Retrotechtacular: Automotive Suspension Is All About Waves

In addition to driving home the need for Steadicam or Optical Image Stabilization, this eighty-year-old video illustrates some elegant solutions the automotive industry developed in their suspension systems. Specifically, this Chevrolet video from 1938 is aimed at an audience that values science and therefore the reel boils down the problem at hand using models that will remind you of physics class.

Model of a wheel with a leaf spring records the effect of a bump on a piece of paper above

The problem is uneven ground — the “waves in the Earth’s surface” — be it the terrain in an open field, a dirt road, or even a paved parkway. Any vehicle traveling those surfaces will face the challenge of not only cushioning for rough terrain, but accounting for the way a suspension system itself reacts to avoid oscillation and other negative effects. In the video this is boiled down to a 2-dimensional waveform drawn by a model which begins with a single tire and evolves to include a four wheeled vehicle with different suspension systems in the front and the rear.

Perhaps the most illuminating part of the video is the explanation of how the car’s front suspension actually works. The wheels need to be able to steer the vehicle, while the suspension must also allow the tire to remain perpendicular to the roadway. This is shown in the image at the top of this article. Each wheel has a swing arm that allows for steering and for vertical movement of the wheel. A coil spring is used in place of the leaf springs shown in the initial model.

You probably know what’s coming next. The springs are capable of storing and releasing energy, and left to their own devices, they’ll dissipate the energy of a bump by oscillating. This is exactly what we don’t want. The solution is to add shock absorbers which limit how the springs perform. The waveforms drawn by the model encountering bumps are now tightly constrained to the baseline of flat ground.

This is the type of advertising we can wholeheartedly get behind. Product engineers of the world, please try to convince your marketing colleagues to show us the insides, tell us why the choices were made, and share the testing that helps users understand both how the thing works and why it was built that way. The last eighty years have brought myriad layers of complexity to most of the products that surround us, but human nature hasn’t changed; people are still quite curious to see the scientific principles in action all around us.

Make sure you don’t bomb out of the video before the very end. A true bit of showmanship, the desktop model of a car is recreated in a full-sized Chevy, complete with “sky-writing smoke” to draw the line. I don’t think it’s a true analog, but it’s certainly the kind of kitsch I always look for in a great Retrotechtacular subject.

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How To Get Into Cars: Handling Mods

As a budding automotive enthusiast, you finally took the plunge and scored yourself a sweet project car. After going through it from top to toe, you’ve done your basic maintenance and it’s now running like a top. Now you’re getting comfortable, you’ve set your sights on turning your humble ride into a corner carving machine. Here’s a guide to get yourself started.

It’s All About Grip

When it comes to creating a handling monster, the aim is to create a car that sticks to the road like glue, and is controllable when it does break loose. Having a car that handles predictably at the limit is a big help when you’re pushing hard on track, particularly for an inexperienced driver. And, whether you’re hitting the canyons on the weekend or trying to slash your laptimes, it’s always nice to have more grip. Through selecting the right parts and getting the set up right, it’s possible to hone your car’s cornering ability to make it a rewarding experience to drive fast and hard. Continue reading “How To Get Into Cars: Handling Mods”

A 3D-Printable Mecanum Wheeled Robot Platform

If your interest lies with robotics there are a multitude of different platforms for you to build. [Teemu Laurila] was frustrated with what was on offer, so designed his own with four-wheel double wishbone suspension and mecanum wheels for maximum flexibility.

It’s a design that has been through multiple revisions since its first iteration in 2015, and along the way it’s clear some thought has gone into it. That double wishbone suspension features an angle for a high ground clearance, and is fully sprung. Drive comes from small motor/gearboxes at each axle. The chassis meanwhile has plenty of space for a single-board computer, and has been specifically designed with the BeagleBone Black in mind.

This build isn’t fully DIY, as the mecanum wheels appear to be off-the-shelf items, but the rest of the project makes up for this. If you need to make your own, it’s hardly as though there aren’t any projects from which you can borrow components.

Russian EBike Goes Everywhere, Possibly Legal

Electric bikes may be taking the world by storm, but the world itself doesn’t have a single way of regulating ebikes’ use on public roads. Whether or not your ebike is legal to ride on the street or sidewalk where you live depends mostly on… where you live. If you’re lucky enough to live in a place where a bicycle is legally defined as having fewer than four wheels and capable of being powered by a human, though, this interesting bike from Russia might be the best homemade ebike we’ve ever seen. (Video embedded below the break.)

