Balloon Guitar Is An Absolute Gas, Helium Or Not

Guitars are most typically built out of wood. Whether it’s an acoustic guitar with a big open cavity, or a solid-body electric, there’s generally a whole lot of wood used in the construction. However, [Mattias Krantz] shows us that alternative construction methods are entirely possible, by building his own balloon guitar.

The balloon guitar still has a neck, bridge, and strings just like any other. However, in place of the resonant cavity of an acoustic guitar, there is provision to install a large balloon instead. It’s actually quite interesting to watch — with the balloon installed, the guitar delivers much more volume than when played without a resonant cavity at all.

The guitar was actually built to test if swapping out air in the balloon for helium would shift the pitch of the sound. Of course, a guitar’s pitch comes from the tension on the vibrating strings, so changing the gas in the resonant cavity doesn’t directly affect it. Instead, much like inhaling helium to affect the human voice, the change is to the timbre of the sound, not the fundamental pitch itself. It sounds as if the guitar has been given a subtle treble boost.

It’s a fun build, and one that shows us that it’s possible to build musical instruments in many ways, not just using traditional techniques. If you want to further play with your guitar’s sound, though, consider turning to the world of machine learning.

Continue reading “Balloon Guitar Is An Absolute Gas, Helium Or Not” →

Big Audio Visualizer Pumps With The Music

A spectrum analyzer is a great way to create exciting visuals that pulse in time with music. [pyrograf] wanted a big one as a display piece, so set about whipping up something of their very own.

An ESP32 microcontroller serves as the heart of the build, with its high clock rate and dual cores making it a highly capable choice for the job. Audio from a microphone is amplified and pumped into the ESP32’s analog input. Core 0 on the ESP32 then runs a Fast Fourier Transform on the input audio in order to determine the energy in each frequency band. The results of this FFT are then passed to Core 1, which is used to calculate the required animations and pipe them out to a series of WS2812B LEDs.

Where this build really shines, though, is in the actual construction. Big chunks of acrylic serve as diffusers for the LEDs which light up each segment of the spectrum display. Combine the big pixel size with a nice smooth 30 Hz refresh rate on the LEDs, and the result is a rather large spectrum analyzer that really does look the business.

We’ve seen some similar builds over the years, too. Video after the break.

Continue reading “Big Audio Visualizer Pumps With The Music” →

Open Database Shares Resin 3D Printing Settings

3D printing is much like CNC milling or welding or just about any physical manufacturing process, in that good results fundamentally come down to having the right settings. In an effort to aid those working in the resin printing space, [Adam Bute] has put together a community database of resin printing settings.

The site has sections relevant to a variety of resin 3D printers, sorted by manufacturer. Those eager to find the right settings for their given resin and printer merely need to click through and look up the appropriate data. The settings are crowdsourced, provided by manufacturers, community members, and users of [Adam]’s Maker Trainer website.

While it’s still important to run validation tests on a resin printer to get the best results, having a community-sourced list of settings can help users get up and running much more quickly than they otherwise might. It appears that community contributions can’t directly be made yet, but we suspect such a feature is in the works.

We’ve seen similar material databases before for melty-plastic printers, and those have proven to be valuable to the community. We’re sure this resin database will be received in much the same way. If you know about other great resources for printing tips and tricks, do drop us a line!

Tetris Clock Gets Talkative Upgrade

Tetris is arguably one of the most popular video games of all time, and its famous bricks have become cultural icons in themselves, as seen in this clock build from [The Electronic Engineer].

The web interface allows the various sound options to be easily configured.

The basic concept of the Tetris clock is that falling bricks stick together in the shape of numbers to display the time. In this case, the clock is based on the version created by [Brian Lough] which we featured previously. It relies on an RGB LED matrix as a display.

However, the build has had a few upgrades courtesy of [The Electronic Engineer]. With the help of an I2S audio breakout board, the clock can play sounds at various times of day. It’s currently set up with clips from various cartoons announcing lunch and coffee break times. There’s also a web interface added in for configuration purposes, and some text tickers too.

It’s fun to see a popular open project get some upgrades as others dive in to build their own version. We’ve seen some other fun Tetris clocks before, too. Continue reading “Tetris Clock Gets Talkative Upgrade” →

’90s Ford Gets Shift Paddles And A Digital Dash Upgrade

The EA Falcon took Ford’s popular Australian sedan line into the 1990s, even if it gave way to the EB Falcon by the end of 1991. Few would call it high tech, but it introduced several innovations to the platform that were very of its time. One hacker, however, has taken a humble EA Falcon and given it a set of homebrewed modern upgrades.

The maroon EA Falcon has scored a Barra heart transplant as well as some nifty digital upgrades.

The example in question is an EA Fairmont Ghia, which featured a handful of high-tech displays in the dash cluster, which was very on trend in the late 80s and early 90s. This dash has seen much revision, however, and now features a large TFT display and a smaller OLED unit, both of which show various vital statistics for the car. The screens have been neatly hacked in, one as part of the tachometer, the other replacing the original fuel and temperature gauges. With the data displayed on the screen instead, there’s no need for the original dials. Continue reading “’90s Ford Gets Shift Paddles And A Digital Dash Upgrade” →

Can You Help NASA Build A Mars Sim In VR?

No matter your project or field of endeavor, simulation is a useful tool for finding out what you don’t know. In many cases, problems or issues aren’t obvious until you try and do something. Where doing that thing is expensive or difficult, a simulation can be a low-stakes way to find out some problems without huge costs or undue risks.

Going to Mars is about as difficult and expensive as it gets. Thus, it’s unsurprising that NASA relies on simulations in planning its missions to the Red Planet. Now, the space agency is working to create a Mars sim in VR for training and assessment purposes. The best part is that you can help!

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Making A Concrete Pinhole Camera

A pinhole camera is a simple device that can be built out of virtually any simple closed chamber, and is a great way to learn about the basic principles of photography. [amuu] has created a version that can be readily made out of concrete, of all materials!

The photos captured by the camera featured some artifacts from light leaks and grit, but the results are enjoyable for their lo-fi, homebrew aesthetic!

The build starts with the creation of a mold for the concrete, using laminated sheets of foam. The foam is assembled with cut-up pieces of a ballpoint pen serving as cores in the mold. This provides a space for the film winders in the final product. The concrete is then mixed and poured into the mold, and allowed to set. Tapping or vibrating the mold is key to getting all the air bubbles out of the mixture.

Once set, the foam is mechanically removed from the concrete and the camera can be finished off. The internals are given a lick of black paint to improve the camera’s light-tightness. The shutter, pinhole, and film winder are then also fitted to allow the camera to function.

[amuu]’s first attempt to take photos with the camera lead to some results that were pleasingly lo-fi. There are overscan issues on the film and some other artifacts, but overall, the results are esoteric and fun. If you’re not a fan of the concrete camera, though, you can always consider making a 3D-printed pinhole camera instead!