Vodkaman

Thank's Pikeman and Clamboni, I will go away and think carefully about your explanations. http://www.eng.vt.edu/fluids/msc/gallery/vortex/re200.htm Above is the link to the vortex shedding video.

Glider theory Thank you Riverman for the video links, I will try to get to an internet café this weekend to view them. Dean McClain, you are correct that something has to be present to initiate the action but I believe the action is not the result of a laminar flow. This is not to say that this is not possible, only that my explanation differs. I am fairly confident with my solution as it explains a slow ‘S’ motion, also the ‘zig-zag’ of the ‘walk the dog’ jerk motion. To understand what is happening to the glider, we must first consider certain aspects of the average fish. Why is the fish not shaped like a torpedo? Science has taught us that a blunt nosed cylinder is the most efficient shape for moving through water. Fish have been in the evolutionary chain for 100 million years. Darwin’s theory of evolution would indicate that they are closer to perfection than most other living species and yet the bodies are generally deep and humped. You could argue that because the average fish is slow moving, only capable of speed over a very short time, that the requirement for the perfect shape is not necessary to survival. In my opinion this argument is incorrect, the fish has achieved the perfect shape (explanation later in the text). Why does the fish have a pressure sensitive lateral line? The accepted general view is that the fish uses this feature to sense danger from predators and locate movement of other creatures for food etc. this may well be true but is not the main reason for the lateral line (explanation later in the text). Why do fish have scales? This question is one of the great anomalies, a very big unanswered question. Many believe that scales are purely armor for protection. My own theory differs from this idea and will be explained later in the text. Other questions such as what purpose does the dorsal fin serve? And a question aired on this site a few months ago, do fish move their heads when swimming? Will also be answered. I read a thesis document by Tryantafyllou a few months ago, sent to me by prof.dr. Arthur E.P. Veldman, who I contacted to gain permission to use his vortex video clip. This very heavy read discussed how fish use vortices while swimming. It did not discuss the whole story, but concentrated on aspects relevant to its subject. This document was the first clue. If the fish uses vortices to swim, it must first create the vortex. If the fish was torpedo shaped then no vortex would be created due to the streamlined shape. The fish needs the hump back to generate the swirl of water called a vortex. This vortex is reinforced by the fish moving its head from side to side. The fish then leans into the vortex to ride it as it flows down stream. As the fish does this, its body bends. This bending action opens up the scales, which act like small cups, capturing the energy from the vortex, driving the fish forward. Finally, the fish presses against the vortex with its tail, extracting the last bit of energy. The vortex then splits into two smaller vortices, rotating in opposite directions. The next vortex forms on the opposite side of the fish hump and the process repeats. In my opinion, the purpose of the pressure sensitive lateral line, is to inform the fish about the location of the vortex so that the fish can time its movements accordingly. The purpose of the dorsal fin could be to either add extra sensing of the vortex or to actually assist the formation by waving from side to side like a flag. If this theory is true, then evolution has indeed given the fish the perfect shape. So how does all this information relate to our glider lure? I remember seeing a glider lure on this site a few months ago, I specifically remember the humped shape of the back. It struck me as being ugly in form. The purpose of the hump is now clear and the theory holds up. As the lure is pulled through the water, the flow over the hump generates a vortex. This low pressure disturbance pulls the head of the lure to one side and the lure swims at an angle to the retrieve direction. As the vortex flows down stream, the next vortex forms on the opposite side of the hump, drawing the head in the opposite direction. The lure then swims at an angle opposite to the first, hence a slow zig-zag or ‘S’ type motion. The theory also works for ‘walk the dog’ action. When the lure is jerked, the sudden sharp movement generates a strong vortex on one side, causing the lure to ‘zig’ at an angle. The lure comes to a halt and all vortices are gone. The lure is jerked again. But as the lure is already sitting in the water at an angle, the water is forced over the hump in the opposite direction. This forces the lure to change direction and the lure ‘zags’. Thus ‘walk the dog’ is borne. If the theory is correct then there are a number of design considerations to be taken into account for a successful glider. The lure must swim slightly nose down so that good flow over the hump is achieved. This can be done by a forward ballast location and/or mounting the eye slightly rear of the nose. The back of the lure must form a hump about a third to half of the length. The lure can be improved by exaggerating the hump towards its peak, this will help the vortex form cleaner. Also, the body forward of the hump could be flattened, this too would probably improve the vortex, scooping the water up and then pouring over the side. A pair of side ridges could be built into the body, from the nose, running down the lateral line and meeting at the top of the hump. These ridges need only be 1mm deep. They would have the effect of tripping up the flow over the side and strengthen the vortex, a bit like the flat plate lip on a crank. I hope this all gives you food for thought and maybe one or two of you will try the theories out. Personally I am out of action as regards prototyping for the next year or so. Thoughts please!

Where I come from, we use two of them on a hook for bait. That was before I got into to hard baits (avatar).

I think that I've figured it out (in my sleep last night). I'll start typing it out tonight. Sorry in advance, it's not going to be brief.

Are you sure, with my bad reputation for confusing people! Wind a length of string on your finger. Form a loop and place the loop on your finger and pull tight. For safety put at least two. It is the simplest knot of all, but don't forget the superglue!

I have always used a couple of half hitches and applied a spot of superglue to the finished knot. This enables the thread to be trimmed close without danger of it falling apart. A spot of 5 minute epoxy would do the trick also and give a nice finish.

Savacs is studying Hydro' (Sorry Savacs)!

