This film projecter is hiding an Arduino Uno that controls a water-based cooling system.

Cool The Shop With A Thermal Battery-Based System

January 1, 2022 by Kristina Panos 64 Comments

Having any kind of shop is pretty great, no matter how large it may be or where it’s located. If the shop is in an outbuilding, you get to make more noise. On the other hand, it will probably get pretty darn hot in the summer without some kind of cooling system, especially if you don’t have a window for a breeze (or a window A/C unit).

[Curtis in Seattle] built an awesome thermal battery-based cooling system for his shop. The battery part consists of five 55-gallon drums full of tap water that are connected in series and buried a foot underground, about two feet out from the wall. There are two radiators filled with water and strapped to 20″ box fans — one inside the shop, which sends heat from the shop into the water, and another outside that transfers heat out of the water and into the cool night air. Most summer days, the 800-square-foot shop stays at a cool 71°F (21.7°C).

We love that the controls are housed in an old film projector. Inside there’s an Arduino Uno running the show and taking input from four DS18B20 one-wire temperature sensors for measuring indoor, outdoor, battery, and ground temperatures. There are four modes accessible through the LCD menu — idle, cool the shop, recharge mode, and a freeze mode in case the outside temperature plummets. Why didn’t [Curtis in Seattle] use anti-freeze? It’s too expensive, plus it doesn’t usually get that cold. (Although we hear that Seattle got several inches of snow for Christmas.) Check it out after the break.

If you can’t just go burying a bunch of 55-gallon drums in the ground where you live, consider building a swamp cooler out of LEGO.

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3D Printed Model Roller Coaster Accurately Simulates The Real Thing

December 30, 2021 by Robin Kearey 11 Comments

While they don’t give the physical thrill of a real one, model roller coasters are always fun to watch. However, they actually make a poor analog of a full-sized ride, as gravitational force and aerodynamic drag don’t scale down in the same way, model roller coasters usually move way faster than the same design would in the real world. [Jon Mendenhall] fixed this deficiency by designing a model roller coaster that accurately simulates a full-sized ride.

The track and cart are all made of 3D printed pieces, which altogether took about 400 hours to print. The main trick to the system’s unique motion is that the cart is motorized: a brushless DC motor moves it along the track using a rack-and-pinion system. This means that technically this model isn’t a roller coaster, since the cart never makes a gravity-powered drop; it’s actually a small rack railway, powered by a lithium-ion battery carried on board the cart. An ESP32 drives the motor, receiving its commands through WiFi, while the complete setup is controlled by a Raspberry Pi that runs the cart through a predetermined sequence.

The design of the track was inspired by the Fury 325 roller coaster and simulated in NoLimits 2. [Jon] wrote his own software to generate all the pieces to be printed based on outputs from the simulator. This included all the track pieces as well as the large A-frames holding it up; some of these were too long to fit in [Jon]’s 3D printers and had to be built from smaller pieces. The physics simulation also provided the inputs to the controller in the form of a script that contains the proper speed and acceleration at each point along the track.

The end result looks rather slow compared to other model roller coasters, but actually feels realistic if you imagine yourself inside the cart. While it’s not the first 3D printed roller coaster we’ve seen, it’s probably the only one that accurately simulates the real thing. If you’re more interested in a roller coaster’s safety systems, we’ve featured them too.

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Peering Into The Murky Depths Of Alder Lake

December 29, 2021 by Matthew Carlson 17 Comments

The winds of change are in the air for CPUs. Intel has long lorded over the computing world, and they remain a force to contend with, but many challengers gather at their gates. AMD, ARM, IBM, and other X86 designs sense a moment of weakness. In response, Intel released their Alder Lake platform with high-performance and high-efficiency cores, known as Golden Cove and Gracemont, respectively. [Clamchowder] and [cheese] have written up as many details as they were able to suss out about Gracemont.

