00 GMT

From my experiences with a rod built as a hex and a rod built as a penta - both with the same Rate of Change and volume of bamboo in the taper -the Penta rod was about a half line weight stronger than the hex. Unfortunately I do not have any direct experience with finished quads to hex's or penta's other than a quad taper that I converted to the modified Pentalux design (quad strip with guides on it braced by two hex shaped 60 degree strips with two penta shaped strips on top) - as it...

Re: Why opt for a penta or quad?

feeds@yuku.com (bobbeegee) — Fri, 08 Aug 2008 10:09:03 GMT

Sounds like a new thread to me.

Bob

Re: Why opt for a penta or quad?

feeds@yuku.com (David Dornblaser) — Thu, 07 Aug 2008 21:27:34 GMT

Thanks Chris. I know that you fish for big Alaska 'bows, salmon and steelhead with pentas. Have you fished saltwater with one of your pentas?

If I can go back to the original question of this thread; and, let me ask it a little differently: does choosing a quad, penta, or hex configuration change the casting or fish fighting characteristics of a rod of the same taper, length; and, line weight? (assuming that you can something approaching the same taper across the three...

Re: Why opt for a penta or quad?

feeds@yuku.com (ArcticCane) — Thu, 07 Aug 2008 18:57:30 GMT

Unfortunately David, it wasn't all that technical. I simply grabbed a couple sections and started to bend them until they would break. I tried it with my hands tighter and farther apart but I don't have any measurements on how much force it took to break.

From breaking hex and quad sections as well I would guess that it took less force to get the penta apex to pop than it took for a hex or quad to break. That is mostly a hunch and partly has to do with having to...

Why opt for a penta or quad?

feeds@yuku.com (bobbeegee) — Fri, 01 Aug 2008 17:48:18 GMT

Again, just curious.

What are the advantages of a penta or quad constructed rod?
Are they somehow better than the standard hex?
Won't the hex accomplish any cast required in the hands of a good angler?
I will admit they are interesting to read and learn about, but I really don't see the need other than being
a different means to the same end.

I'm not disparaging them, I'm just curious as to why you would invest in and fish one when a...