Lexan and Weight

[MuskieKiller]

If you saw my last post, I ended up going with a belt sander. With my jigsaw and Dremel I can get rough cuts and then quickly sand whatever it is to perfection. I decided to try the belly cut through wire and it seems like it will work out. A few questions. How thick of lexan would you use? The bait is 5.5 inches. Also where would you put the lead? It is German Beech so it’s a hard wood. TIA

[IsaiahW]

I personally use .093 inch polycarbonate on my lures. It seems to be the right thickness for a good action, however I am relatively new to bait making so it might not be the best. To find where to put the weight I usually lightly hold the bait in between my thumb and middle finger as close to the center as possible, usually you will notice it will tip one way or the other because you are not perfectly in the center of mass. I then adjust my fingers until it balances out and put the weight there.

Hope This Helps!

Edited January 24, 2021 by IsaiahW

[exx1976]

Weight placement isn't something any of us are really going to be able to tell you.  You're going to need to make several baits of the same design, and put weight in different places on all of them and see how you like the action.  One lure might do great with weight right in the middle, one might do great with a single weight towards the front, another might do great with two weights evenly spaced apart, another might need more toward the front than the rear..

Also depends on what type of action you're looking for as to where you place the lead.  Further, you're going to need to be very judicious with the amount of lead you use if you intend to have a floating lure.  Beech is much more dense than most of the types of wood used by lure makers, so you don't have much room to play with.

[JD_mudbug]

 

Congrats on getting the belt sander. 

I would go with .093 on a 5.5" lure unless it is going to be over 2 oz. or have a long lip.

From the other post:   Generally, I go with .093" Lexan for small lures 4" to 6.5" usually under 1.5 ounces. I go with 1/8" (.125") Lexan for bigger lures 6.5" to 11" that range from 1.5 to 3.5 ounces. For lures bigger or heavier than those, I go with 3/16" Lexan. Lures near the gray areas in between those ranges may get a thicker or thinner lip depending on the way the lure will be fished and the size of the lip. If the lip is going to be a long lip, I usually go thicker on the lip material because the risk of the lip breaking is higher.

As for weight, I agree with testing on the weight especially using a wood like German Beech. That wood is up there with oak in density. I did not have much luck with oak for lures. You can soft glue or rubber-band the weight on the sealed body to see how the lure sits in a bucket or drag through the tub or other unfrozen spot to see if you get any action. If you put the weight on the center of balance, the lure will sit close to flat. If I am using one ballast weight, usually I put the ballast on the center of balance or slightly forward of it for a shallow diver. On deep divers, I move the weight forward more so the lure sits more nose down. If I am using multiple ballasts, I place the weights on each side of the center of balance and locate them to achieve the same type of nose positions.  I like 2 ballast weights on  big musky/pike jerkbaits and trolling lures with one on each side of the center of balance.

http://www.tackleunderground.com/community/topic/37010-i-built-a-simple-bait-balance-to-find-center-of-mass/

 

[Vodkaman]

Lip function – to create the vortices that cause the lure’s waggle action. It is fact that a sharp edge causes a stronger vortex than a blunt edge. This would suggest that a thin lip would be better, BUT, the knife edge can be achieved with a chamfer.

Bending – lip materials do bend. The bending is a function of material thickness, free length, width and the mechanical properties of the material.

How much bending is acceptable?
Is some bending desirable?

Weight distribution – obviously the thicker the lip then the more the COG of the lure is affected. The thicker lip dragging the COG forward, thus affecting the distribution of ballast. This could be good or bad, but it is all a part of the lures balance. If you double the lip thickness and keep everything else the same then the balance of the lure changes.

