Pedal Powered Hydrofoil Looks Like A Lot Of Fun

April 27, 2012 by 19 Comments

After reading a bicycle-powered hydrofoil build we posted a few days ago, [James] sent in the project that earned him an iron ring from Dalhousie University in Nova Scotia, Canada. It’s a pedal-powered hydrofoil made of carbon fiber and a Titanium drive shaft [James] and five other students in a mech eng senior design class built in 2005.

The Halifoil, as the team called it, is based on a recumbent design and uses twin carbon fiber hulls to keep the rider out of the water when not pedaling. The use of carbon fiber foils and Titanium drive shaft keep the weight down so the rider can easily accelerate to a speed where the hulls come out of the water.

Compared to the last hydrofoil we posted, [James]’ build is much heavier, but one is much better suited to sitting in the middle of a lake, then pedaling to the shore while flying above the water.

Even though the project is several years old, it’s still a very cool build. [James] was kind enough to post the videos of his build residing on the Dalhousie servers on YouTube; you can check those out after the break.

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Hacking The Trampofoil To Be Pedal Powered

April 25, 2012 by 31 Comments

We’ve seen a few different versions of the “trampofoil” before. That’s the contraption that utilizes a hydrofoil and human power to scoot you across the water above the surface. It is somewhat difficult to explain, so just check out the first video after the break to see how the original works.

Today, we stumbled upon a cool video where someone is attempting to make a pedal powered one instead. Their first prototype, shown above is literally just a trampofoil with an added seat and pedal powered prop. They did manage to take it a step further though and came up with a second prototype that has a better designed hydrofoil as well as using a bike frame for the main structure. This looks really fun as you can see in the second video below.

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Baby’s First Star Light Projector And A Foil Slip Ring

March 22, 2012 by 7 Comments

For a newborn, everything is magical; a lack of object permanence means everything is new, wonderful, and novel. What then, could be better than a projected star field circling an infant’s room, gently sending them to sleep?

[Pete] was inspired by this earlier starlight projector that projects a rotating star field onto the walls and ceiling of a nursery. Instead of a rather loud servo, [Pete] used a quiet 12 Volt gear motor that spins the star field at 5 RPM. Like the previous build, a LED was used but [Pete] found a color-changing RGB LED that automatically shifts colors.

The shaft of [Pete]’s gear motor is tiny, and unlike the servo, there’s constant rotation. This meant a slip ring was needed to pass electricity into the spinning sphere. A piece of copper foil and a pair of improvised brushes served just fine. While [Pete]’s project, like its predecessor, doesn’t seem to have any recognized constellations drilled into the sphere, the foil slip ring opens up the possibility for a small microcontroller being fitted inside the globe with blinking lights.

Check out the video of [Pete]’s build in action after the break.
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Foil Impressioning Defeats Security Locks

February 3, 2010 by 32 Comments

Apparently it’s been around for fifteen years but using foil impressions to pick locks is new to us. This is similar to using bump keys but it works on locks that are supposedly much more secure. This method uses a heavy gauge aluminum foil to grab and hold the pins in the correct place for the lock to be turned. The foil is folded over and slits are cut where each pin will fall. It is then inserted into a lock on a tool shaped like a key blank. Jiggle the tool for a bit and the cylinder will turn. This just reminds us that we’re much more dependent on the good will of our fellow citizens to not steal our stuff, rather than the deterrent that a lock provides.

We’ve embedded a detail and fascinating demonstration of this method after the break. The materials in the video are from a Chinese-made kit. We’re not sure where you find these types of locks, but we don’t feel any less secure since our keys could be obtained from a distance anyway.

Update: Video now embedded after the break. The link is down but you can try the Google Cache version.

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3D Print A Drill-Powered Helicopter Toy Because It’s Simply Fun

May 14, 2024 by 8 Comments

These days, you can get a fully remote-control helicopter that you can fly around your house for about $30. Maybe less. Back in the day, kids had to make do with far simpler toys, like spinning discs that just flew up in the air. [JBV Creative] has built a toy just like that with his 3D printer. It may be simple, but it also looks pretty darn fun.

The design is straightforward. It uses a power drill to spin up a geartrain, which in turn drives a small disc propeller. Spin the propeller fast enough and it’ll launch high into the air. The geartrain mounts to the drill via the chuck, and it interfaces with the propeller with a simple toothed coupler. Alternatively, there’s also a hand-cranked version if you don’t have a power drill to hand.

Launching is easy. First, the drill spins the propeller up to speed. Then, when the drill’s trigger is released, it slows down, and the propeller spins free of the toothed coupler, with the lift it generates carrying it into the sky.

Files are available online for those interested. We could imagine this toy could make the basis for a great design competition. Students could compete to optimise the design with more effective gear ratios or better airfoils. We’ve seen similar designs before, too. Video after the break.

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You’ve Probably Never Considered Taking An Airship To Orbit

May 13, 2024 by 65 Comments

There have been all kinds of wild ideas to get spacecraft into orbit. Everything from firing huge cannons to spinning craft at rapid speed has been posited, explored, or in some cases, even tested to some degree. And yet, good ol’ flaming rockets continue to dominate all, because they actually get the job done.

Rockets, fuel, and all their supporting infrastructure remain expensive, so the search for an alternative goes on. One daring idea involves using airships to loft payloads into orbit. What if you could simply float up into space?

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More Microwave Metal Casting

April 16, 2024 by 10 Comments

If you think you can’t do investment casting because you don’t have a safe place to melt metal, think again. Metal casting in the kitchen is possible, as demonstrated by this over-the-top bathroom hook repair using a microwave forge.

Now, just because it’s possible doesn’t mean it’s advisable. There are a lot better ways to fix something as mundane as a broken bathroom hook, as [Denny] readily admits in the video below. But he’s been at the whole kitchen forging thing since building his microwave oven forge, which uses a special but easily constructed ceramic heat chamber to hold a silicon carbide crucible. So casting a replacement hook from brass seemed like a nice exercise.

The casting process starts with a 3D-printed model of the missing peg, which gets accessories such as a pouring sprue and a thread-forming screw attached to it with cheese wax. This goes into a 3D-printed mold which is filled with a refractory investment mix of plaster and sand. The green mold is put in an air fryer to dry, then wrapped in aluminum foil to protect it while the PLA is baked out in the microwave. Scrap brass gets its turn in the microwave before being poured into the mold, which is sitting in [Denny]’s vacuum casting rig.

The whole thing is over in seconds, and the results are pretty impressive. The vacuum rig ensures metal fills the mold evenly without voids or gaps. The brass even fills in around the screw, leaving a perfect internal thread. A little polishing and the peg is ready for bathroom duty. Overly complicated? Perhaps, but [Denny] clearly benefits from the practice jobs like this offer, and the look is pretty cool too. Still, we’d probably want to do this in the garage rather than the kitchen.
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