In some descriptions the demand of the line following the blank in a nice smooth arc must be met. Is there a way to quantify this? Perhaps: The angle between the line entering an eye and the line leaving the eye must be at leats 170 degrees?

Karel

Line should ROUGHLY follow the Blank in the same arch Without to many flat spots

You are correct in looking at the anglethe line forms as it enters and leaves the guide. You want to have this be as close to 180 as possible. The smaller the angle gets, the more pressure that is put on that guide trying to pull it off the blank.

Angles closer to 150 degrees would be more realistic.

The angle will vary with the rod's action (taper), the amount of deflection, and the position of the guide in question.

Any angles approaching about 120-135 degrees would be cause for adding another guide, IMO.

Too severe an arc may be more likely to cause blank fatigue and failure, than it is to cause the loosening of the guide from its wrap, IMO. -Cliff Hall-

Wow, just got a brain wave! Isn't it so that the angle at each guide should be equal (where have i heard that before?) and that when bending the rod to an angle of 90 degrees (when you have 10 guides, so 9 angles) each angle should be 180 - (90/9) = 170 degrees?
Hmm, have to work this one out a bit further. I don't like to bend a blank, without ferrules being wrapped, to 90 degrees. Also 10 guides on a 6 foot rod is a bit too much. I think bending a bit less, let's say until 30 degrees and then trying to get an angle of 180 - (30/9) = about 177degrees at each guide might also do the trick all be it a bit less accurate. This combined with "number of guides = length in foot +1" might be a workable solution for me, don't you think?

Thanks,
Karel

BTW i'm building a rodbuilding site in Dutch (there isn't one). If you want to take a look (and understand dutch), the address is www.karelgol.tk
Tom, if i'm not allowed to post this address (it's a non-commercial site, as i am a non-commercial rodbuilder) please remove the line above or give me a notice and i'll remove it.



Edited 1 time(s). Last edit at 04/06/2005 09:44AM by Karel Gol.

Karel,

You would be supprised that 10 guides would not be too much for that rod. I was shown I believe an 8 foot rod once that had 16 guides on it. People who saw it also thought there were too many guides on it until they tried casting the rod. It performed wonderfully. I know for myself, I try to make the line angle as close to 180 as possible. With using smaller lighter guides, adding more to the rod to keep the angle close to 180 does not hurt rod performance from what I have seen.

Hey Karel,

Your equation would clearly be OK if the blank were uniform, by which I mean that it flexed equally under load from tip to butt. Whereas blanks like that may exist, I doubt we'd like to fish with them. I'm not sure it would work for actual fishing rods.

Because blanks flex asymmetrically, as well as the fact that we have some interest in placing guides near / on ferrules, I think it is unlikely that we could aim for identical anglees at each guide. Thinking about my own rods, even under some serious load the blank bends more per guide throgh the mid section than right in the butt (by eyeball).

Check out the static guide article on this site (shich I just tried for the first time) which discusses three different loads to place guides in different sections of the blank (those that flex under the load).

mark

Some recent testing that I have done suggests that each additional small #6 guide on a 9 foot medium Steelhead rod drops the resonant frequency between 6% and 7%. This drop in resonant frequency means that with a couple of extra guides the finished rod will be on the order of 15% less efficient and therefore less sensitive and will cast on the order of 15% shorter of require that much more force to cast any given distance. These same guides would naturally have less effect on a more powerful rod but would have even more effect on a less powerful rod.
As far as the angle is concerned, if the guides are placed on the blank properly consistance with the blanks natural curve, as the angle decreases there is more force on the rod at that point but the stress on the blank will increase as the distance between guides increases or decrease as the distance between guides decreases. The amount of increase or decrease will be approximately in proportion to distance of the increase of decrease. For, example if the distance between two guides increases by 10% the stress on the rod between the two guides will increase about 10%.
In my judgement, this argues for not using any more guides than absolutely necessary on any rod that will be used to cast with.

OK, i forgot the 3 different loads on the rod from the static test. So i think this also covers
-quote-
Angles closer to 150 degrees would be more realistic.

The angle will vary with the rod's action (taper), the amount of deflection, and the position of the guide in question.

Any angles approaching about 120-135 degrees would be cause for adding another guide, IMO.

Too severe an arc may be more likely to cause blank fatigue and failure, than it is to cause the loosening of the guide from its wrap, IMO. -Cliff Hall-
-unquote-
So for each load situation i would have to aim for 150 degrees. Aiming for 160 would probably cause another eye(perhaps two) to be necessary. So may i conclude that it's a matter of experience at which angle you aim, which works best for you? And then of course, at which angles do you aim?

