Straight Talk On 3D Printing Footwear At Home

Printed footwear is an intriguing idea, but as far as projects go it is somewhat more complex than it first appears. This guide to 3D printing your own clogs not only provides a solid process, but also acts as a list of the challenges and pitfalls involved. After all, a piece of footwear is actually a fairly large object. Failed prints can be costly and time-consuming, so a guide like this is a valuable resource.

First of all, a 3D printer that can handle multi-material printing is called for. The footwear itself will be printed in TPU 90A as a sweet spot for hardness, but the print will require supports and those supports will need to peel away cleanly. The solution is a shoe printed in TPU with a rigid support structure of PLA. Using two different materials in the same print with anything remotely resembling efficiency calls for either a dual-nozzle print head, or a multi-toolhead printer.

3D printing one’s own clogs can be rewarding, if not necessarily cost-effective.

Here we want to take a moment and say that while the guide itself suggests PETG is also a suitable support structure, we suspect this might only be true for the exact filament formulations used in the guide. The safer approach is to use PLA. Why? As we’ve seen in other tests, PETG has been observed to stick extremely well to flex filaments in general, whereas PLA doesn’t really want to stick to anything other than PLA. The exact formulations of TPU and PETG used in the guide might be compatible with one another, but in general we recommend sticking to PLA as a rigid support for flexible filament.

Assuming a capable printer and suitable materials are nailed down, one also needs to worry about keeping the TPU dry. It is very sensitive to moisture, which directly affects print quality. You’ll also need to dial in the settings — a gyroid-patterned infill of 15% provides the right amount of “squish”, which is most effectively fine-tuned by changing the infill pattern rather than the density.

Is it worth the time and effort and filament cost to print one’s own pair of slip-ons versus simply buying a pair of Crocs®? Maybe not, but it can still be rewarding and this guide will help minimize any failed prints in the process. And if you do get a nice print but the TPU is sticking a little too well to the build plate, reach for the isopropyl alcohol.

Teardown Shows Low-Fi Microphone Is Surprisingly Sophisticated

The Ting FX EP-2350 by Teenage Engineering is a standalone microphone with a few extras, including samples and built-in effect presets that can be modified by the user. It also has a distinctive design, and [Sam Holland] does an in-depth teardown that offers some insights that are worth keeping in one’s back pocket. The large, side-mounted lever in particular is an interesting bit, but more about that in a moment.

Inside the device is a single PCB, which has a cutout in the middle for a pair of AAA cells. A Raspberry Pi 2350 drives the device’s functions, supported by various components which [Sam] identifies, although he mostly looks at everything from the perspective of a mechanical engineer as he critiques the design. It’s a clean-looking, intentionally low-fi design that belies how complex the device really is.

The multi-function, chunky, spring-loaded side lever is of particular interest. It has three sensors: two switches and a potentiometer. One switch detects when the lever is at rest, or depressed by any amount at all. The potentiometer mates with the pivot point of the lever, allowing the device to directly sense how far the lever is pushed. The last switch triggers when the lever is pushed all the way in. Together, it forms an intuitive input that combines powering on (the device wakes up from sleep mode as soon as the lever is pressed) with the ability to adjust effects in proportion with how far the lever is pressed, while also bottoming out with a distinct click that itself acts as an input signal.

One other interesting bit is the light pipes that carry light from multiple indicator LEDs to the outside of the device. A textured surface acts as a diffuser and helps the lit surface look smooth, while a coating of silver paint prevents light bleed and (probably) maximizes light transmission through the plastic. Hot glue makes a pretty good light pipe material but if DIY light pipes end up in your next project, sanding the exit surface and giving the rest a coating of silver paint just might be worth a shot. Continue reading “Teardown Shows Low-Fi Microphone Is Surprisingly Sophisticated”

Watch Soldering Up Close And From Any Angle, In VR

A manual skill like soldering is so much easier to learn and grasp when one can watch it in action, and there’s a brand new way to do that using virtual reality (VR). It isn’t just a series of 3D videos shot at someone’s workbench, either.

