The spark plug was a key invention in the history of the internal combustion engine, allowing combustion to be easily controlled and engines to rev faster than messy earlier designs. Mid-century cars tended to rely on points ignition with a distributor and coil, however more modern designs place a coil on top of each individual spark plug. [Roger Moore] decided to build a similar setup for a small model engine on his workbench.
The rig is built with an Arduino, a flyback transformer, a smattering of MOSFETs and passives, an IGBT and a capacitor. The Arduino outputs PWM through a MOSFET which is stepped up through the transformer, and then charges the capacitor. The capacitor is then discharged into a coil mounted on top of the sparkplug of the single-cylinder engine, which fires the spark. The timing of the spark is determined by a Hall effect sensor reading a magnet placed on the flywheel.
Later development aims to shrink the system further to fit on a V10 design [Roger] is planning to make. It’s been done on a small scale before, and we’d love to see another tiny engine with way too many cylinders. Video after the break.
Continue reading “Coil On Plug Ignition For Tiny Engines”
It’s the suburbanista’s weekend nightmare: you’re almost done with the weekly chores, taking the last few passes with the lawn mower, when you hear a pop and bang. The cylinder head on your mower just blew, and you’re out of commission. Or are you? You’ve got a 3D printer – couldn’t it save the day?
If this bench test of plastic cylinder heads is any indication, it’s possible – just as long as you’ve only got 40 seconds of mowing left to do. [Project Farm] has been running all sorts of tests on different materials as field-expedient cylinder heads for small gasoline engines, using everything from JB Weld epoxy to a slab of walnut. For this test, two chunky heads were printed, one from ABS, of the thermochromic variety apparently, the other in PLA. The test went pretty much as expected for something made of thermoplastic exposed to burning gasoline at high pressure, although ABS was the clear winner with two 40-second runs. The PLA only lasted half as long before the spark plug threads melted and the plug blew out. A gasket printed from flexible filament was also tested, with predictably awful results.
As bad as all this was, it still shows that 3D-printed parts are surprisingly tough. Each part was able to perform decently under a compression test, showing that they can stand up to pressure as long as there’s no heat. If nothing else, it was a learning experience. And as an aside, the cylinder heads were printed by [Terry] from the RedNeckCanadians YouTube channel. That video is worth a watch, if just for a few tips on making a 3D-printed copy of an object. Continue reading “Results Of 3D-Printed Cylinder Head Testing Fail To Surprise”
You say you need some graphene so you can invent the Next Big Thing, but you can’t be bothered with processes that yield a few measly milligrams of the precious stuff. Luckily for you there’s a new method for producing gram quantities of graphene. Perhaps unluckily, it requires building a controlled fuel-air bomb.
Graphene is all the rage today, promising to revolutionize everything from batteries to supercapacitors to semiconductors. A molecularly-2D surface with unique properties, graphene can be made in very small quantities with such tedious methods as pulling flakes of the stuff off graphite lumps with Scotch tape. Slightly less ad hoc methods involve lasers, microwaves, or high temperatures and nasty chemicals. But all of these methods are batch methods that produce vanishingly small amounts of the stuff.
The method [Chris Sorenson] et al of Kansas State University developed, which involves detonating acetylene and oxygen in a sturdy pressure vessel with a spark plug, can produce grams of graphene at a go. And what’s more, as their patent application makes clear, the method is amenable to a continuous production process using essentially an acetylene-fueled internal combustion engine.
While we can’t encourage our readers to build an acetylene bomb in the garage, the process is so simple that it would be easily replicated. We wonder how far down it could scale for safety and still produce graphene. Obviously, be careful if you choose to replicate this experiment. If you don’t like explosions and can source some soybean oil and nickel foil, maybe try this method instead. Then you’ll have something to mix with your Silly Putty.
Continue reading “Explosive New Process Produces Graphene By The Gram”
When you have an idea, just go build it. That’s the approach that [GordsGarage] takes with most of his projects, and he’s back in the machine shop again. This time it’s with a rather unique oil candle that uses a spark plug as inspiration. We have to say, the results are on fire.
The spark plug candle was fashioned out of a single piece of 6061 aluminum. To create the scale model, first the stock metal hit the lathe to create the “insulator” section of the plug. From there, he milled in the hex bolt section, then it hit the lathe again to create the threaded section. The inside was bored out to create space for the wick and oil, and then the electrode was installed just above the flame.
This is a pretty impressive scale model and has a great finished look. The only thing that isn’t to scale is the gap for the electrode which is completely necessary to keep the candle from getting smothered. It’s an interesting, unique idea too, which is something that [GordsGarage] excels at. And, if you want to scale his model up a little bit, perhaps you can find some inspiration from this other candle.
This is (video above) perhaps the most abstract way of playing sounds…ever. Yes, we’ve heard Hard Drive music and Obsolete technology bands, but [DJ Sures] brings us the first ever, spark plug instrument.
Much like Velcro and Teflon, the musical spark plug is claimed to be an accident. After testing energy use vs. spark power with his flare stack ignition controller, [DJ Sures] noticed that different frequencies could be produced. It was only a matter of reprogramming before death metal Twinkle Twinkle Little Star is heard. Now he just needs to refine it a bit and build a full stereo cabinet.