Balancing Robot Gallery

Cube Teeter Totter: One Motor, Many Lessons

Balancing robots are always fun to see, as they often take forms we’re not used to, such as a box standing on its corner. This project, submitted by [Alexchunlin], showcases a cool single motor reaction cube, where he dives into many lessons learned during its creation.

At the outset, [Alexchunlin] thought this would be a quick, fun weekend project, and while he achieved that, it took longer than a weekend in the end. The cube’s frame was a simple 3D print with provisions to mount his MotorGo AXIS motor controller. This motor controller was initially designed for another project, but it’s great to see him reuse it in this build.

Once the parts were printed and assembled, the real work began: figuring out the best way to keep the cube balanced on its corner. This process involved several steps. The initial control code was very coarse, simply turning the motor on and off, but this didn’t provide the fine control needed for delicate balancing. The next step was implementing a PID control loop, which yielded much better results and allowed the cube to balance on a static surface for a good amount of time. The big breakthrough came when moving from a single PID loop to two control loops. In this configuration, the PID loop made smaller adjustments, while another control loop focused on the system’s total energy, making the cube much more stable.

By the end of the build, [Alexchunlin] had a cube capable of balancing in his hand, but more importantly, it was a great learning experience in controls. Be sure to visit the project page for more details on this build and check out his video below, which shows the steps he took along the way. If you find this project interesting, be sure to explore some of our other featured reaction wheel projects.

Continue reading “Cube Teeter Totter: One Motor, Many Lessons”

Expanding rack structure

Expanding Racks In The Spirit Of The Hoberman Sphere

If you’re a mechanical engineering wonk, you might appreciate this latest video from [Henry Segerman] wherein he demonstrates his various expanding racks.

[Henry] explains how the basic “double-rack” unit can be combined to make more complex structures. These structures are similar in spirit to the Hoberman sphere, which is a compact structure that can be expanded to fill a large space.

Continue reading “Expanding Racks In The Spirit Of The Hoberman Sphere”

Mousa rotary dial and circuit

Adapting An Old Rotary Dial For Digital Applications

Today in old school nostalgia our tipster [Clint Jay] wrote in to let us know about this rotary dial.

If you’re a young whippersnapper you might never have seen a rotary dial. These things were commonly used on telephones back in the day, and they were notoriously slow to use. The way they work is that they generate a number of pulses corresponding to the number you want to dial in. One pulse for 1, two pulses for 2, and so on, up to nine pulses for 9, then ten pulses for 0.

We see circuits like this here at Hackaday from time to time. In fact, commonly we see them implemented as USB keyboards, such as in Rotary Dial Becomes USB Keyboard and Rotary Dialer Becomes Numeric Keypad.

Continue reading “Adapting An Old Rotary Dial For Digital Applications”

Back to the Future Lunchbox Cyberdeck

Back To The Future Lunchbox Cyberdeck

Our hacker [Valve Child] wrote in to let us know about his Back to the Future lunchbox cyberdeck.

Great Scott! This is so awesome. We’re not sure what we should say, or where we should begin. A lot of you wouldn’t have been there, on July 3rd, 1985, nearly forty years ago. But we were there. Oh yes, we were there. On that day the movie Back to the Future was released, along with the hit song from its soundtrack: Huey Lewis & The News – The Power Of Love.

Continue reading Back To The Future Lunchbox Cyberdeck”

A Steady Vacuum For The Fastest Cassette Tape Drive Ever

If you think of a 1960s mainframe computer, it’s likely that your mental image includes alongside the cabinets with the blinkenlights, a row of reel-to-reel tape drives. These refrigerator-sized units had a superficial resemblance to an audio tape deck, but with the tape hanging down in a loop either side of the head assembly. This loop was held by a vacuum to allow faster random access speeds at the head, and this fascinates [Thorbjörn Jemander]. He’s trying to create a cassette tape drive that can load 64 kilobytes in ten seconds, so he’s starting by replicating the vacuum columns of old.

The video below is the first of a series on this project, and aside from explaining the tape drive’s operation, it’s really an in-depth exploration of centrifugal fan design. He discovers that it’s speed rather than special impeller design that matters, and in particular a closed impeller delivers the required vacuum. We like his home-made manometer in particular.

What he comes up with is a 3D printed contraption with a big 12 volt motor on the back, and a slot for a cassette on the front. It achieves the right pressure, and pulls the tape neatly down into a pair of loops. We’d be curious to know whether a faster motor such as you might find in a drone would deliver more for less drama, but we can see the genesis of a fascinating project here. Definitely a series to watch.

Meanwhile, if your interest extends to those early machine rooms, have a wallow in the past.

Continue reading “A Steady Vacuum For The Fastest Cassette Tape Drive Ever”

The bill of materials and the assembled smartwatch.

Piko, Your ESP32 Powered Fitness Buddy

Over on Hackaday.io there’s a fun and playful write-up for a fun and playful project — the Piko, an ESP32 powered smartwatch.

Our hackers [Iloke Alusala], [Lulama Lingela], and [Rafael Cardoso] teamed up to design and manufacture this wrist-worn fitness wearable. Made from an ESP32 Beetle C6 and using an attached accelerometer with simple thresholds the Piko can detect if you’re idle, walking, jogging, or sprinting; and at the same time count your steps.

Design sketches

The team 3D printed the requisite parts in PLA using the printer in their university makerspace. In addition to the ESP32 and printed parts, the bill of materials includes a 240×240 IPS TFT LCD display, a LIS331HH triple-axis accelerometer, a 200 mAh battery, and of course, a watch strap.

Demonstrating splendid attention to detail, and inspired by the aesthetic of the Tamagotchi and pixel art, the Piko mimics your current activity with a delightful array of hand-drawn animations on its display. Should you want to bring a similar charm to your own projects, all the source is available under the MIT license.

If you’re interested in smartwatch technology be sure to check out our recent articles: Smartwatches Could Flatten The Curve Of The Next Pandemic and Custom Smartwatch Makes Diabetes Monitoring Easier For Kids.

Continue reading “Piko, Your ESP32 Powered Fitness Buddy”

A Lego vehicle crossing a gap between two benches.

Making A LEGO Vehicle Which Can Cross Large Gaps

Here is a hacker showing off their engineering chops. This video shows successive design iterations for a LEGO vehicle which can cross increasingly large gaps.

At the time of writing this video from [Brick Experiment Channel] has been seen more than 110,000,000 times, which is… rather a lot. We guess with a view count like that there is a fairly good chance that many of our readers have already seen this video, but this is the sort of video one could happily watch twice.

Continue reading “Making A LEGO Vehicle Which Can Cross Large Gaps”