Electric Longboard With All-New Everything

We love [lolomolo]’s Open Source electric longboard project. Why? Because he completely re-engineered everything while working on the project all through college. He tackled each challenge, be it electronic or mechanical as it came, and ended up making everything himself.

The 48″ x 13″ deck is a rather unique construction utilizing carbon fiber and Baltic birch. In testing the deck, [lolomol] found the deflection was less than an inch with 500 lbs. on the other end. He modified the Caliber II trucks to add four 2250W Turnigy Aerodrive brushless outrunners driving the wheels with the help of belts. The motors are controlled by VESC, an Open Source speed controller. There are a lot of fun details, like the A123 lithium cells equipped with custom battery management system PCBs.

The board sports 5W RGBW headlights that are so bright he can only run them at 10% PWM, plus RGB LED underlighting. All of it is controlled by an onboard Linux box. You can check out [lolomolo]’s GitHub repository for code, schematics, and CAD files. His Instructable for this project also has more design notes and thoughts.

If sweet longboards are your bag, check out the 3D-printed longboard and the long-distance electric longboard we published previously.

Open Source Modular Rocket Avionics Package

Cambridge postgraduate student [Adam Greig] helped design a rocket avionics system consisting of a series of disc-shaped PCBs arranged in a stack. There’s a lot that went into the system and you can get a good look at it all through the flickr album.

Built with the help of Cambridge University Spaceflight, the Martlet is a 3-staging sounding rocket that lifts to 15km/50K feet on Cesaroni Pro98 engines. [Adam]’s control system uses several Arm Cortex M4s on various boards rather than having just one brain controlling everything.

Each disc is a module that plays a specific role in the system. There are a couple of power supply boards sporting twin LTC2975 able to supply custom power to a dozen different circuits. The power system has a master control board also sporting an M4. There’s an IMU board with the guidance system — accelerometer, magnetometer, gyroscope, and barometer, all monitored by an algorithm that computes the rocket’s position and attitude in-flight. There’s a radio board with a GPS receiver and an ISM band radio transceiver for telemetry, as well as a datalogger with 10 thermocouple measurement channels. Engines are controlled by the pyro board which controls firing currents on four different channels. The vertical spacers also serve to transmit power and data to neighboring boards.

If you’re interested in learning more, check out the project’s code and schematics on [Adam]’s GitHub repository.

[Adam] is no stranger to these pages, with his Nerf Vulcan turret published a few years back, as well as his balloon tracking rig published more recently. Photos are CC-SA and can be found in [Adam]’s Flickr feed.

Hackaday Prize Entry: SafeRanger, A Roving Power Plant Monitor

Engineering student [Varun Suresh] designed his SafeRanger rover to inspect oil and gas power plants for abnormal temperatures as well as gas leaks. The rover explores critical areas of the factory, and data is sent to a control center for analysis.

[Varun] built his robot around a Devastator chassis kit from DFRobot, and equipped it with a FLIR Lepton thermal camera and an MQ2 gas sensor, both monitored by a Raspberry Pi. The twin brushless DC motors are controlled by an L293D motor driver IC in conjunction with an Arduino Nano; steering is accomplished with an HC-05 Bluetooth module and a mobile app.

We could see technology like this being implemented in a labyrinthine facility where a human inspector might have a difficult time reaching every nook and cranny. Or just let it wander ar0und, looking for trouble?

Reamer Regrinding Using A Toolpost Spindle

How often have you wished you could reduce the size of a drillbit? [Ben Katz] has a bunch of projects in mind that use a tight-tolerance 22mm bore–but he didn’t have a 22mm reamer handy. Rather than buy one, he thought, why not regrind a larger one to the right size?

He first ground down the shank to fit in the lathe’s drill chuck. Once it was loaded into the chuck,  he reground the edge of a 7/8″ (22.225mm) reamer, reducing its diameter down to 22mm by spinning it on his lathe in conjunction with a toolpost spindle with a grinding wheel attached. The final diameter was 21.995mm—off by 5 microns!

[Ben]’s homebuilt spindle is a cool project in itself, and we publish a lot of posts about those handy tools. Check out our pieces on a brushless DC motor used as a CNC spindle, and this 3D printer outfitted with a spindle. Also check out [Ben]’s electric tricycle build we featured a few years ago.

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Hackaday Prize Entry: Archelon ROV Explores The Ocean

Acendtech Robotics is a 4H robotics club located in Freehold, NJ, and their centerpiece project is the Archelon, an underwater drone they built out of PVC pipes. It’s also a Hackaday Prize entry designed to monitor marine traffic, the seabed, piers, jetties, and other underwater constructions.

The Archelon uses eight thrusters constructed out of bilge pumps that have been hacked to add a propeller, leaving the motor sealed safely inside.

The ROV’s motors are controlled by an Arduino Mega along with two motor driver boards, each board driving two pairs of DC motors. There’s also a robot claw rotated by another modified bilge pump, opened and closed by a waterproof servo. The on-board electronics including a Teensy 3.2 are sealed inside a 1/2″ acrylic tube sealed with rubber o-rings and custom-milled stainless steel endcaps. Connected to the Teensy are the ROV’s cameras as well as an ATTiny88, which in turn control the motors.

Students working with the Archelon learn not only the technical aspects of building a ROV like assembly and programming, but also its mission, learning how to take test samples of agar to study pollutants in the maritime environment.

Lasering Axonometric Fonts

I am something of an Inkscape fan. If you’re not familiar with the application, it’s like an Open Source version of Adobe Illustrator. Back when I was a production artist I’d been an Illustrator master ninja but it’s been four years and my skills are rusty. Plus, Inkscape is just enough different in terms of menus and capabilities that I had a hard time adapting.

So I created some wooden lettering with the help of Inkscape and a laser cutter, and I’m going to show you how I did it. If you’re interested in following along with this project, you can find it on Hackaday.io.

While playing around with Inkscape, I noticed you can create a variety of grids, including axonometric grids. This term refers to the horizon lines in an orthographic projection. In other words, it helps make things look 3D by providing perspective lines.

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Fool Giants With Novelty-Sized Gold Bricks

If you ever wondered how to make a giant-sized gold bar out of sheets of pink household insulation, well, there is a video showing you the steps. YouTube workshop guru [Jimmy DiResta] built oversized prop gold bricks out of foam. He cut sheets of 1.5″ Owens Corning foam insulation on his Saw Stop, making angled edges onto each piece so they could fit together in the trapezoidal ingot shape we know and love.

The pieces were put together with Great Stuff insulating foam sealant, the sort of spray foam used for filling up gaps in your house’s insulation, but here serving as glue.  [Jimmy] created lettering by lasering out the shapes in what appears to be cardboard, then gluing the letters in place, using the leftover material from the laser cut to place the letters in neat rows. He then sanded down the edges, priming and painting the bars with gold paint–but there were too many imperfections visible so he re-sanded and repainted.

We have been inundated in foam projects recently, like this ultralight built out of foam insulation and a foam cutter built with a 9V battery.

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