DIY Magnet Handling Tool Puts An End To Placement Errors

January 14, 2023 by Donald Papp 10 Comments

I’m sure we can all agree that the worst time to find out a magnet is the wrong way around is after glue has been applied. With that in mind, [erick.siders] created the parametric Magnet Placer tool.

Color-coded tools, one for each polarity.

Picking up and placing magnets into assemblies can be an error-prone process, because magnet polarity cannot be directly identified or sensed by either sight or fingertips. This tool helps by acting a lot like a suction pickup tool — press the plunger down, and a magnet can be picked up, release the plunger, and the magnet lets go. Simple, and effective.

Since the tool is polarity-dependent (depending on which orientation the pickup magnet is mounted into the internal plunger), [erick.siders] suggests printing two tools and color-coding them. That way, one can choose the right tool based on the situation and be confident that the magnets are right-side-up, every time.

The tools use a long metric bolt, a magnet, and a spring, but none of those parts are particularly critical. We also love the way that the end result has no gaps or openings into the moving parts, which means nothing can get caught on or inside anything during use or storage.

It’s a parametric design and the CAD files (in both Fusion 360 and STEP flavors) are provided, so modification should be a breeze. And if you happen to be using PrusaSlicer, remember you can now drop STEP format files directly in for slicing.

Increasing PV Solar Cell Efficiency Through Cooling

January 14, 2023 by Maya Posch 54 Comments

An unavoidable aspect of photovoltaic (PV) solar panels is that they become less efficient when they warm up. [Tech Ingredients] explains in a new video the basic reason for this, which involves the input of thermal energy affecting the semiconductor material. In the subsequent experiment, it is demonstrated how cooling the backside of the panel affects the panel’s power output.

There are commercial solutions that use water cooling on the back of panels to draw heat away from panels, but this still leaves the issues of maintenance (including winter-proofing) and dumping the heat somewhere. One conceivable solution for the latter is to use this heat for a household’s hot water needs. In the demonstrated system a heatsink is installed on the back of the panel, with fans passing cool air over the heatsink fins.

On a 100 Watt PV panel, 10 W was lost from the panel heating up in the sun. After turning on the fans, the panel dropped over 10 °C in temperature, while regaining 5.5 W. Since the installed fans consumed about 3 W, this means that the fans cost no extra power but resulted in increased production. Not only that, but the lower temperatures will in theory extend the panel’s lifetime. Though even with active cooling, even the best of PV panels will need to be replaced after a couple decades.

Continue reading “Increasing PV Solar Cell Efficiency Through Cooling” →

Swap The Clock Chip On The Mac SE/30 With An ATTiny85

January 13, 2023 by Tom Nardi 20 Comments

As [Phil Greenland] explains in the first part of his excellent write-up, the lithium battery used to keep the real-time clock (RTC) going on the Macintosh SE/30 has a nasty habit of exploding and leaking its corrosive innards all over the board. Looking to both repair the damage on a system that’s already had a battery popped and avoid the issue altogether on pristine boards, he started researching how he could replace the battery with something a bit more modern.

It turns out, the ATtiny85 is pin-compatible with the Mac’s original RTC chip, and indeed, [Andrew Makousky] had already written some code that would allow the microcontroller to emulate it. This is actually a bit more complex than you might realize, as the original RTC chip was doing double-duty: it also held 256 bytes of parameter random access memory (PRAM), which is where the machine stored assorted bits of info like which drive to boot from and the mouse cursor speed.

But after getting the mod installed, the computer refused to start. It turns out the project targeted earlier machines like the Macintosh Plus and SE, and not his higher-performance SE/30. Thanks to community resources like this KiCad recreation of the SE/30’s motherboard, contemporary technical documents, and his trusty logic analyzer, [Phil] was able to figure out that the timing was off — the code was simply struggling to respond to the faster machine. Continue reading “Swap The Clock Chip On The Mac SE/30 With An ATTiny85” →

A blue enclosure with "IoT AI-assisted Deep Algae Bloom Detector w/Blues Wireless" written on the front. Two black cables run over a wooden desk to a cylinder with rocks on the bottom and filled with murky water. A bookshelf lurks in the background.

Detecting Algal Blooms With The Help Of AI

January 13, 2023 by Navarre Bartz 1 Comment

Harmful Algal Blooms (HABs) can have negative consequences for both marine life and human health, so it can be helpful to have early warning of when they’re on the way. Algal blooms deep below the surface can be especially difficult to detect, which is why [kutluhan_aktar] built an AI-assisted algal bloom detector.

