Mathematical modeling and pure science of lure design

[goldenshinner]

No offense to the elders and Founders(i have massive respect) but Some of this age old testing and Tweeking with endless unknown failures in lure building seems wastefull. It seems we should be advanced enough to at least roughly model lure design using pure mathematics. I know there are design groups out there that have developed such basic formulas for Computer aided design. Anyone have any sharable formulas in the aid of lure design. Im interested in modeling lure shape size relations to lip size shape and possibly add in varriables of weight. or better yet is anyone developing a shareware of such a thing. this would cut wasted Development time down, and would be verry usefull in predicting absolute optimal designs.

[longball]

Didn't Vodkaman try this at one time? I think that there are too many variables eventhough there are guidelines. Not a science.

[BobP]

You're right about the time, effort and failures it takes to prototype crankbaits using typical methods. It can be frustrating. But I would argue that it isn't wasteful but a valuable part of learning the craft. Eventually, you get a feel for what works. As to a pure mathematical approach, I'd welcome one if it yielded reliable build specs. I'm certainly no mathematician but I'm doubtful because we're talking about complex hydrodynamic modeling. If you find one that a monkey (me) can use, let me know!

[LaPala]

Can u mathematically model why a fish will eat your lure or mathematically derive a profile and action that will guarantee strikes?

Even with CAD, it aids rapid prototyping; end of the day, you still need countless hrs on the water to know if the design works and refine the prototype.

[Travis]

Companies say yes. Custom lure builders say no. No winning this arguement, lol.

[Vodkaman]

Goldenshinner, great question. When I started this hobby half a year ago, I asked the same question myself. With no response that satisfied me, I set myself a set of aims or ambitions. I find it easier to stick to these aims if I tell everyone about them. This was a mistake, as I realise now that many TU members have devoted their lives to this recreation.

I announced to the world that I am an engineer who has never fished a crank and bragged that I was going to solve all the crank enigmas, write formulae for everything and change the industry. This naive approach upset a lot of members, in fact, the administration had to shut down one thread because it got so heated. If any of those members are still simmering, please accept my belated apologies. Fortunately, the system crash a few months ago wiped out this embarrassing history, so don’t bother searching for it.

So, what did I calculate? After dragging a few sticks through the water, I realised that their was more to this crank thing than meets the eye. The first thing to do was to establish what was going on from an engineering view, what was happening to make the lure move like it does. My aeronautical background led me to investigate turbulence. After a few web searches on turbulence, this exposed vortices as an entire subject on its own and provided a full explanation of how the lipped lure works. Try web searches on ‘vortex’, ‘vortex shedding’, ‘Kármán vortex street’, after just a couple of hours reading, you will have a very good understanding of the function of the lip. If you want to get a little deeper, search ‘Reynolds number’ and ‘Strouhal number’.

There is a ton of research being done by university students for their degree thesis, a lot of this work is available for free. I found this research was too basic to understand the lure application completely, but by making lots of prototypes and studying what happens, it is possible to fill in the gaps. The first calculation that I was able to perform was to calculate how many waggles per second the lure would perform for a particular lip width and retrieval speed, interesting but totally useless!

These are a few of the BIG questions that most new members ask. Where is the best location of the tow eye? where do you put the ballast? What lip shape is best? How big should the lip be? How do I avoid the dreaded ‘death roll’? All of these questions should be calculable and it was my aim to at least find simple equations that, although not totally accurate, would give a good starting point.

I’m sure many of you formed the impression that I sit in a small room in the attic, performing double integral and partial differential calculus calculations, surrounded by a bank of computers, the floor littered with screwed up sheets of discarded papers, scribbled with theorems and graphs. Wrong. I am a numerical phobic, the day I finished college in 1978, I vowed never to dig anything deeper than a square root. I quickly realised that vortex geometry was one of the most complex areas of mathematical study and well beyond my capability. A university computer will take four days to calculate the flow behind a simple flat plate, so what chance do I have? NONE!

Does this mean that all we have is trial and error? Definitely not. In our daily lives, we are surrounded by ‘stuff’ that we have a basic understanding of, but never need to calculate. A good example would be car engine mechanics. The mathematics for the internal combustion engine or gear box functions would be horrendous, but a basic understanding is all that is needed to fix it.

If all you want to do is duplicate your favourite lure, then you don’t need to understand any of the above. But, if you want to come up with a new design, a knowledge of how it works is all that is required.

