matt duarte

weighting the tail of a swimbait

25 posts in this topic

ok so the first swimbait i made was crude and ugly, im pretty sure i posted a picture and a video a while back...since then i redesigned the body, mainly in the tail section. the first proto swam perfect in every way... now with these new ones im making somethings a little bit off... i weighted it yesterday but didnt weight the tail. i know most people dont weight the tail but most also have the tail hinged with one eye screw, mine has 2 as well as the rest of the joints. now i just did a test run in the pool and it tends to roll on its side. the first one didnt do that (i weighted the tail in the first proto) and the first proto didnt roll at all weather reeled in fast or slow it was flawless... so do you guys think that not weighting the tail can be the problem? there lipless swimbaits and i do have the head of the bait tapering down to the nose like it should..so the not weighting the tail is the only thing i can think of... and like i said the 2 baits are the same just with a diferent shaped tail section...

any thoughts would be great!

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I would not have thought that not weighting the tail would cause the roll. So my first question is, are you sure you didn't change anything apart from the tail, such as ballast location, ballast depth etc?

Assuming the answer is no, there is a small argument that does explain the roll. While the tail section has one eye hinge, any buoyancy will just raise the tail section and not affect the rest of the lure. But by adding two hinge eyes, the tail section cannot swing up (as you have constrained the motion to side only), it takes the other sections upwards with it. So as the tail swings outwards, the upward force of the buoyancy applies twist to the whole lure, hence roll.

I am not convinced by this argument, especially if the body is of a dense material, but if the tail section size was significant and the body material was balsa, then it could happen.

Dave

Edited by Vodkaman

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I would not have thought that not weighting the tail would cause the roll. So my first question is, are you sure you didn't change anything apart from the tail, such as ballast location, ballast depth etc?

Assuming the answer is no, there is a small argument that does explain the roll. While the tail section has one eye hinge, any buoyancy will just raise the tail section and not affect the rest of the lure. But by adding two hinge eyes, the tail section cannot swing up (as you have constrained the motion to side only), it takes the other sections upwards with it. So as the tail swings outwards, the upward force of the buoyancy applies twist to the whole lure, hence roll.

I am not convinced by this argument, especially if the body is of a dense material, but if the tail section size was significant and the body material was balsa, then it could happen.

Dave

ya the first proto had the same hinge style and swam fine..i did change the size of the segments in this one i forgot about that...and didnt really pay attention to how deep i went on the ballast on the first one.. i was pretty much guessing.. i wanted the swimbait (the first proto) to weigh around 4.5 oz so i just made it weigh that... i didnt put as much in this new one..i think the ballast might be the key on this...ill drill deeper into the belly of the bait for the weight, cause i think i did go deep on the first one...

well see how this plays out than, i have a few more blanks cut out (made sure i made a few in case mess ups like this happened)..

whats your guys take on the shape of the joint? like just rounding the edges or the "V" cut joints..will the swim the same or will it be totally different?

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Matt- gee a few pictures would help, I am having similar problems, although not as advanced as you, I have half completed just one.pete

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ok for some reason the gallery wasnt working for me...so i guess im gettng a infraction for this but here you go..maybe the moderater can move it to the gallery for me...

heres the hole drilled for the weights

preweight.jpg

melted the weights and poured in place

meltedweights.jpg

i put a drip of super glue to sucure the weights and then added bondo so i can get a smooth finish

puttybondo.jpg

and last but not least bondo dryed and i sanded it smooth

sandedbondo.jpg

you can see the shape of the joints in the pix...since i took the pix i re-drilled the holes deeper to add more weights higher up in the belly of the beast..

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personally I would move the weight thats the closest to the line tie in the head of the bait to the tail section and and keep it as close to the hinge as possible. Also try to keep your weight as low in the body as you can with removing weight. in other words drill a slightly larger hole. Hope this makes sense.

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so your saying dont go to deep in the belly? the holes in the picture are about 1/4"deep... i redrilled them last night and went about 1/2" in the belly havent got to test it yet but i will when i get home from work .. i also added more weight to the middle section and a tiny bit in the tail..

