Caulking Gun Becomes Useful Press Tool For Fuel Line Fittings

May 11, 2022 by Lewin Day 29 Comments

The simple caulking gun is really useful when you’re working on some bathroom repairs or squirting construction adhesives about the place. However, with a few simple mods, it can become a great help in the mechanic’s workshop too.

It’s a great tool for cleanly pushing fittings into nylon fuel line.

This build consists of a series of 3D-printed parts that can readily be adapted to a garden-variety caulking gun. First up are a pair of fuel line clamps which are fastened together with nuts and bolts, The nylon fuel line is inserted between these, and the bolts are tightened up to hold the line firmly in place at the end of the caulking gun. The fitting to be installed into the line is then placed on the caulking gun’s plunger. It’s then a simple matter of pulling the trigger on the caulking gun to slowly press the fitting into the nylon line.

It’s a great hack which creates a useful linear press with just a few cents of PETG filament. If you find yourself doing a one-off fuel line job on a modern car, this could be just the tool you need. Parts are available on Thingiverse for those eager to print their own. The design is made for 3/8ths inch line, but could readily be modified or recreated to suit other diameters.

3D-printed tools can be useful in all kinds of ways, even in heavy-duty applications like press tooling. It often doesn’t have the same longevity of traditional metal tooling, but for small one-off jobs, the price saving is often more important than the hardiness of the tooling itself. If you’ve whipped up some great 3D-printed tools of your own, don’t hesitate to drop us a line!

Theory, Practice, And Ducted Fans

May 10, 2022 by Elliot Williams 9 Comments

About a year ago, [Wyman’s Workshop] needed a fan. But not just a regular-old fan, no sir. A ducted fan. You know, those fancy fan designs where the stationary shroud is so close to the moving fan blades that there’s essentially no gap, and a huge gain in aerodynamic efficiency? At least in theory?

Well, in practice, you can watch how it turned out in this video. (Also embedded below.) If you’re more of a “how-to-build-it” type, you’ll want to check out his build video — there’s lots of gluing 3D prints and woodworking. But we’re just in it for the ducted fan data!

And that’s why we’re writing it up! [Wyman] made a nice thrust-testing rig that the fan can pull on to figure out how much force it put out. And the theory aimed at 652 g of thrust, which was roughly confirmed. And then you get to power: with a 500 watt motor, he ended up producing 47 watts. Spoiler: he’s overloading the motor, even though he used a fairly beefy bench grinder motor.

So he re-did the fan design, from scratch, to better match the motor. And it performed better than the theory said it would. A pleasant surprise, but it meant re-doing the theory, including the full volume of the fan blade, which finally brought theory and practice together. Which then lead him design a whole slew of fan blades and test them out against each other.

He ends the video with a teaser that he’ll show us the results from various inlet profiles and fan cones and such. But the video is a year old, so we’re not holding our breath. Still, if you’re at all interested in fan design, and aren’t afraid of high-school physics, it’s worth your time.

Don’t care about the advantages of ducted fans, but simply want to make your quad look totally awesome? Have we got the hack for you!

Continue reading “Theory, Practice, And Ducted Fans” →

A square PCB with a Raspberry Pi Pico mounted in the middle

Identify Radioactive Samples With This DIY Gamma-Ray Spectrometer

May 3, 2022 by Robin Kearey 37 Comments

If you’re a radiation enthusiast, chances are you’ve got a Geiger counter lying around somewhere. While Geiger counters are useful to detect the amount of radiation present, and with a few tricks can also distinguish between the three types of radiation (alpha, beta and gamma), they are of limited use in identifying radioactive materials. For that you need a different instrument called a gamma-ray spectrometer.

Spectrometers are usually expensive and complex instruments aimed at radiation professionals. But it doesn’t have to be that way: physics enthusiast [NuclearPhoenix] has designed a hand-held gamma spectrometer that’s easy to assemble and should fit in a hobbyist budget. It outputs spectral plots that you can compare with reference data to identify specific elements.

A PCB with a sensor wrapped in black tape — The scintillator and sensor are wrapped in black tape to block out ambient light.

The heart of the device is a scintillation crystal such as thallium-doped sodium iodide which converts incoming gamma rays into visible light. The resulting flashes are detected by a silicon photomultiplier whose output is amplified and processed before being digitized by a Raspberry Pi Pico’s ADC. The Pico calculates the pulses’ spectrum and generates a plot that can be stored on its on-board flash or downloaded to a computer.

