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Swimbait Swims Sideways
27 replies to this topic
Posted 30 March 2011 - 01:33 PM
Just finished testing multiple configurations of my swimbait and they all swim at about a 45 degree angle. I've placed the eyelet in three different locations (low, middle of bait, high (above eyes). I have also tried one medium egg sinker (in the first segment as in picture) and two medium egg sinkers as ballast weights. The material is polystyrene and I was attempting to make a slow and/or fast sink bait. Length is 6.5". My thought is that the bait is too slim and for some reason generates an uneven pressure on the bait surface. Next I am going to try adding weights in the other sections to move the center of mass further back. Also may consider making a floater version by adding no weights but having balsa wood inserts along the top of the bait to decrease the specific density. The material is polystyrene with a specific density of 1.1-1.2 g/cm3. Also may consider adding a crankbait style lip on the front to see if that helps even out the swim.
Any other ideas?
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Posted 30 March 2011 - 02:38 PM
some ideas i have:
ditch the pelvic and anal fins (possibly dorsal too)
make the bait taller from back to belly
add more weight if neither of these work.
Posted 30 March 2011 - 02:39 PM
I think it is a ballast problem, as you already suspect, judging from your comments.
You have ballast in the front section, but there is nothing to tell the other sections which is up and which is down. I think the other sections are dragging the bait onto it side. When I build swimbaits, I treat each section as a separate lure and balance it so that it sits horizontally and is close to neutral buoyancy.
Your body material is heavier than water before you start adding hardware and ballast. That lure is going to sink fast. You should consider a lighter material or add micro balloons, to get some buoyancy going. The more buoyancy you have, the more ballast you can add and the more vertical stability you will get.
Adding a lip is not going to solve this problem, in fact it will probably make it worse. This is all just my opinion. The lure is looking good.
Posted 30 March 2011 - 04:38 PM
First of all, that's a terrific looking lure. Great work!
I agree about the problem probably being the fins, especially the ones that stick out (pelvic?). Those fins provide lift, and they could be causing the problem.
I would try eliminating those first, and then the others one at a time, if it still leans.
If you are dead set against losing the fins, try making them thinner, so they don't have enough thickness to act as wings.
I go about weighting my four section jointed baits differently than Dave.
I use PVC decking, which is buoyant enough that the lures lie on their sides before they're ballasted, even with all the hooks and split rings attached.
After I've shaped, hinged, and hardwared my lures, I float them in a bucket of water.
I determine my ballast by adding 1/8 oz egg sinkers to the tines of the front treble hook, one at a time, until the bait sits straight. For floaters, I stop once the lure sits level, with only the back and top of the tail sitting out of the water.
For sinkers, I add additional weights on the rear hook tines if needed until I get the rate of fall I want.
I use 1/4" lead wire for the actual ballast. It weighs about 8 grams per inch, so I can measure the weight I need, and cut it with a drywall knife.
Then I drill 3 ballast holes in the bottom of the front section, and add as much 1/4" lead wire as I need to match the ballast I've determined the lure requires.
If there's not enough room in the front section, I begin adding weight to the second section until I've got it right.
I never add weight to the tail section, because I always want that to be buoyant enough to keep it up when it's swimming, so the lure stays horizontal on the retrieve. I have some baits with weighted tails, and they swim tail down, which isn't the look I want.
You did a great job with that mold, and I look forward to seeing your finished lures.
Posted 30 March 2011 - 06:14 PM
On my swimbaits (I dont make many) I use a ballast line from the nose to the center of the tail and make the bait thinner at the bottom than the top and giving the bait a kind of a "V" profile. The way Iv have it figured is the less buoyant the bottom the less ballast I need to help it float strait and the ballast line works like a fulcrum instead of the bottom trying to pull the bait down the top is trying to pull the bait up, Getting the center of gravity in the right spot is the hardest thing Iv learned,
As for your bait I love it and the weighting for a floater is going to be tricky to much it will sink not enough and it will sit with a lean to one side.
Posted 30 March 2011 - 06:39 PM
Thanks for the input. I will try (1) balancing each segment, (2) lighter material like polypropylene (density 0.9 g/cm3) (3) remove the fins, and (4) on my next version which is an 8" I will make more of a v-profile. One thing I did notice is the bait would switch from 45 to 135 degrees and vice-versa if I drastically changed the retrieval speed. Might be interesting to perform a formal design-of-experiments, although I would rather get it swimming correct first and then begin a DOE to produce fine-tuned results.
I may keep one or two with the side angle swim, they actually mimic a severely injured fish but its not the kind of swim I want all the time.
Posted 30 March 2011 - 11:38 PM
You will learn more if you do the changes one at a time and test after each, or you will not find out what effect each change has.
The fin lift theory was interesting and could well be the problem, but I will stick with ballast. It was also interesting reading the variations in ballasting methods.
Posted 31 March 2011 - 01:16 AM
Good looking mold. While I am somewhat new to the molding process I am familiar with functionality from building wood baits.
I agree with Vodka man on this one. There are plenty of similar baits that have the fins protruding out that swim fine. With enough ballast it has to swim upright unless something else is way out of wack and based on how refined that mold looks I doubt thats the problem. I don't make lipless swimmers but I know of some very successful guys that do and they treat eat section independently (ballasting and balancing each one) with the exception of the last segment. When the entire lure is balanced like that all the momentum goes into the swim and doesn't get wasted on pulling and fighting from one section to the other.
I disagree with the other two notions: If you make the back taller your going to require more ballast not less....it will have more of a tendency to lay on its side not less.
I also disagree with thinning the bottom and rounding the top: Again you are placing more weight above the center of gravity and it will want to roll even harder to its side not less. I'm willing to entertain why this wouldn't be so.
