Vortices, what's going on?

[UKandy]

Hi guys, not posted for a while I've been doing some more lure testing out on the water.

I've been working on a 7" one piece jerk/glide bait for some time now & have tried quite a few different things out throughout my testing stages, as I am using a resin/foam mix for the body (bottom half resin, top half foam) I have been messing around with all sorts of different mixes to achieve the buoyancy I thought I needed.

My first batch of test lures produced one lure that stood out from the rest, it had a really nice side to side swimming action on a steady retrieve & if paused upon the retrieve would glide maybe just over a foot in either direction, nothing hugely amazing but it worked well, the problem I had with this lure was it suffered from some belly roll, which became more obvious as it got closer to the rod tip.

This particular lure that worked well from the first test batch had 2 ballast placements, one was slightly infront of the centre of balance & one was slightly behind the centre of ballance (this ballast was basically as far back as needed to have the lure sink in a horizontal manner) the ballast holes were quite deep and near to the centre line of the lure, which I believed could be contributing to the belly roll I was seeing whilst retrieving the lures.

With that said I went back to the drawing board with the intention to correct the belly roll on the lures & maybe get a slightly greater glide. My thoughts were to use a heavier resin on the bottom half of the lures, this should mean that I would need less ballast which would allow me to keep the centre of gravity even lower down within the body, which hopefully would cure the belly roll problem.

After making the second batch of lure bodies with the heavier resin, I still felt that the ballast holes would be too deep & close to the centre line of the lure, so I opted to split the ballast so there were 2 ballast placements next to eachother just infront of the centre of balance & 2 placements next to eachother behind the centre of balance, this allowed for much shallower holes and kept the centre of gravity on the lure very low down.

Next was to get out & test the new batch of lures on the water, I found that on a steady retrieve the lures had lost nearly all of the nice side to side swimming action that the first batch of lures had produced & they pretty much had no glide action at all on a pause of the reel, whilst I was stood there thinking what exactly was going on, I happened to give the reel handle a really quick half jerk turn, which caused the lure to glide off in one direction about 4feet, surprised by this I reproduced the glide in the other direction with another swift jerk of the reel handle, I was baffled, these lures had lost nearly all action on any type of retrieve apart from a really quick jerk on the reel handle, I also noted that when the lures got closer to the rod tip the action would fade and the lures basically became a torpedo & still produced a slight belly roll.

This has got me rather confused as to what has made such a difference and why the lures would now be acting in this way, I would assume that the vortices would be acting exactly the same on each batch of lures produced, so I'm guessing the slight adjustment in ballast placement has thrown things off, I'm also wondering if using less foam for the top half of the lures would actually help with stability.

If the second batch of lures had kept the nice side to side swimming action on a steady retrieve & then I had been able to produce the 4foot glide with a quick jerk of the reel handle, I feel I would have been on to a real winner, unfortunately I've come to the point were it seems it's either one action or another.

Can any of you more experienced guys please give me any direction of what I can try next to have the lure produce the swimming action & glide action within the same lure, some shop bought ones I have do both, as you would expect, so maybe I'm down to fine line adjustments now.

Two last points I would like to make is that the belly hook on the lures has always been placed directly under the centre of balance, I have not yet tried putting one point of ballast exactly on the centre of balance of the lure & moving the hook placement, not sure if that would help or make a big difference in action, but thought it was worth mentioning, the second point is that the lures are near to critically balanced with an ultra slow sink rate, if I remove the hooks they would float, so could it actually be a point were I'm not using enough ballast to gain a better action in whole (more driving force weight).

Cheers guys, as always your help is massively appreciated 

Andy.

[ravenlures]

Just wondering why half/half and not the whole lure mix resin/micro balloon's which I think will give you overall control of lure weight and then add weights where needed. Not much of a swim bait lure maker but I make musky baits for casting and trolling.

