Sliding Screen Has Wheels, Will Travel

September 28, 2020 by Tom Nardi 5 Comments

For a recent event, [MakerMan] was tasked with creating an interactive display that could move back and forth along an image of the Moscow skyline to highlight different points of interest. The end result is certainly gorgeous, but since this is Hackaday, we were more excited to see all the behind the scenes video of how it was built.

As with many of his projects, this one started with little more than scrap parts. Two metal I-beams were welded together to make a track, and a wheeled cart was fashioned to ride on it. Using a belt and pulley system that’s not unlike a scaled up version of what you might see on a desktop 3D printer, the motor in the cart is able to move the arrangement back and forth with minimal slop.

Installing the motor and pulley in the cart.

The cart actually holds all of the electronics in the project, including the power supplies, MA860H motor controller, a pair of endstop switches, and the Arduino that pulls it all together. A drag chain is used to keep the wires tight to the side of the rail without getting tangled up in anything.

[MakerMan] doesn’t explain much of the software side of this one, though we suppose he might only have been contracted to develop the hardware. But towards the end of the video you can see how the cart, now with large touch screen display mounted on top, moves back and forth when the appropriate commands are sent to the Arduino.

We’re not really sure what application such a contraption would have for the average hacker, but that doesn’t mean we can’t be jealous. There’s just something about huge illuminated screens that just speaks to us.

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Already Have That Book? Get The ISBN 411 Over IoT

September 27, 2020 by Kristina Panos 16 Comments

Have you ever been at the bookstore and stumbled across a great book you’ve been looking for, but had a nagging feeling that you already had it sitting at home? Yeah, us too. If only we’d had something like [Kutluhan Aktar]’s ISBN verifier the last time that happened to say for sure whether we already had it.

To use this handy machine, [Kutluhan] enters the International Standard Book Number (ISBN) of the book in question on the 4 x 4 membrane keypad. The Arduino Nano 33 IoT takes that ISBN and checks it against a PHP web database of book entries [Kutluhan] created with the ISBN, title, author, and number of pages. Then it lets [Kutluhan] know whether they already have it by updating the display from a Nokia 5110.

If you want to whip one of these up before your next trip to the bookstore, this project is completely open source down the web database. You might want to figure out some sort of enclosure unless you don’t mind the shy, inquisitive stares of your fellow bookworms.

Stalled out on reading because you don’t know what to read next? Check out our Books You Should Read column and get back to entertaining yourself in the theater of the mind.

Via r/duino

Food Dispenser Shakes And Rattles

September 27, 2020 by Lewin Day 17 Comments

[Elite Worm] follows a strict diet that involves regularly mixing dry ingredients in varying proportions. The task grew tedious, and thus automation became a tantalising prospect. Enter the DIY shaking food dispenser.

The machine has a simple touch screen interface, with an Atmega328P running the show behind the scenes. The user can store a series of profiles, which each correspond to a different mixture of four base ingredients. Dealing with dry ingredients like oats, chia, and flax, shaking is often necessary to get things moving. To achieve this, the rig packs a hefty DC motor up top, which turns an eccentric shaft, shaking the whole rig. Each ingredient hopper has a servo-controlled nozzle, so ingredients can be dispensed in turn, with a load cell in the base measuring the weight delivered.

It’s a neat system, though [Elite Worm] notes that the device shakes just a little too much, and suspects it won’t hold up in the long term. We suspect a less violent, higher frequency vibration might be less hard on the components, but we’re sure there’ll be some quality engineering going into the next build. We’ve seen [Elite Worm]’s work here before, too. Video after the break.

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DIYing A High End Camera Arm

September 27, 2020 by Lewin Day 21 Comments

One of the first purchases for anyone looking to shoot video should be a tripod. Key to getting clean and stable shots, they can nevertheless be limiting in their range of motion. Wanting something a little more high-end, but dissatisfied with the high cost of commercial options, [Alexandre Chappel] decided to build his own camera arm.

