On the technology spectrum, railroads would certainly seem to skew toward the brutally simplistic side of things. A couple of strips of steel, some wooden ties and gravel ballast to keep everything in place, some rolling stock with flanged wheels on fixed axles, and you’ve got the basics that have been moving freight and passengers since at least the 18th century.
But that basic simplicity belies the true complexity of a railway, where even just keep keeping the trains on the track can be a daunting task. The forces that a fully loaded train can exert on not only the tracks but on itself are hard to get your head around, and the potential for disaster is often only a failed component away. This became painfully evident with the recent Norfolk Southern derailment in East Palestine, Ohio, which resulted in a hazardous materials incident the likes of which no community is ready to deal with.
Given the forces involved, keeping trains on the straight and narrow is no mean feat, and railway designers have come up with a web of sensors and systems to help them with the task of keeping an eye on what’s going on with the rolling stock of a train. Let’s take a look at some of the interesting engineering behind these wayside defect detectors.
There are some utility bicycles on the market, some with electric motors to help carry a good bit of cargo. If you really need to haul more weight than a typical grocery-getter like this, you’ll want to look into a tricycle for higher capacity loads. Nothing you’ll find will match this monstrous electric tricycle hand-built by [AtomicZombie] out of junkyard parts, though. It’s a mule.
Since [AtomicZombie] sourced most of the underpinnings of this build from the junkyard, it’s based on an old motorcycle frame combined with the differential from a pickup truck, with a self-welded frame. He’s using an electric motor and a fleet of lead acid batteries for the build (since weight is no concern) and is using a gear reduction large enough to allow him to haul logs and dirt with ease (and dump them with the built in dump-truck bed), and even pull tree stumps from the ground, all without taxing the motor.
[AtomicZombie] documented every step of the build along the way, and it’s worth checking out. He uses it as a farm tractor on his homestead, and it is even equipped with a tow hitch to move various pieces of equipment around. Unlike a similar three-wheeled electric contraption from a while back, though, this one almost certainly isn’t street legal, but it’s still a blast!
We’re no stranger to Power Wheels modifications, from relatively simple restorations to complete rebuilds which retain little more than the original plastic body. These plastic vehicles have the benefit of nostalgia to keep the adults interested, and naturally kids will never get tired of their own little car or truck to tear around the neighborhood in. Many toys come and go, but we don’t expect Power Wheel projects to disappear from our tip line anytime soon.
For one thing, the new wheels were much thicker than the old ones. This meant cutting away some of the plastic where they mounted so he could get the shafts to slide all the way through. At 5/16″, the original Power Wheels shafts were also thinner than what the axle the wheels were designed for. Luckily, [myromes] found that a small piece of 1/2″ PEX water pipe made a perfect bushing. Then it was just a matter of buying new push nuts to lock them in place.
That got the front wheels on, but that was the easy part. The rears had to interface with the Jeep’s motors somehow. To that end, he cut out circles of plywood and used an equal amount of Gorilla Glue and intense pressure to bond them to the new wheels. He then drilled four holes in them which lined up with the original motor mounts so he could bolt them on.
Things were going pretty well until he tried to replace the Jeep’s rear axle with a length of threaded rod from the hardware store. It wasn’t nearly strong enough, and sagged considerably after just a few test rides. He eventually had to place it with a correctly sized piece of cold rolled steel rod to keep the car from bottoming out.
While the new wheels certainly perform better than the original hard-plastic ones, there’s a bit of a downside to this particular modification. The slippy plastic wheels were something of a physical safety to keep the motors and gearboxes from getting beat up to bad; with wheels that have actual grip, the Jeep’s stock gears are probably not long for this world. But [myromes] says he’s got plans for future upgrades to the powertrain, so hopefully the issue will be resolved before the little ones need a tow back home.
Being able to coast on a bicycle is a feature that is often taken for granted. The use of a freewheel was an improvement made early in the bicycle’s history, for obvious reasons. This also unlocked the ability to build bikes with multiple gears, allowing higher speeds to be easily reached. On a unicycle, however, there’s no chain and the pedals are permanently fixed to the wheel’s axle, meaning that there is (usually) no freewheel and no gearing. [johnybondo] wanted to get some more speed out of his unicycle, though, and realized he could do this with his own homemade internal geared hub for his unicycle.
The internal hub gear was machined and welded by hand as a one-off prototype. There are commercial offerings, but at $1700 it’s almost best to fund your own machine shop. It uses a planet gearset which is more compact than a standard gear, allowing it to fit in the axle. Once all the machining was done, it was time to assemble all of the gears into the hub, lace it to the wheel with spokes, and start pedaling away. Since it was so successful, he plans to build another and lace it to a larger wheel which will allow him to reach even higher speeds. If this isn’t fast enough for you, personally, there are other options available for ludicrous speed.
Now, this gear is still “fixed” in the sense that it’s a permanent gear ratio for his unicycle and it doesn’t allow him to shift gears or coast. There’s no freewheel mechanism so the unicycle can still be pedaled forward and backwards like a traditional unicycle. The advantage of this setup is that the wheel spins 1.5 times for every one revolution of the pedals, allowing him to more easily reach higher speeds.
When you think about it, the axle of a rear-wheel drive vehicle is really just a couple of 90° gearboxes linked together internally, and a pretty sturdy assembly that’s readily available for free or on the cheap. [Donn DIY]’s need for a gearbox to run a mower lead him to a boneyard for the raw material. The video below shows some truly impressive work with that indispensable tool of hardware hackers, the angle grinder. Not only does he amputate one of the half axles with it, he actually creates almost perfect splines on the remaining shortened shaft. Such work is usually done on a milling machine with a dividing head and an end mill, but [DonnDIY]’s junkyard approach worked great. Just goes to show how much you can accomplish with what you’ve got when you have no choice.
We’re surprised to not see any of [DonnDIY]’s projects featured here before, as he seems to have quite a body of hacks built up. We hope to feature some more of his stuff soon, but in the meantime, you can always check out some of the perils and pitfalls of automotive differentials.
Humans seem to have a strange love affair with testing their limits, especially when it comes to spinning. Perhaps they ride the Gravitron while dreaming they’re in NASA’s 20 g test centrifuge. When carnival rides aren’t enough though, a few intrepid hackers bust out the welders and take matters into their own hands. This is a hack that goes by many names, though “The Redneck Spin Chair” will bring up plenty of hits on YouTube.
The design is dead simple. Take a rear differential and axle assembly out of an old car or truck. Rotate it 90 degrees, so the diff is now pointing up. Weld a chair on. Finally, weld on a couple of tow bars. Pulling the whole mess will cause the wheels to spin, which transmits power through the differential and rotates the chair. The ride doesn’t have be pulled very fast, as automotive differentials generally have reduction between 3:1 and 5:1. We’re running things in reverse, so that reduction becomes a multiplier. The result, which can be seen in the video below is a very dizzy rider.
The earliest incarnation of this ride we could find was created at Eagle Mountain in Burtrum, Minnesota. We’re betting this particular hack has been around for decades longer though. The closest in our recent memory is North Street Labs’ Centrifury. Do you know of an earlier incarnation? Let us know in the comments!