The Sub-$100 Easythreed X1 3D Printer, Is It More Than A Novelty?

There was a time when a cheap 3D printer meant an extremely dubious “Prusa i3” clone as a kit of parts, with the cheapest possible components which, when assembled, would deliver a distinctly underwhelming experience. Most hackerspaces have one of these cheap printers gathering dust somewhere, usually with a rats-nest of wires hanging out of one side of it. But those awful kits have been displaced by sub-$200 printers that are now rather good, so what’s the current lowest end of the market? The answer lies in printers such as the sub-$100 Easythreed X1, which All3DP have given a review. We’ve been curious about this printer for a while, but $100 is a bit much to spend on a toy, so¬† it’s interesting to see their take on it.

It’s a tiny printer marketed as a kid’s toy with an unheated bed and a miniature 100mm cubic print volume, so we don’t blame them for pitching their expectations low. They found the supplied slicer to be buggy, but the printer itself to be surprisingly better than they expected. It seems that the Easythreed can deliver reasonable but not superlative small prints amid the occasional disaster, but for under $100, we’d guess that any print is a result. Still, we’ll join them in their assessment that it’s worth spending a bit more on a better printer.

We’ve seen another tiny Easythreed model before, when someone made a novelty wrist-mounted wearable version.

Plastic CPUs Will Bend To Your Will

As microcontroller prices drop, they appear in more things. Today you will find microcontrollers in your car, your household appliances, and even kid’s toys. But you don’t see them often embedded in things that are either super cheap or have to flex, such as for example a bandage. Part of the reason is the cost of silicon chips and part of the reason is that silicon chips don’t appreciate bending. What if you could make CPUs for less than a penny out of flexible plastic? What applications would that open up? PragmatIC — a company working to make this possible — thinks it would open up a whole new world of smart items that would be unthinkable today. They worked with a team at the University of Illinois Urbana-Champaign to create prototype plastic CPUs with interesting results.

This is still the stuff of research and dreams, but a team of researchers did work to produce 4-bit and 8-bit processors using IGZO –indium gallium zinc oxide — semiconductor technology. This tech can be put on plastic and will work even if you bend it around a radius as small as a few millimeters.

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Inside 3D Printing Shoes

If you’ve ever thought about 3D printing shoes, you’ll enjoy watching the video below about a Portland-based company that creates shoes on demand using an HP MJF 5200 3D printer. Granted, this isn’t a printer you likely have in your basement. The one-ton printer costs up to a half-million dollars but watching it do its thing is pretty interesting.

The printer doesn’t create the entire shoe, but just a spongy foam-like TPU footbed and heel. They run the printer overnight and get about a dozen pairs out at once. There’s quite a bit of clean-up to get the piece ready. Of course, there’s also the assembly of the rest of the shoe to take into account.

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Teensy Spectrum Analyzer Has 170 Channels

While high-fidelity audio has come a long way in the past several decades, a lot of modern stereo equipment is still missing out on some of the old analog meters that were common on amplifiers and receivers of the 60s through the 80s. Things like VU meters don’t tend to be common anymore, but it is possible to build them back in to your sound system with the help of some microcontrollers. [Mark] shows us exactly how to reclaim some of the old-school functionality with this twin audio visualizer display.

Not only does this build include two displays, but the microcontroller is keeping up with 170 channels in real-time in order to drive the display. What’s more impressive is that it’s being done all on a Teensy 4.1. To help manage all of the data and keep the speed as fast as possible it uses external RAM soldered to the board, and a second Teensy audio board is used to do the real time FFT analysis. Most of the channels are sent to the display hosting the spectrum analyzer but two are reserved for left and right stereo VU meters on the second display.

The project from [Mark] is originally based on this software from [DIYLAB] so everything is open-source. While it was originally built for a specific piece of hardware, [Mark] has it set up with a line in and line out plus a microphone input so it can be used for virtually any audio hardware now. For another take on the classic VU meter, take a look at this design based on an Arudino instead.

