Homebrew Gel Fuel Keeps The Steam Coming, Legally

All it takes is one knucklehead to go and do something stupid to screw things up for everyone. We’re not exactly sure who the knucklehead is behind the recent ban on hexamine fuel tablets, but given that it’s now proscribed in the UK under the “Control of Poisons and Explosives Precursors Regulations 2023,” we expect that that story is a doozy.

So what’s hexamine, and why should we care if it’s banned? As [Markus Bindhammer] explains, hexamine is a solid fuel commonly used to power model steam engines, among myriad other uses. Its ban leaves a bit of a hole in the model steam community, which [Markus] seeks to fill with this quick and easy gel fuel chemistry project.

The “California Snowball” is a homebrew version of what’s in those solid fuel cans you see heating chafing pans at catered events, with one common brand being Sterno. [Markus] used a saturated solution of calcium acetate (6 g in 50 ml of water) and added that to 150 ml of ethanol; commercial formulations usually use methanol to prevent anyone from drinking the stuff, with varying degrees of success. The calcium acetate forms a gel that looks like whipped cream and traps the ethanol inside. The gel can be easily scooped up and spread around, and burns with a clean, smokeless flame.

It may not exactly be a “plug and play” replacement for hexamine tablets, but one does what one can. And if there’s one thing we can celebrate about model steam engineers, it’s their persistence. We got a bunch of them together last year for a Hack Chat with [Quinn Dunki], and their passion for making things move with steam was pretty impressive.

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The Secrets Of The Pop Pop Boat

Many kids get an early introduction to mechanics with tin pop-pop boats. If you haven’t played with one – you’re missing out! Pop Pop boats are fun toys – but how they work is often misunderstood. To clear this up, [Steve Mould] takes a deep dive into the theory of operation of the pop pop boat.

Most people think these toys operate like a simple steam engine, with water being flashed into steam inside a tiny tin boiler. Turns out that’s not the case. To explain the physics, [Steve] commissioned a glass version of the boat.

The glass boat shows that during normal operation, there isn’t any water at all in the “boiler” at all. The water is only in the boat’s small exhaust tubes. The air inside the tank is heated by a candle. The air expands and pushes the water out of the tubes. This allows the air to cool, and return to the tank. The water then rushes back up the tubes, and the process repeats.

One of the more interesting facts of the video is that the glass boat doesn’t pop. The popping sound associated with the boat is actually made by the tin diaphragm on top of the “boiler”.

[Steve] has gotten pretty good at explaining complex topics using clear cutaway models. If this tickles your fancy, check out his water computer.

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Low Cost Haptic VR Gloves Work With Hacked Steam Games

[Lucas VRTech] has made some significant progress with building force-feedback type haptic gloves for use with Steam VR games. The idea is pretty straightforward: the end of the finger is attached to a cable, which is pulled from inside a sprung-loaded spool; the kind used for hanging ID cards on.

The spool body can rotate, but a peg protruding from it engages with the arm of a co-located servo motor. This produces a programmable stop position. But it is a hard stop, and it is not possible with the current hardware to detect precisely when the stop is reached, nor is it possible to control the force it is pushing with. Such features are not difficult to achieve, its just a matter of a little more development with some custom mechatronics.

The current prototype has a focus on cost, which is great as an early development platform. By leveraging 3D printing and off-the-shelf parts that are easy to source; just a handful (chuckle!) of potentiometers, some servo motors and one from any number of ESP32 dev boards and you’re done. The real work is on the software side of things, as the games themselves need to be modified to play ball with the VR glove hardware. This has been achieved with a combination of a custom steam driver they call OpenGloves, and community developed per-game mods. A few titles are available to test right now, so this is definitely something some of us could build in a weekend and get involved with.

The hardware source for the glove mount and per-finger units can be found on the project GitHub, together with the ESP32 source for Arduino.

For some other haptic-related inspiration, here’s a force-feedback mouse, and for a more hand-off feedback, we have a wind-blaster project.

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3D Printed Parts Hold Up To Steam Heat

Steam turbines are at the heart of all manner of industrial machinery, particularly that used for power generation. [Integza] decided he needed to better understand this technology, and decided to build one himself – using 3D printing, at that. 

First, a steam source was needed, with a pressure cooker on an electric stove pressed into service. The steam was passed out via a nozzle printed in resin, which better resists heat than most FDM-printed parts. Similarly, a turbine wheel was printed in resin as well, with the steam outlet pointed directly at its vanes.

