Cheap Deburring Tool Is Game Changer For 3D Printing

3D printing’s real value is that you can whip up objects in all kinds of whacky geometries with a minimum of fuss. However, there’s almost always some post-processing to do. Like many manufactured plastic objects, there are burrs, strings, and rough edges to deal with. Fussing around with a knife to remove them is a poor way to go. As explained by [Adrian Kingsley-Hughes] on ZDNet, a deburring tool is the cheap and easy solution to the problem.

If you haven’t used one before, a deburring tool simply consists of a curved metal blade that swivels relative to its straight handle. You can drag the curved blade over the edge of a metal, wooden, or plastic object, and it neatly pulls away the burrs. There’s minimal risk of injury, unlike when pulling a regular blade towards yourself. The curved, swiveling blade is much less liable to slip or jump, and if it does, it’s far less likely to cut you.

For plastic use, just about any old deburring tool will do. They last a long time with minimal maintenance. They will wear out faster when used on metals, but you can get replacement blades cheap if you happen to need them. It’s a tool every workshop should have, particularly given they generally cost less than $20.

Given the ugly edges and rafts we’re always having to remove from our 3D prints, it’s almost egregious that printers don’t come with them bundled in the box. They’re just a bit obscure when it comes to tools; this may in fact be the first time Hackaday’s ever covered one. If you’ve got your own quality-of-life hacks for 3D printing, sound off below, or share them on the tipsline! We have able staff waiting for your email.

Shake Your PCB Etching, With An Old Optical Drive

Easy PCB fabrication in China has revolutionised electronic construction at our level, but there are still times when it makes sense to etch your own boards. It’s a messy business that can also be a slow one, but at least a project from [earldanielph] takes away one chore. It agitates the etchant solution round the board, by moving the tank backwards and forwards on the drawer of an old optical drive.

The first part of the build is simply removing all parts of the drive except the drawer mechanism and its motor. This is still, in most cases, a DC motor, so an Arduino can easily drive it with a motor control shield. It’s worth a moment to reflect on how little there is to a modern optical drive.

The Arduino receives a sketch that moves the tray backward and forward, and a piece of ply is attached to the tray. This becomes a stand for a plastic tub containing the etchant and board, and the liquid is soon swishing back and forwards over the surface. You can see the result in the video below the break. Definitely a saving over manual agitation. It’s an inventive machine, but it’s not the first PCB agitator we’ve seen.

Continue reading “Shake Your PCB Etching, With An Old Optical Drive”

A schematic for a continuity tester that modulates its pitch based on the resistance measured

Op Amp Contest: Clever Continuity Tester Tells You Where The Problem Is

A continuity tester, as found on most multimeters today, is a great tool for finding broken connections and short circuits. But once you’ve found a short, it’s up to you to figure out which part of the circuit it’s in – a tedious job on a large PCB with hundreds of components. [John Guy] aims to ease this task with a continuity tester that modulates the beeper’s tone according to the resistance measured in the circuit. Tracking down a short circuit is then simply a matter of probing multiple points along a track and observing whether the pitch goes up or down.

The circuit is based on a single AD8534 quad op amp chip. The first stage measures the voltage across the circuit under test in response to small current and amplifies it. The resulting signal is fed into a voltage-controlled oscillator (VCO) made from one op amp connected as an integrator and another working as a comparator with hysteresis. Op amp number four amplifies the resulting square wave and drives a speaker. A low-pass filter makes the sound a bit more pleasing to the ears by removing the higher notes.

[John] paid particular attention to the PCB design to make it easy to assemble despite having a large number of SMD components on a small board. He even placed a parts list on the rear silkscreen, so anyone can assemble it even without the accompanying documents. The resulting board can be placed in a laser-cut acrylic case, turning it into a neat handheld instrument that will definitely find a place in any engineer’s toolbox. Measuring resistance through sound is not as accurate as using a full four-wire setup with an ohmmeter, but will be much faster and easier if you just want to find that annoying solder bridge hiding somewhere on your board.

Making Neon Trees The Easy Way With No Oven Pumps Required

Neon lamps are fun and beautiful things. Hackers do love anything that glows, after all. But producing them can be difficult, requiring specialized equipment like ovens and bombarders to fill them up with plasma. However, [kcakarevska] has found a way to make neon lamps while bypassing these difficulties.

