Every now and then someone gets seriously inspired, and that urge just doesn’t go away until something gets created. For [Paulius Liekis], it led to creating a roughly 1:20 scale version of the T08A2 Hexapod “Spider” Tank from the movie Ghost in the Shell. As the he puts it, “[T]his was something that I wanted to build for a long time and I just had to get it out of my system.” It uses two Raspberry Pi computers, 28 servo motors, and required over 250 hours of 3D printing for all the meticulously modeled pieces – and even more than that for polishing, filing, painting, and other finishing work on the pieces after they were printed. The paint job is spectacular, with great-looking wear and tear. It’s even better seeing it in motion — see the video embedded below.
We all have reasons why we’re not building cool robots. “I don’t have a lasercutter.” “I don’t have a 3D printer.” [JAC_101]’s hexapod robot dances all over your excuses with its tongue-depressor body and pencil-eraser feet!
Some folks like to agonize over designs, optimizing this and tweaking that on the blackboard. Other folks just build stuff and see what works. If you’re in the mood for some of the latter, check out some of the techniques at work here. Tongue depressors make a simple frame, and servos are lashed on with zip ties in place of fancy servo mounts (or hot glue). Photoresistors are soldered directly to their load resistors, making a simple light sensor. It’s all very accessible and brutally minimalistic, but it seems to walk. (Check out the video, below.)
Arduino code is available for you to play with, naturally.
The usual way robotics is taught – and nearly everything, for that matter – is simple. A teacher gets a pre-built module or kit, teaches the students how to use the kit, and class is adjourned. There are significant and obvious drawbacks to this. [Kevin Harrington]’s entry for the Hackaday Prize turns that pedagogy on its head. It’s a robotics development platform that encourages everyone to create their own robots from scratch, starting with the question, ‘how many legs do you want your robot to have’.
Bowler Studio uses OpenCV for image processing, a kinematics engine, a JCSG-based CAD and 3D modeling engine to interface with motors, create 3D models according to kinematic models, feed imaging data to a robot, and create graphical interfaces for robots. It’s an entire robotics creation studio in a single package, and of course everything can be backed up to the cloud.
The electronic backbone is another one of [Kevin] and Neuron Robotics’ projects, DyIO, a USB peripheral that makes for a great robotics platform. The DyIO can control up to 24 servos, enough for a very, very complex robot, and also has the ability to control motors, read encoders, or just blink pins.
These two projects together make for a great way to learn the ins and outs of robots that are a little more complex than a simple wheeled robot, and expandable enough to make some really, really cool projects
The 2015 Hackaday Prize is sponsored by:
Hexapods are wonderful things. With their elegant gait and insect-like caricature, they’re an instant hit for coffee-table-conversation-starters. They’re also wonderfully expensive, with the redundancy of each leg chewing viciously into your pocket. This price point is a deal-breaker for many, but for others, it’s a challenge to let one’s design skills defy that barrier. [Mike Estee] is one such engineer who’s done his best to design away a stock structure with a cardboard variant that wont break the bank.
On the table, [Mike] assembles his hexapod frame from budget servos, corrugated cardboard, paper clips, and tape. The result is a hexapod frame that can be built for practically just the cost of the servos (about $80 in this case). In his posts, [Mike] details the design evolution of the frame focusing especially on the legs, which he intended to be folded from a single sheet. After a few revisions, [Mike] succeeded, and he’s graciously posted his latest revision on his blog [PDF].
While we’ve certainly seen impressive budget hexapods before, we really appreciate the elegance and simplicity of a design made entirely from a single sheet of cardboard. His progress is a step forward to reaching a ubiquitous low-cost, force-control based robot platform. While that’s a milestone many of us hope to see in the future, he’s done a fantastic job designing a proof-of-concept frame template that anyone can cut out and assemble with a couple of spare hours.
LVBots, a club for robot building enthusiasts in Las Vegas, held an open house the week of CES. This was the only trip [Sophi] and I took away from the conference halls of The Strip and it was a blast! The group holds meetings twice a month in a space provided by Pololu — a well-known robotics and electronics manufacturer headquartered just south of McCarran International Airport.
