Author: Bryan Cockfield

1836 Articles

Using Solar Air Heating To Dry Clothes

July 17, 2026 by 23 Comments

About a month ago, [Greenhill Forge] built a few solar panels to collect energy from the sun. Unlike solar photovoltaics, which turn sunlight directly into electricity, these were designed to gather solar thermal energy with air. These types of panels can gather a tremendous amount of energy for a very low cost, and although the first video only went into the theory of their operation, his latest video actually shows us how to use that energy in a practical way.

The video starts by building a new solar panel, using upgraded materials and building methods compared to the previous versions which should improve the efficiency. There’s some data analysis of the performance, but at the end of the video [Greenhill Forge] actually hooks one of these up to a clothes dryer to explore its real-world efficacy. This process involves disconnecting the electric heater, removing one of the blower fans, and building a new flange to accept the heated air from the solar panel. A microcontroller keeps an eye on the incoming air temperature and controls a fan to try to hit the target temperature.

After an hour of drying, the test clothing was completely dry, with the only electricity used to turn the drum in the dryer. This is more than an order of magnitude of reduction in the power needed to dry clothes, which is fairly impressive. [Greenhill Forge] also notes that systems like these could augment off-grid systems not only for clothes drying but for home heating, greenhouse heating, or drying out various crops and that they could reduce strain on an electrical system that otherwise relies on resistive heating methods. There are many ways of building these panels, so be sure to check out his first video for ideas. Continue reading “Using Solar Air Heating To Dry Clothes” →

Five Solar Air Heating Methods Tested

July 4, 2026 by 63 Comments

For as good as solar panels are at converting sunlight directly into usable electricity, especially for how cheap they’re becoming, they can still only gather around 20-30% of the energy that hits them. That’s fine if you have a large roof or a huge tract of land, but if you have limited space and need to do something like heat a home, there are better options available to capture more of that energy. [Greenhill Forge] has built five solar air heating panels to test this concept, and do it much more inexpensively than commercial options.

These solar heaters use sunlight to heat a fluid, in this case air, and move that heated fluid to another space. Each panel is about two square meters, insulated on all sides except the top, and configured in a way that air can flow past something that the sun has heated. The first panel, a control, does not use a glazing to help trap this heat, but the rest all have a polycarbonate window to increase the greenhouse effect of the panels. The four remaining all experiment with the way air flows around a black corrugated steel sheet to gather more of the heat, with the fifth panel using a set of black screen instead.

With the panels all set out in the sun, [Greenhill Forge] is using a set of thermocouples from a previous project to measure the efficiency of each panel. Surprisingly, he found that the panel using the layers of screen was the best at gathering energy, although he notes several times that these types of panels are extremely sensitive to changes in physical configuration, so this is not the most definitive test possible. However, at only around $100 per panel it’s quite a deal if the goal is a usable space heater that doesn’t use any fuel or grid electricity.

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Microdistillery For Microchemistry

July 3, 2026 by 21 Comments

Much like radio operators being encouraged to use the least possible amount of power to make a contact, chemists have a similar rule encouraging using the least amount of materials in experiments. Not only is this rooted in economics, but in safety as well; if something goes wrong it’s generally good if there’s not excess amounts of reactants. With modern techniques, though, it’s possible to bring experimental chemistry down to incredibly small scales, and [Marb’s lab] found that they needed a custom built still for these new, diminutive experiments.

The first step is to build the heating component of the still. This is provided with a few custom aluminum parts for the base and a pair of heaters originally meant for 3D printers, with the assembled unit wrapped in insulation. The heater accomodates a 25 mL round-bottom flask. Temperature control of the heating mantle is provided by a controller mounted to a DIN rail which receives power from a 24V power supply, and an additional temperature probe is added to measure the temperature of the distillate. A test run with water shows the small still quickly and efficiently evaporating the water up to a condenser.

Although building a still doesn’t have to be technically difficult, building something this small that’s effective and safe is a bit more challenging than a backyard moonshining operation. Scaling chemical reactions down can often be a challenge but is possible with the right mindset and equipment. We’ve seen miniaturization of many things that we might not have expected including hydrogen production, aluminum smelting, and even the construction of a microscope.

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Modern E-Ink Dashboards, Kindle And Otherwise

July 3, 2026 by 13 Comments

People have been attempting to turn Kindles into more than e-readers since the first devices came out nearly two decades ago. The e-ink displays are low-power and great for displaying information that doesn’t refresh too often, and with Amazon continuing their trend of bricking their older devices there will be more of these devices available. [Hemant] built a weather dashboard with one of his, but since then had requests for other types of e-reader dashboards and has a guide for making more general-purpose use of an old Kindle.

The first approaches outlined here involve the installation of a dashboard client on the Kindle and pointing it at a server that hosts a PNG image of whatever information needs to be displayed. The client simply displays that image and refreshes it at predetermined intervals. There are a number of options for creating that server as well, including using Home Assistant for those who already have a home automation system deployed. The benefit of using Home Assistant is that it’s much more straightforward to gather data for the dashboards from sensors and other peripherals that are already installed.

