Building A Stump Grinder From The Ground Up

July 27, 2021 by Bryan Cockfield 8 Comments

Felling a tree properly is a skill that takes some practice to master, especially without causing any injuries or property damage. Getting the tree cut down though is sometimes only half of the battle, as the stump and roots need to be addressed as well. Unless you have a few years to wait for them to naturally decompose you might want to employ a stump grinder, and unless you want to spend a chunk of money on a stump grinding service or buy your own, you might want to do what [Workshop from Scratch] did and build your own.

This stump grinder isn’t anything to scoff at, either, and might even fool some into thinking it’s a consumer grade tool from a big box store. Far from it though, as almost everything down to the frame is custom machined specifically for this build. The only thing that isn’t built from scratch, including the cutting wheel, is the beefy 15 horsepower motor. Once it gets going it is able to carve stumps down to the ground in no time thanks especially to some gear reductions in the drive line from the motor to the cutting head.

Before anyone mentions safety, it looks like [Workshop from Scratch] has made some upgrades since his last project which was a gas-powered metal cutting chainsaw. Since then it looks like he has upgraded the sheet metal to something a little thicker, even though a stump grinder has arguably lower risk due to the slower speed of the cutting wheel and also to the fact that the cutting medium is wood and not metal. There are also brakes and an emergency shutoff switch. It sure seems like a fine addition to his collection of completely custom tools.

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Building A Big Ol’ Powerful Wheelbarrow

July 10, 2021 by Lewin Day 16 Comments

Sometimes you’ve gotta haul big heavy loads around a wide area. Regular wheelbarrows are fine, but it can quickly grow tiring when one has to make multiple trips. [Workshop from Scratch] instead elected to build a powered wheelbarrow, with plenty of grunt to shift loads about.

The build is absolutely from the ground up, welded up from sections of steel RHS, and given rear steering for plenty of maneuverability. The actual job of steering is handled by a rack repurposed from automotive use, set up with a single-sided attachment to the rear wheel assembly. It’s quite a neat and tidy way of doing the job, and seems to work well. Drive is sent to the front wheels through a hydrostatic lawnmower transmission. A 17-horsepower engine provides plenty of grunt for the job at hand, even coming with electric start already fitted for the ultimate in ease-of-use.

It’s impressive to see just how much of the rig was put together from raw materials; even the fuel tank was fabricated in steel. We’ve seen similar builds from [Workshop from Scratch] before, like this tidy bandsaw. Video after the break.

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Can The Solenoid Engine Power A Car?

June 26, 2021 by Bryan Cockfield 12 Comments

[Emiel] aka [The Practical Engineer] makes all kinds of fun projects in his fully-featured shop, and one of his tangents has been building a series of solenoid engines. These engines mimic the function of an internal combustion engine, with each solenoid acting as a piston. The only problem with [Emiel]’s concept engines, though, was that he never actually put them into a vehicle to prove their effectiveness. This build finally proves that they can work at powering a vehicle.

The project starts with a new engine. [Emiel] chose a V4 design using four solenoids and an Arduino-based controller. After some trouble getting it to operate properly, he scavenged a small circuit board he built in his V8 solenoid engine to help with timing. With that installed, the solenoids click away and spin the crankshaft at a single constant speed. The vehicle itself was mostly 3D printed, with two aluminum tubes as support structures to mount the engine. Even the wheels were 3D printed with a special rubber coating applied to them. With a small drive train assembled, it’s off to the races for this tiny prototype.

While the small car doesn’t have steering and only goes at a constant speed, the proof of concept that these tiny electric engines actually work is a welcomed addition to [Emiel]’s collection of videos on these curious engines. Of course they’re not as efficient as driving the wheels directly with an electric motor, but we all know there’s no fun in that. If you haven’t seen his most intricate build, the V8 is certainly worth checking out, and also shows off the timing circuitry he repurposed for this car.

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Toyota’s Hydrogen-Burning Racecar Soon To Hit The Track

May 13, 2021 by Lewin Day 90 Comments

With the rise of usable electric cars in the marketplace, and markets around the world slowly phasing out the sale of fossil fuel cars, you could be forgiven for thinking that the age of the internal combustion engine is coming to an end. History is rarely so cut and dry, however, and new technologies aim to keep the combustion engine alive for some time yet.

