Remote-Controlled Hypercar Slices Through Air

May 23, 2023 by Bryan Cockfield 17 Comments

Almost all entry-level physics courses, and even some well into a degree program, will have the student make some assumptions in order to avoid some complex topics later on. Most commonly this is something to the effect of “ignore the effects of wind resistance” which can make an otherwise simple question in math several orders of magnitude more difficult. At some point, though, wind resistance can’t be ignored any more like when building this remote-controlled car designed for extremely high speeds.

[Indeterminate Design] has been working on this project for a while now, and it’s quite a bit beyond the design of most other RC cars we’ve seen before. The design took into account extreme aerodynamics to help the car generate not only the downforce needed to keep the tires in contact with the ground, but to keep the car stable in high-speed turns thanks to its custom 3D printed body. There is a suite of high-speed sensors on board as well which help control the vehicle including four-wheel independent torque vectoring, allowing for precise control of each wheel. During initial tests the car has demonstrated its ability to corner at 2.6 lateral G, a 250% increase in corning speed over the same car without the aid of aerodynamics.

We’ve linked the playlist to the entire build log above, but be sure to take a look at the video linked after the break which goes into detail about the car’s aerodynamic design specifically. [Indeterminate Design] notes that it’s still very early in the car’s development, but has already exceeded the original expectations for the build. There are also some scaled-up vehicles capable of transporting people which have gone to extremes in aerodynamic design to take a look at as well.

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We’ve Got A Saxaboom At Home Son

May 21, 2023 by Matthew Carlson 6 Comments

Most parents have heard a familiar story. Their lovely child comes up, having seen a celebrity rocking out with a funny $20 toy from the 80s, and asks for it. Of course, you reply, it’s just 20 dollars. However, a quick scan through eBay reveals that everyone else’s kid has also been asking for this obscure toy for a school event, which now costs around $700. [Ben] found himself in that exact position and made a crucial off-hand comment, “I bet I could make one of those.” That was how his hectic journey into the world of toy reproduction began.

All [Ben] had for reference when recreating a Sax-A-Boom were pictures and sound clips. Modeling complex sweeping shapes in CAD is difficult, and [Ben] commissioned a 3d model from a professional on Fiverr. [Ben] broke down the model into printable sections and tweaked it to account for buttons. After a concerning amount of putty, wet sanding, and elbow grease, [Ben] had a decently smooth body for an instrument. The device’s guts is an ESP32-based board called Sonatino, built around music generation. The music samples came from a virtual instrument clone on GitHub and loaded onto an SD card.

Time pressure crept in towards the end, and [Ben] had to go for some dirty solution that he would have preferred (popsicle sticks and epoxy for button mounting). Yes, there were some gaps and paint flaws, but ultimately [Ben’s] son rocked the school presentation. It’s a beautiful journey through creating something with a high level of finish on a limited timescale.

Perhaps future versions of the Sax-A-Boom can take it further by adding a breath sensor, like this 3d printed MIDI instrument.

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Big Tactile Button Is Silly But Cool

May 18, 2023 by Lewin Day 8 Comments

Every hacker is familiar with those teeny little tactile buttons that are so enjoyable to click over and over again. [ROBO HUB] has built a giant version as a tribute, and it works just like the real thing!

The giant button has been scaled up 20 times compared to the original. For simplicity’s sake, [ROBO HUB] designed this replica to use materials readily available around the home. Thanks to its cardboard construction, it’s easy to replicate with a minimum of tools. One need merely cut out the various sections before assembling them together with hot glue, with popsicle sticks serving as the legs. A juice bottle is used as the primary button itself, with aluminium foil serving as the contacts and rubber bands standing in for the spring.

It’s not the most useful button, given that it it’s quite fragile and has a weak spring return. However, it would be a great teaching tool to show students exactly what’s going on inside an actual button. As a bonus, it looks like it would be remarkably fun to pound on to activate some kind of massive air horn. Just an idea.

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Hackaday Prize 2023: Tiny RC Aircraft Built Using Foam And ESP12

April 29, 2023 by Lewin Day 13 Comments

Once upon a time, a radio controlled plane was a hefty and complex thing. They required small nitro engines, support equipment, and relatively heavy RC electronics. Times have changed since then, as this lightweight RC build from [Ravi Butani] demonstrates.