With all said, if the density of the lure material comes down and the ballast increases in a balanced fashion it will swim upright-physics dictates it. Most styles of bait I've seen like this have the line tow at the center line or just above but thats going to be easy to determine once the weight distribution is straightened out. Them 3:16 ish joints must have required some work.
Keep at it.
Posted 31 March 2011 - 01:57 AM
The pear shape cross section (thin bottom, thick top) does work. I use this shape with all my cranks.
There are two centres under consideration, Centre of Gravity (CoG), where all the downward, gravitational forces act, and Centre of buoyancy (CoB), where all the upward forces act. For the lure to swim upright, the CoG MUST be lower than the CoB (and while we are here, for the lure to swim horizontal, the CoG MUST be directly under the CoB). The pear shape raises up the CoB and thus increases vertical stability.
The problem with this lure, is that there is no buoyancy force. It is only that the lead wants to sink faster than the rest of the body, that tends to keep it upright. With the the force keeping the bait upright being so small, the bait becomes susceptable to other influences like the flow around the pectoral fins (like Mark and Dsaavedra explained).
Posted 31 March 2011 - 12:32 PM
Sorry I didnt read all the posts above..IM TOO A.D.D to take up that much time.... I just read the topic... I would leave it alone.. THAT SOUNDS LIKE A FISH CATCHIN SOB TOO ME!
Bait will look like its dying.
Edited by The_Rookie, 31 March 2011 - 12:33 PM.
Posted 01 April 2011 - 05:49 PM
I have had swimbaits do the same thing and corrected in one of two ways.
Make the material you are building the lure out of heavier............or,
Change how you are weighting the lure.
Posted 03 April 2011 - 03:24 PM
Thanks for the help everyone. I created a new casting with a lighter material and balanced each segment by adding lead. Now the bait swims perfectly. It has a really nice gait, much like the four jointed 316 trout. The fore-section does not move much but the tail oscillates at a very rapid pace.
Posted 03 April 2011 - 03:29 PM
That's a great result. You should post a video.
Thanks for the feedback.
Posted 04 April 2011 - 03:24 PM
Dave, since wer'e on the subject..what is the basic theory or technique of causing a lipless swimbait (like this one) to run "head-steady" and the remaining sections swimming (like a real fish)? Should the front section have the most weight for this to happen? I would love to to hear your input on that.
Posted 04 April 2011 - 04:47 PM
I don't have an answer for you on this one. I have thought about it in the past, but every time I think of an explanation, I think of arguments against. Pretty sure it is a ballast thing though. I will get around to experimenting with this.
Some builders prefer a lot of head movement, some do not. Personally, I am a 'do not'.
Posted 04 April 2011 - 06:48 PM
I have found that the longer your make the head section in relation to the rest of the sections, the less it will move.
I also groove the forehead of the head, like a lipless crank, to add a stabilizing shape.
Edited by mark poulson, 04 April 2011 - 06:50 PM.
Posted 05 April 2011 - 01:35 AM
Cool that you got it resolved so quickly. I know some guys have gone so far as to X-ray baits to see exactly how the ballast is oriented in some of these style of baits.
The observation about the head movement is something I've thought about lately as well. It certainly better mimics how a fish propels itself through the water...it definitely appears more like a fish just cruising along in a normal fashion. Of course, I have some lipped head shakers that get smacked real good on the surface because they looked more stunned, panicked or injured.
It makes sense that a long front section will slow down the motion and create a longer slower movement. I think as well that the orientation of the ballast weight (being more elongated from front to back as opposed to being tightly centrally located in the segment) will act to minimize the head wobbling. It is interesting because typically jointed baits rely on a transfer of motion from front to back. I can only guess that a portion of the action is caused by the turbulence of the water moving over the progressively lighter joints in the rear....its certainly the most popular design out there right now. I even have a large lipped bait from Mr. Ellis @ 3:16 and the head moves so very subtle...it feels to me like there is a significant amount of weight in the first section thats dampening the wobbling effect.
J my 2 cents.
Posted 05 April 2011 - 07:23 AM
Your 2 cents makes sense. Goods points to try in the future.
Although, I guess there is a line that we shouldn't cross. Another words: if we make a bait swim so naturally and consistently, it may look too healthy to get a strike. I guess the idea is to make a bait draw attention to itself.
Saturday I gill-hooked a bass and tried to release him. A few minutes later, he was on the surface lying on his side giving the occasional spash and kick. A true wounded fish. If a lure performed like that, we would probably throw it away. Kind of put a light on things..
Posted 05 April 2011 - 07:48 AM
Good points about too much realism. But even though the bait looks real, it is giving off a different pressure wave pattern to a healthy fish.
The vortices that form around the head of the lure (and the fish), push the segments away and drift down stream away from the lure. Whereas a fish senses these vortices and leans into them, catching the turning water with its scales, thus getting extra forward momentum for free. The fish also grabs the last bit of energy out of the vortex with its tail and the vortex is broken into two vortices swimming in opposite directions.
The point of this techy talk is to point out that the predator picks up on all these pressure waves. Its senses probably tell it that it is not quite right, but it is moving under its own power, so it must be edible, a bit like a tiger eyeing up a Keystone cop. Even the most realistic of swimmers are going to appear injured to the predator. This perfect action that we are looking for, is more for ourselves than the fish. To build a swimmer and see it snaking across a pond, is very satisfying.
Posted 05 April 2011 - 12:03 PM
This is kind of a chicken/egg question.
I understand what you said about the vortices traveling down the sides of the bait, and amplifying the swimming action.
But we are pulling our baits through the water, and the tails are reacting to the passing vortices.
Fish push their bodies through the water with their tails, so it's almost the exact opposite of what we do with our lures.
How do the two different modes of travel relate?