Toyota’s upcoming Corolla Sport-based hydrogen-burning racer. Credit: Toyota media

One of the most interesting technologies in this area are hydrogen-burning combustion engines. In contrast to fuel cell technologies, which combine hydrogen with oxygen through special membranes in order to create electricity, these engines do it the old fashioned way – in flames. Toyota has recently been exploring the technology, and has announced a racecar sporting a three-cylinder hydrogen-burning engine will compete in this year’s Fuji Super TEC 24 Hour race.

Hydrogen Engines?

The benefit of a hydrogen-burning engine is that unlike burning fossil fuels, the emissions from burning hydrogen are remarkably clean. Burning hydrogen in pure oxygen produces only water as a byproduct. When burned in atmospheric air, the result is much the same, albeit with small amounts of nitrogen oxides produced. Thus, there’s great incentive to explore the substitution of existing transportation fuels with hydrogen. It’s a potential way to reduce pollution output while avoiding the hassles of long recharge times with battery electric technologies. Continue reading “Toyota’s Hydrogen-Burning Racecar Soon To Hit The Track” →

Generator Runs On Natural Gas With Field Expedient Tip

March 3, 2021 by Tom Nardi 111 Comments

Many small gasoline engines can be safely modified to run on natural gas or propane with a kit that replaces the carburetor and adds a regulator, providing a reliable alternative fuel source in the event that gasoline is difficult to obtain in an emergency situation. This seat of the pants hack by [HowToLou] is definitively not the safe way to run your generator on natural gas, but if you ever find yourself in a situation where getting the power back on might be a literal matter of life or death, it’s a tip worth keeping in mind.

The basic idea here is that you feed natural gas (though propane should also work) directly into the engine’s intake by way of a hose attached to the air filter box. While cranking the engine, a valve on the gas line is used to manually adjust the air–fuel mixture until it fires up. It’s an extremely simple hack that, in a pinch, you can pull off with the parts on hand. But as you might expect, that simplicity comes at a cost.

There are a few big problems with this approach, but certainly the major one is that there’s nothing to cut off the flow of gas when the engine stops running. So if the generator stalls or you just forget to close the valve after you shut it down, there’s the potential for a very dangerous situation. Additionally, the manual gas valve will be at odds with a generator that automatically throttles up and down based on load. Though to be fair, there are certainly generators out there that simply run the engine flat-out the whole time.

Much like his DIY generator interlock plate that we covered last month, we imagine this project may rub some folks in the wrong way. Admittedly, this isn’t a modification that you should take lightly and certainly not something you’d want to rely on for long-term use. But as the recent situation in Texas has reminded us, drastic times can occasionally call for drastic measures.

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Deleting The Camshafts From A Miata Engine

February 24, 2021 by Danie Conradie 57 Comments

The idea of camless automotive engines has been around for a while but so far has been limited to prototypes and hypercars. [Wesley Kagan] has been working on a DIY version for a while, and successfully converted a Mazda Miata to a camless valve system. See the videos after the break.

There have been many R&D projects by car manufacturers to eliminate camshafts in order to achieve independent valve timing, but the technology has only seen commercial use on Koenigsegg hypercars. [Wesley] started this adventure on a cheap single cylinder Harbor Freight engine, and proved the basic concept, so he decided to move up to an actual car. He first sourced a junkyard engine head to convert, and use as a drop-in replacement for the head on the complete project car. An off-the-shelf double-acting pneumatic cylinder is mounted over each valve and connected to the valve stem with a custom adaptor. The double-acting cylinder allows the valve to be both opened and closed with air pressure, but [Wesley] still added the light-weight return spring to keep the valve closed if there is any problem with the pneumatic system.

The controller is an Arduino, and it receives a timing signal from a factory crankshaft and operates the pneumatic solenoid valves via MOSFETs. After mounting the new head and control box into the Miata, it took a couple of days of tuning to get the engine running smoothly. Initial tests were done using the compressor in his garage, but this was replaced with a small compressor and air tank mounted in the Miata’s boot for the driving tests.

Although the pneumatic system works well for short test drives, the compressor is quite noisy and adds a couple of points of failure. [Wesley] is also working on a solenoid actuated system, which would require a lot more current from the battery and alternator, but he believes it’s a better long-term solution compared to compressed air. However, he is still struggling to find solenoids with the required specifications. Continue reading “Deleting The Camshafts From A Miata Engine” →

Steam Engine Replica From LEGO

January 25, 2021 by Bryan Cockfield 25 Comments

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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