Wayne

[UKandy]

4 hours ago, ravenlures said:

Just wondering why half/half and not the whole lure mix resin/micro balloon's which I think will give you overall control of lure weight and then add weights where needed. Not much of a swim bait lure maker but I make musky baits for casting and trolling.

Wayne

Hi Wayne, after a couple of conversations on here, I was advised that a pure resin/micro balloon mix would never get the same kind of desired action as from a wooden lure, but if a certain type of foam pour was used it would give a much livelier action nearer to that of a wooden lure, it was my decision to go down the middle and give a resin/foam mix a try   don't get me wrong a couple of people on here also pointed out that they thought it wasn't worth the hassle, I was and still are only starting out on my lure journey so I gave it a whurl  right or wrong Im trying!

Andy.

[Vodkaman]

Firstly, great work with your experimenting. There is so much information here, it is going to take several reads to soak it all up.

The 'closer to rod tip' thing makes sense. You are dealing with an action that moves side-to-side, so as the lure comes closer, the offset angle from the centerline increases.

Resin-MB mixes are literally just creating a pure wood alternative. The problem is that the wood alternative that you are creating is very dense, probably around 0.75g/cm³. The lightest material I was able to make with resin-MBs was 0.64g/cm³. So, if you can make a glider with heavy woods then you can make the same glider with resin-MBs. You will have to ask glider experts about that.

That is all I have for now, but will likely return with more confusion

Dave

[UKandy]

10 minutes ago, Vodkaman said:

Firstly, great work with your experimenting. There is so much information here, it is going to take several reads to soak it all up.

The 'closer to rod tip' thing makes sense. You are dealing with an action that moves side-to-side, so as the lure comes closer, the offset angle from the centerline increases.

Resin-MB mixes are literally just creating a pure wood alternative. The problem is that the wood alternative that you are creating is very dense, probably around 0.75g/cm³. The lightest material I was able to make with resin-MBs was 0.64g/cm³. So, if you can make a glider with heavy woods then you can make the same glider with resin-MBs. You will have to ask glider experts about that.

That is all I have for now, but will likely return with more confusion

Dave

Hi Dave great to hear from you, your input is always received with gratitude, so I will look forward to hearing more from you  

I tried to give as much information as possible so people can understand my dilemma, I know there are so many factors that can change a lures action, therefore I thought I'd ask for a little help.

Andy.

[Vodkaman]

Good decision to ask for help, and I hope you get it from experienced designers and builders. Unfortunately, I can only tackle this enigma from a purely theoretical place.

Dave

[UKandy]

Another note I have just made regarding the test lures:

I've been holding one upside down in the palm of my hand and it's very apparent that the lures are wanting to roll over quite aggressively at the slightest amount of tilt, the width of the lure bodies are 18mm and the diameter of the ballast holes are 10mm, I'm not sure if the ballast holes diameter ratio too body width are causing some of the roll problem on retrieve, maybe narrowing the diameter of the holes on another test lure too see?

Just thinking out loud, I could be going down the wrong rabbit hole here interested to know what you guys think & if it would make any difference 

Cheers Andy.

[LHL]

I'm far from an 'expert' but have some anecdotal advice I'd like to give you:

There's a fine balance between stability and instability in a glide and I think you did a great job showing this in your experiments. An 'unstable' lure will have a tendency to roll. This roll is also what causes the lure to have an 'S' swimming pattern when straight retrieved. Instability is increased the higher the center of gravity is. A ballast close to the center line will cause it to roll and the further away from the center line the more stable it will be.

A stable lure will have no roll, and therefore no swimming action on a straight retrieve BUT will often have a really good gliding action when given a hard twitch. It's because this hard twitch/jerk forces a point of momentary instability, and when the lure stabilizes itself it then glides like a torpedo in a straight line either left or right. 

You need something that is stable enough to glide, but unstable enough that it has a small amount of belly roll. From your experiments, I think you found both "extremes." My advice would be to find something in the middle.
Two things I would try:

1. Start with the most stable gliding bait, drill out your weight holes and add the weights. Test it. If it's a torpedo on the straight retrieve, remove the weights, drill the holes deeper (closer to the center line), put them back and test again. Keep doing this to see what happens. My thought is the closer the weights are to the center line, the more it will roll, but the less it will glide. 