So how does a successful swim bait swim? Does it naturally swim in an 'S' shaped pattern or does it require the jerk input to get the zigzag motion. I've never made one, only concentrating on lipped baits so far.

Most split the lure, instal the wire then glue the halves together. I can see how this method would give you problems as the lip would go in after the wire. The method that I use on my prototypes is to cut a slot down the belly (or the back) of the shaped body using a thick cutting disk in a drill (dremel). This allows you to fit the lip first. Form the eye, thread the wire through the lip. Check the length and form the tail eye (and belly). Tuck the wire into the slot and hold in place with superglue. Fill the slot with wood filler or epoxy. The wire can be pushed deeper to allow for fitting the ballast. But there are other ways of solving the ballast problem. Cut a slot in the ballast or fit the ballast as a flat lead plate, recessed to hide it. For a professional finish, effort must be invested to hide the slot but this is not a huge problem. I have used this method from the start and have had no problems. The tricky part is forming the rear eye as when the wire is twisted, the length shortens. But it is not necessary to twist the wire, just bend it over about an inch. It will never pull out.

I've twisted 7 strand and fixed it like solid wire, you must twist it in the same direction as the strand twist or it will unravel. Also, the loop must be kept small as the first heavy load will set the loop in an elongated shape. The small loops make for a very tidy joint. As for durability of a straight through 7 strand hinge, no one has given any feedback for or against.

WOW! Love it all, the lip, paint job AND the photo.

Drinking on the rocks can seriously damage your health! VODKAMAN

Good solution Riverman. I particularly like the fact that it can be dismantled.

I think Fatfingers is on the money, the eye may need to be move back 2 or 3 millimetres. The lure looks really great. I would frame this one for posterity and get on with sorting out the problems. It is very disheartening after all the work, not to have it swim, but this is a good lesson for the future. On the next one, I would take it to the water with just a sealing coat to keep the water out. In fact, I would not plan to take the next one to a finish. Take some cutting gear with you. Take a few diferent size lips and fix them in position with soft glue (UHU) so they can be quickly swapped over. Extend the eye so that it sticks out 3/8 inch, this will enable you to experiment with the eye location. Swim the lure horizontal and make a note of the line angle to the water. Try the ballast a little forward. My guess is the lure is suffering from death roll type 2, I wrote an article on this subject not too long ago called 'death roll'. If you still struggle to get a swimmer, post again with all the information, measurements, ballast positions, materials, etc. This site loves to sort out these type of problems as we have ALL been there. good luck.

I can't remember anyone here suggesting that idea before. So simple, I'm disappointed that I did not think of it myself. Nice one Ernel.

How about putting together some images and slogans for Tee shirts, should be a laugh. Also, if anyone sees a design published here, the pic can be pulled off and given to a T-shirt printer. Keep the pic files small so as not to irritate the management, if the original is required, we can deal with that by PM and e-mails.

Birdy. Excellent tutorial, well written and very easy to understand, something that I am not so good at. I agree with you that it is dificult to decide which forum to present this project as it is half and half. But, personally, I read all the forums and pick up knowledge from them all. Quite often techniques applied to one type of bait can be transferred to another. I would be very interested to read what everyone else thinks about this work. Good job. Send me your Email addy, my work PM does not work, cheers.

Are you using the correct tools for the job, or freehanding. A fly tying vice and a few hackle clamps (not sure of the correct name), make the job so much easier by keeping everything tight. Also the tools enable you to let go of everything without it falling apart. A simple starter book to fly tying will help enormously.

What is causing the thickness problem? Is it something to do with the sprue solidifying too soon, causing back pressure on the soft mould material, I cannot make sense of the problem. If this was the case, then opening the sprue hole would help. But I would get more experienced advice first, I am only theorising (bored at work)!

Basically it all comes down to density. The heavier the wood, the more the weight is spread out and the harder it is to get the action. Not everyone wants masses of action, each to their own preferrences. I prefer balsa, easy to work and good action but there are many disadvantages. Balsa requires through wire, as screw eyes will pull out. Because of its soft texture, it is prone to tooth attack and subsequent paint problems. I have no real experience with the other woods, but if you do word searches on the wood names, you will find the information that you are looking for. Good luck.

Riverman. To be honest, once I arrived at a solution for the hinge, I lost interest in the jointed lure. It was around that time that I made huge leaps forward in the lip theory and concentrated on that. I will eventually get back to the hinge, but at the moment work is severely hindering my progress. I hope someone tries it.

Sound advice BobP.

Welcome Bowman. This is an excellent question and has been asked many times before. In fact it was pretty much the first question that I asked, with very little positive response. Over the last six months their have been many discussions on the subject, so I am giving you a series of words to search this site for. The search function at the top of the page only allows single word searches, so you have quite a bit of reading to do. Unfortunately I am under the thumb at work and do not have the time to present you with direct links. Good luck with it and ask questions. Search words: vortex vortices axis axes buoyancy yaw roll wobble waggle ballast hunt hunter death (as in death roll). Hope this helps. Also read all posts by Skeeter and Lapala.

Finlander. At exactly the same time that I posted, Husky posted the same method on hardbait forum, except his description is far superior to mine. http://www.tackleunderground.com/forum/showthread.php?t=9628 Hope this link works.

Hoodaddy. I checked it out a while back, price is not too scarey. Do you own one, if so I have a bag of questions for you, if you do not mind. Sorry for the mini hijack, but my PM does not work on this office system, the security is as tight as a ducks a---.