A Smarter PSU Converter Leaves the Magic Smoke Inside

Over the years, computers have become faster, but at the same time, more power hungry as well. Way back around the 386 era, most PCs were using the AT standard for power supplies. Since then, the world moved on to the now ubiquitous ATX standard. Hobbyists working on older machines will typically use these readily available supplies with basic adapters to run old machines, but [Samuel] built a better one.

Most AT to ATX adapters are basic passive units, routing the various power lines where they need to go and tying the right pin high to switch the ATX supply on. However, using these with older machines can be fraught with danger. Modern supplies are designed to deliver huge currents, over 20 A in some cases, to run modern hardware. Conversely, a motherboard from the early 90s might only need 2 or 3A. In the case of a short circuit, caused by damage or a failed component, the modern supply will deliver huge current, often damaging the board, due to the overcurrent limit being set so high.

[Samuel]’s solution is to lean on modern electronics to build an ATX to AT adapter with programmable current protection. This allows the current limit to be set far lower in order to protect delicate boards. The board can be set up in both a “fast blow” and a “slow blow” mode to suit various working conditions, and [Samuel] reports that with alternative cabling, it can also be used to power up other old hardware such as Macintosh or Amiga boards. The board is even packed with extra useful features like circuitry to generate the sometimes-needed -5V rail. It’s all programmed through DIP switches and even has an OLED display for feedback.

It’s an adapter that could save some rare old hardware that’s simply irreplaceable, and for that reason alone, we think it’s a highly important build. We’ve talked about appropriate fusing and current limiting before, too – namely, with LED strips. 

 

Quiet Your Car The Cheap and Effective Way

If you’ve been on the Earth for a couple of decades or more, or have just grown up riding around in some older metal, you’d know that cars can be incredibly noisy. If you’re unfamiliar, buy yourself a nice car like a 2000 Honda Civic, strip out all the carpet and interior panels, and go for a drive. Huge amounts of research and development have gone into making modern cars as quiet and comfortable as possible. Through the correct use of sound deadening materials and techniques, a car can be made much quieter and audio quality from the sound system can be improved too. [camerajack21] decided to get to work on their Volkswagen to see what could be done.

The project in question pays special attention to the door panels. These are where the primary speakers are housed, and there were issues with rattles if the speakers were allowed to operate at frequencies below 100 Hz. Weather stripping, foam, and improved fasteners were pressed into service to reduce this issue.

Think of a musical bell. If you touch a small part of the bell with just your finger, it no longer can ring true. You don’t need to wrap your entire hand around a bell to keep it from ringing. Your finger is not absorbing sound, just preventing the bell from ringing.

Focus then moved to the body panels. Special sound deadening material (in this case, Silent Coat brand) was then applied to the insides of the doors and trunk to bring the sound level down. The key to effective application of such materials is not to waste money covering entire panels – the Reddit comments are particularly enlightening here. It only takes a small amount of material to stop a panel from vibrating, with most testing suggesting anymore than 30% coverage of a panel brings diminishing returns.

With your car’s sound environment tidily improved, you might be looking for ways to improve your sound system. There’s plenty of ways to go about it – you can even use guitar effects.

3D Printed Tank Scores Suspension

Tanks are highly capable vehicles, with their tracks giving them the ability to traverse all manner of terrain at speed. An important part of a tank is its suspension setup, without which its treads are far less capable. When [Ivan]  began work on his 3D printed tank project, he couldn’t ignore the comments. His tank would need a suspension system.

The tank build itself is impressive, consisting almost entirely of 3D printed components held together with off-the-shelf bearings and threaded rod. [Ivan] retools the tank from the beginning to fit a pivoting suspension system which is surprisingly simple in its design, yet capable in operation. Particularly impressive are the 3D printed springs, which [Ivan] tunes the stiffness of to suit the weight of the vehicle.

It’s a build that shows just how far you can go when you master the basics of 3D printing and mechanical design. It doesn’t take a lot of advanced theory to design cool things, just a willingness to learn and experiment and the right set of tools behind you. [Ivan]’s tank treads are worth taking a look at, too. Video after the break.

