littleriver Posted June 16, 2015 Report Share Posted June 16, 2015 Hi Dave Yes I am interested , I just found it myself and was reading . I saw the spreadsheet was no longer working and wanted to ask for it but really did not want to be too much trouble. But now that I am back and you have offered .......YES I would very much like to have any info your willing to share. Travis Since you asked , it has been my experience yes they do. It does require some effort and that is why most won't do it . I have a bait that is weighted different than anything I have ever built . I weighted that lure that way because that is what the math told me to do. To date, it is still my most successful design. Quote Link to comment Share on other sites More sharing options...
littleriver Posted June 17, 2015 Report Share Posted June 17, 2015 Dave the other thing that concerned me was the length of the beam . One meter is this correct? That would take up a lot of bench space. Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted June 17, 2015 Report Share Posted June 17, 2015 I have added the images to the scales thread. The beam can be any length that you wish. If you want to make a shorter beam, go for it. Dave Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted June 17, 2015 Report Share Posted June 17, 2015 Looking at the paper scales numbers, I would say 0.1g accuracy is about the limit, not 0.01g. Dave Quote Link to comment Share on other sites More sharing options...
littleriver Posted June 17, 2015 Report Share Posted June 17, 2015 Thank you Dave ! Quote Link to comment Share on other sites More sharing options...
JRammit Posted June 17, 2015 Report Share Posted June 17, 2015 At the risk of sounding like an inappropriate comment... Ive been wondering if a finger scale (like the kind you would find at a "tobacco shop") would be accurate enough for our needs.... I think they run in the neighborhood of $5 and measure down to 1/2 gram Im thinking of asking the "pharmacist" in the for sale section here... I bet he has the hook up! 1 Quote Link to comment Share on other sites More sharing options...
hazmail Posted June 17, 2015 Report Share Posted June 17, 2015 GeeeZZZ guys, go onto the ''bay'' and type in 'Digital Scales' .. They range from $8 to about $20 and you can read either Imperial or Metric--- The also come in a range of increments of 100 gm's, -------------------so you can buy a scale that will cover the range of your lure weight. One of the sets I have will weigh a hair and cost $16. Pete 2 Quote Link to comment Share on other sites More sharing options...
littleriver Posted June 17, 2015 Report Share Posted June 17, 2015 Pete I hear yah I told myself that same thing over 12hrs ago but for some reason my shop light is still on .....maybe it's time to turn the light out.... Quote Link to comment Share on other sites More sharing options...
Loft Posted June 17, 2015 Author Report Share Posted June 17, 2015 Hmmmm.....do any of these equations equal designing a better crank at catching more fish?Not nesesarrily.If your way works for you, i don't se any reason to try and fix it. The reason for this thread, was to explain the effect of moment of inertia. The weighing process was just a part of the process of getting there Loft Quote Link to comment Share on other sites More sharing options...
mark poulson Posted June 17, 2015 Report Share Posted June 17, 2015 I find the amount of energy it takes to overcome the moment of inertia for a body at rest increases mathematically with age. 2 Quote Link to comment Share on other sites More sharing options...
JRammit Posted June 17, 2015 Report Share Posted June 17, 2015 I find the amount of energy it takes to overcome the moment of inertia for a body at rest increases mathematically with age. That explains why the older i get, the harder it is to get outa bed in the morning (ha ha!) 1 Quote Link to comment Share on other sites More sharing options...
littleriver Posted June 18, 2015 Report Share Posted June 18, 2015 Pete, you almost pushed me over edge. But after a good nights sleep and a fresh cup of coffee, i decided to continue my obsession for a free scale made from materials i have on hand. With alot of Vodkaman's help, friends I am delighted to report my bench is now equipped with a" Vman scale 2015" and i could not be happier. Easy to read, store. setup and never requires batteries. Thank you DAVE!!! It looked so good sitting on my static tank I decided to share a picture. Enjoy! 1 Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted June 18, 2015 Report Share Posted June 18, 2015 Very good job. I just knew someone would build it one day. I had to wait nearly 8 years, but I am happy Dave Quote Link to comment Share on other sites More sharing options...
