I have read (not necessarily understood) Cliff Hall’s posts on mathematical guide spacing and Emory Harry’s articles on rod blank characteristics, and just can’t help but think that mathematics - the universal language - has some merit in guide spacing.

It would seem to me that a blank of a given length, with a certain ERN and Action Angle, there should be a specific guide spacing that is optimum for that combination. If there were two 9’ blanks with an ERN of 5.50 and an AA of 60 (moderate), I would think the guide spacing for these two blanks would be identical - replies from knowledgeable people only please!

And before anyone shoots this down, does anyone have historical data of guide spacing based on length, ERN, and AA on the rods they‘ve built? It would be interesting to see the relationship of guide spacing based on same length blanks with various AA (and ERN). I can’t help but think if we take six 9’ blanks with AA’s of 60, 62, 64, 66, 68, & 70, a pattern could be established and MATHEMATICAL spacing formulas could be calculated or a chart could be developed. It just makes sense that a particular blank should fall into a “category”, and that category should contain specific guide spacings (and guide sizes) based on the blank’s length, ERN, and Action Angle - yeah or nay?

Tim -

Yes your idea would work, in a rough way. But the problem comes down to that, AA and ERN are basically averages over the blank (which is what you want those measurments to be). Where as guide placement is fairly specific to an area on the blank.

2 blanks with the same ERN and AA can have different tapers (stouter butt section, more flexible tip) therefor different optimal guide spacing. Most of the blanks would have the same spacing, but a few could be considerably off.

What you would get would not really be any better than a manufacturers guide placement chart. My advice would be follow the static guide placement test, which I usually use a formula or manufacturer's guide placement chart as a starting point.

Christian

Not to mention that line size and type, reel size and type, also play major roles in guide sizing and placement.

Mathematical formulas could still work, but not those that currently exist. They simply do not take into account all the various factors that play a role in good guide sizing and placement. It would be nice to simply be able to plug some numbers into a formula of sorts and have it spit out the guide sizes and placement that would be optimum for any particular rod. But you'd have to plug in one heck of a lot of numbers.

What I like to call "interactive" methods, seem to take into account more of these various factors and allow you to quickly bring them into play in determining optimum guide sizing and placement. The only downside is that you do have to familiarize yourself with one of these methods and have some understanding of what you're trying to achieve. But frankly, it's not that hard to do.

...................

I guess I'm not very "knowledgable" but why rack your brain with these numbers and formulas when the interactive methods produce the most accurate results? But what the hey, I'm not very "knowledgable" anyway.

I'll stick with a "common sense" system based on what has been learned by others, whether it applies to my application of fishing, or what I may learn from test casting......................tommorow, lines will get smaller, reels will get better, artificials will be more realistic.....things will change. Formulas can and will be changed. The only reason I even say this is that a "formula" I once swore by ......is now obsolete and junk!!!! compared to todays "newer" products and ideas.....I custom rod is THAT much better if you combine sci"ence" and common "sense" on a rod, based on the information available ,and maybe a little practical creativity on your own.

Preach on brother Mike...


Andy Dear
Lamar Manf.

Tim,
I think that is a really interesting idea. As others have stated there have been a number of equations developed but none that I have seen took into account the different characteristics of a given blank. A model based upon the Common Sense measurements of a particular blank would, in my judgment ,do a much better job than the equations I have previously seen and I think could do a better job than any of the manufacturers recommended guide placement charts. It could even have guide size recommendations based upon both power and action angle.
For most rod builders to use it though I think that it would have to be a piece of software that they could load into their PC and then enter the CCS variables into because the math is not going to be trivial.
However, I am not sure that it would be a major improvement over the static placement method that also allows a little bit of human judgment into the equation. But it is an interesting and thought provoking idea.

"Guides & guide spacing are a lot like religion. Some folks like it this way, some folks like it that way, almost everybody has at least a little, some have way too much, and a few have none at all. By starting a discussion on guides, anyone's strongly held position is likely to violate the fundamental beliefs of at least three other sects. Trying to determine truth in matters of faith will lead to mayhem and bloodshed. However, if we could all drop our guard for a day, admit that we are first and foremost devotees of the List, then we could have a nice ecumenical discussion on guides before reconvening later armed for battle."

