If You Can Measure It, You Must Display It

May 1, 2021 by Elliot Williams 16 Comments

When can you be sure that you’re logging enough data? When you’re logging all of the data! Of course there are exceptions to the above tongue-in-cheek maxim, but it’s certainly a good start. Especially since data storage on, for instance, an SD card is so easy and cheap these days, there’s almost no reason to not record most every little bit of data that your project can produce. Even without an SD card, many microcontrollers have enough onboard flash, or heck even RAM, to handle whatever you throw at them. The trick, then, is to make sense out of that data, and for me at least, that often means drawing pretty pictures.

I was impressed this week by a simple but elegant stepper motor diagnosis tool hacked together by [Zapta]. Essentially, it’s a simple device: it’s a “Black Pill” dev board, two current sensors, an EEPROM for storing settings, and a touchscreen. Given that most of us with 3D printers rely on stepper motors to get the job done, it’s certainly interesting to do some diagnostics.

By logging voltage and current measurement on each phase of a stepper motor, you can learn a lot about what’s going on, at least if you can visualize all that data. And that’s where [Zapta]’s tool shines. It plots current vs motor speed to detect impedance problems. Tuning the current in the first place is a snap with Lissajous patterns, and it’ll track your extruder’s progress or look out for skipped steps for you across an entire print job. It does all this with many carefully targeted graphs.

I was talking to [Niklas Roy] about this, and he said “oh check out my hoverboard battery logger“. Here we go again! It sits inline with the battery and logs current and voltage, charging or discharging. Graphs let you visualize power usage over time, and a real-time-clock lets you sync it with video of using the hoverboard to help make even more sense of the data.

So what are you waiting for? Sensors are cheap, storage is cheap, and utilities to graph your data after the fact are plentiful. If you’re not logging all the relevant data, you’re missing out on some valuable insights. And if you are, we’d love to see your projects! (Hint, hint.)

Homemade EDM Machine Moves From Prototype To Production

April 30, 2021 by Dan Maloney 41 Comments

Of all the methods of making big pieces of metal into smaller pieces of metal, perhaps none is more interesting than electrical discharge machining. EDM is also notoriously fussy, what with having to control an arc discharge while precisely positioning the tool relative to the workpiece. Still, some home gamers give it a whirl, and we love to share their successes, like this work-in-progress EDM machine. (Video, embedded below.)

We’ve linked [Andy]’s first videos below the break, and we’d expect there will be a few more before all is said and done. But really, for being fairly early in the project, [Andy] has made a lot of progress. EDM is basically using an electric arc to remove material from a workpiece, but as anyone who has unintentionally performed EDM on, say, a screwdriver by shorting it across the terminals in a live outlet box, the process needs to be controlled to be useful.

Part 1 shows the start of the build using an old tap burning machine, a 60-volt power supply, and a simple pulse generator. This was enough to experiment with the basics of both the mechanical control of electrode positioning, and the electrical aspects of getting a sustained, useful discharge. Part 2 continues with refinements that led very quickly to the first useful parts, machined quickly and cleanly from thin stock using a custom tool. We’ll admit to being impressed — many EDM builds either never get to the point of making simple holes, or stop when progressing beyond that initial success proves daunting. Of course, when [Andy] drops the fact that he made the buttons for the control panel on his homemade injection molding machine, one gets the feeling that anything is possible.

We’re looking forward to more on this build. We’ve seen a few EDM builds before, but none with this much potential.

Continue reading “Homemade EDM Machine Moves From Prototype To Production” →

Clever Gas Mixer Gets Just The Right Blend For Homebrew Laser Tubes

April 28, 2021 by Dan Maloney 11 Comments

[Lucas] over at Cranktown City on YouTube has been very busy lately, but despite current appearances, his latest project is not a welder. Rather, he built a very clever gas mixer for filling his homemade CO2 laser tubes, which only looks like a welding machine. (Video, embedded below.)