littleriver Posted June 22, 2015 Report Share Posted June 22, 2015 (edited) Update Carved a prototype today to test Loft's moment of inertia equation. I am happy to report it was a complete success. I have to thank Vodkaman, as well for todays success, for whom without the advantages of his Ballast calculator or vman scale this event would not have been possible. Every aspect the equation, program and tool contributed to the build really help eliminate guesswork. They narrowed the possibilities and increased my chances of success. Thank you both! I will be using in the future for all my builds . The lure was practically perfect! <iframe width="420" height="315" src="https://www.youtube.com/embed/U47XCL6AZhk" frameborder="0" allowfullscreen></iframe> Dave the music was selected in your honor. Vic Edited June 22, 2015 by littleriver 1 Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted June 22, 2015 Report Share Posted June 22, 2015 That looks great and goes well with a spot of Mozart - Eine kleine Nachtmusik is a piece I know well having played it many times in brass quartet competitions in my younger days. How could you possibly have known! Dave Quote Link to comment Share on other sites More sharing options...
littleriver Posted June 22, 2015 Report Share Posted June 22, 2015 Dave Some mysteries may never be solved......and that is probably for the best. Here is another video that came up while viewing my own. Just out of curiosity, I watched. I believe it to be relative to the discussion and worth sharing. One has to watch it all to get his point but it is worth the wait. All i can say is ...take that hollow plastic baits..... I always knew my solid wood baits were the real winners. Vic 1 Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted June 22, 2015 Report Share Posted June 22, 2015 that I watched a couple of weeks ago. It is the same thing, but he explains it much clearer. It is a surprising result for sure. Dave Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted June 22, 2015 Report Share Posted June 22, 2015 is brilliant. Informative and entertaining. It is an hour long lecture and could be totally about fishing lures, as it covers inertia and light. Dave Quote Link to comment Share on other sites More sharing options...
mark poulson Posted June 22, 2015 Report Share Posted June 22, 2015 (edited) I watched as much of those videos as I could stand. The two by Walter Lewin were particularly hard to sit through, because he's clearly so sure he's the smartest person in the room that he's insufferable! At least the guy in the second video actually included a correction by someone else. I'm not sure how much these engineering videos relate to lure building, since fishing lures have air inside, which provides the buoyancy, but swim though water, which is a different density, and provides much more resistance. I am a carpenter, not an engineer, so that's about as far as can get, theoretically. In practical terms, just as the most buoyant balsa, which is the lightest because it has the thinnest cell walls or the largest cells and therefore has more air trapped per volume, makes the most active baits, a hollow plastic bait with really thin walls, like the old Speed Traps, are the most active, too, and actually rival the best balsa baits. But they were so fragile that they had a very short life expectancy. And no manuf. today will make a bait that is that fragile. Too bad. The square bill cranks now being produced come closest, as far as really active X'ing, and wobble, and they are hard enough to take a lot of punishment. I am not a lure designer. I have always used a successful commercial lure as a starting point for my lure building. Once I've been able to make a similar lure that works, I have varied that basic design to see what of my own design I could make that would work, and pretty quickly learned a lot about what doesn't work, and, thanks in large part to the help of TU members, what does. As amateur lure builders, we are all somewhat limited in how we can build our lures. Obviously, making hollow plastic lures is beyond the range of most of our building abilities, so we try and achieve similar results with wood, PVC, and resin. I've found that, for me, a well shaped, properly weighted and lipped crank will catch fish, whatever I use to build it. The same principles of lure building apply, no matter what it's built out of. I've added ballast to, and changed the lips of, enough store bought plastic lures to know that hollow plastic lures also follow the same rules. All of this is to say, build a lot, and learn from your mistakes. I've found that, for me, It is the best way, no matter which engineering principles are involved. Edited June 22, 2015 by mark poulson 1 Quote Link to comment Share on other sites More sharing options...
Vodkaman Posted June 22, 2015 Report Share Posted June 22, 2015 I am not a lure designer. Ha! - I beg to differ. You are a very respected lure designer. Dave 2 Quote Link to comment Share on other sites More sharing options...
CNC Molds N Stuff Posted June 22, 2015 Report Share Posted June 22, 2015 Mark, Its been my experience that every man in the room thinks he's thinks hes the smartest guy in the room. Me, you, Dave, everybody. The thing is in some way we are. Even if its only in knowing how we see something. How many times have you heard somebody say they didn't have book smarts, but they have street smarts or something like that? Its their way of trying to quantify in some way how they are smarter than you or me Don't worry about it. In some ways they are. Even the nearly locked in mentally disabled person will have some insights you or I do not have. I am bad about trying to show people how smart I am. Sometimes I am just smart at figuring out how to get my foot out of my mouth. LOL. To the engineering vs experiences thing. Really people? They are so intertwined as to be just plain foolish to think you can get the best results without some of both. Those of us who shoot plastic even if its from rote memorization of what others have said here are relying on both. Without the chemical engineers who developed the plastics, and the past users who experimented and came up with the methods we use we would all be years behind were we are now. I'm not sure what moment of inertia is, but I know that the location of center of gravity, and the concentration of the center of gravity can have a huge affect on how a bait moves. Learning how location and concentration affect that can help me design a bait they way I want faster. I can gain that knowledge by experience or the experience of others, or I can learn the math of how its works and calculate it out on screen. When I take my math (or Dave's math) and combine it with experience (my own or that learned from others) I am sure I can get closer to the desired results in less time and fewer attempts. Can you build a bait that catches fish by picking up a chunk of wood, and a knife and hacking away. Certainly. If you try different things will you eventually find one that works better. Absolutely. Could you get closer faster without luck if you understand the physics of how it worked. Without a doubt. 4 Quote Link to comment Share on other sites More sharing options...