The body of the plane is lightweight foam, and can be assembled in two ways. There’s a relatively conventional layout, using a main wing, tailplane, and rudder, or a pusher model with the main wing at the rear and a canard up front. The open hardware electronics package, which [Ravi] calls VIMANA, consists of an ESP12 module with a pair of MOSFETs to act as two independent motor drivers — allowing the plane to be flown and steered with differential thrust.

For more advanced flight control, it can also command a pair of servos to control ailerons, a rudder, canards, or elevons, depending on configuration. There’s also potential to install an IMU to set the plane up with flight stabilization routines.

Thanks to the low-cost of the VIMANA board, [Ravi] hopes it can be used in STEM education programs. He notes that it’s not limited just to aircraft, and could be used for other motorized projects such as boats and cars. We’ve featured an early version of his work before, but the project has come a long way since then.

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Miniature Concrete Hoover Dam Is Tiny Engineering Done Right

April 21, 2023 by Lewin Day 13 Comments

Growing up, we got to play with all kinds of things in miniature. Cars, horses, little LEGO houses, the lot. What we didn’t get is a serious education with miniature-sized dams. This recreation of the glorious Hoover Dam from the [Creative Construction Channel] could change all that for the next generation.

The build starts with the excavation of a two-foot long curve in a replica riverbed. A cardboard base is installed in the ditch, and used as a base for vertical steel wires. Next, the arch of the dam is roughed out with more steel wires installed horizontally to create a basic structure. The cardboard is then be removed from the riverbed, with the steel structure remaining. It’s finally time to pour real concrete, with a foundation followed by the main pour into foam formwork. The dam is also given 3D printed outlets that can be opened to allow water to pass through — complete with small gear motors to control them. The structure even gets a little roadway on top for good measure.

The finished product is quite impressive, and even more so when the outlets open up to spill water through. Such a project would be great fun for high school science students, or even engineering undergrads. Who doesn’t want to play with a miniature scale dam, after all? Bonus points if you build an entire LEGO city downstream, only to see it destroyed in a flood.

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Rubik’s Cube Solver Does It In 4.56 Seconds

April 2, 2023 by Lewin Day 14 Comments

Solving Rubik’s Cubes is a learnable skill. However, to compete at the top level, you’ll have to train hard. Speed cubers can solve a 3×3 cube in under ten seconds these days, after all. [aaedmusa] was a long way off that speed, but his robot is an absolute demon that solves at a rapid pace.

The robot relies on a Teensy 4.1 microcontroller to run the show, paired with its Ethernet kit for connectivity. It runs six stepper motors via TMC2208 drivers, enabling it to directly actuate each face of the cube. Purists will note, however, that the steppers are fitted with adapters that slot directly into modified center squares on the cube. A regulation Rubik’s, this is not.

The design doesn’t feature a machine vision system to capture the state of the cube. Instead, the cube’s status must be input to a web app on an attached computer. Once the cube’s state is loaded into the program, though, the mechanical job of solving the cube can be achieved in under five seconds. Even with six actuators, that’s not fast enough to beat the human world record of 3.47 seconds, but it’s still pretty darn good.

It’s funny to think that way back in 2011, both robots and humans were so much slower at solving cubes. If only all the world’s problems were as simple as a jumbled up toy from the 1970s.

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Magic 8 Ball Provides Tech Support

March 28, 2023 by Bryan Cockfield 15 Comments

ChatGPT might be making the news these days for being able to answer basically any question it’s asked, those of us who are a little older remember a much simpler technology that did about the same thing. The humble “Magic 8 Ball” could take nearly the same inputs, provided they were parsed in simple yes/no form, and provide marginal help similar to the AI tools of today. For a toy with no battery or screen, this was quite an accomplishment. But the small toy couldn’t give specific technical support help, so [kodi] made one that can.

The new 8 Ball foregoes the central fluid-filled chamber for an STM32 Blue Pill board with a few lithium batteries to power it. The original plastic shell was split in two with a hacksaw and fitted with a 3D printed ring which allows the two halves to be reconnected and separated again when it needs to charge. It uses a circular OLED to display the various messages of tech support, which are displayed when an accelerometer detects that the toy has been shaken.

Granted, most of the messages are about as helpful to solving a tech support issue as the original magic 8 Ball’s would have been, but we appreciate the ingenuity and carefree nature of a project like this. It also did an excellent job at operating in a low-power state as well, to avoid needing to charge it often. There have been a few other digital conversions of these analog fortune tellers as well, like this one which adds GIFs to each of the original answers.