TOPS, The DIY Robot Dog, Has Great Moves

March 15, 2024 by Donald Papp 6 Comments

We love [Aaed Musa]’s TOPS (Traverser of Planar Surfaces) which is a robot dog with custom-made actuators. The DIY is very strong with this project, and the 3D-printed parts alone took a whopping three weeks to print!

There’s additional detail on the electronics and design of TOPS in the build log of the project’s Hackaday.io page, so check it out because there are all sorts of nice design details, like the feet being cast with a silicone outer layer for better traction. We’ve previously covered [Aaed]’s DIY robotic actuator design which we’re delighted to see is put to excellent use in the finished robot.

Of course, a robot’s hardware and physical design is only part of the battle. In fact, [Aaed] says the software side of things was probably the biggest overall challenge. It takes a lot of work to make walking happen, and the process has in fact been a huge learning experience. [Aaed] already has plenty of ideas for a potential TOPS V2.

[Aaed]’s website has video tours of all stages of design and construction of TOPS, and there’s a GitHub repository for all the design details. To see it all in action, check out the short video rounding up the finished robot, embedded here just under the page break.

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A Compact SCARA Arm Plotter

March 14, 2024 by Lewin Day 4 Comments

If you’re unfamiliar with SCARA robots, the acronym stands for Selective Compliance Assembly Robot Arm. This refers to the fact that the arms are rigid in the Z axis but somewhat compliant in the X and Y axes, and that they’re often used for assembly tasks. In any case, you can spend a great deal of money equipping your factory with these robots, or you can build your own for the fun of it. If you’re not endowed with a seven-figure investment for opening a production plant, consider exploring [tuenhidiy’s] project instead.

The build enlists an Arduino Mega as the brains of the operation. It’s paired with a RAMPS controller for running a pair of NEMA 17 stepper motors that actually move the arm in the X-Y plane. Additionally, a tray eject mechanism from a CD/DVD drive is enlisted to act as the Z axis. The frame is assembled from PVC plumbing components and a small amount of aluminium T-slot profile.

The resulting arm isn’t fast in the video we see of the build, but it works as a basic plotter without too much complaint. The benefit of the Z-axis in this case is obvious, as it allows the pen to be lifted off the page where necessary.

We’ve seen plenty of good plotter designs around these parts before, too. Video after the break.

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Rosie The Robot Runs For Real

March 9, 2024 by Al Williams 2 Comments

On the recent 256th episode of the Hackaday podcast, [Kristina] mentioned her favorite fictional robot was Rosie from The Jetsons. [Robert Zollna] must agree since he built a reimagined Rosie and it even caught the notice of mainstream outlet People magazine.

We didn’t find much information outside of the TikTok video (see below; you can use the Guest button if you don’t have an account). However, there were a few clever ideas here. First, the robot mechanism is actually Rosie’s vacuum cleaner. Like a tail wagging a dog, an off-the-shelf floor vac tows the robot body.

Rosie herself is clearly an office chair base with an artistic body. The head rotates, and the mouth appears to open and close, so there’s apparently a little more electronics inside, but that’s nothing you couldn’t throw together with some RC servos and an ESP32.

Some videos cover the build so you might be able to glean more details, but the bite-sized videos aren’t very descriptive even though they are fun to watch. If you thought folks documenting their projects on YouTube was bad, you’re really gonna love the TikTok generation.

We like the look of Rosie, but as a practical matter, we need our robot vac to be smaller, not larger. However, using these off-the-shelf robots as a quick start for a robotics project is reasonable. Especially if you can pick up one cheap. Not that that’s a new idea. They even make stripped-down units with the intent that you don’t want to use them as cleaners.

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The $16 PCB Robot

March 6, 2024 by Al Williams 20 Comments

It is a fun project to build a simple robot but, often, the hardest part these days is creating the mechanical base. [Concrete Dog] has a new open source design for stoRPer that uses a PC board as the base. The board has a Raspberry Pi Pico and motor drivers. The modular design allows you to add to it easily and use custom wheels. The video below shows some treaded wheels and some mechanum wheels with gears.

There are mounting holes for sensors and also a way to put another deck above to hold other circuits, power, or whatever you like. There’s lots you could do with this as a starting point.