We’ve been following [Lucas] on his journey to build a laser cutter from scratch — really from scratch, as he built his own laser tube rather than rely on something off-the-shelf. Getting the right mix of gas to fill the tube has been a bit of a pain, though, since he was using a party balloon to collect carbon dioxide, helium, and nitrogen at measuring the diameter of the ballon after each addition to determine the volumetric ratio of each. His attempt at automating the process centers around a so-called AirShim, which is basically a flat inflatable bag made of sturdy material that’s used by contractors to pry, wedge, lift, and shim using air pressure.

[Lucas]’ first idea was to measure the volume of gas in the bag using displacement of water and some photosensors, but that proved both impractical and unnecessary. It turned out to be far easier to sense when the bag is filled with a simple microswitch; each filling yields a fixed volume of gas, making it easy to figure out how much of each gas has been dispensed. An Arduino controls the pump, which is a reclaimed fridge compressor, monitors the limit switch and controls the solenoid valves, and calculates the volume of gas dispensed.

Judging by the video below, the mixer works pretty well, and we’re impressed by its simplicity. We’d never seriously thought about building our own laser tube before, but seeing [Lucas] have at it makes it seem quite approachable. We’re looking forward to watching his laser project come together.

Continue reading “Clever Gas Mixer Gets Just The Right Blend For Homebrew Laser Tubes” →

Review: Sequre SQ-D60 Temperature Controlled Soldering Iron

April 27, 2021 by Jenny List 38 Comments

Over the past few years a new class of soldering iron has arisen: a temperature controlled iron no longer tied to a bulky mains-powered base station, but using low-voltage DC power and with all electronics concealed in a svelte handle. First came the Miniware TS100, and then many more, with slightly different feature sets and at varying price points. We’ve reviewed a few of them over the years, and today we have the most recent contender in the Sequre SQ-D60. It follows the formula closely, but costs only £20 (about $26). This price puts it in an attractive budget category, and its USB-C power option makes it forward-looking over models with barrel jacks. Description over, it’s time to plug it in and put it through its paces.

What’s In The Box?

That's a lot of extra bits for a budget iron! — That’s a lot of extra bits for a budget iron!

In the box, aside from the handle containing the electronics, were a surprisingly comprehensive array of parts and accessories. The handle itself is similarly-sized to its competitors, being only slightly longer than that of Pine64’s Pinecil. The tip supplied was unexpectedly a slanted chisel, so I may have managed to order incorrectly, though since it shares the same tip design as both the TS100 and the Pinecil I have plenty of alternative tips should I need one. Otherwise there was a little bag of hex screws along with a key and a driver for them, a little stand with a sponge, a set of Sequre stickers, a USB-C to barrel jack cable, and a barrel jack-to-XT60 connector for use with LiPo battery packs. These last two cables are a particularly useful addition.

At first sight the tip doesn’t seem to have any means of being fixed into its socket, but a closer inspection reveals that there is a hex screw hiding underneath a silicone finger sleeve that holds it securely when tightened. The handle has a simple enough interface, with just two buttons and a 3-digit, 7-segment display. Powering it up from a 45 W USB-PD power supply, and it heats up to 300 °C in around ten seconds after pressing one of the buttons. My usual soldering temperature is 360 °C, and it has an interface involving long presses of one of the buttons before they become up and down buttons to select the temperature. In prolonged use the handle doesn’t become noticeably warm, and aside from a slight new-electronics-getting-hot smell there was no immediate concern that it might release magic smoke. Continue reading “Review: Sequre SQ-D60 Temperature Controlled Soldering Iron” →

The Evil Crow Is Ready To Cause Some RF Mayhem

April 27, 2021 by Tom Nardi 34 Comments

There’s no doubt that the RTL-SDR project has made radio hacking more accessible than ever, but there’s only so far you can go with a repurposed TV tuner. Obviously the biggest shortcoming is the fact that you can only listen to signals, and not transmit them. If you’re ready to reach out and touch someone, but don’t necessarily want to spend the money on something like the HackRF, the Evil Crow RF might be your ideal next step.