Dave

[JD_mudbug]

That's a great point on chamfering the lip edges. I don't have confidence in Lexan thinner than .093" lasting long on musky/pike lures. I usually chamfer the edges of .093" Lexan and thicker just in case the thickness could reduce action. I don't get the edge to quite a sharp edge though. I reduce the edge thickness by using a file on an angle at the edges on both faces (except the edge that goes in the lip slot). Then, I use very fine grit sandpaper to smooth any roughness. I leave a thin flat section maybe a 1/3 of the lip's original side that angles out on both sides to the faces. After you get the hang of it, it takes a minute or two to chamfer a lip.

I also usually slightly round any very sharp corners to reduce the chances of cracking the corner off if the lure hits a rock or hits the side of the boat during a fight/netting. I don't like any sharp corners or edges on the lips of musky/pike baits.

[Vodkaman]

JD - I don't even know how critical or effective the chamfer is, but builders who have worked with many materials claim that the thinner fiber boards are the most effective, and this fits with theory.

I like 2mm polycarbonate for all my lures. I only build small lipped lures 3" length. I don't bother with the chamfer. If I was selling and looking for a little bit extra then I would chamfer for sure.

Dave

[JD_mudbug]

The theory just makes sense that with 2 identical items, except for thickness, the thinner item would pass through any medium more easily.  I certainly don't know if chamfering is effective on a lure or when incremental lip thickness would reduce action. I don't see how it can hurt to have the edges chamfered. I figure I might as well do it before I install the lip when it is easy to do. 

My baits tend to be between 5" and 12".  A lot of my baits use 1/8" (.125") or 3.175 mm polycarbonate.  The lips are typically 1" long by  1" wide and larger.  Chamfering could just be a confidence thing for me.  A polycarbonate lip at .125" thick just looks thick when you have it in your hands. It just looks like it would be tough to get that flat side edge on a big lip to cut through the water easily.  I'll take anything that can help get the maximum waggle on a big bait. I don't chamfer 1/16"  (.0625") or 1.5875mm when I do occasionally make smaller baits.  I am on the fence about chamfering .093" (2.3622 mm) but I tend to do it. I don't have 2 mm (.07874") readily available where I am. That would be a nice in-between size to have.

 

[exx1976]

8 hours ago, JD_mudbug said:

The theory just makes sense that with 2 identical items, except for thickness, the thinner item would pass through any medium more easily.  I certainly don't know if chamfering is effective on a lure or when incremental lip thickness would reduce action. I don't see how it can hurt to have the edges chamfered. I figure I might as well do it before I install the lip when it is easy to do. 

My baits tend to be between 5" and 12".  A lot of my baits use 1/8" (.125") or 3.175 mm polycarbonate.  The lips are typically 1" long by  1" wide and larger.  Chamfering could just be a confidence thing for me.  A polycarbonate lip at .125" thick just looks thick when you have it in your hands. It just looks like it would be tough to get that flat side edge on a big lip to cut through the water easily.  I'll take anything that can help get the maximum waggle on a big bait. I don't chamfer 1/16"  (.0625") or 1.5875mm when I do occasionally make smaller baits.  I am on the fence about chamfering .093" (2.3622 mm) but I tend to do it. I don't have 2 mm (.07874") readily available where I am. That would be a nice in-between size to have.

 

It's not about cutting through the water, it's about creating turbulence.  Dave posted a Vortex Shedding video that illustrates this.  A few nights ago, I got curious, and I also found videos for vortex shedding around a square (not as violent) and vortex shedding around a cylinder (even less violet).

I'm certainly no physicist, but in layman's terms, the more time the water has to "smooth back out", in the case of the square, with it's (relatively) much longer sides than a fishing lure lip, or with a cylinder, with it's gradual water splitting and recombining, both produce vortices that are not nearly the same as the thin material in the illustration video Dave posted.

The chamfer helps to thin that edge, which creates more turbulence.

