Design a ray trap

[DavidW]

One of the biggest problems both fishermen and researchers have catching rays ( by line and hook) is that Piranha steal the bait.
Perhaps we could have a friendly competition to try to design a trap that would catch rays but not allow the P's to steal the bait. Something that would allow rays in but make it hard for other fish.
I have some basic ideas ( plexi case, letterbox entrance and weak spring) but probably it isn't very practical but maybe a collective brainstorm would produce some better results for a simple, cheap and easily constructed device ?
If something good turns up we will test the design on the Amazon in real life conditions.
Have at it

 

[DavidW]

In fact, if there is a design that looks workable I will also reward the designer myself.
How does $100 sound for the winner? It has to have a reasonable chance of working well.

 

[LBathory]

i wish i were more handy. this sounds like a cool idea.

 

[jwong1024]

sounds like an awesome idea, and to win a $100 too. the only problem, is that we have no way in testing and improving designs, ideas, and protypes. if it were that easy to build and R&D a trap, i think someone would have done it already.

 

[DavidW]

I think it is more that no-one has really cared before about catching rays without hooks at night in deeper water than you can wade in.

 

[turkeyboy85]

David, you should have brought this up about 6 months ago.... We had a research and development final class for my mechanical design engineering degree. You could have had a group of 5 engineers working on it, including making a working rapid prototype of the final design. In my free time ill draw something up using solidworks and make a video of what i think would work...

 

[DavidW]

P's are not the only offenders but they are the worst.
The trap should , if possible, also be inexpensive, fairly portable/collapsable and/or easily assembled on site.
I am not going to give away my $100 easily!
LOL

 

[MadRussian79]

So what are we talking as far as cost, weight, and assembly time? Also how long do you expect it to last and what size ray are we talking about?

 

[keepinfish]

why are they not using seine nets? just curious, never really thought about how they catch them?

 

[DavidW]

Cheaper is better

We are talking about use in Brazil, where no-one has any money at all

weight....as light as possible ( gotta carry them etc) but still will sink.
Assembly time?
time is not important, but simplicity is.

Sitting on the banks of the river frequently leaves a lot of down time

....waiting for the bodies of your enemies to float by! ( with apologies to the old Japanese proverb LOL)