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Smooth PLA Through the Fire and Flames

3D printing makes it easy to produce complex geometries, but the fused deposition methods generally create parts with poor surface finish, largely due to the layers being highly visible in the finished part. There are a wide variety of ways to deal with this, often involving sanding parts after production, or the use of fillers and paints. [XerotoLabs] has another solution. (YouTube, video below the break.)

To smooth the parts, a butane torch is pressed into service. The flame temperature is kept fairly low, and the torch is used almost like a brush to evenly apply heat to the surface of the part. As the PLA reaches its melting temperature, surface tension helps to smooth the part out. This is very similar to flame polishing which is commonly used in the fabrication of acrylic plastics.

It is a technique that requires some finesse – too much heat or focus on a single area, and you’re liable to end up with a molten plastic blob instead of a nice shiny finished part. Precautions must also be taken to avoid burning yourself or your workshop to the ground. But it’s a useful tool to have in your kit when you’re producing PLA parts that you want to look their best.

We’ve seen other techniques for smoothing PLA, too – the solvent method is particularly interesting. Continue reading “Smooth PLA Through the Fire and Flames”

The Internet of Claw Machines

Remote administration of machines is a very useful tool for all manner of commercial, industrial, and home applications. Now, it’s available for claw machines, too – thanks to [Code Your Venture Free].

The project uses an ESP32 board that includes a battery case on the back for a standard 18650 lithium battery that makes getting small battery powered projects off the ground much easier. You can find them at Banggood and AliExpress, but we’re not 100% sure that they’re kosher because they’re branded WeMos, but don’t show up on WeMos’ website or their official online retail store. Anyway, it’s a cute idea to strap a LiPo cell to the back like that. Let us know in the comments if you know more.

Back to the claw! An off-the-shelf thumbstick is then connected to the ESP32 which is programmed to send packets over the network to control the claw machine, which is wired up with its own network-connected microcontroller. It’s all wrapped up in the usual 3D printed case.

The one problem that the project doesn’t solve is delivery – how does the remote player, whether on the local network or online, collect their prize? We can only assume some cutting-edge form of drone delivery is the solution. It’s not the first remote claw machine we’ve seen, either. Video after the break.

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See-Through Rotary Engine Reveals Wankel Magic

The Wankel rotary engine is known for its troubled life in the mainstream automotive industry, its high power-to-weight ratio, and the intoxicating buzz it makes at full tilt. Popular with die-hard enthusiasts and punishing to casual owners, it stands as perhaps the most popular alternative internal combustion design to see the light of day. There are myriad diagrams out there to explain its operation, but what if you could see inside?

The video comes courtesy of [Warped Perception], and features a small Wankel rotary engine intended for model aircraft. The engine’s end plate is removed and replaced with a transparent plate, making the combustion process visible. Add in a high-speed camera, and you’ve got a recipe for a great technical video.

It starts with a basic explanation of how the Wankel rotary power cycle operates, before cutting to the glorious slow-motion shots of the engine in operation. It also highlights several techniques useful for producing this type of video, such as painting surrounding components black to make it easier to image the parts of interest. The visuals are amazing and very clearly show the  manner in which the intake, compression, power and exhaust strokes function in the engine.

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Recycling and Casting Styrofoam with Solvents

Styrofoam is an ever-present waste material in modern society, being used to package everything from food to futons. It’s also not the easiest thing to deal with as a waste stream, either. With this in mind, [killbox] decided to have a go at recycling some styrofoam and putting it to better use.

The process starts by combining the EPS styrofoam with a solvent called D-limonene. This was specifically chosen due to its low toxicity and ease of use. The solvent liquifies the solid foam and the air bubbles are then allowed to make their way out of the solution. If it’s desired to create a coloured end product, it’s noted that this can be achieved by using other plastic items to provide colour at this stage, such as a red Solo cup.

It’s a slow process thanks to the choice of solvent, but it makes the process much more palatable to carry out in the average home lab setup. It’s possible to then perform casting operations or further work with the recovered material, which could have some interesting applications. It’s not the first plastics recycling project we’ve seen, either – check out this full setup.

[Thanks to Adric for the tip!]