Electric Jeep With Modified Prius Hardware

On the list of cars widely regarded as the most reliable vehicles ever built, up there with the Toyota Land Cruiser, the Honda Civic, and the Mercedes W123 diesels, is the unassuming Toyota Prius. Although it adds a bit of complexity with its hybrid drivetrain, its design eliminates a number of common wear items and also tunes it for extreme efficiency, lengthening its life and causing minimal mechanical stress. The Prius has a number of other tricks up its sleeve as well, which is why parts of its hybrid systems are often used in EV conversions like [Jeremy]’s electric CJ-5 Jeep.

Inside the Prius inverter is a buck/boost converter used for stepping up the battery voltage to power the inverter and supply power to the electric motor. [Jeremy]’s battery is much higher voltage than the stock Prius battery pack, though, which means he can bypass the converter and supply energy from his battery directly to the inverter. Since the buck/boost converter isn’t being used, he can put it to work doing other things. In this case, he’s using it as a charger. Sending the AC from a standard EV charging cord through a rectifier and then to this converter allows the Prius hardware to charge the Jeep’s battery, without adding much in the way of extra expensive electronics.

There are some other modifications to the Prius equipment in this Jeep, though, namely that [Jeremy] is using an open-source controller as the brain of this conversion. Although this video only goes into detail on some of the quirks of the Prius hardware, he has a number of other videos documenting his journey to convert this antique Jeep over to a useful electric farm vehicle which are worth checking out as well. There are plenty of other useful things that equipment from hybrid and electric vehicles can do beyond EV conversions as well, like being used for DIY powerwalls.

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Correlating Electric Cars With Better Air Quality

Although at its face the results seem obvious, a recent study by [Sandrah Eckel] et al. on the impact of electric cars in California is interesting from a quantitative perspective. What percentage of ICE-only cars do you need to replace with either full electric or hybrid cars before you start seeing an improvement in air quality?

A key part of the study was the use of the TROPOMI instrument, part of the European Sentinel-5 Precursor satellite. This can measure trace gases and aerosols in the atmosphere, both of which directly correlate with air quality. The researchers used historical TROPOMI data from 2019 to 2023 in the study, combining this data with vehicle registrations in California and accounting for confounding factors, such as a certain pandemic grinding things to a halt in 2020 and massively improving air quality.

Although establishing direct causality is hard using only this observational data, the researchers did show that the addition of 200 electric vehicles would seem to be correlated to an approximate 1.1% drop in measured atmospheric NO2. This nitrogen oxide is poisonous and fatal if inhaled in large quantities. It’s also one of the pollutants that result from combustion, when at high temperatures nitrogen from the air combines with oxygen molecules. Continue reading “Correlating Electric Cars With Better Air Quality”

The Complex Engineering Of Runways

Airport runways seem pretty simple, just another strip of asphalt or concrete not unlike the roads that our cars drive upon every day. We can even use these same highways as landing strips in a pinch, so you’d assume that the engineering for either isn’t that dissimilar. Of course, you can use a highway for an occasional emergency, but a runway that sees the largest and heaviest airplanes taxi, take off and land on a constant basis is a whole other challenge, as detailed in a recent [Practical Engineering] video and its transcript.

When you consider that an Airbus A380 the take-off weight is up to 550 ton, it’s quite clear what the challenge is for larger airports. Another major issue is that of friction, or lack thereof, as the speeds and kinetic energy behind it are so much higher. One only has to look at not only runway overruns but also when one skids off sideways due issues like hydroplaning and uneven friction. Keeping the surface of a runway as high-friction as possible and intact after hundreds of take-offs, tail-strikes and other events is no small feat.

Of course, the other part of runway engineering is for when things do go wrong and an airplane enters the runway safety areas, or overrun zones. This usually provides some flat and clear space where an airplane can safely bleed off its kinetic energy, with the collapsing surface of the EMAS technology being one of the best demonstrations of how this can be safely and dramatically shortened.

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A small white work truck sitting on a faded road with trees in the background. In its bed is what looks like an enormous drill battery in an upside down position. The "battery" is black with red and yellow stripes. It has the words "125V, 500 Ah, 52 kWh" and "Mr. G's Workshop" emblazoned on the side.

Kei Truck Looks Like A Giant Power Tool

Kei trucks are very versatile vehicles, but their stock powerplant can leave a bit to be desired. If you need more power, why not try an electric conversion?