Edited January 24, 2021 by exx1976

[JD_mudbug]

I am not a physicist either. I saw Dave’s video. His videos are always worth watching.  I think it is about both turbulence/vortex shedding and cutting through the water. It just seems that both factors come into play. No doubt the thin edge helps the water recombine or smooth out. I guess cutting the water is better called inertia.  The initial force required to get a thicker edge to move or cut through the water is greater. The thinner edge will start easier. The same happens on the opposite edge of the when the lip starts the other way on its return. The lip has to start moving before it can create turbulence. This is one the claimed reasons the Jackhammer Chatterbait is so popular. It’s thinner blade starts immediately on the retrieve, after a pause or bumping an object.

[Vodkaman]

Often to understand a function or concept you have to take the idea to extremes. I offer up a ball and dinner plate analogy. The spherical ball can be forced through the water with very little effort, but the flat plate requires a relatively HUGE effort to move through the water even though the diameters are the same.

It is natural to think that water resistance is caused by the weight or force of the water trying to get out of the way of the object, the water pressing on the lip as it is pulled through the water.

The actual truth is a most unnatural concept to grasp which is why I rarely mention it; water resistance is the vortices pulling back on the edge and rear of the plate. Water resistance is NOT water pushing the plate, it is water pulling on the plate.

When watching Olympic swimming events, I noticed that the best swimmers seemed to have a much slower cadence than the also-rans. These super-swimmers have mastered the vortex tow. The irony is that they don’t know why or how they are doing it and neither do their coaches.

Next time you are in a pool or lake, pull your hand hard through the water. You will notice that your hand pulls left and right as the vortices form. As a vortex peels off and a new vortex starts to form then there is less water resistance, less swimming force.

The secret is to control the vortices, to hang on to the single vortex as long as possible without it peeling off. If you pull too hard or fast then the vortex peels off and power is lost.

The double irony; I have not been swimming since I discovered this stuff!

Dave

[exx1976]

2 hours ago, JD_mudbug said:

I am not a physicist either. I saw Dave’s video. His videos are always worth watching.  I think it is about both turbulence/vortex shedding and cutting through the water. It just seems that both factors come into play. No doubt the thin edge helps the water recombine or smooth out. I guess cutting the water is better called inertia.  The initial force required to get a thicker edge to move or cut through the water is greater. The thinner edge will start easier. The same happens on the opposite edge of the when the lip starts the other way on its return. The lip has to start moving before it can create turbulence. This is one the claimed reasons the Jackhammer Chatterbait is so popular. It’s thinner blade starts immediately on the retrieve, after a pause or bumping an object.

You've completely missed it.  The thin edge makes it MORE DIFFICULT for the water to smooth out, not easier.  You don't want the water to smooth out. Turbulence creates vortices, not smooth water.

Also, the thickness of the lip doesn't have much to do with inertia at all - unless the lip weighed many pounds.  The force you are likely trying to refer to is drag, or resistance, which still would have no effect unless the lip was sticking straight out the front of the lure, perfectly parallel to the angle at which you are pulling the lure forward.  However, the lip is in the water at an angle.  You are pulling forward, from the front of the lure.  The lip is facing at a downward angle.  The force you are trying to overcome (Dave's incredibly scientific and correct explanation notwithstanding) is the force being exerted against the flat face of the lip, not the edge of it.

Edited January 24, 2021 by exx1976

[JD_mudbug]

I understood it with the hand in the water example. It's definitely counter intuitive.

 

 

Edited January 24, 2021 by JD_mudbug

[Vodkaman]

The forces are at the edge and rear face of the lip, but let's not make this a science class pop-quiz.

Dave

[JD_mudbug]

Dave, in an alternate reality, I see you working with the Tall Man from Phantasm.

'I think those spheres could be improved a bit'.

[Vodkaman]

JD - The spherical domain enclosed by the tall man's spell of 4πr³/3 is an intriguing and fascinating subject. It is the simplest shape and yet the most difficult to carve. I have actually experimented with spherically derived shapes and the resulting actions are interesting. If you pull a sphere through water you get a pure spiral action.

