suspension

18 Articles

Tablet Suspension System Avoids Fatigue At Bedtime

May 3, 2025 by 12 Comments

You know how it is. You’re all cozy in bed but not quite ready to doze off. You’re reading Hackaday (Hackaday is your go-to bedtime reading material, right?) or you’re binge-watching your latest reality TV obsession on your tablet. You feel the tablet growing heavier and heavier as your arms fatigue from holding it inches above your face. You consider the embarrassment you’ll endure from explaining how you injured your nose as the danger of dropping the tablet gradually increases. The struggle is real.

[Will Dana] has been engineering his way out of this predicament for a few years now, and with the recent upgrade to his iPad suspension system he is maximizing his laziness, but not without putting in a fair amount of hard work first.

The first iteration of the device worked on a manual pulley system whereby an iPad was suspended from the ceiling over his bed on three cords. Pulling on a cord beside the bed would raise the bracket used for holding the iPad out of the way while not in use. This new iteration takes that pesky cord pulling out of the user’s hands, replacing it with a motorized winch. A spot of dark ink on one of the cords in combination with a light sensor helps to calibrate the system so that the ESP32 which controls it always knows the proper limits of operation.

Of course, if, like [Will], you’re using an ESP32, and your room is already fully controlled by a voice interface, you may as well integrate the two. After all, there is no sense in wasting precious energy by pressing buttons. Utter a simple command to Alexa once you’re tucked in, and it’s time for hands-free entertainment.

We’ve covered several of [Will]’s previous creations, such as his Motorized Relay Computer and Harry Potter-inspired Sorting Hat.

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3D-Printed RC Car Focuses On Performance Fundamentals

January 20, 2025 by 8 Comments

There are a huge number of manufacturers building awesome radio-controlled cars these days. However, sometimes you just have to go your own way. That’s what [snamle] did with this awesome 3D-printed RC car—and the results are impressive.

This build didn’t just aim to build something that looked vaguely car-like and whizzed around on the ground. Instead, it was intended to give [snamle] the opporunity to explore the world of vehicle dynamics—learning about weight distribution, suspension geometry, and so many other factors—and how these all feed into the handling of a vehicle. The RC side of things is all pretty straightforward—transmitter, receiver, servos, motors, and a differential were all off-the-shelf. But the chassis design, the steering, and suspension are all bespoke—designed by [snamle] to create a car with good on-road handling and grip.

It’s a small scale testbed, to be sure. Regardless, there’s no better way to learn about how a vehicle works on a real, physical level—you can’t beat building one with your own two hands and figuring out how it works.

It’s true, we see a lot of 3D printed RC cars around these parts. Many are built with an eye to robotics experimentation or simply as a learning exercise. This one stands out for its focus on handling and performance, and of course that nicely-designed suspension system. Video after the break.

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An image of the inside of a vehicle wheel. An outer ring gear is attached to two articulated sets of three small helical gears attached to a central sun gear. A shaft from the right side enters into the sun gear.

A Revolution In Vehicle Drivetrains?

December 6, 2023 by 47 Comments

Power delivery in passenger vehicle drivetrains hasn’t changed much since the introduction of the constant velocity (CV) joint in the 1930s. Most electric vehicles still deliver power via the same system used by internal combustion cars. Hyundai/Kia has now revealed a system they think will provide a new paradigm with their Universal Wheel Drive System (Uni Wheel). [via Electrek]

What appears at first to be a hub motor is in fact a geared wheel that keeps the motor close without the problem of high unsprung weight. Power is fed into a sun gear which can move independently of the wheel allowing the system to maintain a more consistent driveline and avoid power variability over the range of suspension travel like you’d find in a CV joint experiencing high deflection.

We have some concerns about the durability of such a system when compared with the KISS and long development history of CV joints, but we can’t deny that moving the motors of an electric vehicle out to the corners would allow more packaging flexibility for the cargo and passenger areas. We’re also excited to see open source replicas make their way into smaller robotics projects now that the images have been released. If you’ve already made one in CAD, send us a tip at tips@hackaday.com.

Looking for more interesting innovations in electric cars? How about an off-grid camper van? If you think automakers are overcomplicating something that should be simple, read the Minimal Motoring Manifesto.

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A Simple Air Suspension Demo With Lego Technic

January 25, 2023 by 19 Comments

The most common suspension systems on automobiles rely on simple metal springs. Leaf spring and coil spring designs both have their pros and cons, but fundamentally it’s all about flexing metal doing the work. Air suspension works altogether differently, employing gas as a spring, as demonstrated by this simple Lego build from [JBRIX]. 

