Tool Hacks

3131 Articles

Two 3D-printed enclosures, one blue and one red, sit on a workmat. In front of the blue enclosure, a soldering iron sits in a blue-and-yellow soldering iron stand.

Building A Homemade Induction Soldering Iron

November 7, 2026 by 3 Comments

Despite not being inherently any better at converting electricity into heat, induction-heated soldering irons often considerably outperform conventional irons with an identical power rating. They manage this by directly heating the iron tip with an internal induction coil, rather than conducting heat from a heater cartridge farther back — a design which makes induction irons very responsive, stable, and, unfortunately, expensive. [Frank Zhao], though, managed to design and build two induction soldering irons of his own.

In some ways, the handpiece of an induction-heated soldering iron is simpler than a resistive iron. Induction-powered soldering irons don’t have temperature sensors or any kind of electronic temperature control. Instead, the tip’s temperature is set by the cartridge material’s Curie point; once the cartridge reaches this temperature, the heating efficiency drops off sharply. This self-regulation means that most of the project’s complexity is contained in the power supply, which supplies an RF signal to the induction coil.

Here, [Frank] had two previous projects to work off of, and he based one design on each. The first was the work of [SergeyMax], who’d reverse-engineered a Metcal soldering iron and built his own induction iron based on it. This relied, however, on components hard to find outside of Russia, so [Frank] updated it to use parts available in America. It uses a frequency of 13.56 MHz and an F-type connector, making it compatible with the handpiece assemblies from a number of commercial manufacturers, including Hakko and Metcal. For a measure of portability, it can be powered through an XT30 connector or USB-PD and fits in a compact case.

[Frank]’s second, more inexpensive design was based on the open-source RadioThermal project, but adds the same XT30 and USB-PD power options, allows power level selection with external jumpers, and protects the circuit with a fuse. This design operates at 470 kHz, and uses a custom-built handpiece designed around a commercial soldering iron tip.

We’ve seen induction irons here before, albeit in a considerably less polished form. Alternatively, if you’re interested in seeing what’s inside a normal soldering iron tip, check out this teardown of a T12 tip.

Finger Joint Cutter Uses A Jigsaw Blade, But Not As We Know It

November 5, 2026 by 36 Comments

Around these parts, finger joints (or box joints) are usually the product of laser cutting. [bluesyann] shows us a method of using a stationary jigsaw, a custom blade, and 3D-printed jig to create a DIY box joint cutter whose results look impressive. What’s appealing is not just the end result, but the fact that the whole system is made from little more than an inexpensive tool, scrap wood, and common hardware.

A DIY wide blade cuts each notch in a single go.

In [bluesyann]’s system, the jigsaw is fixed in place to make a stationary cutter. The saw itself is nothing special; it’s the wide blade that makes the difference. It cuts a notch in a single go, and it’s made by epoxying together multiple blades to make a single extra-wide one. Jigsaw blades are not expensive, and they’re easy to snap into pieces. By using a total of three blades (snapping two of them into pieces) one can create the wide version shown here.

With a stationary jigsaw sporting an extra-wide blade that cuts the same notch every time, all that remains is a way to get the spacing right. The solution there is a 3D-printed jig that each freshly-cut notch fits onto as the next one is cut.

There are a few other details, but those are the important bits. One does have to do a bit of trial and error to get things dialed in, but once they are, it’s off to the races.

If one prefers a less hands-on method of cutting box joints, check out this robotic table saw which automates the process.

A black 3D printed machine sits on a workbench. A coil of copper wire is suspended from one side of it, and a screen on the front of it reads "Homing".

Automatic Coil Winder Takes The Tedium Out Of Actuators

October 23, 2026 by 4 Comments

Anyone who’s ever built their own motors knows how tedious winding the coils soon becomes; in [Larry]’s case, the issue was even worse. He’s building his own flip-dot matrix display, and each dot uses two electromagnetic coils to flip a magnet in the dot. Rather than wind each of these by hand, therefore, he built his own coil-winding machine.

The coil winder uses two stepper motors: one to wind wire onto the bobbin, and one to move the wire guide carriage back and forth, distributing the wire evenly across the bobbin. The bobbin is held in place by a retainer, which doubles as a tie point for the end of the wire. The spool of wire rotates on a pair of bearings, and the wire is fed between two pieces of foam to provide adjustable tension. The housing is mostly 3D-printed, with some metal rods, bearings, and belt drives fleshing out the structure. On the electronics side, a Teensy controls the winder, with an OLED display and a rotary encoder for control. Before beginning on a coil, it homes the guide carriage against an end-stop switch, then winds on layers, keeping track of the number of layers applied.

We’ve seen a few coil winders here in the past, including a 3D printer adapted to winding stators. For more on this winder’s application, check out [Larry]’s flip-dot design.

DOOM Ported To A $30 Clamp Meter

October 23, 2026 by 11 Comments

DOOM. Boil it, mash it, stick it in a stew, it’s the game that runs on anything and everything. Now, the classic shooter is running on a rather unlikely target—a cheap clamp meter of very limited resources, thanks to the work of [Artur Bieniek].

