Fridge Compressor Turned Into Capable Little Four-Stroke Engine

December 2, 2020 by Dan Maloney 18 Comments

Never underestimate the power of a well-stocked junk bin. Along with a TIG welder and mechanical ingenuity bordering on genius-level, all of which come to bear on this fridge compressor to four-stroke engine build.

The video posted by [Let’s Learn Something] is long, but watching it at double speed doesn’t take away much from the enjoyment. By using a piston-type compressor, a lot of the precision machining is already taken care of here. Adding the intake and exhaust valves, camshaft, timing chain, carburetor, and ignition system are still pretty challenging tasks, though. We loved the home-made timing chain sprockets, made with nothing more than a drill and an angle grinder. In a truly inspired moment, flat-head screws are turned into valves, rocker arms are fabricated from bits of scrap, and a bolt becomes a camshaft with built-up TIG filler. Ignition and carburetion are cobbled together from more bits of scrap, resulting in an engine that fired up the first time — and promptly melted the epoxy holding the exhaust header to the cylinder head.

Now, compressor-to-engine conversions aren’t exactly new territory. We’ve seen both fridge compressors and automotive AC compressors turned into engines before. But most of what we’ve seen has been simple two-stroke engines. We’re really impressed with the skill needed to bring off a four-stroke engine like this, and we feel like we picked up quite a few junk-box tips from this one.

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Mazda Investing Big In Advanced Gasoline Tech With Skyactiv-X

October 20, 2020 by Lewin Day 122 Comments

Electric cars, as a concept, were once not dissimilar from the flying car. Promised to be a big thing in the future, but hopelessly impractical in the here and now. However, in the last ten years, they’ve become a very real thing, with market share growing year on year as new models bring greater range and faster charging times.

With their lower emissions output and ever-improving performance, one could be forgiven for thinking that traditional combustion engines are all but dead. Mazda would beg to differ – investing heavily in new technology to take the gasoline engine into the next decade and beyond. Continue reading “Mazda Investing Big In Advanced Gasoline Tech With Skyactiv-X” →

1/3 Scale Hybrid RC Car With A Scratch-Built 125cc V10 Engine

September 20, 2020 by Danie Conradie 20 Comments

Scale model engines are fascinating pieces of engineering, and RC cars are always awesome to play with, no matter your age. [Keith57000] has gone over the top on both, creating a seriously impressive hybrid RC car built around a custom 125 cc V10 engine.

[Keith57000] started building the V10 engine back in 2013, after completing a 1/4 scale V8. The build is documented in a forum thread with lots of pictures of his beautiful craftsmanship. Most of the mechanical components were machined on a manual lathe and milling machine. No CNC, just lots of drawings and measurements, clever use of dividing heads, and careful dial reading. The engine also features electronic fuel injection with a MegaSquirt controller.

The rest of the car is just as impressive as the power plant. The chassis is bent tube, with machined brackets and carbon fiber suspension components. Two electric skateboard motors are added to give it a bit more power. The three speed gearbox is also custom, built with gears scavenged from a pit bike and angle grinder. It uses two small pneumatic pistons to do the shifting, with a clever servo mechanism that mechanically switches the solenoid valves. Check out all fourteen build videos on his channel for more details.

An amateur project of this complexity is never without speed bumps, which [Keith57000] details in the videos and build thread. It has taken seven years so far, but it is without a doubt the most impressive RC car we’ve seen. His skill with manual machine tools is something we rarely get to see in the age of CNC. We’re looking forward to the finished product, hopefully screaming around a track with a FPV cockpit.

True Craftsmanship: Pneumatic Powered Drone Wasn’t Made To Fly

August 10, 2020 by Danie Conradie 16 Comments

From time to time it’s good to be reminded that mechanical engineering can also be art. [José Manuel Hermo Barreiro], also known as [Patelo], is a retired naval mechanic with a love for scale model engines. Using only basic tools and a lathe, he has built a non-flying hexacopter display model, each propeller turned by a tiny single cylinder motor that runs on compressed air. From the tiny components of the valve systems, the brass framed acrylic windows into the crankcases, and the persistence of vision disc on the exhaust, the attention to detail is breathtaking.