ARM has done a multi-multi core design (big.LITTLE) for several years where they have a mix of high-power, high-performance cores and smaller, low-power cores. This allows the scheduler to make tradeoffs between power and performance. Typically the smaller cores in an ARM design are simpler in-order processors, having more in common with a microcontroller than with a full-scale desktop core. Many people have made an obvious comparison with the apparent similarities between ARM’s approach and Intel’s new offerings as Gracemont is based on Intel’s old Atom core, a low-power single issue, in-order processor. Continue reading “Peering Into The Murky Depths Of Alder Lake” →

Laser Doping His Way To Homemade Silicon Chips

December 28, 2021 by Dan Maloney 8 Comments

It’s a pity that more electronics enthusiasts haven’t taken the hobby to its ultimate level: making your own semiconductors. There are plenty of good reasons for that: chief among them is the huge expense involved in obtaining the necessary equipment. But for the sufficiently clever, there are ways around that.

[Zachary Tong] is dipping his toes into the DIY semiconductor world, and further to the goal of keeping costs to a hobbyist scale, is experimenting with laser doping of silicon. Doping is the process of adding impurities to silicon wafers in a controlled manner to alter the electrical properties of the semiconductor. [Zach]’s doping method is a more localized version of the simple thermal diffusion method, which drives a dopant like phosphorus into silicon using high temperatures, but instead of using a tube furnace, he’s using a fiber laser.

The video below shows his two-step process, which first blasts the silicon oxide layer off the wafer before doping with the laser shining through a bath of phosphoric acid. The process is admittedly fussy, and the results were mixed at best. [Zach]’s testing seems to suggest that some doping occurred, and it even looks like he managed to make something reasonably diode-like using the method.

Although the jury is still out on [Zach]’s method, we thought the effort was the important bit here. Granted, not everyone has a fiber laser kicking around to replicate his results, but it’s always good to see progress in the DIY semiconductor field. Here’s hoping [Zach]’s work, along with the stuff that [Sam Zeloof] is doing, kicks off a spate of garage semiconductor fabs.

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Experiments With A Nernst Lamp

December 22, 2021 by Al Williams 14 Comments

Every biography of Edison talks about how the secret to the incandescent lamp was to remove the air from the bulb. That’s true when you use conventional filaments, but a man named Nernst found that using a filament that was already oxidized would allow you to create a lamp that would operate fine in the normal atmosphere. [Jaynes Network] takes a look at these oddities which date back to the 1800s in a recent video that you can see below.

The lamps use a ceramic filament, but the downside is that the filament needs to be hot to allow the lamp to work. The experiment takes a zirconium oxide rod and attempts to light it up. The heat source is a propane torch.

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How To Forge A Skillet From Scratch

December 22, 2021 by Lewin Day 11 Comments

Cookware isn’t something we typically build ourselves; you’d want a well-equipped metal shop to do the job and do it right. [Torbjörn Åhman] has just that, however, and set about forging a stout-looking skillet from scratch.

The build starts with a round disc of steel serving as a blank for the project. The blank is spun up and the outer perimeter ground down thinner with an angle grinder in what looks like a moderately sketchy operation. A forge is then used to heat the blank so that it can be shaped into a pan using a hammer. Slowly, as the metal is beaten one way and then t’other, the skillet begins to form. A belt sander takes off high points on the outside, and a torch is then used to square up the base of the pan so it sits nicely. Finally a handle attached with some stout rivets, and the newly formed piece of cookware gets a seasoning with sunflower oil.

The project shows just how many special skills are required to make even simple cookware by hand. It’s nice to see some keeping the old methods alive, too. Video after the break.

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Bubble Lights Made From Scratch

December 21, 2021 by Lewin Day 21 Comments

Bubble lights are mesmerizing things to watch, up there with lava lamps as one of the nicer aesthetic creations of the mid-20th century. [Tech Ingredients] decided to head into the lab to whip up some of their own design, taking things up a notch beyond what you’d typically find in a store.

Bubble lights have a liquid inside glass that is held under a vacuum. This reduces the boiling point of the fluid, allowing a small heat input to easily create bubbles that float to the top of the chamber inside. The fluid used inside is also chosen for its low boiling point, with [Tech Ingredients] choosing dichloromethane for safety when using flames to work the glass.

The video shows off the basic glass working techniques required to make the glass bubble tubes, as well as how to build the bases of the bubble lamps that light the fluid up and provide the heat to create bubbles. The use of different materials to create nucleation points for the boiling fluid is also discussed, giving different visual effects in the final result. It’s a great primer on getting started building these beautiful decorations yourself.

Bubbles are pretty things, and with different techniques, we’ve even seen them used to make displays. Video after the break.

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