Keep Your Lungs Clean And Happy With A DIY Supplied-Air Respirator

July 9, 2024 by Dan Maloney 13 Comments

The smell of resin SLA printing is like the weather — everybody complains about it, but nobody does anything about it. At least until now, as [Aris Alder] tackles the problem with an affordable DIY supplied-air respirator.

Now, we know what you’re thinking, anything as critical as breathing is probably best left to the professionals. While we agree in principle, most solutions from reputable companies would cost multiple thousands of dollars to accomplish, making it hard to justify for a home gamer who just doesn’t want to breathe in nasty volatile organic compounds. [Aris] starts the video below with a careful examination of the different available respirator options, concluding that a supplied air respirator (SAR) is the way to go.

His homebrew version consists of an affordable, commercially available plastic hood with a built-in visor. Rather than an expensive oil-free compressor to supply the needed airflow, he sourced a low-cost inline duct fan and placed it outside the work zone to pull in fresh air. Connecting the two is low-cost polyethylene tubing and a couple of 3D printed adapters. This has the advantage of being very lightweight and less likely to yank the hood off your head, and can be replaced in a few seconds when it inevitably punctures.

Another vital part of the kit is a pulse oximeter, which [Aris] uses to make sure he’s getting enough oxygen. His O₂ saturation actually goes up from his baseline when the hood is on and powered up, which bodes well for the system. Every time we pick up the welding torch or angle grinder we wish for something like this, so it might just be time to build one.

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Building An IR Thermometer That Fits On Your Keychain

July 5, 2024 by Tom Nardi 11 Comments

Non-contact infrared (IR) thermometers used to be something of an exotic tool, but thanks at least in part due to the COVID-19 pandemic, they’re now the sort of thing you see hanging up near the grocery store checkout as a cheap impulse buy. Demand pushed up production, and the economies of scale did the test. Now the devices, and the sensors within them, are cheap enough for us hackers to play with.

The end result is that we now have projects like this ultra compact IR thermometer from [gokux]. With just a handful of components, some code to glue it all together, and a 3D printed enclosure to wrap it all up, you’ve got a legitimately useful tool that’s small enough to replace that lucky rabbit’s foot you’ve got on your keys.

If this project looks familiar, it’s because the whole thing is closely related to the LiDAR rangefinder [gokux] put together last month. It shares the same Seeed Studio XIAO ESP32-C3 microcontroller, 0.49 inch OLED display, and tiny 40 mAh LiPo battery. The only thing that’s really changed, aside from the adjustments necessary to the 3D printed enclosure, is that the LiDAR sensor was replaced with a MLX90614 IR temperature sensor.

[gokux] has put together some great documentation for this build, making it easy for others to recreate and remix on their own. Assembly is particularly straightforward thanks to the fact that both the display and temperature sensor communicate with the ESP32 over I2C, allowing them to be wired daisy chain style — there’s no need for even a scrap of perfboard inside the case, let alone a custom board.

Two of these boards next to each other, one showing the front, assembled, side with the MCU and supporting components soldered on, and the other showing the back, patch panel, side, with wires connecting the MCU pads to testpoints leading to the supporting components

Try Out MCUs With This Jumperable TSSOP20 Adapter

June 29, 2024 by Arya Voronova 7 Comments

There are so many new cool MCUs coming out, and you want to play with all of them, but, initially, they tend to be accessible as bare chips. Devboards might be hard to get, not expose everything, or carry a premium price. [Willmore] has faced this problem with an assortment of new WCH-made MCUs, and brings us all a solution – a universal board for TSSOP20-packaged MCUs, breadboard-friendly and adaptable to any pinout with only a few jumpers on the underside.

The board brings you everything you might want from a typical MCU breakout – an onboard 3.3V regulator, USB series resistors, a 1.5K pullup, decoupling capacitors, and a USB-C port. All GPIOs are broken out, and there’s a separate header you can wire up for all your SWD/UART/USB/whatever needs – just use the “patch panel” on the bottom of the board and pick the test points you want to join. [Willmore] has used these boards for the CH32Vxxx family, and they could, no doubt, be used for more – solder your MCU on, go through the pin table in the datasheet, do a little point-to-point wiring, and you get a pretty functional development board.

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Reviving A Free 1990s Millport CNC Vertical Mill

June 28, 2024 by Maya Posch 25 Comments

When faced with the offer of free machining equipment, there is no realistic way to say ‘no’. This is how [Anthony Kouttron]’s brother [Thomas] got to pick up a large 1990s-era CNC machine as a new companion for his growing collection of such equipment. The trickiest part of the move to the new location was getting the machine to fit through the barn doors, requiring some impromptu disassembly of the Z-axis assembly, which required the use of an engine crane and some fine adjustments with the reinstallation. With that [Thomas] and [Anthony] got to gawk at their new prize in its new home.

