Little Quadruped Has PCB Spine And No Wiring

October 29, 2024 by Danie Conradie 10 Comments

Dealing with all the wiring can quickly become a challenge on robots, especially the walking variety which have actuators everywhere. [Eric Yufeng Wu] sidestepped the wiring issue by creating Q8bot, a little quadruped where all the components, including the actuators, are mounted directly on the PCB.

[Eric] uses a custom PCB as the spine of the robot, and the eight servos plug directly into connectors on the PCB. With their bottom covers removed, the servos screw neatly into a pair of 3D printed frames on either side of the PCB, which also have integrated 14500 battery holders. The PCB is minimalist, with just the XIAO ESP32C3 module, a boost converter circuit to drive the servos, and a battery fuel gauge. Each SCARA-style leg consists of four SLS 3D printed segments, with press-fit bearings in the joints.

The little one moves quickly, and can even do little jumps. For this prototype, most of the control processing is done on a laptop, which sends raw joint angles to the onboard ESP32 via the ESP-Now protocol. We think this little robot has a lot of development potential, and fortunately [Eric] has made all the hardware and software files available for others to build their own.

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Hackaday Links: August 25, 2024

August 25, 2024 by Dan Maloney 8 Comments

The Sun has been remarkably active lately, so much so that it might have set a new sunspot record. According to the sun watchers at the Space Weather Prediction Center, on August 8, the Solar Dynamics Observatory snapped a picture that was positively bedazzled with sunspots. Counting methods vary, but one count put the sunspot number at a whopping 337 that day. That would be the largest number since 2001, during the peak of Solar Cycle 23. The sunspot number is highly correlated with solar storms and coronal mass ejections; more spots mean more magnetic activity and more chance for something to go very, very wrong. We’ve been pretty lucky so far with Solar Cycle 25; despite being much more active than the relatively lazy Cycle 24 and much stronger than predicted, most of this cycle’s outbursts have been directed away from Earth or only dealt us a glancing blow. Seeing all those spots, though, makes us think it’s only a matter of time before we get hit with something that does more than make pretty lights.

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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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Small Footprint Scara Laser Engraver Has Massive Build Area

August 31, 2021 by Danie Conradie 22 Comments

One of the limitations of the conventional Cartesian CNC platforms is that the working area will usually be smaller than its footprint. SCARA arms are one of the options to get around this, as demonstrated by [How To Mechatronics], with his SCARA laser engraver.

This robot arm is modified from the original build we featured a while back, which had a gripper mounted. It uses mainly standard 3D printer components with 3D printed frame parts. The arms lengths are sized to fold over the base and take up little table horizontal space when not in use. It can work in a large semi-circular area around itself, and if a proper locating and homing method is implemented, it can be moved around and engrave a large area section by section.

One of the challenges of SCARA arms is rigidity. As the cantilevered arm extends, it tends to lean over under its weight. In [How To Mechatronics]’s case, it showed up as skewed engravings, which he managed to mitigate to some degree in the Marlin firmware.

Another possible solution is to reduce the weight of the arms by moving the motors to the base, as was done with the Pybot or dual-arm SCARA printers like the RepRap Morgan.

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PyBot Is A 3D Printed SCARA Arm For The Masses

October 19, 2020 by Tom Nardi 10 Comments

We’ve all seen videos of blisteringly fast SCARA arms working on assembly lines, and more than a few of us have fantasied about having that same kind of technology for the home shop. Unfortunately, while the prices for things like 3D printers and oscilloscopes have dropped lower than what many would have believed possible a decade ago, high-performance robotics are still too pricey for the home player.

Unless of course, you’re willing to build it yourself. The PyBot designed by [jjRobots] is an open source robotic arm that should be well within the means of the average hardware hacker. One could argue that this is a project made entirely possible by desktop 3D printing; as not only are most of the structural components printed, but most of the mechanical elements are common 3D printer parts. Smooth rods, linear bearings, lead screws, and NEMA 17 motors are all exceptionally cheap these days thanks to the innumerable 3D printer kits that make use of them.

A custom control board keeps the wiring tight.