Many feel that it’s all been done and there is nothing left to discover, all the lip and body shapes have been developed and all that is left is to copy the best and present it better. This is so wrong. It is my opinion that the last hundred years of crank design has barely scratched the surface of lure design. With a basic understanding of how it works, totally new lures can be designed.

So what did I achieve in my half a year? I have solved the ‘hunting’ enigma, how it works and how to reproduce it. I discovered a new movement (similar waggle but at half the frequency). These two discoveries alone will give me enough new lure designs to fill a shop. I have a trolling lure design (not built or tested) that will exceed 10mph, why anyone would troll that fast is beyond me, but TU asked the question. I have explored casting problems and developed a simple hinged lip which improves casting distance by approximately 20%. I have developed a simple hinging method for multi segment lures. The top two will be brought to the TU table once the copy infringement issues have been addressed (sorry). The point of this ‘back slapping’ paragraph is to show you that there are endless discoveries to be made in the sea of crank design and, contrary to my opinion six months ago, you don’t need a calculator.

Lapala is right, as he was six months ago. Ideas still need to be tested and tweaked. I have a huge collection of failures in a shopping bag. As my knowledge increases, I re-visit them occasionally, to see if I was on to anything, you never know.

[spare tire]

Well said, I'm still working on designs myself, but have a long way to go. That is what keeps this hobby so interesting. Vodkaman, I wasn't on the board before so I didn't see tha past threads you were talking about before, but you have been nothing but helpful to me and others that asked. THANKS

[Palmetto Balsa]

VodkaMan, I remember the old thread and that was a mess, but I kept reading it. Curiosity I guess. Your input on this board has been valuable and opened up many discussions and new thoughts.

About the hunting thing. Are you saying that you have it so you will be able to reproduce a bait with a hunting action (predictably unpredictable) every time? (I can reproduce a bait with a predictable Death Roll every time:wink: ). If you make all baits that hunt the fish will get tired of it and look for something else. Lets keep it at 5%-8% of quality handmade baits that can hunt for the sake of the fish.

As far as computer testing baits. What crankbait manufacturer comes to mind? The Berkley Frenzy.

"Working closely with leading Tour pros, Berkley

[KcDano]

Vodkaman was the only one I know on TU that possesed a true understanding of what forces cause a lure to function as we know. He was gracious enough to share this information with myself and several others. Once you are enlightened to the fact of vortex shedding you soon realize the bulk of what has been put forth on what makes a lure move, is less than correct. Often we can predict the end result of our efforts without a true understanding of what is actually taking place. As the history of lure making dictates, tinkering as oppossed to scientific theory, has proved to be the genesis of many advancements in lure design to date. However, what we contemplate at this date as beyond our scope of understanding or application will some day become a reality in lure design. And if one doubts the application of scientific theory, in lieu of empirical knowledge as a means to achievce a desired result in lure design. Consider the fact, Vodkaman with no real experience in crankbait building or fishing managed to create a bait that "hunts" and can explain the theory behind it.

Dave, Thanks Again!

Dan

[Lure--Prof]

Good posts Vodkaman, Palmetto Balsa! As to this: What have I learned? Weight placement is critical. (Palmetto Balsa), it marks a major achievement in one's personal development in the art and science of lure building!

Dean

[tinman]

Legitimate, thought provoking question & very good responses. But to me it's like asking an artist why he doesn't just use paint by numbers. IMHO there's no shortcuts, but everybody has their own means to reach an end, I guess. Great thred!

[gdowdy]

The Berkley Frenzy is my go to bait in the deep diver. It is the most perfectly desigined by computer bait out there. BUT I feel confident that they spent 1000s of hours testing it in their tanks and fielding testing on lakes before they came up with a marketable lure. If it takes that much trial and error by a company with all of their resources, then what makes us think that we can shortcut the process.

[Lure--Prof]

The Berkley Frenzy is my go to bait in the deep diver. It is the most perfectly desigined by computer bait out there. BUT I feel confident that they spent 1000s of hours testing it in their tanks and fielding testing on lakes before they came up with a marketable lure. If it takes that much trial and error by a company with all of their resources, then what makes us think that we can shortcut the process.

This is exactly what their marketing people want you to think. Because every company, and every individual luremaker making great lures (where lure companies begin) besides Berkley, has done it that way. When I read that statement by Berkley I understand that it expresses their marketing philosophy which is basically, "We develop superior fishing products utilizing scientific procedures unavailable, and therefore superior to other people and companies because we are a mega-corporation with zillions of dollars to spend on fishing lure development". This is the same method with which they've successfully marketed Powerbait, Gulp. Notice the amount of commercials they do which includes some portion shot in a faux laboratory. I'm satisfied that there would still be a crankbait industry without Berkley, and considering the probable small market share that their hard baits comprise, they must indeed lose millions of dollars...which of course is okay with them because they are Mega-Lure and in it for the long haul, and their bean-counters completely understand this.

