A V2 Rocket Inspired Steam Turbine Skateboard Is Just Around The Corner

[Integza] never fails to amuse with his numerous (and sometimes really sketchy) attempts to create usable thrust, by pretty much all means possible and the latest video (embedded below) attempting to run a reaction turbine from decomposing hydrogen peroxide, doesn’t fail to disappoint. The inspiration came from the WWII V2 rocket, which used Sodium Permanganate to breakdown Hydrogen Peroxide. This produced high pressure steam, which spun a turbine, which in turn drove the turbopumps that delivered the needed huge quantity of alcohol and liquid oxygen into the combustion chamber.

After an initial test of this permanganate-peroxide reaction proved somewhat disappointing (and messy) he moved on to a more controllable approach — using a catalytic converter from a petrol scooter in place of the messy permanganate. This worked, so the next task was to build the turbine. Naturally, this was 3D printed, and the resulting design appeared to work pretty well with compressed air as the power source. After scaling up the design, and shifting to CNC-machined aluminium, it was starting to look a bit more serious. The final test shows the turbine being put through its paces, running from the new precious metal catalyst setup, but as can be seen from the video, there is work to be done.

There appears to be a fair amount of liquid peroxide passing through into the turbine, which is obviously not desirable. Perhaps the next changes should be the mount the catalyser vertically, to prevent the liquid from leaving so easily, as well as adding some baffling to control the flow of the liquid, in order to force it to recycle inside the reaction vessel? We can’t wait to see where this goes, hopefully the steam-turbine powered skateboard idea could actually be doable? Who knows? But we’re sure [Integza] will find a way!

With steam power, there’s more than one way to get usable rotational work, like using a reciprocating engine, which can be expanded to a whole machine shop, and whilst boiling water (or catalytically decomposing Hydrogen Peroxide)  provides high pressure gas, how about just using boiling liquid nitrogen? Possibly not.

Continue reading “A V2 Rocket Inspired Steam Turbine Skateboard Is Just Around The Corner”

You Can 3D Print A Working Reciprocating Steam Engine

3D prints aren’t typically known for their heat resistance. However, [Integza] noted that using the right techniques, it was possible to 3D print parts that could handle steam heat without failing. Thus, the natural progression from there was to build a piston-type steam engine.

The sliding valve alternately feeds steam to each side of the piston.

Resin prints are key here, as the melting point of such parts is much higher than that of those turned out by typical FDM printers. Try this same build using PLA for the hot parts, and you’ll quickly end up with a pile of molten goo.

To make such an engine work, valves are required to allow steam to flow into alternating sides of the piston to let it reciprocate continuously. A simple slide valve is used, allowing steam to flow to one side of the piston and the other alternately, as driven by an arm coming off the flywheel attached to the engine’s output shaft.

Tested on compressed air and steam, the engine ran continuously, chugging away enthusiastically. However, steam performance was compromised by the low pressure output of just 1.5 bar from [Integza]’s pressure cooker. Similarly, the cooker’s steam capacity was low, so the engine ran for just 15 seconds.

However, it suggests that with a better supply of steam, the printed steamer could indeed run for some time. If you’re not into the wetter engines out there, though, consider extruding a Stirling engine instead. Video after the break.

Continue reading “You Can 3D Print A Working Reciprocating Steam Engine”

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.

Continue reading “Fail Of The Week: Learning How Not To Silver Solder”

Liquid Nitrogen Isn’t Suitable For Steam Engines

Liquid nitrogen is fun stuff to play with, as long as you’re careful and avoid freezing your own fingers off and shattering them on the workbench. As the liquid turns to gaseous nitrogen at around -196 C, [The Action Lab] figured that it could be used to propel a simple steam engine at room temperature. Testing this out had amusing results.

The device under test is a Hero’s Engine, otherwise known as an aeolipile. This consists of a hollow sphere filled with water, fitted with a series of nozzles that shoot out steam when the vessel is heated. Via the rocket principle, this causes the device to rotate about its axis.