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Casting Parts In Urethane: Tips From A Master

When you want a couple copies of a thing, you can 3D print ’em. When you want a ton of them, you might consider making a mold. If those are the shoes you’re in, you should check out this video from [Robert Tolone] (embedded below). Or heck, just check out all of his videos.

Even just in this single video from a couple years back, there are a ton of tips that’ll help you when you’re trying to pour resin of just the right color into a silicone mold. Mostly, these boil down to testing everything out in small quantities before pouring it in bulk, because a lot changes along the way. And that’s where [Robert]’s experience shines through — he knows all of the trouble spots that you need to test for.

For instance? Color matching. Resin dyes are incredibly concentrated, so getting the right amount is tricky. Mixing the color at a high concentration first and then sub-diluting it slowly allows for more control. But even then, the dried product is significantly lighter than the mixture, so some experimentation is necessary. [Robert] sneaks up on just the right color of seafoam green and then pours some test batches. And then he pours it in the exact shape of the mold just to be sure.

That’s just one of the tips in this video, which is just the tip of the mold-casting iceberg. Pour yourself a coffee, settle down, and you’ll learn something for sure. If you’re into more technical parts and CNC machining, we still love the Guerilla Guide after all these years.

Much thank to [Zane] for tipping us off to this treasure trove.

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Edging Ahead When Learning On The Edge

“With the power of edge AI in the palm of your hand, your business will be unstoppable.

That’s what the marketing seems to read like for artificial intelligence companies. Everyone seems to have cloud-scale AI-powered business intelligence analytics at the edge. While sounding impressive, we’re not convinced that marketing mumbo jumbo means anything. But what does AI on edge devices look like these days?

Being on the edge just means that the actual AI evaluation and maybe even fine-tuning runs locally on a user’s device rather than in some cloud environment. This is a double win, both for the business and for the user. Privacy can more easily be preserved as less information is transmitted back to a central location. Additionally, the AI can work in scenarios where a server somewhere might not be accessible or provide a response quickly enough.

Google and Apple have their own AI libraries, ML Kit and Core ML, respectively. There are tools to convert Tensorflow, PyTorch, XGBoost, and LibSVM models into formats that CoreML and ML Kit understand. But other solutions try to provide a platform-agnostic layer for training and evaluation. We’ve also previously covered Tensorflow Lite (TFL), a trimmed-down version of Tensorflow, which has matured considerably since 2017.

For this article, we’ll be looking at PyTorch Live (PTL), a slimmed-down framework for adding PyTorch models to smartphones. Unlike TFL (which can run on RPi and in a browser), PTL is focused entirely on Android and iOS and offers tight integration. It uses a react-native backed environment which means that it is heavily geared towards the node.js world.

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A Simple RP2040-Based Audio DSP Board

If you’re one of those people who got into building electronics for the purpose of making music, then this Raspberry Pi RP2040-based audio DSP project by [DatanoiseTV] might be of interest. Provided is a FreeRTOS template application for creating Eurorack compatible synthesizers, effects processors, and similar DSP-based audio widgets.

The hardware platform has the usual Eurorack connectivity, including MIDI in, Control Voltages (CV) and the usual 5V-compatible triggers. An audio output is provided to send the audio out to the system mixer or any other analog modules. Additionally, connections are provided for a rotary encoder, a few push buttons, and an OLED display to allow construction of a rudimentary user interface on the module, if that is required.

The application template is generic enough, however the project is intended to be used with the Vult DSP transcompiler. Vult is a high-level programming language designed to enable easy creation of audio synthesizers and similar, producing C++ code as an output of the compilation process. This is then wrapped up with the RTOS goodies (although you don’t actually need them) to drop onto the RP2040 in the usual way, via the handy USB-C port. So, if you’re looking to get into DSP-based Eurorack modules for your homebrew synth rack, this might be a good place to start.

Just like the RP2040 isn’t the most obvious choice for a DSP application, neither is the ESP32 for that matter, but who cares? many modern micros are more than capable of audio DSP these days, with or without the dedicated functionality.