To really stress test the parts, more steam was required.  To achieve this, hydrogen peroxide was pumped through a manganese dioxide catalyst impregnated into steel wool to create steam. This made an absolute mess, but the printed parts nevertheless survived.

The steam turbine didn’t do any useful work, but was able to survive the high temperatures at play. We’d love to see such a device actually used to bear some load, perhaps in some sort of 3D printed power generating turbine design.

Alternatively, if you prefer your steam turbines more classically driven, consider this build. Video after the break.

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Valve Reluctantly Shows How To Mod The Steam Deck

As the narrator in this official instructional video from Valve reminds the viewer several times, the gaming company would really rather you not open up your brand new Steam Deck and start poking around. They can’t guarantee that their software will function should you start changing the hardware, and since there’s no source for replacement parts yet anyway, there’s not much you can do in the way of repairs.

That said, Valve does believe you have the right to take apart your own device, and has produced the video below as an aid to those who are willing risk damaging their new system by opening it up. Specifically, the video goes over how to replace the most likely wear items on the handheld, namely the thumb sticks and the SSD. It seems inevitable that the stock thumb sticks will wear down after a couple years of hard use, so we’re glad to see they are easily removable modules. As for the SSD, it stands to reason that users would want to swap it out for faster and higher capacity models as they become available in the coming years.

Sooner or later, these are going to need to be replaced.

Now to be clear, we appreciate Valve making this video, and would love to see other manufacturers be so forthcoming. But we have to admit that some of its messaging does seem a bit heavy handed. The narrators admonition that users who open their Steam Deck are literally taking their lives into their own hands due to the danger of potentially rupturing the system’s lithium-ion battery is a bit hyperbolic for our tastes. The constant reminders of how badly you could bungle the job just comes off as overly preachy, though to be fair, we probably aren’t the intended audience.

Outside of its obvious gaming functions, we’re excited too see what the community can do with the Steam Deck. With official reference material like this, perhaps we’ll even start seeing some hardware modifications before too long. Though we wouldn’t blame you for hitting the Mute button halfway through.

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The interior of a failed boiler.

Fail Of The Week: Learning How Not To Silver Solder

Sure, there are subtleties, but by and large it’s pretty easy to pick up soldering skills with a little practice. But wait! Not all soldering is created equal, and as [Quinn Dunki] learned, silver soldering is far harder to get right.

Granted, the job [Quinn] is working on is much more demanding than tacking some components to a PCB. She has been building a model steam engine, a task fit to put anyone’s machining skills to the test. And a steam engine needs a boiler, which is where the silver soldering comes in. As she explains in the video below, silver soldering, or “hard” soldering, uses solder that melts at a much higher temperature than “soft” solders like we’re used to in electronics. That’s a big advantage in the heat and pressure of a boiler, but it does pose some problems, many of which [Quinn] managed to discover as she tried to assemble her copper beast.

It turns out that heating a big hunk of copper evenly without burning off the flux actually isn’t that easy, though you can’t say she didn’t give it the old college try. In the process, she managed to share a number of tidbits that were really interesting, like the fact that drawing acetylene from a tank too fast can be dangerous, or that model steam boilers have to be certified by qualified inspectors. In the end, her boiler couldn’t be salvaged, and was put to the saw to determine the problem, which seems to be her initial choice of heating with oxyacetylene; after that initial failure, there was little she could do to save the boiler.

As [Quinn] says, “Failure is only failure if you don’t learn from it.” And so it may be a bit unfair to hang “Fail of the Week” on this one, but still — she has to go back to the beginning on the boiler. And we already know that model steam engines aren’t easy.

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Steam Engine Replica From LEGO

If engineering choices a hundred years ago had been only slightly different, we could have ended up in a world full of steam engines rather than internal combustion engines. For now, though, steam engines are limited to a few niche applications and, of course, models built by enthusiasts. This one for example is built entirely in LEGO as a scale replica of a steam engine originally produced in 1907.

The model is based on a 2500 horsepower triple-expansion four-cylinder engine that was actually in use during the first half of the 20th century. Since the model is built using nothing but LEGO (and a few rubber bands) it operates using a vacuum rather than with working steam, but the principle is essentially the same. It also includes Corliss valves, a technology from c.1850 that used rotating valves and improved steam engine efficiency dramatically for the time.

This build is an impressive recreation of the original machine, and can even run at extremely slow speeds thanks to a working valve on the top,  allowing its operation to be viewed in detail. Maximum speed is about 80 rpm, very close to the original machine’s 68 rpm operational speed. If you’d prefer your steam engines to have real-world applications, though, make sure to check out this steam-powered lawnmower.

Thanks to [Hari] for the tip!

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