A Simple One-Handed Solder Feeder

July 27, 2023 by Lewin Day 46 Comments

Soldering can get frustrating when you’re working fast. It often feels like you don’t have enough hands, particularly on jobs where you need to keep feeding solder in a hurry. To solve that issue, [mulcmu] developed a simple one-handed solder feeder.

The solder is fed out of the tip by simply dragging it with the thumb.

The intended use-case is for busy work like soldering long pin headers. The one-handed device allows solder to be continually fed while the other hand uses the soldering iron. It solves a long-running problem for [mulcmu], after their experiments with techniques inspired by TIG welding came to nought.

The design uses a pen-like form factor. A 3D-printed hollow tube has a wire ferrule inserted in the end, which serves as the tip of the device through which solder is fed. The tube has a cutaway, which allows the user to feed solder through using an easy motion of the thumb. The solder itself is fed from a spool in a regular bench top holder. If more slack is required in the solder feed, one simply pins the solder down in the device and tugs to draw more out.

If you find yourself regularly soldering repetitive jobs by hand, this could be a gamechanger for you. Those working in through-hole would be perhaps best served by this device. Meanwhile, if you’ve got nifty tool hacks of your own to share, don’t hesitate to let us know!

Breaking Land Speed Records With An RC Car

July 19, 2023 by Lewin Day 23 Comments

Building and running a land speed record car is an expensive business that requires incredibly wealthy benefactors. Doing it on a smaller scale with a radio control car is still pricy, but more within the reach of the individual. [ProjectAir] has been working on just that, and recently set out to break records with a car of his own design.

The car runs a Jetcat 220 engine capable of delivering 220 newtons of thrust, built into a custom aluminium chassis with streamlined bodywork. Early runs saw it reach 112 km/h, but the goal was to push it beyond 150 km/h to break the standing Guinness World Record.

With an RC event running on a local runway, [ProjectAir] had the venue and opportunity to make an attempt. It was tough going, with the car throwing off its nosecose in one run, while rough weather brought further struggles. Strong crosswinds played a role in a violent crash on the car’s fastest pass, which ripped the car apart and destroyed the engine. However, in the end, it had done enough to secure a record at over 152 km/h, even if its later faster efforts didn’t officially count.

It’s clear that the car has come a long way since [ProjectAir’s] initial efforts in 2022, and we can’t wait to see where the project goes next. Video after the break.

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Halbach Array Makes Magnets Strong, Weak

July 16, 2023 by Al Williams 15 Comments

If you want a strong magnet, the obvious answer is to buy one. However, for a variety of reasons, you might want to combine several smaller magnets. There are a few ways to do this, but the Halbach array, as [wannabemadsci] explains, allows you to make an array of magnets where one side is very strong, and the other side is very weak.

The example uses a 3D-printed housing and five cube magnets. To form a Halbach array, the poles of the magnets are in a specific orientation that effectively rotates ninety degrees for each — in this case — cube.

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PicoDebugger Makes Development Easier

July 12, 2023 by Lewin Day 12 Comments

Debugging a Raspberry Pi Pico is straightforward enough; it simply involves hooking up something up to the USB and SWD pins. [Mark Stevens] whipped up the PicoDebugger to make this job easier than ever before.

The Raspberry Pi Foundation developed the Picoprobe system to allow a RP2040 to act as a USB to SWD and UART bridge for debugging another Pico or RP2040. The problem is that hooking it up time and time again can be fussy and frustrating.

To get around this, [Mark] whipped up the PicoDebugger board, which directly connects most of the important pins for you. Drop a Pico into the “Target” slot, and you can hook up the PicoDebugger to its UART lines with the flick of a DIP switch. The SWD pins can then also be connected via jumpers if so desired. It also features a 2×20-pin header to allow the target to be wired into other hardware as necessary.

It’s a neat project, and it certainly beats running a bird’s nest of jumper wires every time you want to debug a Pico project. Simply dropping a board in is much more desirable.

We’ve seen some other neat debug tools over the years, too. If you’ve got your own development productivity hacks in the works, don’t hesitate to let us know!