[Ron “Mr. G” Grosinger] is a high school auto shop and welding teacher who worked with his students to replace the 40 hp gas motor in this Daihatsu Hijet with the 127 hp of a Hyper 9 electric motor. The motor sits in the original engine bay under the cab and is mated to the stock transmission with a custom adapter plate made from plate steel for less than $150. We really appreciate how they left all the electronics exposed to see what makes the conversion tick.

The faux battery was made by a foam sculptor friend out of urethane foam shaped with a carving knife and then painted. It slides on a set of unistrut trolleys and reveals the 5 salvaged Tesla battery modules that power the vehicle. The fold down sides of the truck bed allow easy access to anything not already exposed if any tweaking is necessary.

We’ve seen a kei truck become a camper as well or an ebike powered with actual power tool batteries. If you’re thinking of your own electric conversion, which battery is best?

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Bike Spokes, Made Of Rope

We know this one is a few years old, but unless you’re deep into the cycling scene, there’s a good chance this is the first time you’ve heard of [Ali Clarkson’s] foray into home made rope spokes. 

The journey to home-made rope spoke begun all the way back in 2018, shortly after the company Berd introduced their very expensive rope spokes. Berd’s spokes are made of a hollow weaved ultrahigh molecular weight polyethylene (UHMWPE) rope with very low creep. They claim wheels stronger than steel spoke equivalents at a fraction of the weight. Naturally forum users asked themselves, “well why can’t we make our own?” As it turns out, there are a handful of problems with trying this at home.

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Nixie Gear Indicator Shines Bright

When you’re driving a car with a stickshift, it’s pretty easy to keep track of which gear you’re in. That can be a little bit more difficult on something like a motorcycle with a sequential shifter. [decogabry] built a neat gearshift indicator to solve this issue.

An ESP32 devboard is used as the brain of the build. It’s paired with an ELM327 dongle over Bluetooth, which is able to hook into the bike’s ODB diagnostic port to pick up data like engine RPM, wheel speed, and coolant temperature. The first two factors are combined in order to calculate the current gear, since the ratio between engine RPM and wheel speed is determined directly by the gear selection. The ESP32 then commands a Philips ZM1020 Nixie tube to display the gear, driving it via a small nest of MPSA42 transistors. A separate self-contained power supply module is used to take the bike’s 12 volt supply up to the 170 volts needed to run the tube. There is also a small four-digit display used to show status information, RPM, and engine temperature.

Notably,  [decogabry] made this build rather flexible, to suit any bike it might be installed upon. The gear ratios are not hard coded in software. Instead, there is a simple learning routine that runs the first time the system is powered up, which compares RPM and wheel speed during a steady-state ride and saves the ratios to flash.

We’ve featured projects before that used different techniques to achieve similar ends. It’s also interesting to speculate as to whether there’s a motorcycle vintage enough to suit a Nixie display while still having an ODB interface on board as standard. Meanwhile, if you’re cooking up your own neat automotive builds, don’t hesitate to drop us a line.

Inside Air Traffic Control

It is a movie staple to see an overworked air traffic controller sweating over a radar display. Depending on the movie, they might realize they’ve picked the wrong week to stop some bad habit. But how does the system really work? [J. B. Crawford] has a meticulously detailed post about the origins of the computerized air traffic control system (building on an earlier post which is also interesting).

Like many early computer systems, the FAA started out with the Air Force SAGE defense system. It makes sense. SAGE had to identify and track radar targets. The 1959 SATIN (SAGE Air Traffic Integration) program was the result. Meanwhile, different parts of the air traffic system were installing computers piecemeal.

SAGE and its successors had many parents: MIT, MITRE, RAND, and IBM. When it was time to put together a single national air traffic system the FAA went straight to IBM, who glued together a handful of System 360 computers to form the IBM 9020. The computers had a common memory bus and formed redundant sets of computer elements to process the tremendous amount of data fed to the system. The shared memory devices were practically computers in their own right. Each main computing element had a private area of memory but could also allocate in the large shared pool.

The 9200 ran the skies for quite a while until IBM replaced it with the IBM 3083. The software was mostly the same, as were the display units. But the computer hardware, unsurprisingly, received many updates.

If you’re thinking that there’s no need to read the original post now that you’ve got the highlights from us, we’d urge you to click the link anyway. The post has a tremendous amount of detail and research. We’ve only scratched the surface.

There were earlier control systems, some with groovy light pens. These days, the control tower might be in the cloud.