This Creative Commons licensed board combines two CC1101 radio transceivers and an ESP32 in one handy package. The radios give you access to frequencies between 300 and 928 MHz (with some gaps), and the fact that there are two of them means you can listen on one frequency while transmitting on another; opening up interesting possibilities for relaying signals. With the standard firmware you connect to a web interface running on the ESP32 to configure basic reception and transmission options, but there’s also a more advanced RFQuack firmware that allows you to control the hardware via Python running on the host computer.

Using the Evil Crow RF without a computer.

One particularly nice feature is the series of buttons located down the side of the Evil Crow RF. Since the device is compatible with the Arduino IDE, you can easily modify the firmware to assign various functions or actions to the buttons.

In a demonstration by lead developer [Joel Serna], the physical buttons are used to trigger a replay attack while the device is plugged into a standard USB power bank. There’s a lot of potential there for covert operation, which makes sense, as the device was designed with pentesters in mind.

As an open source project you’re free to spin up your own build of the Evil Crow RF, but those looking for a more turn-key experience can order an assembled board from AliExpress for $27 USD. This approach to hardware manufacturing seems to be getting popular among the open source crowd, with the Open-SmartWatch offering a similar option.

[Thanks to DJ Biohazard for the tip.]

Pneumatic Can Crusher Awaits Your Command

April 26, 2021 by Tom Nardi 22 Comments

A powerful robot awaiting for a verbal command to crush its foes might sound like something from a science fiction film, but now it’s a permanent fixture of the [Making Stuff] garage. (Video, embedded below.) Thankfully this robot’s sworn enemy are aluminum cans, and the person controlling it with their voice isn’t a maniacal scientist, just a guy who’s serious about recycling. Well, we hope so anyway.

The star of the show is a heavy duty wall-mounted can crusher that [Making Stuff] built from some scrap steel and a pneumatic cylinder hooked up to the garage’s compressed air system. A solenoid operated valve allows an Arduino with attached ESP-01 to extend the cylinder whenever the appropriate command comes over the network. In this case, the goal was to tie the crusher into Google Assistant so a can would get smallified whenever one of Google’s listening devices heard the trigger phrase.

Obviously, those who’d rather keep Big Data out of their recycling bin don’t have to go down the same path. But that being said, having to give a specific voice command to activate the machine does provide a certain level of operational safety. At least compared to trusting some eBay sensor to tell the difference between an aluminum can and a fleshy appendage.

After crushing a few cans with his new toy, [Making Stuff] noticed a fairly troubling flaw in the design. Each time a can was crushed he had to reach into the maw of the machine to push its little flattened carcass out of the way. In other words, he was one bad line of code away from having one good hand.

The solution ended up being a new hose that runs from the exhaust port of the valve to the crushing chamber: once the cylinder retracts, the air exiting the valve pushes the crushed can out the rear of the machine and into a waiting pail underneath. Very slick.

Even if you’re not interested in the voice control aspect, this is a great design to base your own can crusher on. While it’s always a treat when a fully automatic crusher comes our way, we’ll admit the challenges of getting one to work reliably probably aren’t worth the hassle.

Continue reading “Pneumatic Can Crusher Awaits Your Command” →

Building A Gas-Powered Pressure Washer

April 23, 2021 by Lewin Day 23 Comments

While you can always buy the tools you need, there’s something to be said for the satisfaction gained when you pick up a tool you built yourself. [Workshop From Scratch] has built a following out of building his own gear, the latest of which involved putting together a gas-powered pressure washer.

The key to the build was to keep things completely self-contained. All the consumables – water, soap, and wax – are kept onboard the washer to avoid having to run hoses and so on. A small gas engine is the heart of the build, hooked up to a high-pressure water pump. It even comes complete with a starter motor, making it a certified luxury garden tool. It’s also hooked up to two tanks holding cleaning solutions for car washing purposes, which feed into the pump via an auxiliary port for mixing. It’s all assembled on a custom steel frame welded together from rectangular hollow sections.

It’s a build that demonstrates how you can use your skills to build tools that suit your workflow, rather than just putting up with whatever is available off-the-shelf. We’ve seen his work before, too – building other tools like this motorised plasma cutter. Video after the break.

Continue reading “Building A Gas-Powered Pressure Washer” →