DIY Pipe Inspector Goes Where No Bot Has Gone Before

If you think your job sucks, be grateful you’re not this homebrew sewer inspection robot.

Before anyone gets upset, yes we know what [Stargate System] built here isn’t a robot at all; it’s more of a remotely operated vehicle. That doesn’t take away from the fact that this is a very cool build, especially since it has to work in one of the least hospitable and most unpleasant environments possible. The backstory of this project is that the sewer on a 50-year-old house kept backing up, and efforts to clear it only temporarily solved the problem. The cast iron lateral line was reconfigured at some point in its history to include a 120-degree bend, which left a blind spot for the camera used by a sewer inspection service. What’s worse, the bend was close to a joint where a line that once allowed gutters and foundation drains access to the sewer.

To better visualize the problem, [Stargate] turned to his experience building bots to whip up something for the job. The bot had to be able to fit into the pipe and short enough to make the turn, plus it needed to be — erm, waterproof. It also needed to carry a camera and a light, and to be powered and controlled from the other end of the line. Most of the body of the bot, including the hull and the driving gear, was 3D printed from ABS, which allowed the seams to be sealed with acetone later. The drive tracks were only added after the original wheels didn’t perform well in testing. Controlling the gear motors and camera was up to a Raspberry Pi Zero, chosen mostly due to space constraints. An Ethernet shield provided connectivity to the surface over a Cat5 cable, and a homebrew PoE system provided power.

As interesting as the construction details were, the real treat is the down-hole footage. It’s not too graphic, but the blockage is pretty gnarly. We also greatly appreciated the field-expedient chain flail [Stargate] whipped up to bust up the big chunks of yuck and get the pipe back in shape. He did a little bit of robo-spelunking, too, as you do.

And no, this isn’t the only sewer bot we’ve ever featured.

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The Challenges Of Charging Drones From Power Lines

Drones that charge right on the power lines they inspect is a promising concept, but comes with plenty of challenges. The Drone Infrastructure Inspection and Interaction (Diii) Group of the University of South Denmark is tackling these challenges head-on.

The gripper for these drones may seem fairly straightforward, but it needs to inductively charge, grip, and detach reliably while remaining simple and lightweight. To attach to a power line, the drone pushes against it, triggering a cord to pull the gripper closed. This gripper is held closed electromagnetically using energy harvested from the power line or the drone’s battery if the line is off. Ingeniously, this means that if there’s an electronics failure, the gripper will automatically release, avoiding situations where linemen would need to rescue a stuck drone.Accurately mapping power lines in 3D space for autonomous operation presents another hurdle. The team successfully tested mmWave radar for this purpose, which proves to be a lightweight and cost-efficient alternative to solutions like LiDAR.

We briefly covered this project earlier this year when details were limited. Energy harvesting from power lines isn’t new; we’ve seen similar concepts applied in government-sanctioned spy cameras and border patrol drones. Drones are not only used for inspecting power lines but also for more adventurous tasks like clearing debris off them with fire. Continue reading “The Challenges Of Charging Drones From Power Lines”

Soldering, Up Close And Personal

A word of warning before watching this very cool video on soldering: it may make you greatly desire what appears to be a very, very expensive microscope. You’ve been warned.

Granted, most people don’t really need to get this up close and personal with their soldering, but as [Robert Feranec] points out, a close look at what’s going on when the solder melts and the flux flows can be a real eye-opener. The video starts with what might be the most esoteric soldering situation — a ball-grid array (BGA) chip. It also happens to be one of the hardest techniques to assess visually, both during reflow and afterward to check the quality of your work. While the microscope [Robert] uses, a Keyence VHX-7000 series digital scope, allows the objective to swivel around and over the subject in multiple axes and keep track of where it is while doing it, it falls short of being the X-ray vision you’d need to see much beyond the outermost rows of balls. But, being able to look in at an angle is a huge benefit, one that allows us a glimpse of the reflow process.

More after the break

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Tiny Prisms Let You See What Lies Beneath A BGA Chip

Compared to through-hole construction, inspecting SMD construction is a whole other game. Things you thought were small before are almost invisible now, and making sure solder got where it’s supposed to go can be a real chore. Add some ball grid array (BGA) chips into the mix, where the solder joints are not visible by design, and inspection is more a leap of faith than objective proof of results.

How it works.