What some companies won't say in order to increase market share...sheesh!

Dean

[scoop10]

I'm sorry. I have a hard time believing great new innovations are out there that are going to redefine crankbait design. If it was going to happen, the Japanese would have done it by now.

As for creating "hunting" baits, there are custom bait designers on this site that can produce them consistently. That's no new innovation.

The reason they don't consistently produce these baits are two-fold:

_ One, if they are selling baits, purposely trying to produce "hunting" baits will produce more complaints than sells. Yes, some fishermen understand the value of a bait that performs within that realm of consistent erradicacy. Many do not.

_ Two, trying to produce baits that run on a ragged edge, you're inevitably going to produce more that are throw-aways, IMO.

[Lure--Prof]

_ Two, trying to produce baits that run on a ragged edge, you're inevitably going to produce more that are throw-aways, IMO.

Scoop10,

If you make enough of them, you'll learn what to do and what not to do and eliminate all but the occasional inevitable throwaway that happens with handmade lures; and at worst the throwaways usually have a more normal action. As you said, "As for creating "hunting" baits, there are custom bait designers on this site that can produce them consistently.

Many of the guys who shell out the money for custom lures do understand the value of a lure that has a unique action, especially after having fished one on highly pressured water. So while there may not be a large popular market for these lures, there does exist quite an enthusiest market for these custom baits.

Dean

[Tally]

Let me be the first to say cograts on your findings. It will be interesting to see or hear if what you have discovered is as appealing to the fish, as they are the only thing that tell if a bait is good or not.

I think we can now close the issue to the trial and error session. No matter how good it looks on paper, it still has to be tested and re-worked. I think your bag proves that fact as well as the trash cans others have.

Actually, I have no problem with you not wanting to share your ideas until your infringement papers go through. It is a far cry from what we were talking about in the "heated" post. Having read your post I think I am safe to say that you are not as willing to share as you stated in that post...... at least not until you are protected. Maybe now you understand why not everything is posted on TU.

I follow your post and take what I can get from them. I have no doubt that you are finding things that many are not. On the other hand, some have already figured out the "hunting" bait and can reproduce them everytime. For FACT.....there are some here on TU that play with baits to get them to do certain things. Some of the actions can be explained and some can not.

Is there a "perfect" bait? I doubt that, but we keep trying to make it.

Good luck with your experiments and findings!!!

[Vodkaman]

Thanks all for the kind words. In many respects, TU feels like a large family, even though we have never met. One day, I’m hoping to put that right.

I undertook the search for the hunt as a result of reading Skeeter’s article of a few years ago. All searches on hunting did not reveal a solution, just questions. Out side of TU, there are a few lures that claim to hunt, but the solutions appeared to be body rather than lip. Once you understand the solution, you can look at a bait and tell whether it has a chance of hunting. So you can understand my enthusiasm after finding A solution, especially as I arrived at it from pure theory rather than chance.

Scoop10, very valid points. I had considered the returns point. The first hunter that I made was so erratic (but still under control, no blow outs), I had my doubts whether the fish could actually catch it! Your second point is valid also. For this reason, I am developing the new (to me) movement lure first. Again, has anyone out there already done it? I don’t want to get excited about someone else’s discovery.

Tally, yes I did say that, didn’t I. Having made progress and being in between jobs, I had decided to explore the possibility of starting a lure business, as many of you have. So, it would be foolish to give away my ‘edge’ by publishing. This is probably why no one has posted in response to the many threads that have brought up the subject. But, believe me, I would love to publish it. Six months ago I was very naïve and green, after reading six months of articles on infringement and many other similar valid views, I am now a darker shade of green.

If what Scoop10 states is true, that many lure makers can already make hunters consistently, then maybe it is time to let the ‘cat out of the bag’ and make the hunt option available to all. But you will have to convince me first, a photo would do it.

I believe that there is more than one solution. I have caused lures to hunt by simply bending the tow eye to one side, also, as I stated above, body shape in combination with ballast location could also cause hunting, as suggested by Skeeter years ago (respect). Neither of these are the solution that I am talking about though.

