So, You Found A Foden Steam Lorry In A Field. What Next?

It’s quite likely that many readers will have harbored dreams of owning, or at least driving, a steam engine of some kind. [James Hervey-Bathurst] was lucky enough to do so in a time when it was still possible to find scrap steam-powered machinery for restoration, and at the recent Electromagnetic Field event in the UK he took the time to describe his journey from finding an abandoned steam lorry in a Buckinghamshire field in 1975, to a few years later, taking it to the road.

The talk starts with the story of its retrieval, then the long process of rebuilding, and finally its first run. He’s the owner of Eastnor Castle, the ancestral pile that serves as venue for EMF Camp, so we’re guessing that having somewhere spacious for such a project must have helped. Along the way, we get a comprehensive run through the workings of a 1920s steam vehicle, from its double-expansion compound engine to its three-speed gearbox, stopping for small details like its injectors, and a curious exhaust steam heater designed to reduce the clouds of visible steam.

Most of us will never get the chance to take the wheel of a Foden such as this one, but at least we’ve had a chance for a closer look thanks to EMF. The full video is below the break, meanwhile if you’d like more on steam injectors we have you covered.

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Brown wrapped chrome handlebars leaning against a light grey wall. Near the stem, a series of four small pins protrude from the bars to indicate a full battery charge of 100%.

Sleeper E-bike Has Solenoid Display

[GRMNT] decided to bring his grandpa’s beautiful road bike into the future by making a sleeper e-bike conversion.

Going into the project, [GRMNT] didn’t really know what he was working with, but it turned out grandpa had good taste and was rocking a Bianchi. No stovepipe bike boom stuff here, only high quality Tange steel. After cleaning off the years of grime, it was time to rebuild a second-hand Bafang mid-drive electric motor for the electric boost for the ride.

We really like the custom solenoid-powered display that [GRMNT] built into the handlebars for an excellent electromechanical readout of the battery charge. Coupled with the hand-built battery pack inside a leather case and hidden motor actuation button, this build looks slick without screaming e-bike.

We’ve covered some other conversions in the past including this one using an electric skateboard motor or this plug-and-play kit. If you’d rather power things with your bike, you’ll like this hack that can make everything bike powered.

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Historical Hack: Henri Giffard’s Steam Injectors

Here’s a historical hack for you: you have a big, rolling pressurized kettle, also known as a steam locomotive. It needs water to make up for the steam constantly chuff-chuff-chuffing away, or bad things happen. How do you get water from an unpressurized tender into a high pressure boiler with no moving parts? What you need is a some way to inject steam with no moving parts — a steam injector, if you will. [Marc Flint] found that the steam injectors were the hardest part of a loco to understand, so he made a video for all of us once he’d figured it out.

The steam injector isn’t a new idea. [Henri Giffard] came up with it back in the 1850s to replace expensive and maintenance-hungry pumps. It’s rather ingenious and uses the fluid mechanics uncovered by another European bloke by the name of Bernoulli. First, the high-pressure steam from the boiler goes through a converging-diverging nozzle to drop its pressure and speed its flow up, just as you’d guess if you’ve seen Bernoulli’s laws. Even more vacuum-inducing is the presence of water: the steam, already cooled by its expansion, hits the water in the pipe open to the tender, and condenses into it, shrinking a couple of orders of magnitude, creating a vacuum that draws in no small quantity of feed water. That one we did not expect from Bernoulli, but it makes sense. So how to get from below atmospheric pressure to the 180-odd PSI or more in the boiler?

Well, the water is now moving at a good clip, between the Venturi effect and the momentum gained from absorbing that steam, so another converging nozzle is the trick. Bernoulli’s law, once more! A one-way valve lets the now-pressurized water into the boiler, with a gap in between to dump water while the pressure builds up. It’s a clever trick, and since the steam coming from the boiler makes it back inside along with at least some of its heat energy, it’s much more efficient in both coal and water than running a pump. It’s also a bit of a head scratcher how it works unless someone sits you down to explain it, so we’re glad [Marc] did.

Not many of us are likely to use this knowledge directly — unless we’re firing up a 90 year old boiler or building a new steam locomotive — but seeing how great engineers of years past made use of basic physical laws can serve both as education and inspiration.

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Edison Motors Offering All-Mechanical Trucks, At Least To Start

We’ve been following Canadian startup Edison Motors for some time now, but their latest offering caught us a bit off guard — their BDE series truck will be offered first without the electric hybrid drive that first piqued our interest. They make a good case for why in the video below, in which the production prototype tows around a junked Nikola semi as a sort of memento mori of what Edison does not want to end up as.