2. Start with the better swimming lure. Remove a small amount of weight from the largest ballast and take that little bit you removed and add it back to the bait so that it remains level when sinking. Test it. Keep doing this until you achieve a glide that's far enough with a bit of belly roll and you should be able to also have it swim on the straight retrieve. 

The last thing you could do would be to change the shape of your lure... This sounds like it would be the most difficult but it would be interesting to see what your lure looks like to get a better idea of what's happening. 

[UKandy]

On 12/8/2021 at 9:35 PM, LHL said:

I'm far from an 'expert' but have some anecdotal advice I'd like to give you:

There's a fine balance between stability and instability in a glide and I think you did a great job showing this in your experiments. An 'unstable' lure will have a tendency to roll. This roll is also what causes the lure to have an 'S' swimming pattern when straight retrieved. Instability is increased the higher the center of gravity is. A ballast close to the center line will cause it to roll and the further away from the center line the more stable it will be.

A stable lure will have no roll, and therefore no swimming action on a straight retrieve BUT will often have a really good gliding action when given a hard twitch. It's because this hard twitch/jerk forces a point of momentary instability, and when the lure stabilizes itself it then glides like a torpedo in a straight line either left or right. 

You need something that is stable enough to glide, but unstable enough that it has a small amount of belly roll. From your experiments, I think you found both "extremes." My advice would be to find something in the middle.
Two things I would try:

1. Start with the most stable gliding bait, drill out your weight holes and add the weights. Test it. If it's a torpedo on the straight retrieve, remove the weights, drill the holes deeper (closer to the center line), put them back and test again. Keep doing this to see what happens. My thought is the closer the weights are to the center line, the more it will roll, but the less it will glide. 

2. Start with the better swimming lure. Remove a small amount of weight from the largest ballast and take that little bit you removed and add it back to the bait so that it remains level when sinking. Test it. Keep doing this until you achieve a glide that's far enough with a bit of belly roll and you should be able to also have it swim on the straight retrieve. 

The last thing you could do would be to change the shape of your lure... This sounds like it would be the most difficult but it would be interesting to see what your lure looks like to get a better idea of what's happening. 

Sorry for my late reply!

Thank you for the information you have supplied it's really appreciated, all good advice & I like the ideas you have suggested trying out, as soon as I have time I will get back to the lure blanks & do more testing.

 

On my next batch of testing I will add some pictures from start to finish so everyone has a better visual of the testing stages!

 

Many thanks again for your help,

Andy.

[RiverSmallieGuy]

I do not know a ton about controlling belly roll, but what I can offer is a bit of "logical" advice. I had only just found this thread, so I know I am very late to the party. What will say, though, is that when you think about belly roll, the lure is rotating around a point, or maybe a line. I believe that the point of roll is somewhere around the top of the ballast holes-- as in the deepest part of them. Not 100% on that, but I have had occasional anecdotal evidence to that. When something is rotating around a point like that, you can treat it like a jointed swimbait weight, just on a much smaller scale and on a different plane. What I think of in lures like that is a lever, and Vodkaman spoke about it brilliantly in his Glider Theory thread. He had said something along these lines: "Take a 3 foot wooden dowel rod grab it right in the middle. Place 1/4lb of lead on each side, then try to rotate it very aggressively-- its not easy to get that very fast, smooth motion you want. Place the lead right by your hand on both sides, and you can do it a lot quicker, and easier." You can think about this when trying to control belly roll. If you can find the approximate location of the point of which the lure rotates around when it has it's belly roll, then you can place a denser, smaller substance such as tungsten in the very bottom of the ballast holes. This would act as a lever that prevents the lure from rolling. This is just an idea, but I think it would work, or at least remove some of it. It is indeed more expensive, though.

 

Braden