Steam turbines have helped drive a large chunk of our technological development over the last century or so, and they’ll always make for interesting DIY. [Hyperspace Pirate] built a small turbine and boiler in his garage, turning fire into flowing electrons, and learning a bunch in the process.
[Hyperspace Pirate] based the turbine design on 3D printed Pelton-style turbines he had previously experimented with, but milled it from brass using a CNC router. A couple of holes had to be drilled in the side of the rotor to balance it. The shaft drives a brushless DC motor to convert the energy from the expanding steam into electricity.
To avoid the long heat times required for a conventional boiler, [Hyperspace Pirate] decided to use a flash boiler. This involves heating up high-pressure water in a thin coil of copper tube, causing the water to boil as it flows down the tube. To produce the high-pressure water feed the propane tank for the burner was also hooked up to the water tank to pressurize it, removing the need for a separate pump or compressed air source. This setup allows the turbine to start producing power within twelve seconds of lighting the burner — significantly faster than a conventional boiler.
Throughout the entire video [Hyperspace Pirate] shows his calculation for the design and tests, making for a very informative demonstration. By hooking up a variable load and Arduino to the rectified output of the motor, he was able to measure the output power and efficiency. It came out to less than 1% efficiency for turning propane into electricity, not accounting for the heat loss of the boiler. The wide gaps between the turbine and housing, as well as the lack of a converging/diverging nozzle on the input of the turbine are likely big contributing factors to the low efficiency.
It might seem a little bit counterintuitive, but one of the more carbon-neutral ways of heating one’s home is by burning wood. Since the carbon for the trees came out of the air a geologically insignificant amount of time ago, it’s in effect solar energy with extra steps. And with modern stoves and well-seasoned wood, air pollution is minimized as well. The only downside is needing to feed the fire frequently, which [Anders] solved by building a robot.
[Anders]’ system is centered around a boiler, a system which typically sits in a utility area like a basement and directs its heat to the home via another system, usually hot water. An Arduino Mega controls the system of old boat winches and various motors, with a grabber arm mounted at the end. The arm pinches each log from end to end, allowing it to grab the uneven logs one at a time. The robot also opens the boiler door and closes it again when the log is added, and then the system waits for the correct set of temperature conditions before grabbing another log and adding it. And everything can be monitored remotely with the help of an ESP32.
The robot is reportedly low-maintenance as well, thanks to its low speed and relatively low need for precision. The low speed also makes it fairly safe to work around, which was an important consideration because wood still needs to be added to a series of channels every so often to feed the robot, but this is much less often than one would have to feed logs into a boiler if doing this chore manually. It also improves on other automated wood-burning systems like pellet stoves, since you can skip the pellet-producing middleman step. It also eliminates the need to heat your home by burning fossil fuels, much like this semi-automated wood stove.
One of the core principles of the open-source movement is that anyone who wants to build on a piece of work, in whatever way they want, is easily able to. With source code freely available, the original project can be expanded upon, modified, updated, or simply looked at and used as inspiration. Usually we think about this in the realm of software freedom, but hardware is an important component as well. And not just electronics hardware, either. [Norm] demonstrates this espresso machine which was built on these open-source foundations.
The project takes some inspiration from the open-source Gaggiuino project, which was another build that modified an entry-level espresso maker with finer control over temperature and pressure. [Norm] was not willing to sacrifice his espresso machine for this cause, though, which is how this machine with its cobbled-together hardware came to be. An older machine with some worn parts was sacrificed to the coffee gods instead, making use of its pumps, boiler, and a few other bits of hardware especially from the hydraulics system. The software control is built around the Gaggiuino project, and includes a custom control board for user interface.
Right now the coffee maker does indeed work, but [Norm] hopes to make some improvements to the device including adding an enclosure of some sort, both to prevent accidental contact with the boiler and to give it a sleek, professional look. We kind of like it the way it is, while acknowledging that it isn’t quite ready for commercial production like this. It has a similar industrial feel as this espresso machine we featured a few years ago that is made out of old engine components.
There’s no denying that while railroads have switched to diesel and electric as their primary power sources, there’s a certain allure to the age of steam. With that in mind, a group of Pennsylvania train fans are bringing the alleged fastest steam train back from extinction.
It takes real dedication to build a 428-ton device from scratch, but these rail aficionados seem to have it in spades. Armed only with the original blueprints and a lot of passion, this team has already finished construction of the boiler and nose of the Class T1 replica which is no small feat. This puts the train at approximately 40% complete.
Some changes are planned for the locomotive including a change to fuel oil from coal and replacing the poppet valves prone to failure with camshaft-driven rotary valves. While not original hardware, these changes should make the train more reliable, and bring the world record for the fastest steam locomotive within reach. If the T1 replica can reach the 140 MPH storied of the originals, it will smash the current record of 126 MPH held by a British train, the A4 Mallard, which would be exciting indeed.
Speaking of Pennsylvania and steam, a trip to Scranton is a must for anyone interested in the age of rail.