RUSS GOODING: [www.goldenwitch.com]
[www.bamboorodmaking.com]

I just got home from a friend's home. A few glasses of wine, some Russian food, Mexican Tres Leches cake, some more wine and good conversation and I come home to this discussion. In my drunken stupor I can not figure out if the discussion is about some unproven equation that Einstein left us or a Thomas Aquinus theory of religion. Seriously, I try to keep my rod building as simple as I can.

IMO, an empirical correlation between rod taper and guide spacing could be used to generate a modified geometric progression spacing formula that gives a good "fit" (correlation coefficient) to the data. But it would take the guide layouts from dozens of rods with very similar characteristics to develop a database that has statistical significance, with respect to making valid generalizations and to developing reliable formulas / equations. Without a large enough set of data, further progress would be hindered.

There would still be the opinion that every rod and spine is a little different. Developing and using such mathematical formulas would probably be of interest to only ~ 20% of the rod-builders anyway. ... It's not that it can't be done. It's just that it is too easy to use other (interactive) methods for guide spacing that are far less complicated than some formulas, and yet yield consistently satisfying results. ... This is very much a "to each his own" subject.

I have had contact with ~ half a dozen rod-builders who use various mathematical formulas to arrive at a FIRST APPROXIMATION for their guide spacing. Some tweak the formulas; some tweak again during the Static test. But all recognize that these formulas have a narrow / specific application, and that that range of utility has to be respected. ...

Happy Thanksgiving. -Cliff Hall, Gainesville, FL-USA+++

Consider:
GUIDE SPACING FORMULAS –
How & Why They DO & DON'T Work
Cliff Hall 640 VIEWS 26 REPLIES 10-20-05 05:44
[www.rodbuilding.org]

GEOMETRIC-PROGRESSIVE Spacing-Distance Formula:
S(N) = [N * T] + [N * (N-1) / 2] * D

I think if I added anything that may one day make a useful contribution to this subject, it is the modification of the formula to make the (N-1) factor into an (N-X) factor, where X = the number of guides in the tip section that you decide should have equal interval spacing. [ If (N-X) < Zero, then Set S(N) = N*T ]

And I think it is useful to introduce the idea that this " D " parameter should be considered like a "rate of expansion", or "rate of increase" of the spacing interval. Several rod-builders used a percentage rate of increase to calculate the next interval, and that worked to simplify the math and yield similar, if not identical, results to the more elaborate and explicit form of the equation. And they selected that percentage rate of increase based on their experience, the number of guides used, and repeated application of their methodology.

The value of D could be chosen explicitly by the rod builder, as well as calculated by setting S(N) = B, and solving for D. Also, D could also be correlated to the rod taper, such that larger values of D are for faster tapers, and smaller values of D are for slower tapers. But D could also be affected enough by the rod-builder's choice for guide style and sizes that suggesting too strong a correlation between D and rod taper may blind us from seeing a more significant relationship of D with other variables.

I recently began to consider that the use of a feathering finger applied to the fishing line as it leaves the spool lip during the cast of a fixed-spool spinning rod could have a significant affect on guide placement. It certainly reduces line slap, and may affect the placement of the butt guide. This feathering can have as much affect on line flow as guide placement, while only reducing casting distance ~ 5%.

Add how feathering can transform almost any guide placement method into a better guide layout scheme, and then the Static Deflection Test begins to emerge as the main and final determinant of guide placement. And I would dare declare that no equation, however carefully contrived, could compare to bending the rod to see how it will behave and where the guides need to go in their FINAL placement. ...

IMO, Cliff Hall+++



Edited 3 time(s). Last edit at 11/23/2005 01:35AM by Cliff Hall.

Does it really matter if we have some crazy formula to tell us where to put guides. We all start at the same place, a blank, some tape, a few guides, and what we think is one good eye. Everything we do is subjective, there is no science, no formula to tell us what to do. If there was a formula for everything, we could kiss our "custom rodbuilding" booties good bye. That's my two cents, now let's keep it real, that's why we all post here to share ideas. I don't think a formula is liberating, it's restricting. That's just my feeling and does not reflect the others that respond upon this board. Thank you , Bryan.

All that said -- I still like the KISS method

Cliff,

You're still leaving out many of the factors that would determine optimum guide sizing and placement, unless I've skipped over something in your post. What about reel spool size and line diameter?

I also believe that a mathematical formula could be developed to do this sort of thing, but it would have to include all the major factors that play into good sizing or placement or it won't really do anything that other formulas aren't already doing.