Before the formal part of the gathering started there were several builds being shown off. [Claire] and [Brian] recently participated in an AT&T sponsored hackathon. Their creation is a robotic closet. The system involves moving racks of clothing which are tracked by a smartphone app. Interesting features discussed for the software include monitoring when each garment was last worn, last washed, and if it is appropriate for current weather conditions. Dig into the code in their repo.
In other parts of the room a pair of line-following robots did their thing, and a couple of sumo-bots competed to push each other out of the ring. A large group was gathered around the projector watching videos of robots of all types, brainstorming about the difficult parts, how they were overcome, and how these methods may be applied to their own build. I can attest that hanging with a group of people who are trying to cue up the most amazing robot demonstrations makes for amazing viewing!
As the organized part of the meeting began I was delighted to hear about a standing challenge from the LVbots group. The Tabletop challenge has multiple phases that serve to encourage builders to start modestly and then iterate to achieve new goals:
Phase 0: bring a robot to LVBots
Phase 1: travel back and forth without falling off
Phase 2: find an object and push it off
Phase 3: push object into a goal
[Nathan Bryant] was one of the two robot builders trying out the challenge on this night. He built this hexapod from balsa wood and three servo motors and was testing Phase 1. The bot includes a sensor dangling out in front of the robot to detect then the table surface is no long below. At that point it backs up a few steps, turns in place, and proceeds in the opposite direction. [Nathan] mentions that he worked out all the movements in a spreadsheet and that future firmware upgrades will dramatically increase the speed at which the bot moves. We love the audible cadence of the bot which is easily observed in the video above. At one point a leg dangles over the edge and it looks like [Nathan] pushed the bot back but I don’t remember him actually touching it so I’m calling this a trick of camera angle.
One phase further in the Tabletop Challenge is [Joe Carson]. He exhibited a wheeled robot he’s been working on that includes a gripper arm on the front. The robot looks around the table for a predefined color, in this case provided by a highlighting marker. When found the bot approaches, grips, and then proceeds to move the marker over the void where it is dropped out of existence; at least from the robot’s point of view.
After talking with a few of the judges for The Hackaday Prize, documentation will be a large factor in determining who wins and takes a trip to space, and who is left with their feet safely planted on the ground. Stubby the Hexapod is one of the most well documented projects in the running. There are already two hardware revisions for the walking mechanism, several board layouts for the controller, and more project log entries than you can shake a stick at.
Stubby is the brainchild of [The Big One] (a.k.a. [Wyatt] with [Warren], [Princess Sparkle], and [exot] filling out the rest of the team). The project originally began as an educational robotics project meant for teaching [Wyatt]’s kids the ins and outs of robotics and electronics. He’s doing this by developing an open source hexapod robot platform, complete with a frame, electronics board, and a lot of interesting code driving 18 hobby servos.
The frame for Stubby’s first hardware revision is rather interesting; it’s able to be reproduced with nothing more than a scroll saw. The latest revision is a complete rethinking of hexapod locomotion using 2DOF legs and a more mechanical gait.
Being completely open source and very well documented, you can already make your own Stubby hexapod with a scroll saw and the files on [Wyatt]’s site. If 3D printing is more your thing, there’s also a few files to help you with that.
You can check out a few videos of the different Stubby revisions below:
The project featured in this post is a semifinalist in The Hackaday Prize.
A while back, we had a sci-fi contest on Hackaday.io. Inspired by the replicators in Stargate SG-1, [The Big One] and a few other folk decided a remote-controlled hexapod would be a great build. The contest is long over, but that doesn’t mean development stopped. Now Stubby, the replicator-inspired hexapod is complete and he looks awesome.
The first two versions suffered from underpowered servos and complex mechanics. Third time’s the charm, and version three is a lightweight robot with pretty simple mechanics able to translate and rotate along the XYZ axes. Stubby only weights about 600 grams, batteries included, so he’s surprisingly nimble as well.
The frame of the hexapod is designed to be cut with a scroll saw, much to the chagrin of anyone without a CNC machine. There are three 9g servos per leg, all controlled with a custom board featuring an ATMega1284p and an XBee interface to an old Playstation controller.
Video of Stubby below, and of course all the sources and files are available on the project site.