Installing a client like this might seem straightforward, and it can be, provided that the Kindle involved is jailbroken or capable of being jailbroken. An Amazon update recently broke many modern devices’ ability to execute the jailbreak, so not every Kindle can do this anymore. But [Hemant] goes into detail about this and also outlines some methods for using generic e-ink displays instead, and also dives into the hardware and software behind building a server to host the dashboard images for those without Home Assistant already running. It’s a great overview for those who have always wanted something like this but never knew where to start.

No-Drill Sailing Kit For A Canoe

July 1, 2026 by 4 Comments

The first known use of humans using wind to perform mechanical work with machines dates back to ninth-century Persian windmills. But if we count sailing vessels among those machines, the history goes back to sometime just before the invention of written language. Since then, humans have been sailing everything from the tiniest of Sunfish to the largest of shipping vessels, and even sailing boats like canoes that aren’t typically designed for efficient sailing. For those who already own a canoe, the conversions can be straightforward but often involve drilling into the hull. This homemade conversion kit, on the other hand, requires no drilling at all.

The first, and most obvious, part of the conversion is to add a mast and sail. [Tea]’s primary setup does involve drilling a mast thwart into the gunwales of the canoe, but he also built an alternative setup which clamps to the gunwales and the bow deck instead. The standing lug sail is then hoisted on an unstayed wooden mast. The next major component of the build are a pair of leeboards which also clamp to the gunwales and function like a centerboard, and can be adjusted for one’s preferred amount of weather helm. Rounding out the stern of the boat is a custom-built rudder with a pair of lines in lieu of a tiller which can be positioned anywhere along the length of the boat.

All of the wooden parts of this build were custom-built from common lumber with finishing touches from a router to soften all of the hard edges. Canoe sailing is fairly popular, although without the leeboards these common sailing kits are often meant for downwind sailing only. A complete setup like this turns it into a much more capable craft. Without a canoe as a base vessel to start with, though, a complete sailing vessel can be built from common lumber as well.

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Web Tool Lets You Take Steam Controller For A Drive

June 30, 2026 by 7 Comments

One of the simplest robots to make is a bristlebot — a motor with an offset weight is attached to the head of a toothbrush, and the resulting vibrations will move the contraption across a flat surface. [Very Lazy Pixels] recently took this idea a bit further by turning the Steam Controller into a steerable, bristlebot-like robot.

To drive one’s Steam Controller across a desk, all that is needed is for a computer with a paired controller and a Chromium-based browser. From there, using the WASD buttons, the web interface converts traditional video game inputs into controller motion by spinning the controller’s rumble motors at a specific frequency. With precise control of these motors, the controller can move forwards and backwards and even turn, which is a great deal more advanced than the traditional bristlebots generally manage.

Part of what makes this possible is Valve’s willingness to release information about many of their products to the general public, enabling anyone to modify or upgrade those products to their liking. While not completely open source, it’s a step in the right direction and enables fun projects like these. We’ve seen other Valve products turned into surprisingly barebones single-board computers as well as custom portable workstations thanks to this philosophy.

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Piano Escapement Migrates To Drum Kit

June 29, 2026 by 6 Comments

For as popular as the piano is in music studios, homes, and schools, it almost defies logic. Compared to a guitar, harmonica, or drum set, pianos are incredibly complex machines that can have somewhere on the order of 8,000 moving parts in a case that can easily weigh hundreds of pounds and which often responds quite poorly to seasonal changes in temperature and humidity. But for putting up with all of these downsides, musicians are rewarded with an instrument that uniquely responds to touch, style, and emotion. A big reason for that is that mechanical complexity, and [Super Valid Designs] is attempting to bring that design to a drum set.

Compared to the complex machinery that connects the movement of a piano’s key to its hammer striking a string, a kick drum pedal is much simpler. It can only bounce off of the drum or get “buried” where the beater remains pressed up against the drum after hitting it. [Super Valid Designs] wanted something with a bit more finesse and control, so he first 3D printed a mechanism that throws the beater towards the drum head and then disconnects it mechanically from the pedal, so that it rebounds even if the pedal stays depressed. The next steps were more difficult, which involved making sure the mechanism reset itself in a repeatable way, without making too much noise of its own. This involved trying out a few different ideas and printing a massive amount of subtly different linkages, but in the end he’s left with a machine that nearly replicates all of the parts of a piano’s escapement,

The end goal of this project wasn’t simply to reproduce piano mechanisms on a drum set, though. [Super Valid Designs] hopes to make a kick drum that’s much smaller than those found in traditional kits, and since smaller drums respond poorly when the beater remains on or near the drum after striking it, a mechanism like this will dramatically improve the performance of the smaller drum and help reduce the requirement for perfect technique. And, maybe in 50 years or so, these types of escapements will take over the drumming world just like the piano escapement took over keyboards after its invention in the 1700s. Some simpler piano actions have been built before, but the complexity seems to be a requirement for all of the tasks they need to do whether its for a piano or a drum.

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