Vibrating Flasher

[Shadowkiller]

I've decided to post my vibrating flasher design in a seperate topic. The Powerhead topic was getting bit big...

Basic structure:

4 down lights ie the ultra bright 12Volt lights you can buy for your home.
1 random voltage circuit (my friend Ben is designing it)
1 vibrating paddle with vibrating motor mounted on it.

The lights are mounted in PVC pipe in a cross configuration and water proofed. The variable volts circuit will trigger transistors to flash the lights. Hopefully the frequency of vibration and flashing will be roughly proportional.

A pipe will extend below the cross to house the circuit/batteries and the vibrating paddle. The cap of the pipe will have slot cut with the paddle inserted to half of it sticks out. The motor will be mounted on the internal part of the paddle. I will use Silicone to seal the paddle joint.

I decided to do it with an extra paddle to eliminate the damping effect that would occur should the motor be mounted directly to the housing. The weight of the housing (and ballast needed to make it sink) will have a considerable damping effect.

Hopefully construction will begin this weekend...

I will post sketches tonight hopefully...
:hmm

btw If anyone is interested in robotic and other electronic stuff check out www.wollonong.apana.org.au/~ben

 

[Shadowkiller]

Ben's website is down until he gets of his butt and fixes the ISP problems..

He's our webmaster at Apana..

 

[andrsn]

how about isolating your ballast from your invention? should reduce dampening significantly.

yeah, pics would be cool.

andrsn

 

[Shadowkiller]

I thought about hanging some weight below the unit but would prefer to keep the whole thing as compact as possible. The fewer things that can get tangled the better. I've run some equations and found that by using my paddle idea and a heavy case the vibrations should be transmitted to the water more effeciently. Though the dampening factor of silicone is still a mystery..

Pics are going to have to wait until I can post from home (I'm at work atm). At home I can't log into any password protected websites due to problems with out proxie settings... long story...:hmm

Does anyone have a rough idea of a frequency of vibration emitted by dying fish? I've noticed Bonito vibrate a lot faster than say a Scad or Blackfish. Guess tuning the vibrator will be an empirical excersise. :duh

 

[andrsn]

frequencies...

the larger the fish, the lower the frequency. just remember that different stages of death or types of wounding results in minor changes in frequency. the key is to match the amplitude w/ your frequency. lower frequencies w/ high amplitudes is where you'll run into the johnny issue.

 

[Abriapnea]

Hey Shadowk. , are you familiar with the "buzzbomb" ?It gives off vibrations when spinned that drive mackerel wild .
I use it when nothing comes to my flashers . Downside is it really agitates the fish , makes them skittish . Jacks however show almost no interest .

 

[nebbian]

If anyone's interested in the BuzzBomb, here's the homepage for it.

There was something similar used on a spearfishing trip that shadowkiller and I went on a couple of months ago -- it was a device that looked like a ladder, and the guys were pulling it up and down in the water, making the little plates spin like crazy. It seemed to be attracting the kingfish a bit, although I couldn't get near the suckers, they were so deep.

I've come up with an electronic design for a pseudo random pulse generator which is quite simple and cheap, and hopefully should prove interesting to kingfish. I still can't get the 1 metre kingfish I saw last weekend out of my head... if a poorly speared salmon can be so interesting to a kingfish, then I'm sure a crazy shaking underwater christmas tree will be irresistable!

 

[Griff]

That Ladder sound like a Rob Allen wobble plate flasher. did it have a big squid on the bottem?
i've made my own ladder type setup using perspex mirrors. i'm going to be testing it tomorrow.

 

[Iyadiver]

Can we make a fish vibrator that emits rumble which is equivalent to "FISH" language that means :

" Ohhhhh Baby, Yeah !!! I'm comin...more, more "

Maybe we can real attract horny fishes, not all fish are hungry you know...

 

[Abriapnea]

Originally posted by Griff

i've made my own ladder type setup using perspex mirrors.

Griff , stick a pink squid on the bottom , it's the bees knees for couta
Hope you remembered to seal the edges of your plates thoroughly , seawater seeping in will blacken the mirror eventually .
Good luck .

 

[andrsn]

Originally posted by Iyadiver
Can we make a fish vibrator that emits rumble which is equivalent to "FISH" language that means :

" Ohhhhh Baby, Yeah !!! I'm comin...more, more "

Maybe we can real attract horny fishes, not all fish are hungry you know...

IYA, i thought you were married?!

 

[Shadowkiller]

Iya: The last thing we need is some 200lb fish trying to hump our legs while 25m down...
Actually the fish equivalent of alcohol would be certain pheromones and tidal/moon phases. And I'm telling you right now Iya, I ain't building a tidal generator and anti-gravity moon controller. I'm busy on the weekend.

What nebbian aka Ben (post above) is refering to is the RA Chicken. Works pretty well but is darn expensive. When jigged the horizontal parts rotate and vibrate. There are also ball bearings inside to rattle around.

Abri: Never heard of a "Buzzbomb", "Buzzbong" yes.

As for amplitude (intensity) vs frequency. I guess a small paddle is going to mimic a small fish. It wouldnt be practicable to mimic say a 60cm Salmon thrashing around but a 25cm Scad (baitfish which kingies love) should be managable.

Funny thing: When Ive speared Luderick which then went ballistic the kingies have never shown up. The one time I had an almost dead Salmon (twitching slightly) on my stringer I had kingies surrounding me...

 

[Iyadiver]

Anderson I am married, YES, but that doesn't stop me from being a happy weekend warrior.... ha ha ha ha. All u need is stealth mode practice.

Tell if if this is possible............
Say we record a fish being shot and all its vibration on a video camera. Some has an external underwater microphone. Later we use some spectrum analyzer or whatever high tech sound card we have on the PC to isolate the frequency of the vibration. It could be in the low hz where it is beyond our ears. With audio tools we can ID the specific frequency and its "pattern". Make sense ?

Later we may mimic bait balls being attacked by predators, maybe an underwater speaker might do this job. In fact if with a proper U/W speaker that can emit wide range of frequency well below 5Khz, to say 20Hz ( subwoofer ), it might be easier to make than a vibrator where audi frequency output is very mechanical. U can emit all kind of sound from a CD recorder and have less hassle of mechanical failures from a speaker. U can even set loudness as easy as installing an additional amplifier.
I recalled that if u play decently loud on the boat where the speakers are mounted on the fiberglass body, I can hear the music underwater if I am only a few meters off the boat.

Wha da ya say engineers ???

 

[poacher]

Shadow
You live almost halfway betwwen Warrila and Pt Kembla should be able to buy something that vibrates from one of those places.
A woman I know said that dolhin ones are very good. :hmm