One of the six hand crafted pneumatic motors

[Patelo] started the project on paper, and created a set of detailed hand-drawn blueprints to work from. Sadly a large part of the build took place during lockdown, and was not filmed, but we still get to see some work on a crankcase, connecting rod, camshaft, propellers, flywheel, and exhaust tubes. It is very clear that [Patelo] knows his way around his lathe very well, and is very creative with custom tools and jigs. The beautiful machine took approximately 1,560 hours to build, consists of 265 individually made parts held together with 362 screws.

We previously featured tiny V-12 engine that [Patelo] built around 2012. At that time he was 72 years of age, which means he should be around 80 now. We can only hope to come to emulate him one day, and that we get to see more of what comes out of his workshop. Hats off to you, sir.

A Wood Gas Powered Lawn Mower

August 5, 2020 by Danie Conradie 44 Comments

When mowing the lawn, you generally have a choice of pushing power, electric or gasoline. Thanks to the nutty inventor [Colin Furze], you can now add wood gas to the list, as long as you don’t mind some inconvenience. He built a wood gas generator on top of a formerly gasoline powered lawn mower, so he can now run his lawn mower on wood chips.

Wood gas generators have been used with internal combustion engines for a very long time, reaching their peak in the later parts of WW2 when fuel shortages plagued Europe. When wood is burned at high temperature but with limited oxygen, it produces a combustible gas mix that can be fed into an internal combustion engine. [Colin]’s generator went through a number of iterations, and the problem-solving that goes into a project like this is always interesting to watch. We would not recommend running tests like these indoors, but we suppose no [Colin Furze] video would be complete without a bit of danger.

On his first version he had an extraction fan that was too close to the outlet of the burn chamber, so it melted very quickly. The combustion temperature was also not high enough, which required some changes to the chamber geometry. The main problem that plagued the project was filtering out the moisture and tar. [Colin] did eventually get the lawn mower to run on wood gas, but tar was still getting into the engine, which prevented it from starting the second time. The filtering system will need some refinement, which [Colin] will address in his next video, which he also hints will involve some sort of diabolical swing set. Continue reading “A Wood Gas Powered Lawn Mower” →

This V8 Makes A Shocking Amount Of Power

March 20, 2020 by Bryan Cockfield 32 Comments

As a work of art, solenoid engines are an impressive display of electromagnetics in action. There is limited practical use for them though, so usually they are relegated to that realm and remain display pieces. This one from [Emiel] certainly looks like a work of art, too. It has eight solenoids, mimicking the look and internal workings of a traditional V8.

There’s a lot that has to go on to coordinate this many cylinders. Like an internal combustion engine, it takes precise timing in order to make sure that the “pistons” trigger in the correct order without interfering with each other through the shared driveshaft. For that, [Emiel] built two different circuit boards, one to control the firing of each solenoid and another to give positional feedback for the shaft. That’s all put inside a CNC-machined engine block, complete with custom-built connecting rods and shafts.

If you think this looks familiar, it’s because [Emiel] has become somewhat of an expert in the solenoid engine realm. He started off with a how-to for a single piston engine, then stepped it up with a V4 design after that. That leaves us wondering how many pistons the next design will have. Perhaps a solenoid version of the Volkswagen W12?

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See-Through Catalytic Converter

February 1, 2020 by Bryan Cockfield 16 Comments

There’s always something to be learned from taking things apart. Sometimes the parts can be used for other things, sometimes they can be repaired or improved upon, but sometimes it’s all in good fun. Especially in this case where extremely high temperatures and combustible gasses are involved. This is from the latest video from [Warped Perception] that lets us see inside of a catalytic converter as its operating.

Catalytic converters are installed on most vehicles (and other internal combustion engines) in order to process unburned hydrocarbons from exhaust gasses with a catalyst. These can get extremely hot, and this high temperature complicated the build somewhat. There were two prototypes constructed for this build and the first was a cross-section of a catalytic converter with a glass window sealed on in order to allow the viewing of the catalyst during the operation of a small engine. It was easy to see the dirty exhaust gasses entering and cleaner gasses leaving, but the window eventually blew off. The second was a complete glass tube which worked much better until the fitting on the back finally failed.

A catalytic converter isn’t something we’d normally get to see the inside of, and this video was worth watching just to see one in operation in real life. You could also learn a thing or two about high-temperature fittings as well if you’re so inclined. It might be a nice pairing with another build we’ve seen which gave us a window into a different type of combustion chamber than ones normally found on combustion engines.

Thanks to [Ryoku] for the tip!

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