Another day, another Kickstarter. While we aren’t often keen on touting products, we are keen on seeing robotics and unusual mechanisms put to use. The Goliath CNC has long since surpassed its $90,000 goal in an effort to put routing robots in workshops everywhere.
Due to their cost and complexity, you often only find omni-wheels on robots scurrying around universities or the benches of robotics hobbyists, but the Goliath makes use of nine wheels configured as three sets in a triangular pattern. This is important as any CNC needs to make compound paths, and for wheeled robots an omni-wheel base is often the best bet for compound 2D translation.
What really caught our eye is the Goliath’s unique positioning system. While most CNC machines have the luxury of end-stops or servomotors capable of precise positional control, the Goliath has two “base sensors” that are tethered to the top of the machine and mounted to the edge of the workpiece. Each sensor connects to the host computer via USB and uses vaguely termed “Radio Frequency technology” that provides a 100Hz update for the machine’s coordinate system. This setup is sure to beat out dead-reckoning for positional awareness, but details are scant on how it precisely operates. We’d love to know more if you’ve used a similar setup for local positioning as this is still a daunting task for indoor robots.
A re-skinned DeWalt 611 router makes for the core of the robot, which is a common option for many a desktop milling machine and other bizarre, mobile CNCs like the Shaper Origin. While we’re certain that traditional computer controlled routers and proper machining centers are here to stay, we certainly wouldn’t mind if the future of digital manufacturing had a few more compact options like these.
Omnidirectional wheels are one of the hardy perennials of the world of invention. There seems to be something about the prospect of effortless parallel parking that sets the creative juices of backyard inventors flowing, and the result over the years have been a succession of impressively engineered ways to move a car sideways.
The latest one to come our way is courtesy of Canadian inventor [William Liddiard], and it is worthy of a second look because it does not come with some of the mechanical complexity associated with other omnidirectional wheel designs. [Liddiard]’s design uses a one-piece tyre in the form of a flexible torus with a set of rollers inside it which sits on a wheel fitted with a set of motorised rollers around its circumference. The entire tyre can be rotated round its toroidal axis, resulting in a tread which can move sideways with respect to the wheel.
The entire process is demonstrated in a video which is shown below the break, and the small Toyota used as a demonstration vehicle can move sideways and spin with ease. We would be wary of using these wheels on a road car until they can be demonstrated to match a traditional tyre in terms of sideways stability when they are not in their omnidirectional mode, but we can instantly see that they would be a significant help to operators of industrial machines such as forklifts in confined spaces.
Continue reading “Liddiard Omnidirectional Wheels”
[Harris] has an interesting answer to the inevitable question about what he did on his summer vacation: he built a pair of electric roller blades. [Harris] is an Electrical Engineering student at the University of Nottingham, and he completed the first version of what he calls Skelecs just before he went back to college. He has documented the process from the initial concept and building his own controller board, through his failures at correctly drilling the steel base, to his first drive down the road.
His build uses a pair of small 120W hub motors attached to a steel chassis, which is attached to a pair of cannibalized rollerblade boots.
It’s a bit of a Frankenstein build (he currently has the batteries and controller stuffed into a pants pocket, which isn’t really a practical long-term solution), but it works. A bit too well, in fact: [Harris] says that a combination of speed and a bumpy road detached one of the batteries and sent him flying. He’s not letting a minor injury and a bit of blood put him off, though: he’s already started work on version 2, which will use lighter aluminum construction and a pair of omniwheels for easier steering and more control. We’ll believe that claim when we see it.
Remember, powered skateboards are over — non hackers got their hands on them so they’re commonplace. Hipster hackers need to drop that build and start on your own pair of Skelecs.
Continue reading “Powered Skateboards are Passe; Skelecs the New Hotness”