Karel

Karel Gol - Let's take a step back from the question of line angles in the Static Deflection Test for a moment and take a look at the bigger picture. Let's remember that using too few guides may cause the rod to break. Using too many guides of excessive mass may reduce casting distance and seriously decrease the rod's sensitivity and casting efficiency.

The Static Deflection Test is only one of several systems for deciding the number of guides to use on a rod and how far apart to place those guides. A Casting Test would be another (often done after the load test). A guide sizing and preliminary placement scheme (like the Concept System for spinning rods or one of the Spiral methods for conventional rods) may be the first step for many builders. Fly rods are very different from trolling rods, etc., and your own priorities for function and performance have to be considered.

Just keep in mind what your fishing rod needs to be able to do well:
- CAST the bait or lure the required distance to reach the fish.
- PRESENT & WORK the bait or lure to attract a strike.
- FIGHT A FISH in a way that ensures success for the angler.
- PERFORM with an OVERALL SENSE of satisfaction and sport.
These criteria are the primary consideration; the actual line at the guide is secondary; so long as the load is smoothly distributed and the rod casts well and the line does not rub over the blank when deeply flexed.

Save the serious geometry for roof truss design. You may only drive yourself "batty" (crazy) if you try too strictly to adhere to some formula for the line angle at any given guide under load. Remember Emory's caution that adding mass to the rod (with more guides) changes the rod's "feel". And remember Sledden's advice to use more guides that are very light to achieve a smoother load / line distribution as needed.

Best Wishes, Karel. This is design by a synergy of considerations, not the achievement or discovery of some innate perfection. -Cliff Hall, Florida-U.S.A.

Woops! - Mr. Fussy left out an important word at the end of Paragraph #3: "ANGLE"

"These criteria are the primary consideration; the actual line ANGLE at the guide is secondary; so long as the load is smoothly distributed and the rod casts well and the line does not rub over the blank when deeply flexed."

"See ya later, Alligator, ... in a while, Crocodile, ..." -Cliff Hall, FL-U.S.A.-

Emory, that is very interesting. I'm assuming you're talking about guides located near the tip--isn't it right that these guides will have the largest effect on RF?

I've long harbored the suspicion that Fuji's "New Concept" system is part physics and part marketing. Yes, the SMALLER and lighter guides really do make the rod more efficient, even though the 'cone of flight' isn't as direct as the traditional setup. But the claim that MORE guides also contribute to the improved casting/sensitivity always seemed a bit like a marketing ploy to compensate for the smaller profits from smaller guides. My last few rods have had a 'traditional' number of New Concept-sized guides, and seem to cast and fight fish as well as any others I've built.

I was just looking for an easy, measurable way to get to a satisfying guide placement. As a teacher in technology i like to measure things instead of looking and guessing. I'm only concerned for guide placement on fly rods, so the line touching the blank is not a concern for me blank. Sorry, have to go, my pupils are calling.

Karel

Tom,
Yes, you are right. The weight of the guide has a great deal more effect as you get closer and closer to the tip of the rod. As near as I can tell from the research that has been done that I am familiar with, a given amount of weight will have logarithmically more effect as it is added closer and closer to the tip.

I share your suspicion about the Concept System. I think that the primary advantage that it has is that it can permit the use of smaller lighter guides. But if you add more guides so that their weight equals the weight of the cone of flight method then it seems to me you have thrown away its major advantage. More guides will more uniformly distribute the stress but I do not see any reason why the Concept System requires any more guides toward the tip than the cone of flight does in terms of the stress distribution

Emory,
Exactly. As far as I know, inadequate stress distribution wasn't a big problem with the earlier cone of flight method--it's not like rods were breaking left and right. The arguments for the New Concept system centered on sensitivity and an increase in casting distance, not support for the rod when fighting fish. Correct me I'm wrong, but most rods break due to abuse (especially high-sticking), not because they have too few guides. I even have a 9 foot surf rod I built and love that has only 5 guides, and both casts and fights fish beautifully.

Tom,
I agree with you that most rods are broken by either high sticking or by impact, hitting them on something. But rods can certainly be broken by over stressing them and the farther apart the guides are the higher the stress will be. But I agree with what you are implying that the Concept System as layed out by Fuji suggests too many guides. I am a fan of the Concept System in principal because it permits smaller and lighter weight guides particularly close to the tip. But if you increase the number of guides to the point that they weigh as much as the guides in the cone of flight system then I do not see how the Concept System buys you anything. The casting distance will not be higher and the efficiency, sensitivity, will not be higher. I do not see any reason why more guides are required with the Concept System then are required with cone of flight. The stress on the rod is a function of how many guides or actually the distance between guides. If you can use the same number of guides with the Concept System but they are smaller and therefore lighter than with the cone of flight, now you have bought something, higher efficiency, better sensitivity, and longer casts or less effort far any given distance you cast.