Design Problem

[Big Epp]

I'm working on this jointed lure.  I don't know if it'd be called a swim-bait, a wake-bait, or what exactly, but it didn't work.  I'm wondering what you think the problem is.  I have two ideas:

1) the flat cut front side of the joint is too wide, and therefore blocks the water from pushing against the second section.

2) the tail piece is catching water evenly, causing it to stabilize the second piece instead of causing it to move back and forth.

I cut the end off the tail, but have not tub tested it again yet. 

[AZ Fisher]

Boot style tails are traditionally used on soft baits that are more flexible than wood. If you remove the sides of the tail and create more of a bass/gill vertical tail I think you'll see better action.

[Vodkaman]

You have got your V-joint totally the wrong way around.

Put the chamfer on the front piece and the Vee on the rear.

But, you are dealing with a rear lip, so not sure how this will pan out. I would suggest decide if you are working with hard baits or soft baits, and get rid of the boot tail.

But, I have experimented with boot tails on hard baits. It is an untested area, and so I would also encourage experimentation. What you have to determine is what comes from the rear lip and what comes from the front.

What often happens is a conflict between the front vortices and the rear.

I am conflicted with my advice. I would like you to continue experimenting

Dave

 

Edited March 4, 2020 by Vodkaman

[Vodkaman]

If you reverse the Vee, you may find a double action; A slow Sss action derived from the front of the lure, and a more rapid oscillation from the tail boot.

Here is a video of an experiment with a soft bait. The idea was a bulbous nose to create action from the front, in a swimbait style, and a boot to create action at the rear. The result is kind of what was expected, but more front action than rear.

I believe there is more life in this idea, and you are on that road

Dave

 

[Hillbilly voodoo]

I would listen to Dave on this one 

[Vodkaman]

Hillbilly - Like I said; an interesting area largely unexplored.

Dave

[Big Epp]

Thanks @Vodkaman, when it didn't work, my first thought was, "there must be something wrong with the vortices."  This is not something I would have thought about, except for having read some of your previous posts.

I'll keep working on this, and will post updates as to progress made.

[Vodkaman]

Big Epp - this one is worth investing some time, believe me. Come back with results, preferably video, and perhaps I can guide. But it is largely down to you and note taking. You must record everything and don't throw failures away.

Expect to have to go through many iterations. This is all a part of breaking new ground. You have to establish the rules, the design parameters.

I don't think I have posted the Big Ed vid before. I was waiting for the right opportunity.

Dave

Edited March 4, 2020 by Vodkaman

[Hillbilly voodoo]

26 minutes ago, Vodkaman said:

Hillbilly - Like I said; an interesting area largely unexplored.

Dave

I probably still have a boot tail jointed hard bait somewhere. It has a shorter tail section, flat joint and the boot is made of lexan I screwed into the back of the tail. Fish did not care for it and it had hook up issues when it got bit so I just never followed through 

Just noticed something on Big epp’s design that I did and it kills the action. If that is a hook hanger coming out of the boot tail the hook weight kills the action. 

[Big Epp]

Good catch @Hillbilly voodoo!  I didn't have a hook on it when I tested it, but I wondered if that might happen.  Also, I'm glad you mentioned the lexan tail boot... I was going to try that.

[Hillbilly voodoo]

The lexan worked I did that so I could try different sizes and shapes for the tail just by screwing them in

I would not call mine a great success though. It was one of those projects I just put aside and moved onto other things 

 

[Vodkaman]

Yes, agreed, no hook in the tail for sure. Perhaps just behind the hinge.

This lure is definitely a combination of front shape and rear boot size, with the correct hinge geometry.

For prototype purposes, I would fix the joint Vee geometry and work out some adjustable/ replaceable rear boot. Always include hooks in the testing as they have a profound effect.

Initial prototypes do not need to catch fish, you are only looking for an acceptable, pleasing or unusual action. A simple screw exchange of rear boot is all that is required until a reasonable action is achieved.

Then build a working lure to test on fish, comparing with regular lures.

It is a long process.

Dave

[KennyP]

19 hours ago, AZ Fisher said:

Boot style tails are traditionally used on soft baits that are more flexible than wood. If you remove the sides of the tail and create more of a bass/gill vertical tail I think you'll see better action.

Because these are flexible I would assume that the angle of the boot fluctuates.  Would changing the angle of the boot possibly help?

Edited March 5, 2020 by KennyP

[Hillbilly voodoo]

26 minutes ago, KennyP said:

Because these are flexible I would assume that the angle of the boot fluctuates.  Would changing the angle of the boot possibly help?

You might be onto something because if my memory is correct the one I made the boot is angled. 
 

I will have to find one of the boot baits I made to see what I did 

[mark poulson]

I have made two piece hard baits, and the only way I found to get good action in them is to add a lip.

Otherwise, I would keep the forward facing V, nested into a concave V rear face of the front section, and eliminate the boot tail completely.  The two lure sections will swim in an S shaped glide bait action.  In your case, the boot tail is dampening the action, like a wind sock, not enhancing it.