After taking images of deep algal blooms with a boroscope, [kutluhan_aktar] trained a machine learning algorithm on them so a Raspberry Pi 4 could recognize future occurrences. For additional water quality information, the device also has an Arduino Nano connected to pH, TDS (total dissolved solids), and water temperature sensors which then are fed to the Pi via a serial connection. Once a potential bloom is spotted, the user can be notified via WhatsApp and appropriate measures taken.

If you’re looking for more environmental sensing hacks, check out the OpenCTD, this swarm of autonomous boats, or this drone buoy riding the Gulf Stream.

An E-Ink Progress Bar For Your Unborn Child

January 13, 2023 by Tom Nardi 12 Comments

Having a child is a major milestone in a person’s life, and there’s a long list of things to get done before that little bundle of joy kicks and screams its way into the world. What better way to make sure you’ve still got time to paint the nursery and assemble the crib than to have an automated loading screen that shows just how far along the organic 3D printing process is?

This fetal development tracker was put together by [mokas] using Adafruit’s ESP32-S2 powered MagTag. As the name implies, the all-in-one electronic ink development board is designed so that it can be adhered to a metallic surface with integrated magnets. The idea is that you can pop a battery in the low-power device, stick it on your refrigerator, and have a regularly updated display of…well, whatever you want. Continue reading “An E-Ink Progress Bar For Your Unborn Child” →

Arduino Library Brings Rtl_433 To The ESP32

January 13, 2023 by Tom Nardi 9 Comments

If you have an RTL-SDR compatible radio there’s an excellent chance you’ve heard of the rtl_433 project, which lets you receive and decode signals from an ever-expanding list of supported devices in the ISM radio bands. It’s an incredibly useful piece of software, but the fact that it requires an external software defined radio and a full-fledged computer to run dictated the sort of projects it could realistically be used for.

But thanks to the rtl_433_ESP Arduino library developed by [NorthernMan54], we’re now able to pack that functionality into a much smaller package. All you need is an ESP32 microcontroller and a CC1101 or SX127X transceiver module. If you’re looking for a turn-key hardware platform, the documentation notes the LILYGO LoRa32 V2 board includes the required hardware, plus adds a handy OLED display and microSD slot. It should be noted that the range of these radios don’t compare particularly well to a full-size RTL-SDR device, but that probably won’t come as much of a surprise. Continue reading “Arduino Library Brings Rtl_433 To The ESP32” →

DIY Fiber Laser Adds Metal Cutting To The Mix

January 13, 2023 by Dan Maloney 28 Comments

Sadly, the usual CO₂-powered suspects in the DIY laser cutter market are woefully incapable of cutting metal. Sure, they’ll cut the heck out of plywood and acrylic, and most will do a decent job at engraving metal. But cutting through a sheet of steel or aluminum requires a step up to much more powerful fiber laser cutters. True, the costs of such machines can be daunting, but not daunting enough for [Travis Mitchell], who has undertaken a DIY fiber laser cutter build that really caught our eye.

Right off the bat, a couple of things are worth noting here. First — and this should be obvious from the fountains of white-hot sparks in the video below — laser cutters are dangerous, and you should really know what you’re doing before tackling such a build. Second, just because [Travis] was able to cut costs considerably compared to a commercial fiber laser cutter doesn’t mean this build was cheap in absolute terms — he reports dropping about $15,000 so far, with considerable ongoing costs to operate the thing.

That said, there doesn’t appear to be anything about this build that anyone with some experience building CNC machines wouldn’t be able to tackle. The CNC side of this is pretty straightforward, although we note that the gantry, servos, and controller seem especially robust.

The laser itself is an off-the-shelf machine, a Raycus RFL-C1000 fiber laser and head that packs a 1,000-Watt punch. There’s also the required cooling system for the laser, and of course there’s an exhaust system to get rid of the nasty fumes.

All that stuff requires a considerable investment, but we were surprised to learn how much the consumables cost. [Travis] opted for bottled gas for the cutter’s gas assist system — low-pressure oxygen for carbon steel and high-pressure nitrogen for everything else. Refills are really pricey, in part because of the purity required, but since the proper compressor for the job is out of the budget for now, the tanks will have to do. And really, the thing cuts like a dream. Check out the cutting speed and precision in the video below.

This is but the first in a series of videos that will detail the build, and if [Travis] thought this would whet our appetites for more, he was right. We really haven’t seen many DIY fiber laser builds, but we have seen a teardown of a 200-kW fiber laser that might tickle your fancy.

Continue reading “DIY Fiber Laser Adds Metal Cutting To The Mix” →