A Compact Strain Wave Gear Assembly

Strain wave gearing is a clever way to produce a high-efficiency, high ratio gearbox within a small space. It involves an outer fixed ring of gear teeth and an inner flexible ring of teeth which are made to mesh with the outer by means of an oval rotor distorting the ring. They aren’t cheap, so [Leo Vu] has had a go at producing some 3D-printable strain wave gearboxes that you could use in your robotic projects.

He’s created his gearbox in three ratios, 1:31, 1:21 and 1:15. It’s not the most miniature of devices at 145mm in diameter and weighing well over a kilogram, but we can still imagine plenty of exciting applications for it. We’d be curious as to how tough a 3D printed gear can be, but we’d expect you’ll be interested in it for modest-sized robots rather than Formula One cars. There’s a video featuring the gearbox which we’ve placed below the break.

This certainly isn’t the first strain wave gearset we’ve brought you, more than one 3D printed project has graced these pages. We’ve even brought you a Lego version. Continue reading “A Compact Strain Wave Gear Assembly”

That Super Mario Bros. C64 Port Was Too Good For This World

It was foolish to think that the adventure of the Mario Bros. would ever exist outside of the castle walls of the Nintendo Entertainment System. Except for that one time it did. The Hudson Soft company was a close collaborator with Nintendo, and parlayed that favor into being tasked with bringing Super Mario Bros. to platforms beyond the NES. The result of that collaboration would be 1986’s Super Mario Special, a port for the NEC PC-88 line of desktop computers. What ended up on that 5.25″ floppy sounded reminiscent of the Famicom original, but with a grand total of four colors (including black) and not a single scrolling screen in sight; Super Mario Special felt decidedly less than spectacular to play. Those eternally flickering sprites mixed with jarring blank screen transitions would never make it outside of Japan, so for a large swath of the world Mario would remain constrained to a gray plastic cartridge for years to come.

There are no shortage of ways to play Super Mario Bros. these days. Emulation in all of its various official and unofficial forms has taken care of that. Virtually everything with a processor more capable than the NES’s 6502 can play host to the Mushroom Kingdom, however, machines more contemporary with the NES still lacked access to the iconic title.

Enter the 2019 port of Super Mario Bros. for the Commodore 64 by [ZeroPaige]. A culmination of seven years work to port the game onto one of the most prolific computers of the eighties was a clear feat of brilliance and an amazing bit of programming that would have taken 1986 by storm. No pale imitation, this was Mario on the C64. Despite all of the nuance in recreating the jump-and-run model of the original paired with enveloping all eight sound channels of a dual SID chip setup, Nintendo saw fit to stifle the proliferation of this incredible 170 kB of software because they claim it infringes on their copyright.

Continue reading “That Super Mario Bros. C64 Port Was Too Good For This World”

Wing Opens The Skies For Drones With UTM

Yesterday Alphabet (formerly known as Google) announced that their Wing project is launching delivery services per drone in Finland, specifically in a part of Helsinki. This comes more than a month after starting a similar pilot program in North Canberra, Australia. The drone design Wing has opted for consists not of the traditional quadcopter design, but a hybrid plane/helicopter design, with two big propellers for forward motion, along with a dozen small propellers on the top of the dual body design, presumably to give it maximum range while still allowing the craft to hover.

With a weight of 5 kg and a wingspan of about a meter, Wing’s drones are capable of lifting and carrying a payload of about 1.5 kg. This puts it into a category of drones far beyond of what hobbyists tend to fly on a regular basis, and worse, it involves Beyond Visual Line Of Sight (BVLOS for short) flying, which is frowned upon by the FAA and similar regulatory bodies. What Google/Alphabet figures that can enable them to make this kind of service a commercial reality is called Unmanned aircraft system Traffic Management (UTM).

UTM is essentially complementary to the existing air traffic control systems, allowing drones to integrate into these flows of manned airplanes without endangering either. Over the past years, it’s been part of NASA’s duty to develop the systems and infrastructure that would be required to make UTM a reality. Working together with the FAA and companies such as Amazon and Alphabet, the hope is that before long it’ll be as normal to send a drone into the skies for deliveries and more as it is today to have passenger and cargo planes with human pilots take to the skies.

Make Physics Fun With A Trebuchet

What goes up must come down. And what goes way, way up can come down way, way too fast to survive the sudden stop. That’s why [Tom Stanton] built an altitude recording projectile into an oversized golf ball with parachute-controlled descent. Oh, and there’s a trebuchet too.

That’s a lot to unpack, but suffice it to say, all this stems from [Tom]’s obvious appreciation for physics. Where most of us would be satisfied with tossing a ball into the air and estimating the height to solve the classic kinematic equations from Physics 101, [Tom] decided that more extreme means were needed.

Having a compound trebuchet close at hand, a few simple mods were all it took to launch projectiles more or less straight up. The first payload was to be rocket-shaped, but that proved difficult to launch. So [Tom] 3D-printed an upsized golf ball and packed it with electronics to record the details of its brief ballistic flight. Aside from an altimeter, there’s a small servo controlled by an Arduino and an accelerometer. The servo retracts a pin holding the two halves of the ball together, allowing a parachute to deploy and return the package safely to Earth. The video below shows some pretty exciting launches, the best of which reached over 60 meters high.

The skies in the field behind [Tom]’s house are an exciting place. Between flying supercapacitors, reaction wheel drones, and low-altitude ISS flybys, there’s always something going on up there.

Continue reading “Make Physics Fun With A Trebuchet”