Things are changing rapidly on the home front. I have accepted a new job in Malaysia and start in four weeks. This will seriously put things on hold for at least three years. I intend to continue with the lure design, but not sure I can sit on this theory. I am relieved that I don’t need to pursue protection any longer, it would be like trying to patent gravity.

Getting the fishes approval is one of my biggest problems. I am going to have to prove them in USA as that is were the market is. UK is a dead zone for cranks, at least were I live (very few pike waters).

As for Scoop10’s view on new ideas. My ‘change the world’ comment was meant as a ‘tongue in cheek’ joke, sorry (English humour). I believe that there are many new ideas out there waiting to be discovered. It is probably not worth discussing the answer lies hidden in the future. I think my point is that if you are a believer, then you are more likely to find the new idea, than if you are not. Is your cup half full or half empty?

Tally’s comments on the trial and error, refer back to one of my original lost posts. I objected to having to guess my way through to a successful lure and wanted a ’leg up’ on the knowledge ladder. Understanding the theory of how the lure works will take away the random guess work and endless unexplained failures for those new to the art. Prototype testing and lots of it, is always going to stay with us, as it does in industry. I design in the car industry. Even though the ‘new’ design is virtually the same as the previous model, it still goes through several iterations of design, fine tuning the structure to the new body shape, to maximise the crash performance. In lure terms, fine tuning to get the desired action. We both appear to be on the same page now, this is a good thing.

Once again, a very good original thread has been hijacked, apologies for that. I think someone should start a thread on hunting and lets put it to bed for good. I will not start it, as others got there before me and I would like them to reveal and get the credit. If those ‘in the know’ want to discuss the idea privately, PM me, I will try to respect all your views.

[JBlaze]

Vodkaman, I have the ultimate respect for your views and theories. I don't always understand all that you say. But, you give examples and experiments to help me/us understand what you are talking about, that is greatly appreciated. You have helped me a lot. Especially with understanding the movements of a crankbait and what causes them. I hope that you do well in your new job in malaysia. I also hope you continue to be active on the TU board. You are very helpful and always make posts which are interesting and relevant to the subject of tackle building.

I now look forward to learning about a hunting crankbait. This is a new term for me. Is this something new or is it just another term for a searchbait? If it is something new, What does a hunting bait do that is different from an common, ordinary production made crankbait?

[DeHeron]

The first calculation that I was able to perform was to calculate how many waggles per second the lure would perform for a particular lip width and retrieval speed, interesting but totally useless!

Vodkaman....this is not useless. I have been thinking about this for the last few weeks! It ought to be on the darn package! I am tired of trying baits to see what they do, and then retire them to the Wall of Shame. I would like to know WPS before I bought the lure. Slow...or Fast waggles. These are things that I am looking at in choosing a bait! There should also be a rating for the distance it waggles. Does it waggle 10 degrees or does it waggle 140 degees? I wish I had a dollar for everytime somebody said you really ought to try this bait..It has a real nice tight wobble! Then you get it on the water and the thing nearly rips your arm off! At least some companys let you know if it has rattles or not. There will allways be something to improve on... including lure design!

[oldthunder]

Vodkaman.....I love this and I for one will be sorry to see you go to Malaysian if it means you'll be leaving TU...

There are many things I do not understand about what you are trying to explain but the great thing about you is, you'll always provide a reference. As a lure builder myself and one who does have his own business, I am always intrigued by the process and the difficulty lure making brings. There are SOOOO many variables. I am desparately trying to wrap my head around the "hunting lure" thing. The more I can read and learn, the better.

There is so little time for me to learn these things because of my terminal illness but that is not the issue here. The issue is your learning curve and process as a lure maker. I am most happy that you CANNOT plug a mathematical equation in and come up with the "perfect lure". Where's the creative process in that?

I am very thankful that I found TU and that members like Vodkaman, Skeeter, Tally, Dean McClain and others share what knowledge they have with the rest of us.....

Again thanx for working the grey matter between my ears. The smoke detectors are going off as we speak.....

Oldthunder

www.eaglelures.com

Life is too short....FISH HARD!!!!

[RiverMan]

Well if it makes you guys feel any better I posed this same question on TU many years ago and ultimately it ended up with no answers. If we were all working with perfectly predictable materials and methods such as injectable molds with tolerances out to .0001 and hard plastics I think it would make things considerably easier. But...when one considers the amount of variables within a single piece of wood, wood types, etc, the picture gets considerly less clear. Really much of this work has been done already and all one has to do is look at the works of others. I am not talking about a direct copy of another lure necessarily but if you want a bait to dive shallow, deep, etc., there is literally thousands of examples to help guide you through the process.

