RC Trike Handles Great With Rear Steering

July 2, 2019 by Lewin Day 5 Comments

Small robotics builds with three wheels are plentiful. The most typical configuration is to have the two front wheels drive and turn the vehicle in a skid-steer configuration. The third wheel is often a simple caster. However, this isn’t the only way to go, and [markus.purtz] has put together a build that does things differently.

The build is a small, radio-controlled FPV trike. Instead of the usual skid-steer setup, the rear wheel is mounted on a pair of horizontal bearings which allows it to pivot left and right. A servo is used to control the rear wheel position, with a pair of tie rod ends used to connect the horn to the rear steering assembly. It’s not the only unconventional design choice, either – magnets are used to affix the top plate to the vehicle chassis, rather than screws or clips. For video, the user can mount either a small dedicated FPV camera, or a GoPro with the included mount.

Without any code or control details posted, we can’t be 100% sure how it all works. However, from the video, it appears that both front wheels are being driven at the same speed, with steering handled solely by the rear wheel. This is apparent when driving on a smooth surface, where the vehicle can be seen to slide when turning. While it’s unlikely this setup has many advantages over a simpler differential steering build with a caster, it does show that rear steering can be effective on its own.

It’s a build that shows off the benefits of using proper bearings and mechanical parts in a design. With today’s online marketplaces, it’s never been easier to find what you need. Parts are on Thingiverse for those interested in replicating the design. Meanwhile little FPV bots remain popular, and we’re sure we’ll continue to see them coming in. Video after the break.

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FarmBot Unveils New CNC Gardening Robot Models

July 1, 2019 by Jenny List 16 Comments

Across the Northern Hemisphere it is now summer and the growing season is in full swing. Vigorous plants that will soon bear tasty fruit are springing forth from the soil, but unfortunately so are a lush carpet of weeds that require the constant attention of the gardener. “If only there were a machine that could take that on!” she cries, and as it happens she’s in luck.

The FarmBot is an open-source robotic vegetable grower able to take care of all aspects of sowing and tending a vegetable plot. We first saw them five years as a semifinalist in the first Hackaday Prize. This is a CNC machine for the raised beds of your backyard garden. Give it power, water, and a WiFi connection, and FarmBot goes into service planting, watering, weeding, and monitoring the soil. Now they’ve shipped over a thousand of their Genesis model and today have announced of a pair of new models that promise to make their technology more accessible than it ever has been.

FarmBot moisture sensor and watering head — FarmBot has a tool changer. Soil moisture sensor and watering heads are shown here.

In a nod to Tesla, FarmBot is calling this their “Model 3 moment” — the new offering is smaller and leaner to appeal to a wider customer base than their well-heeled, CNC machine loving, early adopters. The new FarmBot Express and Express XL models are now shipped 95% pre-assembled to lower the bar on getting up and running. They cover two sizes of planting bed: 1.2m x 3m or 2.4m x 6m, with an MSRP of $2295/2795 although there is currently an $800 launch discount available.

For us, FarmBot is the success story of an early Hackaday Prize entrant. From a great idea and a functional prototype, the project has successfully made the transition to commercial viability and holds a genuine promise of making the world a better place by helping people grow some of their own produce. Who knows, in five years time it could be your idea that’s reaching commercial viability, we think you should enter the Hackaday Prize too!

Fish Hooks Embedded In Robot Toes Make Them Climb Like Cockroaches

June 28, 2019 by Pat Whetman 5 Comments

Take a dozen or so fish hooks, progressively embed them in plastic with a 3D printer and attach them to the feet of your hexapod and you’ve got a giant cockroach!

A team of researchers at Carnagie Mellon University came up with this ingenious hack which can easily be copied by anybody with a hexpod and a 3D printer. Here you can see the hooks embedded into the ends of a leg. This ‘Microspine technology’ enables their T-RHex robot to climb up walls at a slightly under-whelming 55 degrees, but also grants the ability to cling on severe overhangs.

Our interpretation of these results is that the robot needs to release and place each foot in a much more controlled manner to stop it from falling backwards. But researchers do have plans to help improve on that behavior in the near future.

Sensing and Closed Loop Control: As of now, T-RHex moves with an entirely open-loop, scripted gait. We believe that performance can be improved by adding torque sensing to the leg and tail actuators, which would allow the robot to adapt to large-scale surface irregularities in the wall, detect leg slip before catastrophic detachment,and automatically use the tail to balance during wall climbs.This design path would require a platform overhaul, but offers a promising controls-based solution to the shortcomings of our gait design.

No doubt we will all now want to build cockroaches that will out perform the T-RHex. Embedding fish hooks into plastic is done one at a time. During fabrication, the printer is stopped and a hook is carefully laid down by human hand. The printer is turned on once again and another layer of plastic laid down to fully encapsulate the hook. Repeat again and again!