[NuclearPhoenix] wrote a convenient program to help analyze the output data and made all design files open-source. The hardest part to find will be the scintillation crystal, but they do pop up on auction sites like eBay now and then. We’ve featured an Arduino-based gamma spectrometer before; if you’ve always wanted to roll your own scintillators, you can do that too. Continue reading “Identify Radioactive Samples With This DIY Gamma-Ray Spectrometer” →

Screenshot of a logic analyzer software, showing the SDA channel being split into three separate traces

I2C Tap Helps Assign Blame For SDA Conflicts

May 2, 2022 by Arya Voronova 8 Comments

If you’ve ever debugged a misbehaving I2C circuit, you probably know how frustrating it can be. Thankfully [Jim] over at Hackaday.io, has a proto-boardable circuit that can help!

Inter-integrated circuit bus (aka I2C) uses open collector outputs on a two wire interface. Open collector means a device connected to the I2C bus can only pull the bus down to ground. Chips never drive a logic “HIGH” on the wires. When nothing is driving the lines low, a weak resistor pulls the lines up to VCC. This is a good thing, because I2C is also a multidrop bus — meaning many devices can be connected to the bus at the time. Without open collector outputs, one chip could drive a high, while another drives a low – which would create a short circuit, possibly damaging both devices.

Even with all this protection, there can be problems. The SCL and SDA lines in the I2C communication protocol are bidirectional, which means either a controller or a peripheral can pull it low. Sometimes, when tracing I2C communications you’ll need to figure out which part is holding the line low. With many devices sharing the same bus, that can become nigh-impossible. Some folks have tricks with resistors and analog sampling, but the tried and true method of de-soldering and physically lifting chip pins off the bus often comes into play.

[Jim’s] circuit splits SDA signal into controller-side and peripheral-side, helping you make it clear who is to blame for hiccups and stray noise. To do that, he’s using 6N137 optoisolators and LMV393 comparators. [Jim] shared a NapkinCAD schematic with us, meant to be replicate-able in times of dire need. With this design, you can split your I2C bus into four separate channels – controller-side SDA, peripheral-side SDA, combined SDA and SCL. 4 Channels might be a lot for a scope, but this is no problem for today’s cheap logic analyzers.

Continue reading “I2C Tap Helps Assign Blame For SDA Conflicts” →

An oscilloscope with its probes stored in drawers below it

Clever Scope Probe Drawers Keep Your Workbench Tidy

May 1, 2022 by Robin Kearey 20 Comments

Probes are an essential component of a good oscilloscope system, but they have the nasty habit of cluttering up your workbench. If you have a four-channel scope, it’s not just several meters of cable that get in the way everywhere, but also four sets of all those little clips, springs, cable markers, and adjustment screwdrivers that need to be stored safely.

[Matt Mets] came up with a clever solution to this problem: a 3D printed cable organizer that neatly fits below your scope. It has four drawers, each of which has enough space to store a complete probe and a little compartment for all its accessories. A cable cutout at the front allows you to keep the probes plugged in even when they’re not in use.

It’s a beautifully simple solution to a common problem, and with the STL files available on Printables anyone with a cluttered workbench can build one for themselves. If, however, you’d like to keep those probes even closer at hand, have a look at these probe caddies. Continue reading “Clever Scope Probe Drawers Keep Your Workbench Tidy” →

The laser module shown cutting shapes out of a piece of cardboard that's lying on the CNC's work surface

Giant CNC Partners With Powerful Laser Diode

April 30, 2022 by Arya Voronova 13 Comments

[Jeshua Lacock] from 3DTOPO owns a large-format CNC (4’x8′, or 1.2×2.4 m), that he strongly feels is lacking laser-cutting capabilities. The frame is there, and a 150 W CO2 laser tube has been sitting in a box for ages – what else could you need? Sadly, at such a scale, aligning the mirrors is a tough and finicky job – and misalignment can be literally blinding. After reading tales about cutters of such size going out of alignment when someone as much as walked nearby, he dropped the idea – and equipped the CNC head with a high-power laser diode module instead. Having done mirror adjustment on a few CO2 tube-equipped lasers, we can see where he’s coming from.

Typically, the laser modules you see bolted onto CNC heads are firmly under three watts, which is usually only enough for engraving. With a module that provides 5 watts of optical power, [Jeshua] can cut cardboard and thin plywood as well he tells us even 10 W optical power modules are available, just that he didn’t go for one. We reckon that 20 W effective power diodes are not that far into our future, which is getting very close to the potential of the blue box “40 W but actually 35 W but actually way less” K40 laser cutters we cherish. [Jeshua]’s cutter is not breaking speed limits, but it’s built on what’s already there, and the diode is comparatively inexpensive. Equipped with a small honeycomb surface and what seems to be air assist, it’s shown in the video cutting an ornamental piece out of cardboard!