Jed V.

[LaPala]

I am 100% with what Jed said.

Unless ur building is 100% consistent (okay 98.99%) with your CAD designed & modeled lure it doesn't makes sense to mathematically derive what you want to built. Mathematical model can help u understand how a lure works and explain it empirically but that is not the only way. And as i mentioned in page 1, how do you determine how the fish will like it based on mathematics? Does a 20 cycle per minute lure work better than a 15 cycle lure? I can built a lure; test it in water and calculate the cycles with stop motion photography faster than I can draw a 3D model & run all the calculation and set all the preset parameters in a fluid flow analysis. Plus with 3D modeling you'll have to built the prototype model too. eventually

Handmade lures can be looked at as functional art and should at least be a notch above production lures. Else how would you justify not going the easy way out & buy production lures and/or buy & tweak. You might say I can mold my lures too but catch 22 will be the accuracy translated from your CAD model too. Most of the available CAD/CAM and prototyping machines are way beyond the means of an average hobby lure maker. Even with CNC, it remains if the machine has the tolerance to cut what you draw. A lot of times, production is a trade off between ease of production & what is envisioned. Multi part & multi mold is just introducing increasing errors in your production.

PS: Anyone done a detail lure with CNC? I did try once and the time spent on drawing the 3d wire mesh - 16hrs; actually cutting on the CNC machine for both sides on a 21/4" lure actually took 8 hrs with 5 change of tool bits. Turns out to be a dud too. Worth the time spent? (I didn't mention the hours spent learning the 3D modeling software & translation of model to CNC g-code either) YA maybe I can market the lure as Computationally Optimized, would you buy it?

[Lure--Prof]

LP, you probably just explained where all those Berkley hours of research work went: Hand carving CAD designs to specification!

Good insights into what is possible and what is practical LP and Jed!

Dean

[clemmy]

I've read this thread with great interest, and I guess it's time to throw in my two cents worth.

I think we are all mostly aiming for the same thing: Creating a better lure to catch fish. Now better means different things to different people. To some it is better lure performance, to others it is better because of the thrill/challenge of fooling a fish on your own creation, and so on.

I think the WAY we approach making a lure is largely based on left/right brain thinking, and shaped by experience.

A very creative person might come up with a very original notion, and persevere because he doesn't know that it "shouldn't" work well according to conventional science. Thus true breakthroughs can happen, and I think, the origin of the "why didn't I think of that?" moment.

Now I personally am in the medical field, and my nature and experience favors a more scientific approach to luremaking, much like I imagine it does for VodkaMan. The "artsy" method of individually trying things for a lure, I.e. trial and error does work, but is not as efficient in many cases, and scientific understanding can shorten a learning curve of making a lure do what you are designing it to do. Of course we can often learn more by our mistakes, those that "should" behave one way, but don't.

Which one is best? I truly believe that A) it depends on the person and We ALL use both approaches, only with varying degrees.

That's part of what makes TU great! One might have ideas on paint schemes, while another might be a wiz at lip design. The Whole of TU is therefore greater than the sum of it's parts..

Hope I didn't offend any,

Clemmy

P.S. Vodkaman, I still havent been able to recieve that file... Any chance you could try one last time by sending it to another member and having them try to forward it to me? (thanx again!)

[doomdart]

But I would argue that it isn't wasteful but a valuable part of learning the craft. Eventually, you get a feel for what works.

BobP

But...when one considers the amount of variables within a single piece of wood, wood types, etc, the picture gets considerly less clear.

Riverman

I can built a lure; test it in water and calculate the cycles with stop motion photography faster than I can draw a 3D model & run all the calculation and set all the preset parameters in a fluid flow analysis. Plus with 3D modeling you'll have to built the prototype model too.

LaPala

Which one is best? I truly believe that A) it depends on the person and We ALL use both approaches, only with varying degrees.

Clemmy

Well, I read the thread and resisted chiming at first. Revisited and agree with the quotes above and many others. That is not to say that Vman, or anyone else is "wrong." In fact, I think they are right in a different way.

Clemmy said it best. I'm trial and error, but others could look at an unknown bait and know as much about what it will do in the water by visual inspection and simply picking it up.

I think when working in wood, the theories are quite useful, but the ultimate test is in the trial and error. But who can argue if a guy can make a hunting lure with predictability.

I have made a few, but not with an amount of predictability.