Even Joke Torpedoes Are Pretty Hard To Get Right

It’s rare that makers get involved in out-and-out munition production. It’s dangerous, and usually frowned upon by local authorities. That said, it can be fun to experiment around, and [Ivan] does just that, attempting to launch a 3D-printed torpedo from a kayak. The build may have been done as a marketing exercise, but it raises some interesting questions about naval engineering.

The first revision consists of a 3D-printed hull, containing a rubber-band powered propeller. A soda bottle filled with compressed air is then used as a warhead, fitted with a contact fuse to release its charge on impact. Unfortunately, initial tests were underwhelming, with the rubber band mechanism failing to provide any real forward propulsion.

A trip back to the drawing board was due, and the design was revived with a brushless motor powerplant instead. This allowed the torpedo to trawl, albeit slowly, through the water. It also proved that the compressed air “warhead” could successfully discharge, albeit with less of a bang, more of a whimper.

The build, while undertaken for the sake of fun, does highlight some of the engineering challenges inherent in building a working torpedo. There were issues with buoyancy, as well as providing the torpedo with enough power to move quickly in the water. On top of this, the matter of guidance is also an important one. We’d love to know how the Hackaday commentariat would go about solving these issues when undertaking their own build – let us know down below. We’ve seen others tackle similar builds before, too. Video after the break.

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Citizen Scientist: Hedy Lamarr

For all the destruction and human misery unleashed during World War II, it was also a time of incredible creativity and ingenuity. In America, it was a time when everyone wanted to pitch in. Young men and women enlisted and were shipped overseas, and those left behind kept the factories running full tilt. Even Hollywood went to war, with its steady output of films that gave people a little glamour and provided an escape from the horror and loss of the war. Hollywood stars lined up to entertain troops and raise money for the war effort, and many joined up and fought too.

But one Hollywood star made an unconventional contribution to the war effort, and in the process proved that beauty and brains are not always mutually exclusive. This is the story of Hedy Lamarr, movie star and inventor.

“The Most Beautiful Woman in the World”

By the time she was 23 in 1937, Hedwig Eva Maria Kiesler was a genuine film star in her native Austria. She was also trapped in an unhappy marriage to a rich and powerful Austrian munitions magnate, Fritz Mandl. Hedy was miserable as a trophy wife, adorning the dining room as her husband entertained rich and powerful guests – including Mussolini and Hitler – over long dinners in one of his mansions. They dismissed her; clearly a woman so beautiful could have nothing else to offer, an empty head perched on a graceful neck. But she was far from stupid, and while her husband discussed business with the men who were building the Axis arsenal, Hedy listened and learned.

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Robot Subs Compete

These Autonomous Underwater Vehicles are all competing in the 12th annual AUVSI competition. They have to complete an underwater obstacle course that involves some tight maneuvering, retrieval of a briefcase, dropping bombs, and firing torpedoes. We’ve seen several UAVs before, but we haven’t ever seen them weaponized and in action. Yeah, those weapons don’t look lethal, but isn’t that just a matter of ammunition?