[kcakarevska] used the technique to great effect on some neon tree sculptures.
The trick is using magnesium ribbon, which is readily available form a variety of suppliers. The ribbon is cut into small inch-long fragments and pushed into a borosilicate tube of a neon sculpture near the electrode. Vacuum is then pulled on the tube down to approximately 5 microns of pressure. The tube is then closed off and the electrode is heated using an automotive-type induction heater. In due time, this vaporizes the magnesium which then creates a reactive getter coating on the inside of the tube. This picks up any oxygen, water vapor, or other contaminants that may have been left inside the tube without the need for an oven vacuum pumping stage. The tube is then ready to be filled with neon. After about 24 to 48 hours of running, the getter coating will have picked up the contaminants and the tube will glow well.

It’s a useful technique, particularly for complex neon sculptures that won’t readily fit in an oven for pumpdown. If the glasswork is still too daunting, though, you can always use other techniques to get a similar look. Video after the break.

Continue reading “Making Neon Trees The Easy Way With No Oven Pumps Required”

A Temperature-Sensing Magnetic Stir Bar

Magnetic stirring bars are the coolest piece of equipment you’ll see in a high-school chemistry lab. They’re a great way for agitating a solution without having to stand there manually and do it yourself. [Applied Science] has now made a magnetic stir bar that features an integrated temperature sensor.

The device is essentially an RFID temperature sensor snuck inside a custom-made magnetic stir bar. The bar is paired with a smart hotplate base that displays the temperature readings. As a bonus, it can detect when the magnetic stir bar is out of place or not in sync, prompting it to slow down the spin motor until the stir bar is turning properly again.

The video also notes that the stir bar could be instrumented for even greater functionality. A Hall effect sensor could measure the magnetic slip angle of the stir bar, and provide useful readings of liquid viscosity. Alternatively, a pressure sensor in the stir bar could potentially measure liquid level based on hydrostatic pressure.

It’s a great quality-of-life improvement for regular lab work. It eliminates the need for bulky temperature probes that often get in the way. We’ve featured some interesting temperature sensors before, too.

Continue reading “A Temperature-Sensing Magnetic Stir Bar”

Radio Waves Bring The Heat With This Microwave-Powered Forge

Depending on the chef’s skill, many exciting things can happen in the kitchen. Few, however, grab as much immediate attention as when a piece of foil or a fork accidentally (?) makes it into the microwave oven. That usually makes for a dramatic light show, accompanied by admonishment about being foolish enough to let metal anywhere near the appliance. So what’s the deal with this metal-melting microwave?

As it turns out, with the proper accessories, a standard microwave makes a dandy forge. Within limits, anyway. According to [Denny], who appears to have spent a lot of time optimizing his process, the key is not so much the microwave itself, but the crucible and its heat-retaining chamber. The latter is made from layers of ceramic insulating blanket material, of the type used to line kilns and furnaces. Wrapped around a 3D printed form and held together with many layers of Kapton tape, the ceramic is carefully shaped and given a surface finish of kiln wash.

While the ceramic chamber’s job is to hold in heat, the crucible is really the business end of the forge. Made of silicon carbide, the crucible absorbs the microwave energy and transduces it into radiant heat — and a lot of it. [Denny] shares several methods of mixing silicon carbide grit with sodium silicate solution, also known as water glass, as well as a couple of ways of forming the crucible, including some clever printed molds.

As for results, [Denny] has tried melting all the usual home forge metals, like aluminum and copper. He has also done brass, stainless steel, and even cast iron, albeit in small quantities. His setup is somewhat complicated — certainly more complex than the usual propane-powered forge we’ve seen plenty of examples of — but it may be more suitable for people with limited access to a space suitable for lighting up a more traditional forge. We’re not sure we’d do it in the kitchen, but it’s still a nice skill to keep in mind.

Continue reading “Radio Waves Bring The Heat With This Microwave-Powered Forge”

Bust Out That Old Analog Scope For Some Velociraster Fun!

[Oli Wright] is back again with another installation of CRT shenanigans. This time, the target is the humble analog oscilloscope, specifically a Farnell DTV12-14 12 MHz dual-channel unit, which features a handy X-Y mode. The result is the Velociraster, a simple (in hardware terms) Raspberry Pi Pico based display driver.

Using a Pico to drive a pair of AD767 12-bit DACs, the outputs of which drive the two ‘scope input channels directly, this breadboard and pile-of-wires hack can produce some seriously impressive results. On the software side of things, the design is a now a familiar show, with core0 running the application’s high-level processing, and core1 acting in parallel as the rendering engine, determining static DAC codes to be pushed out to the DACs using the DMA and the PIO.

Continue reading “Bust Out That Old Analog Scope For Some Velociraster Fun!”