This Millport vertical mill is effectively a Taiwanese clone of the Bridgeport vertical mill design, though using an imported servo control system from Anilam. The most exciting part about a CNC machine like this is usually the electronics, especially for a well-used machine. Fortunately the AT-style PC and expansion cards looked to be in decent condition, and the mill’s CRT-based controller popped up the AMI BIOS screen before booting into the Anilam S1100 CNC software on top of MS-DOS, all running off a 1 MB Flash card.

Which is not to say that there weren’t some issues to be fixed. The Dallas DS12887 real-time clock/NVRAM module on the mainboard was of course dead. After replacing it, the BIOS finally remembered the right boot and input settings, so that the CNC machine’s own controls could be used instead of an external keyboard. This just left figuring out the Anilam controls, or so they thought, as a range of new errors popped up about X-lag and the Distribution Board. This had [Anthony] do a deep-dive into the electronics cabinets to clean metal chips and repair broken parts and floating pins. After this and a replacement Anilam Encoder this Millport vertical mill was finally ready to be put back into service.

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What You Can See With A SEM?

June 19, 2024 by Al Williams 4 Comments

The last time we used a scanning electron microscope (a SEM), it looked like something from a bad 1950s science fiction movie. These days SEMs, like the one at the IBM research center, look like computers with a big tank poised nearby. Interestingly, the SEM is so sensitive that it has to be in a quiet room to prevent sound from interfering with images.

As a demo of the machine’s impressive capability, [John Ott] loads two US pennies, one facing up and one face down. [John] notes that Lincoln appears on both sides of the penny and then proves the assertion correct using moderate magnification under the electron beam.

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A Brief Look Inside A Homebrew Digital Sampler From 1979

June 17, 2024 by Dan Maloney 12 Comments

While we generally prefer to bring our readers as much information about a project as possible, sometimes we just have to go with what we see. That generally happens with new projects and work in progress, but it can also happen with old projects. Sometimes very old indeed, as is the case with this digital sampling unit for analog oscilloscopes, circa 1979.

We’ve got precious little to go on with this one other than the bit of eye candy in the video tour below and its description. Luckily, we’ve had a few private conversations with its maker, [Mitsuru Yamada], over the years, enough to piece together a little of the back story here — with apologies for any wrong assumptions, of course.

Built when he was only 19, this sampler was an attempt to build something that couldn’t be bought, at least not for a reasonable price. With no inexpensive monolithic analog-to-digital converters on the market, he decided to roll his own. A few years back he recreated the core of that with his all-discrete successive approximation ADC.

The sampler shown below has an 8-bit SAR ADC using discrete CMOS logic and enough NMOS memory to store 256 samples. You can see the ADC and memory cards in the homebrew card cage made from aluminum angle stock. The front panel has a ton of controls and sports a wide-range attenuator, DC offset, and trigger circuit with both manual and automatic settings.

It’s an impressive build, especially for a 19-year-old with presumably limited resources. We’ve reached out to [Yamada-san] in the hope that he’ll be able to provide more details on what’s under the hood and if this still works after all these years. We’ll pass along whatever we get, but in the meantime, enjoy.

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3D Printing A Bottle Labeling Assembly Line

June 16, 2024 by Tom Nardi 9 Comments

We’re not completely sure why [Fraens] needs to label so many glass bottles at home. Perhaps he’s brewing his own beer, or making jams. Whatever the reason is, it was justification enough to build an absolutely incredible labeling machine that you could mistake for a piece of industrial gear…if it wasn’t for the fact that majority of the device is constructed out of orange 3D printed plastic.

As we’ve come to expect, [Fraens] has documented the build with a detailed write-up on his site — but in this case, you’ve really got to watch the video below to truly appreciate how intricate the operation of this machine is. Watching it reminded us of an episode of How It’s Made, with the added bonus that you not only get to see how the machine functions, but how it was built in the first place.

Nearly every part of the machine, outside the fasteners, smooth rods, a couple of acrylic panels, and a few sections of aluminum extrusion, were 3D printed. You might think this would result in a wobbly machine with sloppy tolerances, but [Fraens] is truly a master of knowing when and where you can get away with using printed parts. So for example, while the glue rollers could be done in printed plastic, they still needed metal rods run through the middle for strength and proper bearings to rotate on.

Looking at the totality of this build, it’s hard to imagine how it could have been accomplished via traditional methods. Sure you could have sourced the rollers and gears from a supplier to save some plastic (at an added expense, no doubt), but there’s so many unique components that simply needed to be fabricated. For example, all the guides that keep the label heading in the right direction through the mechanism, or the interchangeable collars which let you select the pattern of glue which is to be applied. Maybe if you had a whole machine shop at your disposal, but that’s a lot more expensive and complex a proposition than the pair of desktop 3D printers [Fraens] used to crank out this masterpiece.

If the name (and penchant for orange plastic) seems familiar, it’s because we’ve featured several builds from [Fraens] in the past. This one may be the most technically impressive so far, but that doesn’t diminish the brilliance of his vibratory rock tumbler or cigarette stuffing machine.

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