Magnetic Couplings Make This Lego Submarine Watertight

July 7, 2020 by Dan Maloney 14 Comments

Although you’d be hard-pressed to tell in some areas, it’s summer in the northern hemisphere, which always seems to bring out the projects that require a swimming pool for adequate testing. The [Brick Experiment Channel]’s latest build, a submersible made almost entirely from Lego, is one such project and has us pining for weather that makes a dip sensible rather than suicidal.

The sub featured in the video below is a significant improvement over the “Sub in a Jug” approach the [Brick Experiment Channel] favored for version 1. Rather than starting with a vessel specifically designed not to hold water, the hull for this vessel is an IKEA food container, with a stout glass body and a flexible lid with silicone seals. And instead of penetrating the hull for driveshafts and attempting to seal them, this time around he built clever magnetic couplings.

The couplings transmit torque from the motors on the inside to gears and props on the outside. And where the first version used a syringe-pump ballast tank to control the depth, this one uses vertical thrusters. The flexible lid proved to be a problem with that scheme, since it tended to collapse as the depth increased, preventing the sub from surfacing. That was solved with some Lego bracing and adjustment of the lead shot ballast used to keep the sub neutrally buoyant.

This looks like a ton of summer fun, and even if you don’t have Legos galore to work with, it could easily be adapted to other materials. There are a ton of other fun [BEC] Lego builds to check out, some of which we’ve covered, including a Lego drone and a playing card shooter.

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The Spin Cycle: Washing Machine Motor Converts 10-Speed To E-Bike

July 6, 2020 by Bryan Cockfield 77 Comments

The “Spin Cycle” is an amazing electric bicycle built using a motor salvaged from a washing machine; when the puns are this perfect you have to roll with them. [jimminecraftguy’s] creation is one of the most hacked-together yet functional electric vehicle we’ve seen in a long time.

The drive train of this bicycle starts with a brushless DC motor from a washing machine. It has been slightly modified to run on 48 volts, and is installed inside the triangle of the bike’s frame. It has a chain driving the bike’s crank, retaining the original chain and gearing setup (unlike many electric bike hacks that utilize hub motors). The crank has also been specially modified to include a freewheel, a necessary feature so that the motor can operate without spinning the pedals. Everything except the motor has been custom fabricated including the mounts and the electronics.

[jimminecraftguy] reports speeds of 110 kph which is a little crazy for a 20-year-old aluminum frame bike, and we’d guess it’s not street legal in many jurisdictions, but we can’t really find much fault with this build in general based on the amount of innovation required to get this working at all. A few more improvements for the build are in the works, including improved batteries and a cover for the sides to keep the local law enforcement from getting too suspicious. We can’t wait to see the final version. Continue reading “The Spin Cycle: Washing Machine Motor Converts 10-Speed To E-Bike” →

Live Map Of London Tube Created In PCB And Lights

July 5, 2020 by Bryan Cockfield 20 Comments

If you’re a frequent traveler on a public transit system, it can be helpful to know when the trains or buses are arriving and if there are any delays. We might reach for a tablet to mount on the wall, but that relies on keeping the OS, the software, and its library dependancies up to date. For true reliability you’ll need to build directly in hardware, which is exactly what this map of the London tube system uses.

The base map is printed directly on PCB, with LEDs along each of the major routes to indicate the current location of the trains. A few small chips handle the WiFi connection — it appears to our eye to be an ESP8266 — and pulling the information about the trains from the London Underground API (it would be virtually impossible to build everything for this project in hardware). The hardware can be easily reprogrammed, and with the PCB layout this could be adapted for other public transit fairly easily.

Even apart from the philosophical differences on design between hardware and software approaches, we still appreciate the aesthetic of LEDs on PCB. In fact, we’ve seen a whole host of artwork on PCBs ever since the price came down dramatically in the past two decades.

Thanks to [Al] for the tip!

The Segway Is Dead, Long Live The Segway

June 30, 2020 by Tom Nardi 87 Comments

Before it was officially unveiled in December 2001, the hype surrounding the Segway Human Transporter was incredible. But it wasn’t because people were excited to get their hands on the product, they just wanted to know what the thing was. Cryptic claims from inventor Dean Kamen that “Ginger” would revolutionize transportation and urban planning lead to wild speculation. When somebody says their new creation will make existing automobiles look like horse-drawn carriages in comparison, it’s hard not to get excited.

There were some pretty outlandish theories. Some believed that Kamen, a brilliant engineer and inventor by all accounts, had stumbled upon some kind of anti-gravity technology. The kids thought they would be zipping around on their own Back to the Future hover boards by Christmas, while Mom and Dad were wondering what the down payment on a floating minivan might be. Others thought the big secret was the discovery of teleportation, and that we were only a few years out from being able to “beam” ourselves around like Captain Kirk.

Even in hindsight, you really can’t blame them. Kamen had the sort of swagger and media presence that we today associate with Elon Musk. There was a general feeling that this charismatic maverick was about to do what the “Big Guys” couldn’t. Or even more tantalizing, what they wouldn’t do. After all, a technology which made the automobile obsolete would change the world. The very idea threatened a number of very big players, not least of which the incredibly powerful petroleum industry.