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Matt,

Is that lure PVC?

I ask because, since I've changed to PVC from poplar, and started using larger screw eyes and bicycle spokes for hinge pins, adding ballast has become a little more tricky for me.

All of my first four piece PVC baits, even the floaters, sat with the tail a little lower. In those, I was using the same 1/8oz. egg sinker with a cotter pin run through it and spread as my hook hangers, first and third section.

I typically shape and hinge a PVC bait, add the hooks, and float test it in a 5 gallon bucket on my driveway. Since it's waterproof, I can blow the water off afterward, hit it with a hair dryer, and be ready to proceed with either adding ballast, or priming and painting.

I just made a PVC version of my 6" crappie, three piece, but I didn't weight the rear hook hanger. Instead, I put almost all the ballast in the head, and a little in the middle section.

I did this to counter act the heavier PVC material and the heavier hinge hardware.

The lure sits the same now as the original wood version, which swam great and caught fish.

I decided to make one out of PVC because the wooden version is constantly getting splits in the top coat. I think it's because it's so tall and thin, 2 1/2" tall, that there is a lot of wood movement. Plus the carving on the head is where the splitting is occurring, so I think there's a weak spot in the film.

I would play around with the weighting by adding weight to the front and back hooks, or taping it to the belly, until I was happy with how the bait swam. Then I'd drill and add the weight where it's needed.

PVC is different enough from wood that I had to relearn where to add my ballast.

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mark: no these are still my wood protos... once figured out i will be molding them out of featherlite resin...

ok well adding more weight was the trick... it swims awesome fast or slow but.....theres always a but right... now its swims as if it had a lip, kinda has a side to side wobble as it swims in the "s" pattern..i mean its not bad but i dont want it to do that lol... any advice on how the wobble got there? maybe i drilled to deep in the belly for the weights? thats the only thing i can think of..its a skinny bait 3/4 to a 1" thick.. but i dont see that being the problem...since Triple trouts and a lot of other baits have a skinny profile..

thanks

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First off, their is nothing wrong with posting pics of your lure in this forum, provided it adds to, or clarifies a point in the technical discussion. If you posted a pic of the final result, with no technical discussion invited, merely to gain praise, then you would get a deserved infraction.

I am assuming that you moves the nose weight to the tail. This solved the roll. This fits in with my thoughts. But now thee head moves side to side.

By removing the nose weight, you have shifted the CoG rearwards. The forces that create the 'S' action apply a slight side force to the nose. By moving the CoG, you have given this force more leverage.

I think you need to move the rear weight in the head, to the original nose position, to move the CoG forward.

You should percevere with this and achieve the lure that YOU want, not just what you end up with. It may be an idea to post more pics to show where you are upto now.

Dave

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just my :twocents:

to stop a "swim"-bait from "rolling" without stuffing it with balast, i try to put the balast as low as posible (due to a distinct keel effect).

especially round sided "swim"baits tend to "bellyroll"

"deep" holes for balast, can get close to x-axys 0.

bellyweightqx1.th.jpg

i.e. javallon hard

Edited by dramone

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Sorry, I have had a further thought on this problem. Rather than moving the rear weight in the front section, I think it would be better to move the centre weight to the nose position. This would still move the CoG forward slightly, thus helping the leverage problem. But it would also increase the inertia of the front section, reducing its ability to move side to side (waggle). Here is an explanation that I have used before:

Take a 3' length of broom handle, tie half a brick to each end and twist it with your wrist. The stick is hard work to twist. Now move the half bricks to the centre, ether side of your hand and repeat the twist test. Now it is much more easy to twist.

Sorry for confusion.

Dave

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thanks guys! for all your help ill post some pix of where im at now so you can get a better idea...maybe a video to help visulize..

dramone: so you saying that the top picture or the bottom is a bette rway of doing it? mine are drilled like the top pic..i think i might of drilled past the centerline and thats whats causing the wobble? defently trail and error

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Matt,

I think you'll have to "rinvent the wheel", that is, play with ballast weight and position, once you switch to the featherlite resin. Different materials had different buoyancy characteristics.

