Less Stinky Resin Two Ways

May 13, 2021 by 12 Comments

After watching [Uncle Jessy’s] video about soy-based 3D printing resin from Elegoo and their miniature air purifiers, we couldn’t decide if the resin doesn’t smell as bad as some other resins or if the air purifier works wonders. Maybe it is a bit of both.

We’ve used Eryone super low odor resin and it has less smell than, say, paint. It sounds like the Elegoo is similar. However, we are always suspicious of claims that any resin is really made with natural ingredients. As [Brent], who apparently has a PhD in chemistry, pointed out, AnyCubic Eco resin makes similar claims but is likely only partially made from soy. Sure, a little less than half is soy-based, but then there’s the other half. Still, we suppose it is better than nothing. That video (also below) is worth watching if you ever wondered why resin solidifies under UV light or what a monomer is.

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Toyota’s Hydrogen-Burning Racecar Soon To Hit The Track

May 13, 2021 by 90 Comments

With the rise of usable electric cars in the marketplace, and markets around the world slowly phasing out the sale of fossil fuel cars, you could be forgiven for thinking that the age of the internal combustion engine is coming to an end. History is rarely so cut and dry, however, and new technologies aim to keep the combustion engine alive for some time yet.

Toyota’s upcoming Corolla Sport-based hydrogen-burning racer. Credit: Toyota media

One of the most interesting technologies in this area are hydrogen-burning combustion engines. In contrast to fuel cell technologies, which combine hydrogen with oxygen through special membranes in order to create electricity, these engines do it the old fashioned way – in flames. Toyota has recently been exploring the technology, and has announced a racecar sporting a three-cylinder hydrogen-burning engine will compete in this year’s Fuji Super TEC 24 Hour race.

Hydrogen Engines?

The benefit of a hydrogen-burning engine is that unlike burning fossil fuels, the emissions from burning hydrogen are remarkably clean. Burning hydrogen in pure oxygen produces only water as a byproduct. When burned in atmospheric air, the result is much the same, albeit with small amounts of nitrogen oxides produced. Thus, there’s great incentive to explore the substitution of existing transportation fuels with hydrogen. It’s a potential way to reduce pollution output while avoiding the hassles of long recharge times with battery electric technologies. Continue reading “Toyota’s Hydrogen-Burning Racecar Soon To Hit The Track” →

Realistic Mission Control Box Is A Blast For All Ages

May 13, 2021 by 19 Comments

A lot of electronic busy boxes that are built for children are simply that — a mess of meaningless knobs and switches that don’t do much beyond actuating back and forth (which, let’s be honest, is still pretty fun to do). But this Mission Control Center by [gcall1979] knocks them all out of orbit. The simulation runs through a complete mission, including a 10-minute countdown with pre-flight system checks, 8.5 minutes of powered flight to get out of the atmosphere that includes another four tasks, and 90 minutes to orbit the Earth while passing through nine tracking stations across the world map.

That’s a lot time to keep anyone’s attention, but fortunately [gcall1979] included a simulation speed knob that can make everything go up to 15 times faster than real-time. This knob can be twiddled at any time, in case you want to savor the countdown but get into space faster, or you don’t have 90 minutes to watch the world map light up.

The main brain of this well-built box is an Arduino Mega, which controls everything but the launch systems’ mainframe computer — this is represented by bank of active LEDs that blink along with the voice in the sound clips and runs on an Arduino Uno and a couple of shift registers. To keep things relatively simple, [gcall1979] used an Adafruit sound board for the clips.

We love everything about this build, especially the attention to detail — the more important pre-flight tasks are given covered toggle switches, and there’s a Shuttle diagram that lights up as each of these are completed. And what Shuttle launch simulator would be complete without mushroom buttons for launch and abort? Grab your victory cigar and check out the demo video after the break.

Is your child too young to be launching the Shuttle? Here’s an equally cool busy box with toddler brains in mind.

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Hybrid Rocket Engine Combines Ceramic Aerospike With 3D Printed Fuel

May 13, 2021 by 23 Comments

[Integza] has worked hard over the last year, crafting a variety of types of rocket and jet engine, primarily using 3D printed parts. Due to the weaknesses of plastic, all of which conflict with the general material requirements for an engine that gets hot, he has had less thrust and more meltdowns than he would have liked. Undeterred, he presses on, now with a hybrid rocket aerospike design. The goal? Actually generating some thrust for once!

