Author: Danie Conradie

431 Articles

A DIY Enclosed Motorcycle To Keep You Dry In The Rain

May 5, 2021 by 41 Comments

Motorcyclist’s vulnerability to bodily harm and weather has spawned several enclosed motorcycle designs over the years. Fascinated by the idea, [Meanwhile in the garage] finally got around to building his own. (Video, embedded below.)

The vehicle started life as a 125cc scooter, stripped of all the unnecessary bits, he welded a steel cockpit onto it. A windshield, doors, and side windows were also added. The ends of the handlebars were cut off and reattached at 90 degrees to fit inside the narrow cockpit. A pair of retractable “training wheels” keep the vehicle upright and at slow speeds.

Legalities aside, we can’t help but think that the first test drives should not have been on a public road. It almost ended in disaster when a loose axle nut on the front wheel caused steering oscillations which caused the vehicle to tip over. Fortunately, there were no injuries and only light cosmetic damage, so a more successful test followed the first.

While many companies have tried, enclosed motorcycles have never achieved much commercial success. Probably because they inhabit a no-mans-land between the rush and freedom of riding a motorcycle and the safety and comfort of a car.

For some less extreme conversion, check out this electric motorcycle, or a rideable tank track.

Continue reading “A DIY Enclosed Motorcycle To Keep You Dry In The Rain” →

3D Printed Camera Crane For The Workshop

May 5, 2021 by 7 Comments

When you make a living building stuff and documenting the process camera setups take up a lot of time, breaking expensive equipment is an occupational hazard. [Ivan Miranda] knows this all too well, so he built a fully-featured camera crane to save his time and camera equipment. Video after the break.

The basic design is a vertical mast with a pivoting camera mounted to the end. The aluminum mast telescopes for increased vertical adjustability, and rides on a plywood base with caster wheels. The aluminum pivoting arm is counterweighed to offset the camera head, and a parallel bar mechanism allows the camera to hold a constant vertical angle with the ground. Thanks to the explosion of home gyms during the pandemic, gym weights were hard to find, so [Ivan] used an ammo can filled with sand and screws instead. A smaller sliding counterweight on top of the arm allows for fine-tuning. [Ivan] also wanted to be able to do horizontal sliding shots, so he added a pulley system that can be engaged with a clutch mechanism to keep a constant horizontal angle with the camera. Most of the fittings and brackets are 3D printed, some of them no doubt on his giant 3D printer.

We can certainly see this crane meeting its design objectives, and we can’t help but want one ourselves. [Alexandre Chappel] also built a camera crane a while back which utilized a completely different arm mechanism. As cool as these are, they still pale in comparison to [mingul]’s workshop-sized 8-axis CNC camera crane. Continue reading “3D Printed Camera Crane For The Workshop” →

Prioritising Mechanical Multiplexer

May 4, 2021 by 17 Comments

When automating almost any moderately complex mechanical task, the actuators and drive electronics can get expensive quickly. Rather than using an actuator for every motion, mechanical multiplexing might be an option. [James Bruton] has considered using it in some of his many robotics projects, so he built a prioritizing mechanical multiplexer to demonstrate the concept.

The basic idea is to have a single actuator and dynamically switch between different outputs. For his demonstration, [James] used a motor mounted on a moving platform actuated by a lead screw that can engage a number of different output gears. Each output turns a dial, and the goal is to match the position of the dial to the position of a potentiometer. The “prioritizing” part comes in where a number of outputs need to be adjusted, and the system must choose which to do first. This quickly turns into a task scheduling problem, since there are a number of factors that can be used to determine the priority. See the video after the break to see different algorithms in action.

Instead of moving the actuator, all the outputs can connect to a single main shaft via clutches as required. Possible use cases for mechanical multiplexers include dispensing machines and production line automation. Apparently, the Armatron robotic arm sold by Radioshack in the ’80s used a similar system, controlling all its functions with a single motor.

[James] knows or two about robotics, having built many of them over the last few years. Just take a look at OpenDog and his Start Wars robots. Continue reading “Prioritising Mechanical Multiplexer” →

Robotic Gripper From A Squishy Ball

May 4, 2021 by 11 Comments

Soft robotic grippers have some interesting use cases, but the industrial options are not cheap. [James Bruton] was fascinated by the $4000 “bean bag” gripper from Empire Robotics, so he decided to build his own.

The gripper is just a flexible rubber membrane filled with small beads. When it is pushed over a object and the air is sucked out, it holds all the beads together, molded to the shape of the object. For his version [James] used a soft rubber ball filled with BBs. To create a vacuum, he connected a large 200cc syringe to the ball via a hose, and actuated it with a high torque servo.

It worked well for small, light objects but failed on heavier, smooth objects with no edges to grip onto. This could possibly be improved if the size and weight of the beads/BBs are reduced.

For some more soft robotics, check out this soft 3D printed hand, and the flexible electrically driven actuators. Continue reading “Robotic Gripper From A Squishy Ball” →

Feel What The Temperature Is Like Outside Without Leaving Your Bed

May 4, 2021 by 17 Comments

Your smartphone might be able to tell you what the weather is like outside, but you’d have to go outside yourself to really feel it. To do this from the comfort of your own bed, [Sagarrabanana] built a clock that lets you really feel the temperature. Video below with English subtitles.

It is basically a box with a solenoid inside to knock out the time, and a Peltier plate on top. Give the box two knocks, which are detected by a piezo element,  and it will tell you the current time down to 15 minute increments in “bell tower” format. Give it three knocks, and the ESP8266 will fetch the ambient outside temperature from a cloud service and cool or heat the Peltier element to that temperature, using a H-bridge motor driver module. The code and design files are available on GitHub if you want to build your own.

All the components are housed inside an attractive 3D printed box with a machined wood top. Although we think this is a very interesting idea, we can’t help but suspect that it might be counterproductive for getting you out of bed on those cold winter mornings.

While alarm clocks are falling out of favor, they are still a popular build for hackers. We’ve covered one that looks like it came from a fallout shelter, and another with a very cool looking VFD display. Continue reading “Feel What The Temperature Is Like Outside Without Leaving Your Bed” →

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.

Continue reading “Active Suspension On A DIY Racing Car” →

Reverse Engineering Self-Powered Wireless Switches

May 2, 2021 by 30 Comments

The plethora of wireless communications technologies have cut the comms wire for many applications, but these devices still require power. For home automation, this might mean a battery or mains power, but there is also an alternative that we don’t see often: Kinetic power. [Bigclivecom] bought some kinetic switches from eBay and gave it his usual reverse engineering treatment.

True to the marketing, these switches do not require external power or a battery to send a wireless signal. Instead, it harvests energy from the magnetic latching action of the switch itself. When the switch is actuated, a small current is induced in a coil as the polarity of the magnetic field through its core changes rapidly. Through a series of diodes and resisters, the energy is stored in a capacitor, which is then used to power a small transmitter chip. The antenna coil is wrapped around the switch housing.

The receiver side is powered by mains and includes a relay output for lights. It would be really nice to have a hacker-friendly module for projects. We would be curious to see the range that these devices are capable of.

The same technology is used inside the Philips Hue Tap switch, of which Adafruit did a teardown a few years ago. If you want to learn more about RF modulation, check out the crash course article we put out a while back. Of course, the RTL SDR is an indispensable and affordable tool if you want to do some experimentation.

Continue reading “Reverse Engineering Self-Powered Wireless Switches” →