As far as a wobbling head, I also have a side to side wobble in my four piece swimbaits. Weighting the front of the head cuts down on the wobble, but doesn't eliminate it. I don't think it's a bad thing for a lure. The more action, the better.

My three piece lures have a much more stable head, and the tail flaps like a flag on a fast retrieve. I'm pretty sure it's due to the three piece configuration.

I use a 2/1/1/1 ratio for my four piece lures, but more of a 1/1/1 1/2 ratio for the three piece lures, since they are only 4 1/2" plus the tail. This isn't scientific. I just looked at the lure bodies, layed out how much space I needed for hardware and ballast, and cut. It worked out for me.

Dumb luck, plus copying the basic layout of already proven lures, like the Triple Trout.

I'm in the middle of making a batch of lures for sale right now, so I don't have the mental energy to play around with segment sizes and ballast locations to try to determine a more precise answer.

That's a problem for a different day. :?

mark: no these are still my wood protos... once figured out i will be molding them out of featherlite resin...

ok well adding more weight was the trick... it swims awesome fast or slow but.....theres always a but right... now its swims as if it had a lip, kinda has a side to side wobble as it swims in the "s" pattern..i mean its not bad but i dont want it to do that lol... any advice on how the wobble got there? maybe i drilled to deep in the belly for the weights? thats the only thing i can think of..its a skinny bait 3/4 to a 1" thick.. but i dont see that being the problem...since Triple trouts and a lot of other baits have a skinny profile..

thanks

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Mark, another question. I'm not sure that I understand what you are saying about the ratio that you use on your lures. 2/1/1/1 and 1/1/1 is this the head length to body section lengths ratio?

Thanks, John

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Yes John. It's the head to other section ratios.

I've found that 1 1/8" is about the shortest section I can make and still have room for hardware and ballast, so my smallest four piece would have a 2 1/4" head, and three 1 1/8" sections, plus the plastic tail.

My 4 1/2" three piece has a 1 1/4" head and mid section, and a 2"+-tail section.

I'm sure other ratios work. This is just what's worked for me, so far.

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This isn't much of a helpful post from me but sometimes wood densities can really throw a lure out of sync. Even within the same wood plank densities can be different. I've come accross this problem on occasion with my smaller cranks. There isn't anything you can do about it. My advice, make another one the exact same way as you did the original and see if it swims any different. Not saying that this is for sure the problem. Considering that you made this lure identical to the original and have a different swim, it just sounds like a wood density issue that I've had before. This is also another reason why guys start switching to pvc.

Also, try applying silly puddy to the bait in different areas. Sometimes, the hydrodynamics can be slightly off and can be greatly affected by the wood's density. Just my :twocents:

Good luck.

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Gadawgs. Moving a centre weight to the front does not move the CoG to the front, it shifts the CoG to the centre of the front section, given that the forward and rear weights are identical. But it does dramatically increase the inertia of the front section.

This will reduce the head 'waggle', but not eliminate it. In fact, for the lure to work properly, a certain amount of 'waggle' is required, but barely visible is sufficient.

Dave

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Vodkaman, I liked your analogy with the broomstick and bricks.

A-mac brings up a good point, the problems you are seeing may be largely related to the density of the material you are using to build the lure.

One thing I have found makes a difference is how smooth the joints are operating. The slightest "catch" in the motion of the joint seems to magnify once the bait gets in the water.

Swimbaits are a relatively new topic on TU and with time I expect we will better understand the cause of problems such as rolling, wobbling, coming in on its side, etc.

jed

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Please do not get me wrong, I am learning with the rest of TU. I am just applying engineering principles. Also, I am reading everything that has been written, watching every video, making notes and trying to put a theory of operation together that explains everything. I don't expect to br right everytime, if my suggestions don't work out, please let me know, or I don't learn.

I promise that when I solve the theory thing, it WILL be published here.

Dave

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I didn't meen to imply that move the weight forward in the head would eliminate the head motion but it most cases it will significantly reduce it.

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