The clamp meter in question is the FNIRSI DMC-100, which can be had for the low price of just $30 or so if you know where to look. It’s a far cry from the many thousands of dollars you’d pay for a heavy old 486-based machine back in 1993. [Artur] got the doomgeneric engine running on the Artery AT32F415 chip that runs the clamp meter.

The chip is pretty capable, with its 150 MHz clock speed, though the 32 KB of RAM posed rather a big limitation to the project. It may be one of the lowest RAM DOOM ports out there. Even with this limit, [Artur] was able to get Episode 1 of Freedoom: Phase 1 loaded on to the thing, including E1M1 to E1M9 along with the title screen, intermissions, the finale, the menu, and four save slots. Color graphics are displayed on the meter’s 320 x 240 screen, and there are even sound effects on the built-in buzzer. Controls are mapped to the rather curious choice of a DJI RC-N1 drone controller.

We’ve seen DOOM running on everything from desk phones to completely custom CPUs. These days you have to try pretty hard to find something it hasn’t already been ported to.

Continue reading “DOOM Ported To A $30 Clamp Meter” →

An Open Source Linear Capacitive Encoder

October 22, 2026 by 19 Comments

If you’ve ever pulled apart a set of digital calipers, you’ve probably marvelled at the capacitive encoder that does all the measuring work. There’s nothing stopping you from using the same techniques yourself, as [Nick] demonstrates with an open-source capacitive encoder of his own design.

The sensor PCB works by by having a grid of eight transmitting antennas, etched into a PCB, beneath a larger receiving antenna. The transmitting antennas pulse out a pattern as the sensor PCB moves, with the signals bouncing back from the reflector PCB which is fixed in place. The varying capacitance caused by the position of the reflector elements relative to the sensor PCB varies the strength of the pulses hitting the receiving antenna. A microcontroller—in this case an STM32—can read those pulses to determine the displacement of the sensor PCB relative to the reflector down to a very fine degree. In this case, to an accuracy of 40 micrometers. Not bad!

If you need ultra-fine linear tracking for something you’re building, you might find this project very useful. Files are available on Github for the curious, along with a great explainer on exactly how the capacitive coupling becomes a positional reading. You can also study previous teardowns we’ve featured on cheap digital calipers, just to round out your education further. If you’re working on your own impressive workshop equipment, or subcomponents of such things therein, don’t hesitate to let us know on the tipsline!

An Open Micro-Manipulator Improved

October 19, 2026 by 4 Comments

If you need a micro-manipulator, you probably already have a good idea of what it does. For example, you might be moving a probe over an IC die or wafer. You might be looking at something through a microscope. The key is moving something in very small, precise increments along three axes. An open-source design for a micro-manipulator has seen significant improvements lately. You can see several videos about the device below.

The device uses stepper motors, parallel kinematics, and miniature ball joints to achieve precise motion. The recent version 4.0 update fixes a few problems. According to the GitHub page:

  • Self-collision during homing fixed.
  • Connection of the ball joint block with screws only was not well constrained and could be rotated a bit.
  • No reliable way to ensure consistent linkage rod length
  • Unnecessary ball joint friction
  • Accurate ball position heavily dependent on print quality and corner rounding
  • Rubber bands could not be changed or removed once glued in.

Continue reading “An Open Micro-Manipulator Improved” →

A man's hand is seen adjusting a lever connected to a lens, which is pointing down towards the windings of a small motor. A screen behind this shows an image of the windings, taken from an angle slightly to the side.

Building A Microscope With A 3D View

October 18, 2026 by 12 Comments

As electronic components grow ever smaller, a microscope has become an increasingly indispensable tool for any fine work; when inspecting electronics, though, especially solder joints, [Corebb] found a top-down view too limiting, so he built his own microscope with a rotating side-angle view.

The microscope itself is made of a commercial C-mount microscope lens assembly and a USB camera; the lens has a variable magnification factor up to 200x, which is plenty for electronics work, and is mounted on an adjustable stand to move the focal point. This is paired with an LED ring for illumination and two polarizing filters, one mounted on the lens and one one the lighting ring; when adjusted to 90 degrees from each other, these eliminate glare from reflective surfaces.

To view subjects from the side, [Corebb] built a snap-on adapter. This uses a pair of mirrors to capture a view from the side of the object and direct this through the main microscope lens. An additional concave lens compensates for the increased length of the optical path, and ball bearings let the whole adapter rotate around the microscope and capture the subject from any angle. [Corebb] tried 3D-printing the adapter, but found that flexing caused too much jitter; in addition to being sturdier, a machined aluminium part reduced shadows by allowing for thinner supports. The adapter snaps onto the microscope with small magnets, which keep the optical path consistently aligned.

This isn’t the first time we’ve seen a soldering microscope with a view from the side, but this does look much more affordable. If you’d like to try the polarized light source with your microscope, we’ve covered that before.