We hackers have been equipping CNCs with laser diodes for a while, but on a way smaller scale and with less powerful diodes – this is definitely a step up! As a hacker, you should have at least some laser cutting options at your disposal, and this overview of CO2 cutters and their availability can get you started. We’ve also given you detailed breakdowns about different sides of laser cutting, be it the must-have of safety, or the nice-to-have of air assist.

Continue reading “Giant CNC Partners With Powerful Laser Diode” →

Building A Swiss Army Lab With Software Defined Instrumentation

April 29, 2022 by Tom Nardi 33 Comments

It’s a fair bet that anyone regularly reading Hackaday has a voltmeter within arm’s reach, and there’s a good chance an oscilloscope isn’t far behind. But beyond that, things get a little murky. We’re sure some of you have access to a proper lab full of high-end test gear, even if only during business hours, but most of us have to make do with the essentials due to cost and space constraints.

The ideal solution is a magical little box that could be whatever piece of instrumentation you needed at the time: some days it’s an oscilloscope, while others it’s a spectrum analyzer, or perhaps even a generic data logger. To simplify things the device wouldn’t have a physical display or controls of its own, instead, you could plug it into your computer and control it through software. This would not only make the unit smaller and cheaper, but allow for custom user interfaces to be created that precisely match what the user is trying to accomplish.

Wishful thinking? Not quite. As guest host Ben Nizette explained during the Software Defined Instrumentation Hack Chat, the dream of replacing a rack of test equipment with a cheap pocket-sized unit is much closer to reality than you may realize. While software defined instruments might not be suitable for all applications, the argument could be made that any capability the average student or hobbyist is likely to need or desire could be met by hardware that’s already on the market.

Ben is the Product Manager at Liquid Instruments, the company that produces the Moku line of multi-instruments. Specifically, he’s responsible for the Moku:Go, an entry-level device that’s specifically geared for the education and maker markets. The slim device doesn’t cost much more than a basic digital oscilloscope, but thanks to the magic of software defined instrumentation (SDi), it can stand in for eleven instruments — all more than performant enough for their target users.

So what’s the catch? As you might expect, that’s the first thing folks in the Chat wanted to know. According to Ben, the biggest drawback is that all of your instrumentation has to share the same analog front-end. To remain affordable, that means everything the unit can do is bound by the same fundamental “Speed Limit” — which on the Moku:Go is 30 MHz. Even on the company’s higher-end professional models, the maximum bandwidth is measured in hundreds of megahertz.

Additionally, SDI has traditionally been limited to the speed of the computer it was attached to. But the Moku hardware manages to sidestep this particular gotcha by running the software side of things on an internal FPGA. The downside is that some of the device’s functions, such as the data logger, can’t actually live stream the data to the connected computer. Users will have to wait until the measurements are complete before they pull the results off, though Ben says there’s enough internal memory to store months worth of high-resolution data.

Of course, as soon as this community hears there’s an FPGA on board, they want to know if they can get their hands on it. To that end, Ben says the Moku:Go will be supported by their “Cloud Compile” service in June. Already available for the Moku:Pro, the browser-based application allows you to upload your HDL to the Liquid Instruments servers so it can be built and optimized. This gives power users complete access to the Moku hardware so they can build and deploy their own custom features and tools that precisely match their needs without a separate development kit. Understanding that obsolescence is always a problem with a cloud solution, Ben says they’re also working with Xilinx to allow users to do builds on their own computers while still implementing the proprietary “secret sauce” that makes it a Moku.

It’s hard not to get excited about the promise of software defined instrumentation, especially with companies like Liquid Instruments and Red Pitaya bringing the cost of the hardware down to the point where students and hackers can afford it. We’d like to thank Ben Nizette for taking the time to talk with the community about what he’s been working on, especially given the considerable time difference between the Hackaday Command Center and Liquid’s Australian headquarters. Anyone who’s willing to jump online and chat about FPGAs and phasemeters before the sun comes up is AOK in our book.

The Hack Chat is a weekly online chat session hosted by leading experts from all corners of the hardware hacking universe. It’s a great way for hackers connect in a fun and informal way, but if you can’t make it live, these overview posts as well as the transcripts posted to Hackaday.io make sure you don’t miss out.