See soldering in action from any angle, with fine details preserved even close up.

PCB Hand-Soldering Basics is a series of thirteen videos that demonstrate soldering using Gaussian splats, a method of displaying 3D content that allows the viewer to freely look at things from any angle. Gaussian splats aren’t new, but what makes this different is the sheer level of detail and the fact that it’s focused on handheld tool use rather than displaying a famous location, landmark, or something similarly “big”.

Throughout the videos fine detail on the iron, parts, and the PCB itself remain visible from any angle and even from close up. Here’s a short video captured from within a VR headset that is probably the next best thing to seeing it yourself.

An educational production, it was was made in cooperation with the Department of Electrical and Electronic Engineering at Imperial College London. A few more details are in a LinkedIn post by [Tanmay Lad], who was part of the team involved in the production. The goal is to offer a unique, front-row seat to hand soldering with the ability to zoom in or look at it in 3D from any angle.

Not familiar with Gaussian splats? We’ve previously covered a great overview. They look great and are computationally cheap to render, and being able to get up close and see such detail is not really something one expects.

Track Bird Visitors With A Raspberry Pi And A USB Mic

Avian Visitors is a lovely project by [Teddy Warner] that uses a Raspberry Pi and microphone to keep track of which birds have been visiting your home, and creates a colorful illustration of recent visitors on top of it all.

It reports on a web interface of its own making, but what really takes things to a new level is an optional, stylish E-Ink panel that shows the last 24 hours’ worth of visitors at a glance in a collage.

The key to identification is BirdNET (GitHub here), a deep learning classifier from Cornell that can reliably identify and classify more than 11,000 species worldwide based on sound alone.

Based on that information, the system pulls bird images from a reference set for the region and creates a collage representing the breadth and frequency of visitors in a single image. The larger the image of a bird, the more frequently it was heard.

That’s a cool project, but [Teddy] took things one step further by setting up a color E-Ink display to show a running summary of all the avian visitors the system identifies. [Teddy] has a knack for leveraging projects into wall-mounted art, as we saw with his generative art wall plotter. Continue reading “Track Bird Visitors With A Raspberry Pi And A USB Mic”

Robotic Screw And Bolt Sorter Seeks A New Challenge

As someone who disassembles and repairs hardware, [Aad] eventually ended up with a huge collection of mixed bolts and screws. This led to creating the automatic bolt and screw sorting system you see here, although in a way it is just a proof of concept. Bolts and screws happen to be a useful application for now, but the system is capable of sorting just about any small objects.

A bit of machine vision detects the size and shape of each object. Weight can also be measured.

Mixed pieces go onto a large conveyor belt, shown on the right. This feeds a few screws at a time down a chute, where they roll onto an illuminated platform.

Above the lit platform is a camera, and machine vision is used to detect the size and shape and orientation of each screw. A robotic gripper on a gantry picks the screws up one by one — separating them first if they happened to clump together — and places each in a drop-off cart. The cart drops the object into a receptacle with its brethren, making sure similar ones are grouped together. Watch it in action in the video, embedded below the page break.

It’s a great build that shows fancy components aren’t necessary for good results. Servos and steppers are controlled with an ESP32-WROOM board, and a piezo sensor detects screws falling off the conveyor. Some of you may have noticed a repurposed Ultimaker 3D printer serving as the bulk of the system, its hot end having been replaced with a gripper that can raise and lower. The overhead camera is an ESP32-CAM adapted to accept M12 lenses so it can focus on the platform.

There’s one more feature worth mentioning — the system also has the ability to measure the weight of a picked object by placing it onto a moveable inspection platform, which can optionally put it under a USB microscope for a closer look. Everything is controlled by a nearby PC, so there’s a lot of flexibility built into the system.