While some of the details of this build might be lost on those of us who do not know any Slavic languages, the video itself shows off the features of this electric vehicle build quite well. It has a custom built frame with two wheels up front, each with its own independent suspension, allowing it to traverse extremely rough terrain with ease even a mountain bike might not be able to achieve. It seems to be powered by a relatively simple rear hub in the single rear wheel, and can probably achieve speeds in the 20 km/h range while holding one passenger and possibly some cargo.

The impressive part of this build isn’t so much the electrification, but rather the suspension components. Anyone looking for an offroad vehicle may be able to take a bit of inspiration from this build. If you’re more interested in the drivetrain, there are plenty of other vehicles that use unique electric drivetrains to check out like this electric boat. And, if you happen to know Russian and see some other interesting details in this build that the native English speakers around here may have missed, leave them in the comments for us.

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Both Explanation And Build For This Artwork Are Beautiful

Sometimes you encounter projects that defy description, as is the case with this one. So perhaps it’s best to start with what this project is NOT. It is not a sphere. It is not a perpetual energy device. It has neither a sloppy build nor a slapdash video. This IS a motorized rhombicuboctahedron that is a well-explained with high-quality parts and loving attention to detail by [Wolfram Glatthar]. At its heart is an exercise in building a moving device with the barest minimum of friction. Without no grinding in the mechanism, the electronics will probably wear out first. Low friction also means low power consumption, and an hour of sunlight can run the device for two-and-a-half days. Take a look at the video below the break.

Along the sides are a balancing ring with threaded screw sockets and the load-bearing magnets which suspend the bulk of the rhombicuboctahedron using repulsion. Everything is stabilized by a ceramic sphere touching a sapphire glass plate for a single point of contact between some seriously tough materials. The clear sapphire furthers the illusion that everything is floating, but genuine magnetic suspension would require much more power.

Acoustic levitation cannot be forgotten as another powered source of floating or you can cheat and use strobe light trickery.

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3D Printed Tank Scores Suspension

Tanks are highly capable vehicles, with their tracks giving them the ability to traverse all manner of terrain at speed. An important part of a tank is its suspension setup, without which its treads are far less capable. When [Ivan]¬† began work on his 3D printed tank project, he couldn’t ignore the comments. His tank would need a suspension system.

The tank build itself is impressive, consisting almost entirely of 3D printed components held together with off-the-shelf bearings and threaded rod. [Ivan] retools the tank from the beginning to fit a pivoting suspension system which is surprisingly simple in its design, yet capable in operation. Particularly impressive are the 3D printed springs, which [Ivan] tunes the stiffness of to suit the weight of the vehicle.

It’s a build that shows just how far you can go when you master the basics of 3D printing and mechanical design. It doesn’t take a lot of advanced theory to design cool things, just a willingness to learn and experiment and the right set of tools behind you. [Ivan]’s tank treads are worth taking a look at, too.¬†Video after the break.

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Hovering Questions About Magnetic Levitation

Who doesn’t love magnets? They’re functional, mysterious, and at the heart of nearly every electric motor. They can make objects appear to defy gravity or move on their own. If you’re like us, when you first started grappling with the refrigerator magnets, you tried to make one hover motionlessly over another. We tried to position one magnet over another by pitting their repellent forces against each other but [K&J Magnetics] explains why this will never work and how levitation can be done with electromagnets. (YouTube, embedded below.)

In the video, there is a quick demonstration of their levitation rig and a brief explanation with some handy oscilloscope readings to show what’s happening on the control side. The most valuable part, is the explanation in the article where it walks us through the process, starting with the reason permanent magnets can’t be used which leads into why electromagnets can be successful.

[K&J Magnetics]’s posts about magnets are informative and well-written. They have a rich mix of high-level subjects without diluting them by glossing over the important parts. Of course, as a retailer, they want to sell their magnets but the knowledge they share can be used anywhere, possibly even the magnets you have in your home.

Simpler levitators can be built with a single electromagnet to get you on the fast-track to building your own levitation rig. Remember in the first paragraph when we said ‘nearly’ every electric motor used magnets, piezoelectric motors spin without magnets.

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