The suspension system is employed on a Lego Technic car, with a relatively unsophisticated design. The car has no real form of propusion, and serves solely to demonstrate the air suspension design. They may look like dampers, but the system is actually using Lego pneumatic pistons as springs for each wheel. The pistons are connected to the upper control arm of a double wishbone suspension setup. Each piston is pneumatically connected to a main reservoir. With the reservoir, and thus the pistons, pressurized, the suspension system can support the weight of the car. If a bump perturbs a wheel, the piston compresses the air in the system, which then returns the piston to its original position, thus serving as a spring. If the reservoir is vented, the suspension collapses. Air springs on real, full-sized automobiles work in basically the same way. However, they usually have a separate reservoir per corner, keeping each wheel’s suspension independent.

Overall, if you’re working on some kind of Lego rambler, you might find this suspension concept useful. Alternatively, you might simply find it good as a learning aid. If you want to learn more about oddball suspension systems, we can help there too. Video after the break.

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Smart Bike Suspension Tunes Your Ride On The Fly

January 23, 2023 by 23 Comments

Riding a bike is a pretty simple affair, but like with many things, technology marches on and adds complications. Where once all you had to worry about was pumping the cranks and shifting the gears, now a lot of bikes have front suspensions that need to be adjusted for different riding conditions. Great for efficiency and ride comfort, but a little tough to accomplish while you’re underway.

Luckily, there’s a solution to that, in the form of this active suspension system by [Jallson S]. The active bit is a servo, which is attached to the adjustment valve on the top of the front fork of the bike. The servo moves the valve between fully locked, for smooth surfaces, and wide open, for rough terrain. There’s also a stop in between, which partially softens the suspension for moderate terrain. The 9-gram hobby servo rotates the valve with the help of a 3D printed gear train.

But that’s not all. Rather than just letting the rider control the ride stiffness from a handlebar-mounted switch, [Jallson S] added a little intelligence into the mix. Ride data from the accelerometer on an Arduino Nano 33 BLE Sense was captured on a smartphone via Arduino Science Journal. The data was processed through Edge Impulse Studio to create models for five different ride surfaces and rider styles. This allows the stiffness to be optimized for current ride conditions — check it out in action in the video below.

[Jallson S] is quick to point out that this is a prototype, and that niceties like weatherproofing still have to be addressed. But it seems like a solid start — now let’s see it teamed up with an Arduino shifter.

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High-Speed Sled Adds Bicycle Suspension

January 19, 2023 by 3 Comments

While you might have bought the best pair of skis in the 90s or 00s, as parts on boots and bindings start to fail and safety standards for ski equipment improve, even the highest-quality skis more than 15 or 20 years old will eventually become unsafe or otherwise obsolete. There are plenty of things that can be done with a pair of old skis, but if you already have a shot ski and an Adirondack chair made of old skis, you can put another pair to use building one of the fastest sleds we’ve ever seen.

[Josh Charles], the creator of this project, took inspiration from his father, who screwed an old pair of skis to the bottom of an traditional runner sled when he was a kid. This dramatically increased the speed of the sled, but eliminated its ability to steer. For this build [Josh] built a completely custom frame rather than re-use an existing sled, which allowed him to not only build a more effective steering mechanism for the skis, but also to use bicycle suspension components to give this sled better control at high speeds.

This build is part of a series that [Josh] did a few years ago, and you can find additional videos about it documenting his design process and his initial prototypes and testing. The amount of work he put into this build is evident when it’s seen finally traversing some roads that had been closed for winter; he easily gets the sled up in the 30 mph range several times. If you’re looking to go uphill in the snow, though, take a look at this powered snowboard instead.

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Active Suspension On A DIY Racing Car

May 2, 2021 by 14 Comments

In automotive engineering, almost every design choice is a trade-off, like performance versus fuel economy, straight-line speed versus cornering, or strength versus weight. Inspired by controversial technology for the 2020 Formula 1 season, [Wesley Kagan] is fitting his DIY racing car with actuators to change the suspension geometry while driving.

The controversial technology in question is Mercedes’ DAS (Dual Axis Steering). By pushing the steering wheel in and out, the driver and change the wheel alignment to toe-out (wheels pointing outwards) for better cornering stability, or neutral for the straight sections.

Like many racing cars, [Wesley] used A-arm suspension on his racing car. By replacing the top arms with telescoping tubes with mounted actuators, the geometry can be actively adjusted. For this proof of concept, he used linear actuators but plans to move to a hydraulic system for improved speed and force. The length of the A-arms is sensed with ultrasonic sensors, while a potentiometer senses the suspension position.

Tuning the software for optimum performance will probably require some track testing which we hope to see in the future. This is not the first time [Wesley] has taken inspiration from a multimillion-dollar project and implemented it in his garage. Just check out how he converted a Miata and a Harbor Freight engine to a Free Valve system.

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