The latest project makes the most of what [Integza] has learned. The aerospike nozzle is 3D printed, but out of a special thick ceramic-loaded resin, using a Bison 1000 DLP printer. This allowed [Integza] to print thicker ceramic parts which shrunk less when placed in a kiln, thus negating the cracking experienced with his earlier work. The new nozzle is paired with a steel rocket casing to help contain combustion gases, and the rocket fuel is 3D printed ASA plastic. 3D printing the fuel is particularly cool, as it allows for easy experimentation with grain shape to tune thrust profiles.

With the oxygen pumping, the new design produces some thrust, though [Integza] is yet to instrument the test platform to actually measure results. While the nozzles are still failing over a short period of time, the test burns were far less explosive – and far more propulsive – than his previous efforts. We look forward to further development, and hope [Integza’s] designs one day soar high into the sky. Video after the break.

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Piggy Bank Slot Machine Puts A Spin On Saving

May 12, 2021 by 7 Comments

Saving money is inherently no fun until the time comes that you get to spend it on something awesome. Wouldn’t you be more likely to drop your coins into a piggy bank if there was a chance for an immediate payout that might exceed the amount you put in? We know we would. And the best part is, if you put such a piggy bank slot machine out in the open where your friends and neighbors can play with it, you’ll probably make even more money. As they say, the house always wins.

Drop a coin in the slot and it passes through a pair of wires that act as a simple switch to start the reels spinning. Inside is an Arduino Uno and a giant printed screw feeder that’s driven by a small stepper motor and a pair of printed gears. The reels have been modernized and the display is made of four individual LED matrices that appear as a single unit thanks to some smoky adhesive film.

This beautiful little machine took a solid week of 3D printing, which includes 32 hours wasted on a huge piece that failed twice. [Max 3D Design] tried rotating the model 180° in the slicer and thankfully, that solved the problem. Then it was on to countless hours of sanding, smoothing with body filler, priming, and painting to make it look fantastic.

If you want to make your own, all the files are up on Thingiverse. The code isn’t shown, but we know for a fact that Arduino slot machine code is out there already. Check out the build and demo video after the break.

As much as we like this build’s simplicity, it would be more slot machine-like if there was a handle to pull. Turns out you can print those, too.

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3D Printed Transistor Goes Green

May 12, 2021 by 29 Comments

We’ll be honest, we were more excited by Duke University’s announcement that they’d used carbon-based inks to 3D print a transistor than we were by their assertion that it was recyclable. Not that recyclability is a bad thing, of course. But we would imagine that any carbon ink on a paper-like substrate will fit in the same category. In this case, the team developed an ink from wood called nanocelluose.

As a material, nanocellulose is nothing new. The breakthrough was preparing it in an ink formulation. The researchers developed a method for suspending crystals of nanocellulose that can work as an insulator in the printed transistors. Using the three inks at room temperature, an inkjet-like printer can produce transistors that were functioning six months after printing.

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Sit Pretty On Would-Be Garbage With An Upcycled Chair

May 12, 2021 by 21 Comments

What’s the coolest thing about doing upholstery work? Aside from the fact that you end up with a new thing to sit on, sometimes the work only involves clever stapling, and no sewing is necessary. Such is the case with [wyldestyle]’s upcycled jeans chair, which started as a bare-wood swivel number from the dump. In fact, this project is almost completely made from recycled materials, except of course for those staples that hold it all together. And really, that heavy-duty stapler is likely the fanciest tool you’d need to make your own.

[wyldestyle] didn’t have any furniture foam, and we think that stuff is too expensive, anyway. So the padding treatment begins with a piece of thick Styrofoam that covers the seat screws and bolts. This is glued in place and trimmed down to match the contours of the chair’s seat and back.

Here’s where things gets tricky: the next step is wrapping over the stiff foam board with a few layers of that foam sheeting stuff that’s often used as packing material. This sheeting needs to be taut, but pull it too tight, and it will rip.

To add some loft to the chair, [wyldestyle] stretched and stapled the stuffing from an old pillow that was headed for the garbage. The final step is strategically scissoring jean scraps to fit, then stretching and stapling those to cover all the layers underneath. We like the way this chair looks, and would probably try to place pockets somewhere useful, like the back of the chair.

It’s a shame that so much denim goes to waste all over the world. There’s often a lot of life left in most of the fabric, which can be repurposed into all kinds of things, including eyeglasses frames using a wicked set of jigs.