Fish/Shrimp trap

thingiverse

This contraption is designed for easy attachment to a plastic bottle, allowing fish or shrimp to navigate through the cone and into the bottle, but hindering their ability to exit. The topmost bridge, dubbed the bait holder, serves as a platform for securing bait using wire or an alternative means. The bait holder is hollow on the inside, serving dual purposes: conserving plastic and facilitating the addition of sand later. The top hole can be sealed with hot glue to increase the trap's weight, enabling it to sink underwater. A miniature sand filter design is incorporated into the project for user convenience. Following the removal of a bottle's top section, the contraption can be inserted inside. Any plastic bottle will suffice, even if its opening is 30% larger than the trap. Plastic bottles tend to shrink significantly when exposed to heat, so the idea is to place the trap within the bottle and then carefully apply heat to the bottle's edge using a candle or lighter to create a snug fit around the trap. A short YouTube video demonstrates the contraption in action: https://www.youtube.com/watch?v=ycHzinhyj5g So, does it work? I've conducted tests with fish, but unfortunately, the results were inconclusive. Fish showed significant interest in the bait, yet refused to enter the cone under any circumstances. To address this issue, I've drilled numerous holes into the bottle to allow water to flow through, making it appear safe for fish. However, even with these modifications, fish continued to avoid entering the cone. As of now, I haven't had the opportunity to test the contraption on shrimp, so I'm labeling it as a "work in progress" for anyone willing to give it a try. Key considerations: * The trap must be printed with 100% infill to prevent buoyancy. I've taken this into account during design. * The base features a short and long end, with the long end intended for insertion into sand or squeezed between rocks, providing stability through attachment to heavy weights. * A hot glue gun was used to melt/smooth the ring near the base, increasing strength while also enhancing grip within the bottle. * For filling the bait holder, I mixed equal parts sand and gypsum, added water, and allowed it to dry before sealing with a glue gun. This resulted in a trap that sinks like a rock without absorbing water.