Ask the average person about steam power and they’ll probably imagine a bygone era, a time when the sky was thick with smoke belched out by coal-burning locomotives and paddle-wheel ships. Steam is ancient technology they’ll say, and has as much to do with modern living as the penny-farthing.
Naturally, the real story is a bit more complex than that. Sure the reciprocating steam engine has fallen out of favor as a means of propulsion, but the concept of running machinery with steam is alive and well. In fact, unless you’re running on wind or solar power, there’s an excellent chance that a steam turbine is responsible for keeping the lights on in your house.
In honor of all things steam, we invited Quinn Dunki to host this week’s Hack Chat. Those who follow her exploits on YouTube will know that over the last several years she’s built a number of steam engines, from miniature scratch-built models to commercial kits that can do useful work. Who better to answer your burning steaming questions?
The first questions in the Chat were logical enough, with several users wanting to know just how hard it is to build a functional steam engine if you don’t have access to a mill or other means of high precision machining. According to Quinn, while better equipment will certainly allow you to build a more powerful and efficient engine, the basic premise is so simple that it doesn’t take much to get one going. If you’ve got a mini lathe and some bar stock, you’re half way there. In fact, they are so forgiving that she opines you’d struggle to build a steam engine that didn’t at least turn over — though that doesn’t mean it will necessarily run well.
Naturally some comparisons were drawn between the complexity of building a steam engine and putting together a small internal combustion engine (ICE). But while they might seem conceptually similar, Quinn cautions that building a working ICE from scratch is far more difficult and dangerous. She explains that steam engines have a tendency to fail gracefully, that is, mistakes in the design or poor tolerances generally result in little worse than wasted steam and extra noise. Comparatively, a faulty ICE design could easily turn into a bomb on your workbench.
Of course, that’s not to say working with steam is without danger. You certainly don’t want to underestimate high pressure steam, which is why boilers that are over 6 in (15 cm) in diameter or that produce more than 100 PSI will often require the operator to be licensed. They may also need to be inspected, though Quinn notes that your local government official probably won’t be able to make heads or tails of your homebrew build — so if you need an official stamp of approval, your best bet is to find a local model engineering club or society that would have the appropriate connections. All that being said, most hobbyists make it a point to try and get their engine running at the lowest pressure possible, so unless you’ve got something really massive in mind, you’ll probably never need to build up more than 60 PSI or so.
A DIY electric boiler and small steam engine.
Another topic of discussion was how to fuel the boiler itself. An electrically powered boiler is perhaps the easiest option, but is somewhat counterproductive if you hope to put your steam engine to useful work. Coal and wood fires are an option, and indeed were commonly used in the old days, but the soot and ash they produce can be a problem.
Quinn also notes that if you’re using such fuels, you need a way to quickly remove the firebox from the boiler in an emergency; something she likens to the starship Enterprise having to eject its warp core before it explodes. For her own projects, Quinn says she uses either an electric element or a camping gas burner.
While most of the questions during this Hack Chat had to do with the work Quinn has already featured on her blog and YouTube channel, naturally there were questions about where things go from here. After she completes the steam engine kit she’s working on currently, she says she’ll likely to back to another scratch-built engine. She also plans on coupling some of her engines to generators, as she’s gotten many requests about seeing these machines put to useful work. Looking further ahead Quinn says she’s interested in casting her own bronze and aluminum components, and specifically wants to work with “lost PLA” casting, which is a variant of lost wax casting that uses a mold based on a 3D printed part.
We’d like to thank Quinn Dunki for stopping by the Hack Chat and sharing some insights into this unique hobby. While a handcrafted boiler or a desktop steam reciprocating engine might not be on the average Hackaday reader’s list of future projects, it’s still fascinating to see how they work. We owe much of our modern life to steam power, so the least we can do is show it some respect.
The Hack Chat is a weekly online chat session hosted by leading experts from all corners of the hardware hacking universe. It’s a great way for hackers connect in a fun and informal way, but if you can’t make it live, these overview posts as well as the transcripts posted to Hackaday.io make sure you don’t miss out.
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.
While almost everyone has a heater of some sort in their home, it’s fairly unlikely that the heat provided by a central heating system such as a furnace is distributed in an efficient way. There’s little reason to heat bedrooms during the day, or a kitchen during the night, but heating systems tend to heat whole living space regardless of the time of day or the amount of use. You can solve this problem, like most problems, with an Arduino.
[Karl]’s build uses a series of radiator valves to control when each room gets heat from a boiler. The valves, with a temperature monitor at each valve, are tied into a central Arduino Mega using alarm wiring. By knowing the time of day and the desired temperature in each room, the Arduino can control when heat is applied to each room and when it is shut off, presumably making the entire system much more efficient. It also has control over the circulating pump and some of the other boiler equipment.
Presumably this type of system could be adapted to a system which uses a furnace and an air handler as well, although it is not quite as straightforward to close vents off using a central unit like this as it is to work with a boiler like [Karl] has. With careful design, though, it could be done. Besides replacing thermostats, we can’t say we’ve ever seen this done before.