Unless, of course, you put the power of optics to work, as [Petteri Aimonen] does with this clever BGA inspection tool. It relies on a pair of tiny prisms to bounce light under one side of a BGA chip and back up the other. The prisms are made from thin sheets of acrylic; [Petteri] didn’t have any 1-mm acrylic sheet on hand, so he harvested material from a razor blade package. The edge of each piece was ground to a 45-degree angle and polished with successively finer grits until the surfaces were highly reflective. One prism was affixed to a small scrap of PCB with eleven SMD LEDs in a row, forming a light pipe that turns the light through 90 degrees. The light source is held along one edge of a BGA, shining light underneath to the other prism, bouncing light through the forest of solder balls and back toward the observer.

The results aren’t exactly crystal clear, which is understandable given the expedient nature of the materials and construction employed. But it’s certainly more than enough to see any gross problems lying below a BGA, like shorts or insufficiently melted solder. [Petteri] reports that flux can be a problem, too, as excess of the stuff can crystalize between pads under the BGA and obstruct the light. A little extra cleaning should help in such cases.

Haven’t tackled a BGA job yet? You might want to get up to speed on that.

Telepresence Robot For “Doing The Rounds”

When you are responsible for maintaining devices at a client’s location, software tools like remote desktop and SSH are great, but sometimes they are not enough. For some problems, you need to get eyes and hands on the device to figure out what’s going on and fix the problem. This is a challenge [Will Donaldson] from EDM Studio is all too familiar with. They develop and maintain interactive museum exhibits all over the world, so they created Omni, a modular telepresence robot for inspection, maintenance, and a variety of other tasks.

The Omni uses a set of three omni-wheels under its base, powered by DC geared motors with encoders, each controlled by a separate motor driver and Arduino Nano. A similar arrangement was used by Mark Rober for his domino art robot. The main controller is a Raspberry Pi 4 running ROS2 (Robot Operating System), which takes inputs from a 360 LIDAR sensor, high-quality camera module, and IMU.

All the components are mounted on a series of plates separated using threaded rods. This arrangement allows for maximum flexibility and space, especially the open-top plate, which has a grid of holes machined in to allow almost anything to be mounted. In this case, a robotic arm is mounted for manipulating the environment. Another neat feature is the charging station connector, consisting of two parallel metal strips on the outside of the robot.

Omni’s mission is very similar to that of Spot, the robotic dog from Boston Dynamics intended, among other things, for Industrial Inspection. What practical purposes would you use Omni for? Let us know in the comments below.

Wall-Climbing Robot Grabs Prize

Gravity is a nice thing to have most of the time, but sometimes it would be nice to be able to ignore it for certain applications. Rock climbing, for example, would be much easier, as would performing bridge inspections in the way that a group of mechanical engineering cadets (students) at The Citadel, a military college in South Carolina, were tasked with doing. Frustrated with the amount of traffic backups that normal bridge inspections caused, they invented a robot that defies gravity, and won a $10k prize for their efforts.

The result is essentially an RC car with a drone built in, or looking at it another way it’s a drone with wheels. The car is able to drive on vertical surfaces to inspect the bridges by using its propellers to force itself onto the surface. The lack of complicated moving parts or machinery, like a cable suspension system or other contraption, makes this device exceptionally versatile for the task at hand, reduces the amount of time needed for inspections, and can do them more safely and without closing lanes of traffic. The group hopes to build a second prototype soon and present it to the Department of Transportation for approval for more widespread use.

The need for tools like these is in high demand now as well, especially in the United States where crumbling infrastructure is often not thought about, taken seriously, or prioritized. Even for bridges that aren’t major pieces of infrastructure, tools like these will prove to be very useful.

Thanks to [Ben] for the tip!

PCB Bring-Up Hack Chat

Join us on Wednesday, April 15 at noon Pacific for the PCB Bring-Up Hack Chat with Mihir Shah and Liam Cadigan!

The printed circuit design process is pretty unique among manufacturing processes. Chances are pretty good that except for possibly a breadboard prototype, the circuit that sits before you after coming back from assembly has only ever existed in EDA software or perhaps a circuit simulator. Sure, it’s supposed to work, but will it?

You can — and should — do some power-off testing of new boards, but at some point you’re going to have to flip the switch and see what happens. The PCB bring-up process needs to be approached carefully, lest debugging any problems that crop up become more difficult than need be. Mihir and Liam from inspectAR will discuss the bring-up process in depth, offering tips and tricks to make things go as smoothly as possible, as well as demonstrating how the inspectAR platform can fit into that process, especially with teams that are distributed across remote sites. If your board releases the Magic Smoke, you’ll want to know if it’s your design or an assembly issue, and an organized bring-up plan can be a big help.

Note: Liam will be doing a simulcast web demo of inspectAR via Zoom. ​

join-hack-chatOur Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, April 15 at 12:00 PM Pacific time. If time zones have got you down, we have a handy time zone converter.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.

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