Now, make no mistake: Edison Motors is going to be selling the series-hybrid version of these big rigs eventually. That truck will have a Scania diesel rated at 500 kW driving electric motors rated at a combined 1800 kW peak power — that’s 2400 ponies. Along with the diesel generator those ponies will be driven by a big o’l battery, but none of that is in the truck in the video. It’s the same cab, and the same frame, but in order to get some revenue in while jumping regulatory hurdles and working the kinks out of the hybrid drive, they put a conventional Cummins diesel and 16-speed transmission in the “Big D” as the truck is known.

The business case makes sense: they don’t want to have their single new product hit a snag, possibly require a recall, and fall into bankruptcy the way the electric truck company Nikola did. The conventional drivetrain also lets them prove their engineering prowess to companies that might like the idea of a Made-in-Canada truck, but be nervous about new technology from a new company.

If you want to know more about the whole diesel-electric scheme, we covered that last year. Edison also has plans to offer its hybrid drive technology for smaller trucks in kit form, which is perhaps the most exciting part from a hacker perceptive.

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Building A Bicycle Dropper Seat Post

A recent addition to mountain bikes is the dropper seat post. This invention is in the vein of office swivel chairs, allowing the seat height to be adjusted with a simple handlebar mounted lever. They are rather fascinating inventions ranging in complexity from simple mechanical systems, to electronic monstrosities actuated by Bluetooth. Inspired by the panoply of possibilities, [kane components] set forth to create such a home-built dropper post. 

Inspired by woodworking bar clamps, [kane’s] design utilizing angled plates binding against a rail inside the dropper post. Two pairs of plates sitting at opposite angles resist opposite forces from either the rider sitting on the post, or the return spring. A simple cable actuated cam moves the plates to a nonbinding position when the lever is actuated, and springs return the plates to a binding rest-state. The return is handled by an air spring pressurized against a piston at the bottom of the shaft.

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3D Printing A Usable Airless Tire

For decades now, companies like Michelin have been teasing us with futuristic-looking automobile tires that don’t use air. Instead, they use a polymer mesh of sorts which maintains the same pressure on the travel surface that a pneumatic tire does, with much less maintenance than their pneumatic counterparts. At least, in theory. There’s a reason that these tires live in the same mythical realm that Half Life 3 and the modern affordable Volkswagen do, and [Berm Peak] decided to discover those reasons for himself.

Of course, [Berm Peak] isn’t building these for his daily driver, an electric pickup truck featured in previous videos of his. He’s putting these on his mountain bike instead, a challenging environment for a tire like this in its own right. When mountain biking at the level he does, punctures and flats can become a real nuisance on the trail, so he set about experimenting with these designs with the 3D printer to see if he could make something rivaling pneumatic technology. After a few design iterations he settled on a TPU-based version with a compliant S-shaped spacing between the tread and wheel. The tire printed in sections that are installed by joining them together on the bike rim with a separate 3D printed rim interface.

At the end of this process [Berm Peak] ends up with a surprisingly capable tire that mostly holds up to his extreme off-road testing, an impressive feat for something 3D printed in his shop. Presumably a company specializing in bicycle tires could build something even more capable, but it turns out that a different technology has already solved all of the problems that airless tires solve. Mountain bikers today almost exclusively ride on tires with sealant, so punctures and flats are essentially a solved problem. But the neon-green airless tires were still a fun project for [Berm Peak] and quite the head-turner out on the bike trails.

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Tearing Down Aircraft Weather Radar Avionics

If you’re flying high in the sky, it’s useful to know if there’s turbulence, heavy rain, or other nasty weather ahead. Onboard weather radar is a useful tool that pilots use to scope out conditions ahead. [Thomas Scherrer] came into possession of a weather radar display from a vintage aircraft, and decided to tear it apart for our viewing pleasure. 

The unit in question is a Bendix PPI-1 plan position indicator. This particular 1971 example was scored from a McDonnell-Douglas DC9. [Thomas] only has the display itself, not the radar that would feed it or the power supply to turn it on. Still, even just the readout unit is super interesting to look inside. Right off the bat, there’s a neat dimming filter on the front, and the case itself is really beautifully designed for service. The design is very much of its time, full of neat wire harnesses and chunky through-hole components.  There are some neat surprises inside, too, like an interesting device shaped like a triangular prism whose purpose we won’t spoil here.

If you’re wondering what one of these units looks like in action, you can see such an example on YouTube. The display basically lights up in areas where there were stronger radar returns indicating weather to be avoided.

We love radars around these parts, and we feature them all the time. Video after the break.

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