Making The Tiny Air65 Quadcopter Even Smaller

October 14, 2025 by Maya Posch 15 Comments

First person view (FPV) quadcopter drones have become increasingly more capable over the years, as well as much smaller. The popular 65 mm format, as measured from hub to hub, is often considered to be about the smallest you can make an FPV drone without making serious compromises. Which is exactly why [Hoarder Sam] decided to make a smaller version that can fit inside a Pringles can, based on the electronics used in the popular Air65 quadcopter from BetaFPV.

The 22 mm FPV drone with camera installed and looking all cute. (Credit: Hoarder Sam)

The basic concept for this design is actually based on an older compact FPV drone design called the ‘bone drone’, so called for having two overlapping propellers on each end of the frame, thus creating a bone-like shape. The total hub-to-hub size of the converted Air65 drone ends up at a cool 22 mm, merely requiring a lot of fiddly assembly before the first test flights can commence. Which raises the question of just how cursed this design is when you actually try to fly with it.

Obviously the standard BetaFPV firmware wasn’t going to fly, so the next step was to modify many parameters using the Betaflight Configurator software, which unsurprisingly took a few tries. After this, the fully loaded drone with camera and battery pack, coming in at a whopping 25 grams, turns out to actually be very capable. Surprisingly, it flies not unlike an Air65 and has a similar flight time, losing only about 30 seconds of the typical three minutes.

With propellers sticking out at the top and bottom – with no propeller guards – it’s obviously a bit of a pain to launch and land. But considering what the donor Air65 went through to get to this stage, it’s honestly quite impressive that this extreme modification mostly seems to have altered its dimensions.

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Give Your Microscope Polarized $5 Shades To Fight Glare

October 13, 2025 by Maya Posch 15 Comments

Who doesn’t know the problem of glare when trying to ogle a PCB underneath a microscope of some description? Even with a ring light, you find yourself struggling to make out fine detail such as laser-etched markings in ICs, since the scattered light turns everything into a hazy mess. That’s where a simple sheet of linear polarizer film can do wonders, as demonstrated by [northwestrepair] in a recent video.

Simply get one of these ubiquitous films from your favorite purveyor of goods, or from a junked LCD screen or similar, and grab a pair of scissors or cutting implements. The basic idea is to put this linear polarizer film on both the light source as well as on your microscope’s lens(es), so that manipulating the orientation of either to align the polarization will make the glare vanish.

This is somewhat similar to the use of polarizing sunshades, only here you also produce specifically the polarized light that will be let through, giving you excellent control over what you see. As demonstrated in the video, simply rotating the ring light with the polarizer attached gives wildly different results, ranging from glare-central to a darkened-but-clear picture view of an IC’s markings.

How to adapt this method to your particular microscope is left as your daily arts and crafts exercise. You may also want to tweak your lighting setup to alter the angle and intensity, as there’s rarely a single silver bullet for the ideal setup.

Just the thing for that shiny new microscope under the Christmas tree. Don’t have a ring light? Build one.

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Removing Infill To Make 3D Printed Parts Much Stronger

October 12, 2025 by Maya Posch 22 Comments

When it comes to FDM 3D prints and making them stronger, most of the focus is on the outer walls and factors like their layer adhesion. However, paying some attention to the often-ignored insides of a model can make a lot of difference in its mechanical properties. Inspired by a string of [Tom Stanton] videos, [3DJake] had a poke at making TPU more resilient against breaking when stretched and PLA resistant to snapping when experiencing a lateral force.

Simply twisting the TPU part massively increased the load at which it snapped. Similarly, by removing the infill from the PLA part before replacing it with a hollow cylinder, the test part also became significantly more resilient. A very noticeable result of hollowing out the PLA part: the way that it breaks. A part with infill will basically shatter. But the hollowed-out version remained more intact, rather than ripping apart at the seams. The reason? The hollow cylinder shape is printed to add more walls inside the part. Plus cylinders are naturally more able to distribute loads.

All of this touches on load distribution and designing a component to cope with expected loads in the best way possible. It’s also the reason why finite element analysis is such a big part of the CAD world, and something which we may see more of in the world of consumer 3D printing as well in the future.

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Bose SoundTouch Smart WiFi Speakers Are About To Go Dumb

October 11, 2025 by Maya Posch 33 Comments

Bose SoundTouch speakers were introduced in 2013, offering the ability to connect to online streaming services and play back audio on multiple speakers simultaneously using the accompanying mobile app. Now these features are about to be removed, including the mobile app, as Bose is set to discontinue support on February 18, 2026. From that point onwards, you can only use them via Bluetooth or physical connectors that may be present, like an audio jack or HDMI port. This includes fancy home theater system hardware like the above SoundTouch 520.

