Laser-Cut Mecanum Wheel for the Budget Roboticist

For the budding roboticist, omniwheels might be the next step in design patterns from your everyday “getting-started” robot kits. These wheels consist of tiny rollers that sit on the perimeter of the wheel and enable the wheel to freely slide laterally. With independent motor control of each wheel, a platform can freely locomote sideways by sliding on the rollers. You might think: “a wheel made of wheels? That sounds pricey…”–and you’d be right! Fear not, though; the folks at [Incubhacker] in Belgium have you covered with a laser-cut design that’s one-click away from landing on your workbench.

For anyone who’s tried to reliably mate flat laser-cut parts at an angle, we can tell you it’s no easy feat. The design here triumphs as both simple and reliable. Not only do they solve this problem elegantly, they also manage to create a design that will bear the load of a robot chassis that will travel with it. Laser-cut designs also usually suffer from a poor range of material options. Here the actual rollers need a bit more grip than what the plywood can provide. They also solve this problem effectively as well too, relying on heat-shrink tubing to provide the traction expected from a conventional wheel.

In the video below, [Incubhacker] takes you through the step-by process of making your own come to life. We’ve certainly seen some impressive laser-cut omniwheels in the past, but we like the simplicity of design combined with the composition of parts that probably already live on our workbenches.

Continue reading “Laser-Cut Mecanum Wheel for the Budget Roboticist”

Hackaday’s Omaha Mini Maker Faire Roundup

The 2nd annual Omaha Mini Maker Faire wasn’t our first rodeo, but it was nonetheless a bit surprising . Before we even made it inside to pay our admission to the Omaha Children’s Museum, I took the opportunity to pet a Transylvanian Naked Neck chicken at one of the outdoor booths. The amiable fowl lives at City Sprouts, an Omaha community farming collective in its 20th year of operation. There seemed to be a theme of bootstrappy sustainability among the makers this year, and that’s great to see.

Just a few feet away sat a mustard-colored 1975 Chevy pickup with a food garden growing in its bed. This is Omaha’s truck farm, an initiative that seeks to educate the city’s kids in the ways of eating locally and growing food at home.  On a carnivorous note, [Chad] from Cure Cooking showed my companion and me the correct way to dry-cure meats using time-honored methods.

Continue reading “Hackaday’s Omaha Mini Maker Faire Roundup”

THP Entry: A Holonomic Drive 3D Printer

holo

[Sugapes] always wanted to cut a few corners and build a really, really cheap 3D printer, but the idea of using linear actuators – pricing them, sourcing them, and the inevitable problems associated with them – scared him away. One day, he realized that moving in a plane in the X and Y dimensions wasn’t hard at all; cars and robots do this every day. Instead of moving a 3D printer bed around with rods and pulleys, [Sugapes] is moving his 3D printer around with wheelsIt’s different, it’s interesting, and it’s the perfect project to show of his creativity for The Hackaday Prize.

The drive system [Sugapes] is using is called a holonomic drive system. In his build, three omnidirectional wheels are attached to continuous rotation servos, each of them mounted 120 degrees apart. The print bed is simply placed on these wheels, and with the right control algorithms, [Sugapes] can move the bed in the X and Y axes. With an extruder on a Z axis above the bed, this setup becomes a 3D printer with a theoretically unlimited XY build axis. Pretty clever, huh?

There are a few problems [Sugapes] will have to overcome to turn this project into a proper printer. The omnidirectional wheels aren’t the best at transferring movement to the bed, so a quartet of USB optical computer mice are being used for a closed loop system. [Sugapes] put up a video of his project, you can check that out below.


SpaceWrencherThe project featured in this post is an entry in The Hackaday Prize. Build something awesome and win a trip to space or hundreds of other prizes.

Continue reading “THP Entry: A Holonomic Drive 3D Printer”

The Auto Parking Mecanum Robot

mecanum

A while back, Hackaday visited the Clark Magnet School in Glendale, California to sneak a peek on their STEM-focused curriculum, FIRST robotics club, awesome A/V classroom, and a shop that puts most hackerspaces to shame. We saw a few builds while we were there, but [Jack]’s auto parking mecanum robot was in a class by itself. It deserves its own Hackaday post, and now that [Jack] is on Hackaday Projects, he’s sharing all the details.

The most impressive aspect of [Jack]’s build is the mecanum wheels; the side plates for the wheels were designed by [Jack] himself and machined on his school’s Haas mill. When the plates came out of the mill they were flat, and each of the fifteen little tabs on the plates needed to be bent at a 45 degree angle. With a CNC jig and a lot of time on his hands, [Jack] bent the tabs for all eight plates.

In addition to the plates, the rollers were custom made from non-expandable polyurethane poured into a CNC milled mold. That’s a one-part mold; [Jack] needed to make sixty of these little parts, one at a time.

The electronics are built around an Arduino Mega communicating with a joystick via an XBee. [Jack] found the relays in the off-the-shelf motor board couldn’t handle the current, so he replaced them with much, much larger ones in a hack job we’d be proud to call our own handiwork. There’s also a little bit of code that allows this motorized cart to pull off the best parallel parking job anyone could ever wish for. You can see that and a few videos of the construction below.

Continue reading “The Auto Parking Mecanum Robot”