Those who’ve researched similar projects might notice that the design of this arm has clearly been influenced by the Mostly Printed SCARA (MPSCARA). But while that robot was designed to carry an extruder and act as a 3D printer, [jjRobots] intends for the PyBot to be more of a general purpose platform. By default it features a simple gripper, but that can easily be changed out for whatever tool or gadget you have in mind.

In the base of the arm is a custom control board that combines an Arduino M0, an ESP8266, and a trio of stepper motor drivers. But if you wanted to build your own version from the parts bin, you could certainly wire up all the principle components manually. As the name implies, the PyBot is controlled by Python tools running on the computer, so it should be relatively easy to get this capable arm to do your bidding.

We’ve seen some impressive 3D printed robotic arms over the years, but the simplicity of the PyBot is particularly compelling. This looks like something that you could reasonably assemble and program over a weekend or two, and then put to work in your ad-hoc PPE factory.

3D Printed SCARA Arm With 3D Printer Components

October 8, 2020 by Danie Conradie No comments

One of the side effects of the rise of 3D printers has been the increased availability and low cost of 3D printer components, which are use fill for range of applications. [How To Mechatronics] capitalized on this and built a SCARA robot arm using 3D-printed parts and common 3D-printer components.

The basic SCARA mechanism is a two-link arm, similar to a human arm. The end of the second joint can move through the XY-plane by rotating at the base and elbow of the mechanism. [How To Mechatronics] added Z-motion by moving the base of the first arm on four vertical linear rods with a lead screw. A combination of thrust bearings and ball bearings allow for smooth rotation of each of the joints, which are belt-driven with NEMA17 stepper motors. Each joint has a microswitch at a certain position in its rotation to give it a home position. The jaws of the gripper slide on two parallel linear rods, and are actuated with a servo. For controlling the motors, an Arduino Uno and CNC stepper shield was used.

The arm is operated from a computer with a GUI written in Processing, which sends instructions to the Arduino over serial. The GUI allows for both direct forward kinematic control of the joints, and inverse kinematic control, which will automatically move the gripper to a specified coordinate. The GUI can also save positions, and then string them together to do complete tasks autonomously.

The base joint is a bit wobbly due to the weight of the rest of the arm, but this could be fixed by using a frame to support it at the top as well. We really like the fact that commonly available components were used, and the link in the first paragraph has detailed instructions and source files for building your own. If the remaining backlash can be solved, it could be a decent light duty CNC platform, especially with the small footprint and large travel area. Continue reading “3D Printed SCARA Arm With 3D Printer Components” →

Geocaching On Mars: How Perseverance Will Seal Martian Samples With A Return To Earth In Mind

July 30, 2020 by Dan Maloney 23 Comments

With the roughly 20-day wide launch window for the Mars 2020 mission rapidly approaching, the hype train for the next big mission to the Red Planet is really building up steam. And with good reason — the Mars 2020 mission has been in the works for a better part of a decade, and as we reported earlier this year, the rover it’s delivering to the Martian surface, since dubbed Perseverance, will be among the most complex such devices ever fielded.

“Percy” — come on, that nickname’s a natural — is a mobile laboratory, capable of exploring the Martian surface in search of evidence that life ever found a way there, and to do the groundwork needed if we’re ever to go there ourselves. The nuclear-powered rover bristles with scientific instruments, and assuming it survives the “Seven Minutes of Terror” as well as its fraternal twin Curiosity did in 2012, we should start seeing some amazing results come back.

No prior mission to Mars has been better equipped to answer the essential question: “Are we alone?” But no matter how capable Perseverance is, there’s a limit to how much science can be packed into something that costs millions of dollars a kilogram to get to Mars. And so NASA decided to equip Perseverance with the ability to not only collect geological samples, but to package them up and deposit them on the surface of the planet to await a future mission that will pick them up for a return trip to Earth for further study. It’s bold and forward-thinking, and it’s unlike anything that’s ever been tried before. In a lot of ways, Perseverance’s sample handling system is the rover’s raison d’être, and it’s the subject of this deep dive.

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