TechyMagThings

If you are a certain age, you doubtlessly remember Heathkit. They produced a wide array of electronic kits that were models of completeness and clear instructions. They started with surplus war parts in 1947 and wound up a major player in ham radio and early personal computers. But they made so many other things like TVs, radio control planes, and test equipment. All of it was made for you to build yourself. [Unseen History] released a video with the story of Heathkit from the start to the finish.

The company started out building kit airplanes, but after the war, they built a kit for an oscilloscope using military surplus. The less than $40 scope was still pricey in 1947 when a pound of bacon sold for 64 cents. But a “real” oscilloscope at the time would cost at least $400. The rest is history.

The Heathkit manuals were made simple enough that anyone could build a kit. But they also contained enough detail that you could truly understand what you built. Heathkit gear is still prized today.

Heathkit lost the kit business when Zenith bought the company, partly due to inattention and partly because fewer people cared about electronic kits. This was hastened by a drop in interest and to the availability of inexpensive electronics that you didn’t have to build. The company limped along with educational materials and home automation. By 2012, it was done. At its peak, the company employed over 1,800 people, and by the end, there were six people who lost their jobs.

We’ve covered Heathkit’s history before. Heathkit appears to have rebooted in some form, but we don’t know much about it.

Solar power has gotten cheap enough that putting up panels is among the cheapest ways of providing energy. This isn’t just the case for bulk electricity on a power grid, either; even small devices are easier and cheaper to power with solar than ever before. For example, landscape lighting which once relied on 12V or 24V DC wires all over one’s yard with a transformer and power supply hidden somewhere have partially been converted to simpler individual solar-powered lights now. These small devices can also be given additional capabilities as [Mauro] demonstrates.

In this case, [Mauro]’s goal was to add on-demand lighting to a solar-powered light which was otherwise motion-activated only. To do this, they added a NRF24L01+ radio inside the light’s housing paired with an STM32 microcontroller. This secondary system is largely separated from the existing control circuitry with the exception of being able to switch the lights and receiving its power from the same solar panel. [Mauro] also created a small library to help with communicating with these new modules, whether that’s using a home automation system like Home Assistant or some other method.

Although adding in a few capabilities to inexpensive solar lighting might seem simple on the surface, a project like this is a gateway to adding in all kinds of interesting features to things with built-in solar panels and lots of free space in their cases. The best example here is the addition of a Meshtastic node to one of these lights, making it convenient and stealthy, but we could also see adding in other remote hardware to a landscape lighting module like a gate sensor or a plant health monitoring system.

A die filer is a useful tool to have if you find yourself filing parts on the regular. It’s basically a machine that reciprocates a file up and down for you so you can focus on filing the part to your desired dimensions. They’re not commonly manufactured these days, so [Richard Huberjohn] set about building his own. 

This die filer relies on a simple mechanism to turn rotational motion from a motor into reciprocating linear motion in the vertical plane. A rotating shaft is connected to a crank, which turns a pin in a slotted carrier attached to a linear bearing. As the wheel turns, the pin slides in the carrier, driving it and the linear rod up and down in turn. Attach a file to this, and you have a working die filer. In this case, the rotating shaft is driven by a pair of DC brushed motors, with output stepped down via a gearbox and then a short belt drive. Speed is varied with the aid of an off-the-shelf controller.

If you’re regularly filing small parts, a build like this could speed your work to a great degree. We’ve featured other DIY machine tool builds before, too. If you’re cooking up your own gear for the home workshop, don’t hesitate to let us know on the tipsline!

The IKEA SKAFTSÄRV is an economical LED accent lamp, but while highly affordable it has only fixed lighting options. [simoneluconi] shows how it can easily be turned into a fully-configurable, WLED-connected, WiFi-enabled RGB lamp with little more than an ESP32-based board.

To do this, the control board of the lamp gets replaced with an ESP32-C3 Super Mini board. Control and automation comes from WLED, open-source software that offers flexible automation and control for LED lights with a wide range of features, including native Android and iOS apps.

Modifying the SKAFTSÄRV lamp is fairly straightforward, but opening the unit does require breaking some glued seams to get inside. Once that’s done, the replacement board fits nicely into the housing and the unit can be closed back up. As far as WLED is concerned, the new lamp has 30 LEDs, WS281x type, GRB color order.

The end result is a stylish accent lamp with built-in diffusor and mount that can be controlled over WiFi with all the features WLED brings, such as easy integration with Home Assistant.

This isn’t the first time IKEA’s LED lighting has been given a powerup. Their pixel-style LED wall-mounted OBEGRÄNSAD, which displays a few canned animations out of the box, got considerably enhanced with a new controller.

Thanks [Crash] for the tip!

After the digital camera rose to prominence, it became a cool hobby to keep taking photos on film. It was even cooler if you did the same with an old motion picture camera. The retro film revival has kept a dedicated bunch of photo labs in business over the years, but it’s still possible to save some cash on development by doing it yourself. If that’s your game, you might try mixing up your own development chemicals. 

As explained by [No Grain No Gain], it’s quite possible to mix up your own ECN-2 chemistry from scratch if you know what you’re doing. ECN-2 is the chemistry you’ll want if you’re trying to develop any of Kodak’s Vision3 films, along with CineStill films.

The problem with traditional methods of making developer is that once it’s mixed up, it doesn’t keep well, and the more you use it, the worse the quality gets. To beat this problem, this method involves producing two stock solutions which can be kept on the shelf for long periods of time. They can then be combined together with a little CD-3 developer on an as-needed basis. This makes it easy to always have fresh developer on hand for the best possible results on every roll processed. To make everything, you’ll need sodium sulfite, potassium bromide, sodium carbonate, sodium bicarbonate, and the specialist CD-3 developing agent. It’s then a simple job to mix up the dry chemicals with a bunch of distilled water to make the two necessary solutions to keep on hand. The video also explains how to deal with RemJet films if you happen to be shooting those.

[No Grain No Gain] estimates that this method can cut the cost of development to as little as 50 cents a roll. There’s plenty of labor involved, but if you want the freshest, best developer on hand for your home lab, it’s a method worth considering.

We’ve explored modern film development techniques before, too. Video after the break.

The vibrobot – a vibrating motor and battery attached to the head of a brush – isn’t truly a robot, since its movement can’t be controlled, but it’s whetted the interest of many future roboticists. With a clever control method, though, it is in fact possible to drive them in any desired direction while using only one motor.

[Namaskar Mitro] based the design of this robot on this research paper; if the vibrating motor is mounted at an angle above the base of the robot, it causes the bot to rotate, and if the motor is mounted off-center from the center of mass, the robot moves in a circle. Crucially, reversing the direction of the motor’s rotation reverses the direction of the robot’s rotation. By rapidly switching the direction of rotation, the bot can move in a series of short, shallow arcs which approximate a straight line.

The robot which [Namaskar] built was based on an ESP-01F microcontroller, which let it be remote-controlled over Wi-Fi. It used a DRF8212 motor driver to control a vibrating pager motor, which was housed inside a 3D-printed enclosure. To move in a straight line, the ESP-01F switches the motor’s direction every 250 milliseconds, which still produces a slightly erratic movement. It can, however, approximately follow a traced path.

This adds to the previous vibrobot control methods we’ve seen: a pair of differentially-driven vibrating motors or a weight-shifting mechanism.

Thanks to [110y6] for the tip!