That is the official line, at least. We have seen the SoundTouch on Hackaday previously, when it was discovered how to gain root shell access to the Linux OS that powers the original SoundTouch system with Telnet access on port 17,000 to pass the listening service the remote_services on command before connecting with Telnet as usual, with root and no password. A quick glance at the comments to that post suggests that this is still a valid approach for at least certain SoundTouch devices.

The fallout from this announcement appears to be twofold: most of all that ‘smart’ features like WiFi-based streaming can be dropped at any time. But it also makes us realize that hardware hackers like us will never run out of new and suddenly obsolete hardware that need our rescue.

Entering The Wild World Of Power Over Ethernet

October 11, 2025 by Maya Posch 50 Comments

As Ethernet became the world-wide standard for wired networking, there was one nagging problem. You already have to plug in the network cable. But then you have to also plug in a power cable. That power cable needs to be long enough. And have the right plug on it for your country. And provide the right current and voltage. That’s how Power over Ethernet (PoE) was born, first in a veritable Wild West of proprietary standards and passive injectors, then in a standardized process. Recently [T. K. Hareendran] wrote a primer on PoE, with more of a DIY intro focus, including some favorite PoE PD (powered device) chips to use in your own design.

You can still totally use passive PoE if that’s your jam, and you have full control over the network and any connected devices. This would allow you to, for example, power your SBCs for a couple of bucks, although for adding PoE to your Mac Mini you may want to look at some more refined options, if only as a safety precaution.

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The Fascinating Waveguide Technology Inside Meta’s Ray-Ban Display Glasses

October 9, 2025 by Maya Posch 26 Comments

The geometric waveguide glass of the Meta Ray-Ban Display glasses. (Credit iFixit)

Recently the avid teardown folk over at iFixit got their paws on Meta’s Ray-Ban Display glasses, for a literal in-depth look at these smart glasses. Along the way they came across the fascinating geometric waveguide technology that makes the floating display feature work so well. There’s also an accompanying video of the entire teardown, for those who enjoy watching a metal box cutter get jammed into plastic.

Overall, these smart glasses can be considered to be somewhat repairable, as you can pry the arms open with a bit of heat. Inside you’ll find the 960 mWh battery and a handful of PCBs, but finding spare parts for anything beyond perhaps the battery will be a challenge. The front part of the glasses contain the antennae and the special lens on the right side that works with the liquid crystal on silicon (LCoS) projector to reflect the image back to your eye.

While LCoS has been used for many years already, including Google Glass, it’s the glass that provides the biggest technological advancement. Instead of the typical diffractive waveguide it uses a geometric reflective waveguide made by Schott, with the technology developed by Lumus for use in augmented reality (AR) applications. This is supposed to offer better optical efficiency, as well as less light leakage into or out of the waveguide.

Although definitely impressive technology, the overall repairability score of these smart glasses is pretty low, and you have to contest with both looking incredibly dorky and some people considering you to be a bit of a glasshole.

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Why Stepper Motors Still Dominate 3D Printing

October 8, 2025 by Maya Posch 43 Comments

It’s little secret that stepper motors are everywhere in FDM 3D printers, but there’s no real reason why you cannot take another type of DC motor like a brushless DC (BLDC) motor and use that instead. Interestingly, some printer manufacturers are now using BLDCs for places where the reduction in weight matters, such as in the tool head or extruder, but if a BLDC can be ‘stepped’ much like any stepper motor, then why prefer one over the other? This is the topic of a recent video by [Thomas Sanladerer], with the answer being mostly about cost, and ‘good enough’ solutions.

The referenced driving method of field-oriented control (FOC), which also goes by the name of vector control, is a VFD control method in which the controller can fairly precisely keep position much like a stepper motor, but without the relatively complex construction of a stepper motor. Another advantage is that FOC tends to use less power than alternatives.

Using a FOC controller with a BLDC is demonstrated in the video, which also covers the closed-loop nature of such a configuration, whereas a stepper motor is generally driven in an open-loop fashion. Ultimately the answer at this point is that while stepper motors are ‘good enough’ for tasks where their relatively large size and weight aren’t real issues, as BLDCs with FOC or similar becomes more economical, we may see things change there.

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