I do most of my cranial development work while sleeping, so you could say that I work in an alternative universe

Dave

[mark poulson]

On 1/24/2021 at 4:08 PM, Vodkaman said:

JD - The spherical domain enclosed by the tall man's spell of 4πr³/3 is an intriguing and fascinating subject. It is the simplest shape and yet the most difficult to carve. I have actually experimented with spherically derived shapes and the resulting actions are interesting. If you pull a sphere through water you get a pure spiral action.

 

I do most of my cranial development work while sleeping, so you could say that I work in an alternative universe

Dave

Does the sphere rotate clockwise or counter clockwise?

[exx1976]

1 hour ago, mark poulson said:

Does the sphere rotate clockwise or counter clockwise?

Depends on which side of the equator you're on. 

[Vodkaman]

Mark - direction is random.

Dave

[mark poulson]

On 1/26/2021 at 5:53 PM, Vodkaman said:

Mark - direction is random.

Dave

Thanks Dave.

[Hillbilly voodoo]

When it comes to weighting crankbaits just float test them it’s so simple even I can do it 

cut lip slot and just pressure fit the lip. Hang hooks because they effect balance. Lastly tape or elastic band weight in assumed locations. When the lure floats level or slippery nose down you are onto something.

when it comes to balance it’s all about achieving the lip angle you want for the action. Once you have the balance you can play with the weight to tighten or open the action. 
 

This is the dumb redneck way but if you prefer Dave likely knows a formal to get you within a C hair of exactly what weight and location 

[Big Epp]

I'm no lure-building psychic either 

For weight placement I like using a hot glue gun.  The stuff cools really quickly and allows me to move the weight around easily.

Anyone use aluminum lips?  If so, what thickness?  I have been thinking about getting some aluminum flashing material to use as lips for smaller lures.  I'd imagine it'll be a little heavier, which might actually help with how the lure floats in the water.

I've tried using old CDs to make lips for smaller lures, as they are made (were made?, does anyone but me use CDs anymore?) from poly-carbonate.  It's pretty tough to snap a CD, but once you start cutting it up and making lips with it it gets pretty snappy.  I've made some 2" jerkbait style lures and the CD lip was probably 1/2x1/2" and it snapped pretty easily. So DON'T use CDs.

[exx1976]

1 hour ago, Big Epp said:

I've tried using old CDs to make lips for smaller lures, as they are made (were made?, does anyone but me use CDs anymore?) from poly-carbonate.  It's pretty tough to snap a CD, but once you start cutting it up and making lips with it it gets pretty snappy.  I've made some 2" jerkbait style lures and the CD lip was probably 1/2x1/2" and it snapped pretty easily. So DON'T use CDs.

That's because they are a layered material, and one of the layers is acrylic.

[Jhnnyboy54]

On 1/24/2021 at 4:05 AM, JD_mudbug said:

The theory just makes sense that with 2 identical items, except for thickness, the thinner item would pass through any medium more easily.  I certainly don't know if chamfering is effective on a lure or when incremental lip thickness would reduce action. I don't see how it can hurt to have the edges chamfered. I figure I might as well do it before I install the lip when it is easy to do. 

My baits tend to be between 5" and 12".  A lot of my baits use 1/8" (.125") or 3.175 mm polycarbonate.  The lips are typically 1" long by  1" wide and larger.  Chamfering could just be a confidence thing for me.  A polycarbonate lip at .125" thick just looks thick when you have it in your hands. It just looks like it would be tough to get that flat side edge on a big lip to cut through the water easily.  I'll take anything that can help get the maximum waggle on a big bait. I don't chamfer 1/16"  (.0625") or 1.5875mm when I do occasionally make smaller baits.  I am on the fence about chamfering .093" (2.3622 mm) but I tend to do it. I don't have 2 mm (.07874") readily available where I am. That would be a nice in-between size to have.

 

I'm a newbie, so take this with a grain, but my thought is, that if nothing else the chamfer would protect the edges of the lips. Also I've seen mentioned somewhere that some makers at least soften the edges to save line from possibly getting cut during a fracas with a trophy or any fish for that matter