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Fail Of The Week: The Little Remote-Controlled Snowblower That Couldn’t

March 3, 2024 by Dan Maloney 17 Comments

[Punxatawny Phil]’s prognostications aside, winter isn’t over up here in the Northern Hemisphere, and the snow keeps falling. If you’re sick of shoveling the driveway and the walk and you don’t have a kid handy to rope into the job, relax — this rapidly assembled junkyard RC snowblower will do just as crappy a job while you stay nice and warm inside.

This build seemed to have a lot of potential at the start, based as it was on a second-hand track-drive snowblower, something that was presumably purpose-built for the job at hand. [Lucas] quickly got to work on it; he left the original gasoline engine to power the auger but took most of the transmission off so that each track could be driven separately with a wheelchair motor. That seemed like a solid idea as far as steering goes, but the fact that he chose to drive the 24 volt motors with a single 12 volt deep-cycle battery worked against him out in the snow.

With a battery upgrade for better traction, the snowblower actually got around in the snow pretty well. [Lucas] also added some nice features, like a linear actuator to remotely engage the auger — a nice safety touch when kids and pets are around — and a motor to control the direction of the chute. Even these improvements weren’t enough, though; it worked insofar as it moved snow from where it was to where it wasn’t, but didn’t really move it very far. To the casual observer, it seems like there’s just not enough weight to the machine, allowing it to ride up over the snow rather than scraping the driveway clean. Check out the video below and see what you think.

Now, we’re not picking on [Lucas] here. Far from it — we enjoyed this build as much as some of his other stuff, like his scratch-built CO2 laser tube and his potty-mouthed approach to Kaizen tool organization. We still think this one has a lot of potential, and we’re glad he vowed to continue working on it for next winter.

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Sketchy Logg Dogg Logging Robot Remote Control Hacking

February 20, 2024 by Maya Posch 9 Comments

When we last left [Wes] amidst the torn-open guts of his Logg Dogg logging robot, he had managed to revitalize the engine and dug into the hydraulics, but one big obstacle remained: the lack of the remote control unit. In today’s installment of the Logg Dogg series, [Wes] summarizes weeks of agony over creating a custom circuit based around a microcontroller, a joystick and a lot of relays and other bits and pieces to drive the solenoids inside the logging machine that control the hydraulics.

Giving the remote controller a bench test before connecting to the logging robot (Credit: Watch Wes Work)

Most of the struggle was actually with the firmware, as it had to not only control the usual on/off solenoids, but also a number of proportional solenoid valves which control things like the track speed by varying the hydraulic flow to the final drives.

This requires a PWM signal, which [Wes] generated using two MOSFETs in a closed-feedback system, probably because open loop controls with multi-ton hydraulic machinery are not the kind of excitement most people look forward to.

Ultimately he did get it sorted, and was able to take the Logg Dogg for its first walk since being rescued from a barn, which both parties seemed to rather enjoy. The background details of this machine and the project can be found in our first coverage.

We’re looking anxiously forward to the next episode, where the controller goes wireless and the sketchiness gets dialed down some more.

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Compact Cycloidal Drive Lives Inside This Custom Brushless Motor

February 16, 2024 by Dan Maloney 7 Comments

With the popularity of robot dogs, many people have gotten on the bandwagon and tried building DIY versions. Most of them end up attaching a gearbox to an off-the-shelf brushless motor and call it a day. Not everyone goes that way, though, which is why this internal cycloidal drive actuator caught our eye.

Taking design cues from the MIT Mini Cheetah, [Aaed Musa] approached his actuator from the inside out, literally. His 3D printed cycloidal gearbox is designed to fit inside the stator of a BLDC motor. And not just any BLDC motor, but one built mostly from scratch using a hand-wound — and unwound, and wound again — stator along with a rotor that started as a printed part but was eventually machined from steel. Apart from its fixed ring, the cycloidal drive was mostly 3D printed, with everything fitting nicely inside the stator.

The video below shows the design and assembly process as well as testing of the finished drive. It seems to do really well with speed and positional accuracy, and it delivers a substantial amount of torque. Maybe a little too much, though; testing it with a heavy weight on the end of an arm got the stator coils hot enough to warp the printed parts within. But no matter; this was only a prototype after all. [Aaed] says improvements are in the works, including replacing all the plastic parts with metal ones.

Need a little background on cycloidal drives? They’re pretty cool.

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