precision trolling

[jjbuoni]

The book precision trolling is an experimental study of the depth that certain lures attain at certain speeds with certain line weights. It does give you a ball park number to set your linecounter when trolling for a particular depth. As a Mathematician I( with a colleague) believe that these results can be attained through a mathematical analysis. However, what is needed and would make my work much easier, is the lift and drag coefficients(similar to lift and drag on airplane wings) of these lures.<br /><br />Has anybody seen such material? I hope to share these results if the project is completetd.<br /><br />Much Tajns in advance.

 

[Bondo]

Re: precision trolling

There's No Lift in the Lures,..... They're built to Dive........<br /><br />The Lift is caused by the Line pulling the Lure.....<br /><br />Without the Lift provided by the Line,...... Most Diving Lures would run right to the Bottom,... However Deep that may be.........<br /><br />And,....... Every Lure will provide a Different Drag Coefficient,....Depending on the Line that's Pulling it.......

 

[jjbuoni]

Re: precision trolling

your 100% correct the so-called "lift" (which is the correct engineering term) is pulling you down and not "lifting" up. Also it is a statics problem with the "force" of the line sitting on one side of the equation with drag and lift among others on the other side.So you are correct there also. Drag and lift are are proportional to the square of the velocity. That constant contains the lift coef and the drag coef varies for each lure ( as you pointed out) and there are a lot of them. I think I can find these experimentally; but perhaps this work has been done(then why bother) and that is my question. Does Storm know what these coefficients are for say hot-n-tots and would they be willing to part with them?<br /><br />The book "Precision Trolling" is written with a boat speed of 2 mph while Scroppo's article on trolling which appeared in "Walleye insider" is written for about 14 lures at 1.6 mph. This is what got me interested in the problem.

 

[neumanns]

Re: precision trolling

If they know it would they release it...unlickly.<br /><br />If you knew them could you mathmatically solve this problem...yes<br /><br />The problem with your theory...Every lure is diffrent. It sound to me like ya want to formulate one calculation to determine depth, but do you want to do this for every lure, and if you do wouldn't you then be the second person to try and market it?

 

[jjbuoni]

Re: precision trolling

Indeed you are corect to say the constants are different for each lure. Hence, one needs to know these constants, namely drag coefficient and lift corfficient for each lure to develop the equations to predict depth. Depth is not the only issue in trolling but that is the first step. <br /><br />The mathematical model, not considering the drag of the line does not seem complicated, once these coefficients are known. The drag of the line and then 50/50 trolling, as in the text precision trolling, may be more complicated.<br /><br />My interest is developing a "mathematical model' to be studied by students with real time experiments. Many of the key physical ideas necessary to build the model are also used in the study of motion in any type of fluid, i.e air is considered a fluid.

 

[bbalcer]

Re: precision trolling

The line used will also be a variable. The different types of line (diameters) will provide different drags as well as the materials will have different bouyant effects. Bouyancy will also have to be taken into account. The best bet would be for you to take several lures and obtain emperical data, then make general assumptions for other lures of similar size, bouyancy and lip size. All holding the line type/size constant. Good luck.<br />Perhaps you could create RAPALA lure tables, much like the NACA airfoil tables.

 

[aquinate]

Re: precision trolling

sixers,<br /><br />This is something I have given some thought to in the past but I lack the physics background to even begin to work out the details. I do a lot of trolling and try to be very precise in lure presentation (depth). The essential question seems to be: given lure x and line type y, what length of line will acheive what depth.<br /><br />I suppose if you graphed the curve for any particular setup, it would eventually flatten out: All the lures I use (crankbait types) have a 'maximum' running depth, regardless of speed, and beyond a certain amount of line, will not run any deeper.<br /><br />What are some concrete steps a person could take toward working out the coefficients for some particular lure? Is this something that could be done 'in the boat' or would a more complicated test be demanded?<br /><br />thanks