Of course, we all know what Dean Kamen actually showed off to the world that fateful day nearly 20 years ago. The two-wheeled scooter was admittedly an impressive piece of hardware, but it was hardly a threat to Detroit automakers. Even the horses were largely unconcerned, as you could buy an actual pony for less than what the Segway cost.

Now, with the announcement that Segway will stop production on their eponymous personal transporter in July, we can confidently say that history will look back on it as one of the most over-hyped pieces of technology ever created. But that’s not to say Kamen’s unique vehicle didn’t have an impact. Continue reading “The Segway Is Dead, Long Live The Segway” →

DIY Plastic Speedboat For One

June 17, 2020 by Bryan Cockfield 32 Comments

Coroplast (short for corrugated plastic) is an interesting material. It has a structure similar to cardboard, but since it’s plastic it’s waterproof and can be used for a unique set of applications. It’s typically used for political yard signs, but there are more fun things to do with this lightweight material than advertise. [Paul Elkins], for example, uses it to make speedboats.

The boats that [Paul] builds make use of a piece of coroplast which he cuts and folds into a basic hull shape. From there he begins to assemble the other things needed to finalize the boat, including strengthening the shape with wood, adding a steering wheel, building a transom to mount the motor to, and placing controls in the cockpit such as throttle and steering. The entire build is enough to propel a single person on a body of water at about five knots, which is impressive.

To make one of these yourself you’ll need a small outboard motor, but all of the other details of the build are outlined clearly in his series of videos. If you want to build your own boat but don’t like the idea of a noisy two-stroke motor right behind you, you can also look into building a boat with a silent mode of propulsion.

And if you’ve got a good supply of Coro, definitely check out [Paul]’s other projects, including a tiny house.

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Crate EV Motor Hits Market: The Swindon Powertrain

June 7, 2020 by Jenny List 82 Comments

Last year brought some exciting news from the unlikely quarter of an unexciting industrial estate in the British town of Swindon, the company Swindon Powertrain announced that they’d be marketing an all-in-one electric motor and transmission. Essentially this would be a crate engine for EV conversions, and since it’s pretty small it would be able to be shoehorned into almost any car. So often these announcements later prove to be vapourware, but not in this case, because Swindon Powertrain have announced that you can now order the HPD as they call it, for delivery in August. It’s not entirely cheap at £6400 ($7846) exclusive of British VAT sales tax, but when its integrated transmission and differential is taken into consideration it starts to seem more attractive when compared to engineering a random motor onto an internal combustion engine transmission.

They provide a product page with links to a load of data, installation information, and even a CAD model, as well as an ordering page in their webshop from which you can pay the deposit with the rest presumably payable in August before delivery. There is also a range of optional extras including matched inverters, drive shafts, a limited slip differential, and a coolant pump, which makes the whole ever more attractive as a package. 80kW should be enough to lend sprightly performance to all but the largest of cars, so we’ll expect to see this motor ever more often in years to come.

There is already a thriving home-made EV scene which we don’t expect this unit to displace. Instead it will find a niche at the professional and semi-professional conversion level, and we wouldn’t be surprised to see an aftermarket springing up offering ready made subframes to fit it to popular cars. If it is a success there will inevitably be copies and probably at a lower price, so it could be the start of a wave of very interesting conversion options. We hope that Swindon Powertrain will do well with it, and will manage to stay one step ahead of the upstarts. You can read our coverage of its announcement and their electric Mini prototype here.

Thanks [Carl Pickering] for the tip.

When A Bike Sharing Startup Goes Away, What Do You Do With The Bikes?

June 3, 2020 by Jenny List 29 Comments

Part of the detritus of many cities over the last few years has been the ubiquitous bicycles and scooters of the various companies that offer them for hourly hire via a smartphone app. They’re annoying when left randomly on pavements by their users, and they sometimes appear to outnumber riders many times over. In 2018 for many cities outside China they became a little less numerous, as the Chinese bike sharing service Ofo contracted its operations and pulled its distinctive yellow machines from the streets. A couple of years later those Ofo bikes that were sold off or simply abandoned by the company and never recovered are still with us. They can be used if their lock is dismantled, but to do that is to ignore the potential of the lock. [Aladds] has written a firmware for Ofo locks that allows them to be unlocked by a code entered upon its buttons.

Onboard the lock are an nRF51822, 4G radio, and of course the lock mechanism itself. The battery is likely to be flat by now, and though he doesn’t tell us what it is it’s worth our pointing out that similar designs sometimes use hazardous LiSOCl2 chemistry which any hacker should be very cautious with. He gives us full instructions for finding the programming connections for the chip, which can either have its stock firmware downloaded for examination, or be wiped for insertion of the new version. To show the code in action there is also a short YouTube video that we’ve put below the break. Meanwhile we’ve peered inside an Ofo lock before, back in 2018.

Continue reading “When A Bike Sharing Startup Goes Away, What Do You Do With The Bikes?” →