We suppose that once all the screws and bolts in a shop are sorted, it only makes sense to sort all the nuts. Are there other objects besides screws and bolts that would be useful to sort with a system like this? If you have any ideas, don’t keep them to yourself! [Aad] would love to hear your comments and ideas, so share them below.

Continue reading “Robotic Screw And Bolt Sorter Seeks A New Challenge”

Wrist Welcomes Wii Nunchuk As Gloriously Ergonomic Macropad

[John Dingley] spends a lot of time editing videos, and as many of us know, when it comes to repetitive tasks the more ergonomic the better.

Keyboard shortcuts exist for common video editing functions, but [John] found that the vast majority of his work needed only three or four of them. Feeling he could do better than a three-key macropad, he turned to what’s perhaps one of the most ergonomic devices ever designed — the Wii Nunchuk.

A Wii Nunchuk is an I2C device, so there needs to be some intermediary device involved if you want to plug it into a computer. [John] solves that with the ANAVI Handle, an open source adapter to make a Nunchuk act like a USB Human Interface Device (HID). That addresses the connectivity problem, but the default firmware on the adapter only treats the Nunchuk as a mouse or joystick, so a few more changes are required before it can be pressed into service as an ultra-comfortable macropad.

The ANAVI Handle runs CircuitPython code on an RP2040, and modifying its behavior is as simple as plugging it in via USB and editing the code right on the device. One has to define some keyboard events, configure the device to act as a keyboard, and send the right events when the buttons or joystick get pushed. [John] provides the code, and walks through the changes on video so even those without any coding experience can get it done.

The Nunchuk design is still being sold and used today, and it’s shown up in all kinds of places. We’ve seen a Bluetooth-enabled one and even seen a Raspberry Pi Zero shoehorned into one, complete with HDMI output.

Continue reading “Wrist Welcomes Wii Nunchuk As Gloriously Ergonomic Macropad”

Get A Remote Terminal With One Binary, One URL, And Zero Config

Launch a single static binary executable, send someone a QR code or URL (or failing that, text a numerical code or shout it across a room), and they’ll get an encrypted terminal in their browser. No VPN, no port forwarding, no firewall modifications, and no account setup required. It’s BitBang by [Rich LeGrand], and there is a lot to go through in this one.

The best part? It’s not actually limited to just firing off a terminal. It’s a whole open framework for establishing an encrypted peer-to-peer connection between two systems over WebRTC without needing either a trusted central authority, or any special network configuration.

The signaling server brokers the handshake, then has no further involvement. By design, it couldn’t see application data even if it wanted to. Click to enlarge.

Opening a remote terminal, transferring files, or accessing web apps on a remote machine’s network is done with bitbang-cli, an implementation of BitBang focused on providing simple, zero-config remote access.

Before we go on, we want to mention that BitBang does require a lightweight, trustless signaling server only to broker the initial connection, but more on that in a moment.

On the machine to be shared, one first downloads the binary. Easiest way to do that is to go to bitba.ng and download manually, or copy and paste the one-line installer to auto-detect one’s system, download the correct release, and verify the checksum.

After the binary is downloaded, simply run it in a terminal and receive a QR code to scan, a URL to copy & paste, or a numerical code if those are inconvenient. On the remote side, one accesses the signaling server and the connection is made — one gets a terminal on the target machine open in the browser tab, with added options for file sharing and accessing web applications on the target network.

The signaling server isn’t involved in authentication or encryption, and couldn’t see private data between the two ends even if it wanted to. Prefer not to use someone else’s regardless? Run your own local instance with bitbang-server.

Originally developed as an easy way to securely make telepresence robots reachable over the Internet with nothing more than a QR code, today it’s a whole framework.

It includes not just the remote-access tool mentioned above, but also a BitBang Octoprint plugin for cloud-free remote access to 3D printers, and bitbang-python is a library for turning local Python web applications into a URL that can be opened from anywhere.

We’re sure some of you are getting more than a few ideas from this. If it lets you bring a project over the finish line, let us know on our tips line.