Did We Overestimate The Potential Harm From Microplastics?

Over the past years there have appeared in the media increasingly more alarming reports about micro- and nanoplastics (MNPs) and the harm that they are causing not only in the environment, but also inside our bodies. If some of the published studies were to be believed, then MNPs are everywhere inside our bodies, from our blood and reproductive organs to having deeply embedded themselves inside our brains with potentially catastrophic health implications.

Early last year we covered what we thought we knew about the harm from MNPs in our bodies, but since then more and more scientists have pushed back against these studies, calling them ‘flawed’ and questioning the used methodology and conclusions. Despite claims of health damage in mice, institutions like the German federal risk assessment institute also do not acknowledge evidence of harm to human health from MNPs.

All of which raises the question whether flawed studies have pushed us into our own Chicken Little moment, and whether it’s now time to breathe a sigh of relief that the sky isn’t falling after all.

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Using 3D Printing And Copper Tape To Make PCBs

In a recent video [QWZ Labs] demonstrates an interesting technique to use 3D printing to make creating custom PCBs rather straightforward even if all you have is a 3D printer and a roll of copper tape.

The PCB itself is designed as usual in KiCad or equivalent EDA program, after which it is exported as a 3D model. This model is then loaded into a CAD program – here Autodesk Fusion – which is used to extrude the traces by 0.6 mm before passing the resulting model to the 3D printer’s slicer.

By extruding the traces, you can subsequently put copper tape onto the printed PCB and use a cutting tool of your choice to trace these raised lines. After removing the rest of the copper foil, you are left with copper traces that you can poke holes in for the components and subsequently solder onto.

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Servicing The ‘Not Serviceable’ Bearings On A Vacuum Power Head

Everyone knows that bearings are a consumable wear item, and that the power head of a vacuum likely contains bearings that will eventually need to be replaced. Yet when the manufacturer wants you to toss out the entire roller and pay $80 for the privilege, that feels rather steep and unnecessary. In the case of [Mark Furneaux], the roller in the power head of his Filter Queen brand vacuum felt particularly over the top to toss, since it’s all fancy wood with very durable brushes.

One of the bearings had stopped being a bearing, resulting in the plastic that held it in place beginning to melt. Fortunately the damage hadn’t progressed to the point where printing a replacement was necessary, so instead it was time to figure out how to remove the bearings without permanent damage. The trick that the manufacturer used was to peen the ends of the metal shafts that the bearings fit onto, requiring some Dremel action to convince them to come off.

After some careful modifications like this, the remnants of the old bearings came off and their replacements could go on. Due to the metal shaft modifications, it is now mostly the plastic caps on either end which grip the bearings, but it seems to work well enough. For $2 in bearings and some labor on [Mark]’s end, he managed to keep a perfectly good roller brush out of the landfill, and future bearing replacements should be much easier.

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Pi Compute Module Powers Fully Open Smartphone

With the powerful off-the-shelf hardware available to us common hardware hobbyist folk, how hard can it be to make a smartphone from scratch? Hence [V Electronics]’s Spirit smartphone project, with the video from a few months ago introducing the project.

As noted on the hardware overview page, everything about the project uses off the shelf parts and modules, except for the Raspberry Pi Compute Module 5 (CM5) carrier board. The LCD is a 5.5″, 1280×720 capacitive one currently, but this can be replaced with a compatible one later on, same as the camera and the CM5 board, with the latter swappable with any other CM5 or drop-in compatible solution.

The star of the show and the thing that puts the ‘phone’ in ‘smartphone’ is the Quectel EG25-GL LTE (4G) and GPS module which is also used in the still-not-very-open PinePhone. Although the design of the carrier board and the 3D printable enclosure are still somewhat in flux, the recent meeting notes show constant progress, raising the possibility that with perhaps some community effort this truly open hardware smartphone will become a reality.

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Create A Tiny Telephone Exchange With An Analog Telephone Adapter

An analog telephone adapter (ATA), or FXS gateway, is a device that allows traditional analog phones to be connected to a digital voice-over-IP (VoIP) network. In addition to this, you can even create a local phone exchange using just analog phones without connecting to a network as [Playful Technology] demonstrates in a recent video.

The ATA used in the video is the Grandstream HT802, which features one 10/100 Mbps Ethernet port and two RJ11 FXS ports for two POTS phones, allowing for two phones to be directly connected and configured using their own profiles.

By using a multi-FXS port ATA in this manner, you essentially can set up your own mini telephone exchange, with a long run of Cat-3 possible between an individual phone and the ATA. Use of the Ethernet port is necessary just once to configure the ATA, as demonstrated in the video. The IP address of the ATA is amusingly obtained by dialing *** on a connected phone and picking 02 as menu option after which a synthetic voice reads out the number. This IP address gets you into the administration interface.

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Restoring A 1924 Frigidaire B-9 Refrigerator Back To Working Condition

Before the refrigerator became a normal part of any kitchen, those with enough money to throw around could get an icebox, which used melting ice to cool food and drinks in a second compartment. As refrigerators became available for sale in the 1920s, this created somewhat awkward transition models, like the 1924 Frigidaire B-9 that [David Allen] recently got offered for a restoration. This was part of the restoration of a 1926 house, which foresaw putting this venerable unit back into operation.

As [David] explains, this refrigerator was still in use until about 1970 when it broke down, and repairs proved tricky. Clearly, the fault wasn’t that severe as [David] got it working again after a number of small repairs and a lot of maintenance. The running unit with its basic elements can be seen purring away in the completion video, with the journey to get there covered in a video series starting with the first episode.

What’s fascinating is that during this aforementioned transition period, the vapor compression electric cooling system was an optional extra, meaning that the basic layout is still that of an icebox. Correspondingly, instead of ice in the ice compartment, you find the low-side float evaporator, with the basement section containing the condensing unit, motor, and compressor. The temperature sensor is also a miracle of simplicity, using bellows that respond to the temperature and thus volume of the evaporator coolant, which trigger a switch that turns on the compressor.

Despite a hundred years having passed since this refrigerator was constructed, at its core it works exactly the same as the unit we have in our kitchens today, albeit with higher efficiency, more electronics, and with the sulfur dioxide refrigerant replaced with something less toxic to us humans.

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Art of 3D printer in the middle of printing a Hackaday Jolly Wrencher logo

Does Carbon Fiber PLA Make Sense?

Carbon fiber (CF) has attained somewhat of a near-mystical appeal in consumer marketing, with it being praised for being stronger than steel while simultaneously being extremely lightweight. This mostly refers to weaved fibers combined with resin into a composite material that is used for everything from car bodies to bike frames. This CF look is so sexy that the typical carbon-fiber composite weave pattern and coloring have been added to products as a purely cosmetic accent.

More recently, chopped carbon fiber (CCF) has been added to the thermoplastics we extrude from our 3D printers. Despite lacking clear evidence of this providing material improvements, the same kind of mysticism persists here as well. Even as evidence emerges of poor integration of these chopped fibers into the thermoplastic matrix, the marketing claims continue unabated.

As with most things, there’s a right way and a wrong way to do it. A recent paper by Sameh Dabees et al. inĀ Composites for example covered the CF surface modifications required for thermoplastic integration with CF.

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