I also believe that our interactive methods are getting so good and easy, that there is not nearly as incentive as their once was for developing a new type of mathematical formula for doing the same thing.

...........

This comment does not qualify as comming from a "knowledgeable" theoretician. But - Why has no one considered entering the numerical values for the force vectors created and applied at the center of gravity of each guide location equal to the mass of the guide frame, ring, thread and finish. Law of the Bayou - Rod Wiggle > Weight of Stuff < Builders Savvy. > directly proportional, < inversly proportional.

While I am at it I will ask the question that has been bugging me - The CC system, in its intended form, normally is applied to blanks prior to building for comparative purposes and I can understand that OK - how many people have performed the test after build to see how much impact their building practices alter the conditions?

Jesse - Lance - Looks like the Post and Picket Slide Rules may be coming back!

Gon



Edited 1 time(s). Last edit at 11/23/2005 09:29AM by Bill Stevens.

That's a good idea, particularly if you use the CCF to see any effective change in the area of blank to rod efficiency. The AA won't change, and unless you use terribly heavy guides or far too many guides, the ERN will only drop by a small amount. But the CCF is the one reading that will readily unveil any major (or minor) changes in rod performance. There will always be some - you degrade performance as soon as you glue on the tip-top, but you're looking to change the naked blank's efficiency by as little as possible. The CCF will readily record the amount of change.

............

Hello to all and a big note of "Thanks" and respect for everyone's Replies to Tim Collins' Post, and for your comments about my (our) attempts to improve on formula methods for guide spacing.

All of you are correct, and have added some very important comments about the shortcomings of guide spacing formulas, and of how formulas can be a nuisance to use, if not more trouble than they are worth. But my contention is, and will remain, that improvements come from attempts at improvement. Improvements do not occur spontaneously, or without effort or collective consultation. And so to that end, I have engaged in Tim Collins discussion. I hope it was not another groaner.

And now I am off to partake in my own religion, to Give Thanks to my Great God & Saviour for the many blessings in my life and family, and for our great USA. May yours be a wonderful holiday filled with the same.

Sealed with a "KISS", -Cliff Hall+++, Gainesville, FL-USA

I was afraid I wouldn't be able to convey my thoughts on this correctly as is evident by some of the responses. Not so much on the mathematical equation side, my thoughts were more along the lines of analyzing previous guide spacing data from blanks of known length, ERN, and Action Angle and see if there's any correlation in respect to guide spaing.

It seems odd that we have a CC database where we can input the blank manufacture, the model, it's length, ERN and Action Angle and then just stop right there without including the guide spacings found to be optimum for that particular blank.

Tim Collins - I think you are especially right and insightful with that comment. But it will take a lot of cooperation and willingness to share on the part of lots of rod-builders to transform that idea into action. In brief, it simply seems that the incentives and / or willlingness to cooperate are just not there.

Spacing data seems to be somewhere between as freely shared as the air we all breath, to as zealously guarded as proprietary information. I have my own theories on why, but they are better left aside for now. It's just, it seems, the way it is.

My apologies, Tim, if my responses seemed to lead your Discussion astray. Happy Thanksgiving, Cliff Hall+++

If someone is not sleeping tonight and pondering these concepts - remember one of the most important variables when the blanks is loaded is the velocity factor. The kinetic energy possessed by a guide at any particular location is impacted by the mass of the guide and the square of the velocity. A guy whipping the tar on a spinning rod develops a lot higher instantaneous tip velocity that a person sweeping a casting rod during the casting motion.

I will be sleeping soundly pondering a plate full of boudin and stuffed mirlitons with shrimp and crabmeat. Who and where is Penn State?

Happy Thanksgiving

Gon Fishn

Tim,
I think that your basic thought of using the CCS measurements, along with other variables, in a model for guide spacing and poitioning is a good one but I am not sure that you will get the optimum spacing by using some sort of an average of all the spacings that others have used. Some, hopefully not too many, are going to use guides that you will judge to be too large and heavy for the application, others, again hopefully not too many, will use too many guides and therefore again add too much weight. I know that I have looked closely at a rod built by a well respected rod builder that posts often on another site and I thought that he had used so many guides on the rod that he had turned the rod into a club. It would not take many like this to really skew your data and give you less than optimum results.