JRammit Posted June 22, 2015 Report Share Posted June 22, 2015 I find the scientific approach interesting!.. Most of it is over my head now, but i think i grasp more as i go along You certainly can build a successful lure without any equasion at all, mainly because most of the work has been done for us by the pioneers of lure building Still there is one word that seperates man kind from all other walks of life.... "Why?" Star shine... Why? Fire hot... Why? Lightening strike kite... Why? Crank bait swim... Why? 1 Quote Link to comment Share on other sites More sharing options...
littleriver Posted June 22, 2015 Report Share Posted June 22, 2015 Hi Mark It took me a couple viewings of the Lewin video I shared to get a sense of how the information he is sharing might be influencing the bait I just made. A great bait by the way. I say it is great because the action is effortless. Sorry the footage is so bad but some things will never be able to be experienced by anyone except the person holding the rod. I could feel every wobble and the the speed of the wobble changed instantly with line retrieval. The bait responded to my every command without effort. I believe this is due in large part because I have the ballast weight near the moment of inertia or axis of rotation. It is like the video you enjoyed where he holds the plank at the end and it requires a lot of enter to move the plank , Get the weight and axis in balance and the bait will move easier no matter the medium. Ben would call this getting all you can out of that particular design by having your ballast right. Two points I would like to make at this time. One, having your ballast not at the axis isn't always a bad thing . It may actually provide an action your looking for in that bait but what I think Lewin is telling us is it is going to take more energy to produce that action. That brings me to my second point, plastic cranks by nature are hollow and most their weight is on the outside and not near the moment of inertia. Some may make an effort to locate their ballast near this point but their is still going to be a more uneven distribution of mass than our wood baits because of the facts( hollow/most mass on outside) i stated earlier. Because of this, the plastic baits will require more energy to get wobble than well made wood clone that is properly weighted. I have made a few crank baits and have experienced both extremes of this principal in action . I made a shallow diving WEC 1 clone a few years ago with the same bill i have on this bait . But, I weighted the lure very differently . It was weighted in a more traditional manner at lowest point of belly . This WEC bait required a great deal of effort to get any action . It was like pulling Manns 30+ deep dive and yet I was just below the surface. This puzzled me until now. Hello Dave I really enjoyed the Lewin video. Thank you for sharing it. He is good at getting your attention and very creative at getting his point across. I learned things I never knew. Things like why the sky is blue or sunsets red but I still have a hard time visualizing a pendulum in my fishing lure. Though ,I thoroughly enjoyed seeing a seventy something swing from one. I was certain he was going to hurt something. I am guessing he was the inspiration for Miley Cirus's pendulum swing antics. Hi Bob you get me. The points made in your response is exactly what i hoped others would get from this thread. Thank you!!! Hi Jeremy yes indeed ........as long as there are questions to be answered we will be asking..... Vic 1 Quote Link to comment Share on other sites More sharing options...
mark poulson Posted June 22, 2015 Report Share Posted June 22, 2015 Bob, I guess I was just put off by Lewin because he reminded me of my father-in-law, an aerospace engineer who worked on the Apollo Program, who delights in showing how smart he is. It is maddening, because he never has a conversation, it's always a pedantic lecture, with questions allowed only so he can further enlighten everyone. He is smart (most engineers are really smart), but he is not very adjusted socially. One of the reasons I use commercial baits as a starting point is because they have already done the engineering. I know that, and don't want to reinvent the wheel, just personalize it a little. I don't think I'm the smartest guy in the room, ever. Experience, and my kids, has taught me that much. But I am sure of what my experience has taught me if something works, even if I'm not sure exactly why something works. I really enjoy reading what you, Dave, and the rest of the builders here on TU post, because I learn something every day. I just read something on the internet that says it all for me: "I just read an article about the dangers of drinking. Scared the shit out of me. So that's it! After today, no more reading!" 2 Quote Link to comment Share on other sites More sharing options...