The build is based around square alumiunium tubing, with the high-tolerance material acting as the arm’s vertical and horizontal rails. 3D printed brackets and adapters are used to bolt everything together, along with several printed components used as drilling guides to help accurately machine the aluminium tubes. Adjustment is built into the carriages that travel along the rails, to help account for any slop in the 3D printed parts. A counterweight system is then installed to ensure the camera doesn’t hit the floor when not in the locked position.

It’s a tidy build, and one that has given [Alexandre] far more flexibility to shoot than his existing tripods. Additionally, adjusting the camera position is much quicker than before. Of course, when you’re building your own rigs, the sky is the limit. Video after the break.

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Rocket Plane Build Aims For High Speed Flight

September 27, 2020 by Lewin Day 19 Comments

[James Whomsley] likes flying, and likes flying fast. After reaching a speed of 114 miles an hour with an RC plane, he wanted to go further and break that record. To do so, he looked towards rocket power, and started a new build.

The design consists of a combination of 3D printed parts, laser-cut plywood bulkheads, and foamboard flight surfaces, with a few carbon fiber stiffeners thrown in here and there. For this early prototype, power is solely from hobby rocket motors, providing thrust for 1.6 seconds, meaning flight times are necessarily short. The craft is launched from an aluminium profile rail thanks to a 3D printed sliding guide pin.

Initial tests with two rocket motors were promising, leading to a second trial with a full six motors fitted. The thrust line was a little low, however, and a major pitch-up just after launch meant the plane only reached around 62 miles an hour. [James] still has a ways to go to beat his previous record, so intends to explore adding ducted fan propulsion to get the plane in the air before using the rockets as a speed booster in steady flight.

Of course, if you can’t lay your hands on rocket engines, you could always consider spinning up your own. (Or ditch the engine entirely.) Video after the break.

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Tesla Turbine Boat Uses Lily Impeller

September 26, 2020 by Lewin Day 19 Comments

Typically in the RC community, radio control boats rely on small nitro engines or electric motors to get around. Fitted with traditional propellers, they’re capable of great speed and performance. Of course, there’s more than one way to skin a cat, as [Integza] shows with his latest build.

As far as the boat side of things is concerned, it’s a basic 3D printed single hull design. The innovation comes in the drivetrain, instead. The boat uses compressed air for propulsion, stored in a battery of four soda bottles, pressurized to 6 bar. The compressed air is used to drive a Tesla turbine of [Integza]’s design, which is 3D printed on a resin printer. Rather then driving a propeller, the Tesla turbine instead turns a Lily impeller, which pulls the boat through the water rather than pushing it along. The impeller uses a nature-inspired design, hence the name, and was also 3D printed, making producing its complex geometry a cinch. The guts of a toy radio control car are then used to control the boat.

Understandably, performance is less than stellar. The limited reserves of compressed air can’t propel the boat long, and the combination of the high RPM Tesla turbine and Lily impeller don’t provide a lot of thrust. However, the boat does move under its own power, demonstrating these oddball technologies while doing so.

[Integza] has been working with these technologies for a while; we featured an earlier Tesla turbine build back in 2018. Video after the break.

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A Digital Guestbook Is A Perfect Hacker Wedding Gift

September 22, 2020 by Lewin Day 2 Comments

With his brother’s wedding coming up, [Sebastian] needed a wedding gift. Rather than purchasing something, he elected to build a digital guestbook so guests could share their well-wishes with the happy couple.

The guestbook has a simple web-based interface, which was accessible over a domain name [Sebastian] registered with the couple’s names ahead of the event. There, users could enter text and draw a friendly message for the digital guestbook. The guestbook itself consists of an ESP32 running a e-ink display, packaged in a tidy 3D printed enclosure featuring the couple’s initials. It regularly queries the web server, and displays the messages it finds on the screen.

It’s a great use of an e-ink display, as it made reading the messages in bright daylight easy where other technologies may have faltered. [Sebastian] was also clever to install some LEDs for the night portion of the reception. We’ve featured a few wedding gifts on these pages before, including this particularly amusing sugar cube. Video after the break.

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