Your robot would need the aforementioned sensing and closed loop control and also the ‘normal’ array of sensors and cameras to enable autonomy with the ability to assess the terrain ahead. Good luck, and don’t forget to post about your projects (check out Hackaday.io if you need somewhere to do this) and tip us off about it! We’ve seen plenty of, sometimes terrifying, hexapod projects, but watch out that the project budget does not get totally out of control (more to be said about this in the future).

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Electric Wheelchair Makes A Great Base For A Big Robot

June 20, 2019 by Lewin Day 33 Comments

Wiring into the joystick is a quick and easy way to hack in custom control to a wheelchair.

Building robots can be fun, and remains a popular pastime among many in the hacker and maker set. However the hardware side of things can be daunting. This is particularly the case for those attempting to build something on a larger scale. A great shortcut is to start with a robust mechanical platform from the outset – and using an electric wheelchair is a great way to do so.

[Nikita] started this project way back in 2009, after finding a broken electric wheelchair at a flea market. It was no longer in fit condition for use as a wheelchair, so [Nikita] was able to score it for the low price of just $50. That’s a great price for a package which includes a robust chassis, wheels, motors and the required controllers to drive it all. With the platform in hand, it was time to get hacking.

Thus far, [Nikita] has gone so far as to strip the wheelchair of all extraneous parts, leaving it as a motorized carriage. Radio control has been implemented with the help of an Arduino, and a couple of “eyes” have been added to give it a little personality. It can also still be driven with the original joystick, which has been relocated on the chassis. Future plans involve adding a level of autonomy to allow the ‘bot to navigate waypoints and recognise faces, both tasks which should be significantly easier with 2019 technology. We’re eager to see where it goes next; we’ve seen great applications of wheelchair hardware before, after all. Video after the break.

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A Robotic Whiteboard Cleaner Keeps The Board Ready To Go

June 15, 2019 by Lewin Day 6 Comments

Wiping a whiteboard can be a tedious chore. Nobody wants to stick around after a long meeting to clean up, and sensitive information is often left broadcast out in the open. Never fear, though – this robot is here to help.

Wipy, as the little device is known, is a robotic cleaner that scoots around to keep whiteboards clear and ready for work. With brains courtesy of an Arduino Uno, it uses an IR line-following sensor to target areas to wipe, rather then wasting time wiping areas that are already clean. It’s also fitted with a time-of-flight sensor for ranging, allowing it to avoid obstacles, or busy humans that are writing on the board.

If Wipy lacks anything, it’s probably discretion. Despite its cute emoji-like face, it’s not really capable of tact, or knowing when it’s not needed. It’s recommended to keep Wipy powered down until you’re completely finished, lest it barge in and start wiping off important calculations before you’re done.

Fundamentally, it’s a fun build, and a great way to learn how to use a variety of sensors. If you’ve done something similar, be sure to let us know on the tips line. Else, consider automating the writing side of things, too. Tongue-in-cheek infomercial after the break.

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Mech Warfare: Like Driving A Building-Sized Robot Through A Busy City

June 7, 2019 by Mike Szczys 20 Comments

The sound a set of machined robot legs tapping on concrete make is remarkable. If for nothing more, the video after the break is worth watching just for this. It’s what caught my attention when I first wandered by the Mech Warfare area at Maker Faire, as one of the competitors had their bot out wandering around as a demo during the setup day.

Installing target plate

Making sure the ammo is set to go

This is truly a hacker’s robotics competition. There are constraints, but there’s also a lot of room for freedom. Meet a dozen or so requirements and you be as creative as you want with the rest. My favorite part is that this is not a destructive event like many the battle-based robot TV shows that tend to turn my stomach. Instead, these robots each carry an electric AirSoft gun and seek to hit any of four target panels on their competitor’s robot. Continue reading “Mech Warfare: Like Driving A Building-Sized Robot Through A Busy City” →

Yet Another Robotic Rubik’s Solver

June 3, 2019 by Lewin Day 4 Comments

The Rubik’s Cube was a smash hit when it came out in 1974, and continues to maintain a following to this day. It can be difficult to solve, but many take up the challenge. The Arduino Rubik’s Solver is a robot that uses electronics and maths to get the job done.

The system consists of computer-based software and a hardware system working in concert to solve the cube. Webcam images are processed on a computer which determines the current state of the cube, and the necessary moves required to solve it. The solving rig is constructed from steel rods, lasercut acrylic, and 3D printed parts, along with an Arduino and six stepper motors. The Arduino receives instructions from the solving computer over USB serial link. These are then used to command the stepper motors to manipulate the cube in the correct fashion.

It’s no speed demon, but the contraption is capable of solving a cube without any problems. Manipulation of the cube is reliable and smooth, and the build is neat and tidy thanks to its carefully designed components. Of course, there are now even Rubik’s Cubes that can solve themselves. Video after the break.

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