Building A Digital Compass With An Arduino

July 12, 2023 by Lewin Day 8 Comments

The magnetic compass has been a crucial navigational tool for around a thousand years or so, perhaps longer. While classical versions still work perfectly well, you can now get digital magnetometers that work in much the same way. [mircemk] decided to whip up a digital compass to demonstrate the value of these parts.

The build uses a HMC5883L magnetometer. While this can detect magnetic fields in three axes, just one is necessary for building a device that operates akin to a traditional compass. The output of the device is read by an Arduino Nano, which is hooked up to a string of WS2812B LEDs and a small OLED display. The LEDs display the bearing of magnetic north, while the OLED screen shows the current angle between the compass’s arrow and magnetic north.

It’s a tidy build that would be a great educational resource for teaching both electronics and navigational skills. We’ve seen similar projects before, like the hilarious Pizza Compass. Video after the break.

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Gas-Powered Fly Swatter Slightly Over-Engineered

July 10, 2023 by Bryan Cockfield 10 Comments

Any good flyswatter ought to be able to break through a hefty piece of wood. At least, that is how [Finn] explains the design philosophy behind this enormous, overpowered flyswatter. Although we don’t know if everyone needs as robust a machine as this to deal with a minor annoyance like a house fly, we can certainly appreciate the over-engineered, extremely powerful (and dangerous) machine that can swat flies but also break through a two-by-four with ease.

The build comes to us in two parts, with the first part documenting the construction of some of the parts of the flyswatter, including the piston-driven gas cylinder. As a bit of a tangent, [Finn] first tests this part by using it to shoot lemons at pieces of plywood. After this initial testing of the gas cylinder, a cam mechanism is installed on the top, and the gas cylinder is slightly modified to pull on a piece of Dyneema rope attached to the cam. At the other end of the rope is a long metal lever with the flyswatter on the end, in this case, made out of a sheet of laser-cut plate steel.

With the addition of a few safety features, like a spring-assisted bumper to keep the flyswatter from swinging too far and hitting its operator, the machine is ready for use. It also eventually received some other upgrades as well including extra weights to prevent the flyswatter from bouncing after firing and a reinforced metal rod to hold the flyswatter after its demonstrations on various dimensional lumber destroyed it. In all likelihood, this is the largest insect-control device we’ve seen since this microwave-powered bug zapper. Now if you are building an insect…

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Thermochromic Treatment Keeps Solderless Breadboards Smokeless

July 8, 2023 by Dan Maloney 17 Comments

There’s a point in a component’s thermal regime that’s between normal operation and overloaded to the point of obvious failure. That’s a dangerous region, because the component isn’t quite hot enough to release the Magic Smoke, but hot enough to singe any finger you poke around with the see if everything’s running right. So if you’re looking to keep your fingerprints unmodified, but you don’t want to invest in a thermal camera, you might want to let this thermochromic breadboard point the way to overloaded components.

We’re not sure where this tip came from, but judging by the look of the website it was sometime in the late 90s. We’re also not sure who’s behind this little hack, so we’ll just credit [improwis]. The idea is pretty simple — white acrylic paint is mixed with thermochromic pigment, and the mixture is carefully painted onto the plastic surface of a standard-issue solderless breadboard. Care is taken to apply thin coats, lest the paint gets into the contacts and really muck things up. Once the paint is dry you’re ready to build your circuit. We have to admit we’re surprised at how sensitive the paint is; judging by the pictures, the heat coming off a 1/4-watt resistor dissipating 350 mW is plenty, even when the body of the resistor is well above the surface of the breadboard. We’d imagine the paint would point out not only hot components but probably the breadboard contacts too, if things got really toasty.

This seems like such a great application of thermochromism, one that’s a bit more useful than clocks and Pi Day celebrations. If you’re going to try this yourself, you’ll have to track down your own supply of thermochromic pigment, though — the link in the article is long dead. That’s not a problem, though, as Amazon sells scads of the stuff, seemingly aimed mainly at nail salons. The more you know.