If you want more action with no lip, make a three piece bait, with no weight in the tail section and a looser rear joint.  It will flap like a flag in the wind on a fast retrieve.  But keep the tail thin, with a simple vertical design.  You don't need the tail to impart action in the bait, you want it to be able to move freely once the action has been passed on down to it by the two previous sections.  Think Dave's vortices, passing along the sides of the bait, and really activating the tail section.

[Hillbilly voodoo]

The boot tail can kick without a lip and it will have a different action then your conventional swimbaits. Even a non jointed boot tail hard bait will have action without a lip. I actually proffered the result I got from the non jointed version 

you guys are going to make me dig around looking for these prototypes. I am try really hard to focus on a couple projects at a time so I complete them instead of my all over the places too many projects habit I have had for years 

 

 

[Vodkaman]

Mark is right.

Attacking the problem mathematically, what frequency would you expect the lip to oscillate at, back and forth being one cycle?

Looking at the body, I would estimate 1 - 2 cycles per second.

Now let's look at the simple maths:

Strouhal number     St = f x d / v

Where - f = frequency (Hz)   d = width of lip metres (m)    v = velocity (m/sec)
St for a flat plate (lip) is between 0.12 ans 0.16.

f = St x v / d

St = 0.12 : v = 1m/s : d = 0.025m (1")

St(0.12) = 4.8 cyc/s : St(0.16) = 6.4 cyc/s.

Conclusions - the speed of the oscillations is way too fast, and so the tail section will barely vibrate.

The boot works for a soft bait because of the very flexible connection which allows the boot to achieve its full movement at 4.8 cyc/s without restriction. On a hard bait, the movement is restricted to the movement of the hinge and the inertia of the rear section. The section barely moves one way before the lip forces reverse and moves the section back.

Dave

Edited March 5, 2020 by Vodkaman

[mark poulson]

7 hours ago, Vodkaman said:

Mark is right.

Attacking the problem mathematically, what frequency would you expect the lip to oscillate at, back and forth being one cycle?

Looking at the body, I would estimate 1 - 2 cycles per second.

Now let's look at the simple maths:

Strouhal number     St = f x d / v

Where - f = frequency (Hz)   d = width of lip metres (m)    v = velocity (m/sec)
St for a flat plate (lip) is between 0.12 ans 0.16.

f = St x v / d

St = 0.12 : v = 1m/s : d = 0.025m (1")

St(0.12) = 4.8 cyc/s : St(0.16) = 6.4 cyc/s.

Conclusions - the speed of the oscillations is way too fast, and so the tail section will barely vibrate.

The boot works for a soft bait because of the very flexible connection which allows the boot to achieve its full movement at 4.8 cyc/s without restriction. On a hard bait, the movement is restricted to the movement of the hinge and the inertia of the rear section. The section barely moves one way before the lip forces reverse and moves the section back.

Dave

Dave,

I love it when you explain things this way.  It makes sense.

[Big Epp]

Thanks for all the input!  I've cut off the boot for this one.  I'll tub test it as is and see what happens, and if I'm not happy with the action I'll add a lip and test again.  There's 1/8oz of weight in the tail section, which may over-stabilize it and prevent it from having much action.  Hopefully by Monday I'll have some progress on this!

@mark poulson "wind sock" is exactly what I was thinking the problem might be.

@Hillbilly voodoo I'd love to see the one's you tried, as there's got to be a way to make this work.

@Vodkaman Thanks for the math!  That was a very precise way to break this down, and while I'm not particularly mathematically inclined it definitely communicated the point.

Thanks all!  This thread has been really helpful so far, and I appreciate all the different approaches and perspectives!

[Big Epp]

Check this out!  Somebody makes a boot-tailed hard-bait:

[Hillbilly voodoo]

That is closer to the proportions of jointed one I made. My tie point was on top of the head roughly where the eyes are on the bait. The face was also steeper 

I will see if I have a boot tail prototype I can find. I have moved since I made them so not sure where they are. I think I have a non jointed one in my glove box but it’s rough unfinished 

[mark poulson]

5 hours ago, Big Epp said:

Check this out!  Somebody makes a boot-tailed hard-bait:

That isn't a boot tail, it's a Huddleston-like swim tail which creates vortices as water passes the sides and causes a gentle side-to-side swimming action.

[Chuck Young]

As I was reading the earlier posts (before the last picture was posted) I was wondering if going to a single hinge point instead of a dual one would enhance the action. I have fished a ton of soft baits with boot tails. The tail doesn't just go side to side. It pitches up and down and rolls as well. I think the tail section should be shorter than the head section.

[mark poulson]

Sprinker and Booyah solve the problem of getting movement in a two piece lure with a boot tail by attaching the boot tail with a swivel:

https://www.tacklewarehouse.com/Booyah_Toad_Runner_Frogs/descpage-BYTRF.html

[Hillbilly voodoo]

So far out the search of the truck only turned up 3 crankbait and one lipless trolling plug prototype.

 

if I don’t find my old boot tail baits I will make a new one just rough to accomplish the action again. With marks comment on the pic post I am wondering if mine will meet the definition of a boot tail though
 

Fighting a cold so I am not rushing to build a new one or search hard for my old ones so don’t expect anything quickly