When filled with water and heated with a candle, the aeolipile spun at up to 2520 RPM. [The Action Lab] next tested it filled with water in a vacuum chamber, with the low pressure causing the water to boil at room temperature. The effect was less impressive however, with the engine spinning at a much slower rate.

The best result was with liquid nitrogen inside the engine. With the nitrogen quickly boiling at room temperature, the aeolipile quickly spun up to a great speed. The engine stand had to be steadied to avoid it tipping over, before the seal at the top of the engine blew off from overpressure.

We’d love to see the same experiment done with a piston-type steam engine, too. Video after the break.

Continue reading “Liquid Nitrogen Isn’t Suitable For Steam Engines”

Staged Train Wrecks: An Idea That Ran Out Of Steam

Before there were demolition derbies, there were train totalings. That’s right, somebody had the idea to take a couple of worn-out train engines that were ready for the scrap heap, point them at each other, and drive them full steam ahead. And their boss said capital idea, let’s do it. This was the late 1890s.

Maybe it wasn’t the safest way to spend an evening, but a staged train wreck was surely an awesome spectacle to behold. Imagine being one of the brave engineers who had no choice but to get the train going as fast as possible and then jump out at the last second. A demolition derby seems like child’s play by comparison.

The largest and most widely-publicized wreck was put on by a man named William George Crush who was trying to find new ways to promote the Missouri-Kansas-Texas passenger railway. Once he got the okay, Crush found a large field surrounded by three hills that made for excellent viewing. He stood up a temporary town complete with a circus tent restaurant, a wooden jail cell, and 200 rent-a-constables.

On September 15th, 1896, forty thousand people gathered to watch two trains collide along a section of purpose-built track. They hit each other going 50 mph (80 km/h) and both engines exploded, sending hot iron projectiles every which way. Several people were injured, a few died, and a hired photographer lost an eye to shrapnel. Train totalings nevertheless continued until the Great Depression of the 1930s, when the practice was discarded as wasteful.

Thanks for the tip, [Martin]!

Converting A Lawnmower Engine To Run On Compressed Air

Our most likely exposure to a steam engine these days will probably come courtesy of a railway locomotive. A machine capable of immense power and probably with significant complexity and engineering  in its construction, something the majority of us will only ever be able to see at second-hand. But there was a period when steam engines were much more accessible, before internal combustion engines and electric motors took on the task of automating hard work you would have found small stationary steam engines in all corners of industry.

These engines are on a scale much more easily embraced by hackers and makers, and though vintage stationary engines are thin on the ground these days there are a significant number of people pursuing their construction by converting modern petrol and diesel engines to a more old-fashioned medium.

[Lindsay Wilson] has a lawnmower engine which a few years ago he converted with the addition of a sleeve valve to run on compressed air. It’s not a steam engine because creating a safe and legal steam boiler is an expensive process, but despite this it amounts to the same thing. The engine in question is a small sidevalve single cylinder Suffolk Punch lawnmower engine from which he has removed and blocked the valve gear, and added a sleeve valve powered by a linkage from the crankshaft and using the spark plug hole as an inlet and outlet. He provides a lot of detail on the sleeve valve’s construction, and it really is a surprisingly simple arrangement. We might look for a harder metal than copper pipe for the guide in which it runs though.

The video below the break shows the engine being run up after a period of storage. It’s an effective device, easily capable of taking more air than his compressor can supply.

Continue reading “Converting A Lawnmower Engine To Run On Compressed Air”

Steam-Powered Machine Shop

It’s sometimes hard to believe how stuff was made over a hundred years ago when electricity wasn’t widely available. One of the most common ways of powering tools was via belt drive — powered by a water mill, or a steam engine, or even horses. [David Richards] has spent a good chunk of time making his own period accurate steam powered machine shop — and it’s fantastic.

It represents approximately what a 1920’s machine shop would look like in America. Not a single tool is newer than 1925. The whole shop is powered by a line shaft using steam power. A massive boiler provides steam for a Pennsylvania built 5 by 5 steam engine, dating back to approximately 1895. Using belts and clutches, it powers a few lathes, drill presses, a mill, and even a shaper — an identical machine to one in the Edison Museum!

Continue reading “Steam-Powered Machine Shop”