A Servo Powered Robotic Arm, But Like You’ve Never Seen Before

We’ve written about a lot of DIY robotic arms. Some of them are high-performance, some are inexpensive, and some are just uniquely fun. This one certainly falls into the last category; whilst watching an episode of Black Mirror, [Gear Down For What] was struck by inspiration for a thin robotic limb. After some iterations he has a final prototype, and it’s quite something to see in action.

To make a robotic arm as slender as possible, the actuators can’t be mounted on the arm itself but must instead drive the arm remotely. There are a number of ways of doing this, and though [Gear Down For What] considered using pneumatics or hydraulics, he opted to keep it simple with RC servos which produced a nifty solution that we really like.

The arm is made out of a series of 3D printed ball joints, allowing rotation in any direction. The tricky bit is transferring the force from the servos to each joint. Initially bare fishing line was considered, but this made the remote joints difficult to control when lower joints were moving. The solution was to use the fishing line inside of tubing, similar to the way that bike brakes operate. This allows the force to be carried to the appropriate joint regardless of lower movement. Each joint needs an x and y tension to allow it to rotate in any direction, which means an army of sixteen servos is needed to operate the eight segment arm.

Robotic arms are always fun to build and we’ve seen some pretty neat uses for them, such as mapping magnetic fields in 3D, or teaching sign language.

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Chemistry And Lasers Turn Any Plastic Surface Into A PCB

On the face of it, PCB production seems to pretty much have been reduced to practice. Hobbyists have been etching their own boards forever, and the custom PCB fabrication market is rich with vendors whose capabilities span the gamut from dead simple one-side through-hole boards to the finest pitch multilayer SMD boards imaginable.

So why on Earth would we need yet another way to make PCBs? Because as [Ben Krasnow] points out, the ability to turn almost any plastic surface into a PCB can be really handy, and is not necessarily something the fab houses handle right now. The video below shows how [Ben] came up with his method, which went down a non-obvious path that was part chemistry experiment, part materials science. The basic idea is to use electroless copper plating, a method of depositing copper onto a substrate without using electrolysis.

This allows non-conductive substrates — [Ben] used small parts printed with a Formlabs SLA printer — to be plated with enough copper to form solderable traces. The chemistry involved in this is not trivial; there are catalysts and surfactants and saturated solutions of copper sulfate to manage. And even once he dialed that in, he had to figure out how to make traces and vias with a laser cutter. It was eventually successful, but it took a lot of work. Check out the video below to see how he got there, and where he plans to go next.

You’ve got to hand it to [Ben]; when he decides to explore something, he goes all in. We appreciate his dedication, whether he’s using candles to explore magnetohydrodynamics or making plasma with a high-speed jet of water.

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This Is Your Solution For Open Source Motion Tracking

The HTC Vive Tracker adds real-world objects to your virtual world. While these real-world objects in virtual environments are now mostly limited to a Nintendo Zapper for a Duck Hunt clone and a tennis racket, the future is clear: we’re going to be playing Duck Hunt and Wii Sports while wearing headsets. The future is so bright, it burns.

Of course, with any piece of neat computing hardware, there’s an opportunity for building an Open Source clone. That’s what [Drix] is doing with his Hackaday Prize entry. He’s created an Open Source Vive Tracker. It’s called the HiveTracker, and it is right now the best solution for tracking objects in a 3D space.

After a few missteps with ultrasonic and magnetic approaches, the team decided to piggyback on the HTC Vive lighthouses. These two base stations scan a laser beam across the room, first vertically, then horizontally. It’s an incredible piece of technology that [Alan Yates] talked about at the 2016 Hackaday Superconference.

While most microcontrollers don’t operate fast enough to see these laser sweeps, the team behind the HiveTracker found one microcontroller, with Bluetooth, and a feature called ‘PPI’. This programmable peripheral interconnect is kinda, sorta like a cross-bar, but designed for more real-time control of applications. With the right software, the team behind the HiveTracker was able to detect the lighthouses and send position and orientation data back to a computer.

This is a stupendous amount of work, and the results are remarkable. You can check out the video below and see that, yes, this is a real, Open Source Vive Tracker.

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Printed It: Logitech C270 Conversion

One of the most practical applications for a home 3D printer is the ability to produce replacement parts; why wait a week for somebody to ship you a little plastic widget when you’ve got a machine that can manufacture a facsimile of it in a couple of hours? But what if your skills and passion for the smell of melting PLA push you even farther? You might move on from printing replacement parts to designing and building whole new devices and assemblies. Arguably this could be considered “peak” 3D printing: using a printer to create new devices which would otherwise be difficult or impractical for an individual to manufacture by more traditional means.

A perfect example is this fantastic total conversion for the Logitech C270 webcam designed by [Luc Eeckelaert]. Officially he calls it a “tripod”, and perhaps that’s how the design started, but the final product is clearly much more than that. It puts the normally monitor-mounted Logitech camera onto an articulated arm, greatly improving the device’s usability. The conversion even includes the ability to manually adjust the focus, a feature the original hardware doesn’t have. It turns the affordable and widely available Logitech C270 into an excellent camera to have on the workbench for documenting projects, or pointing at the bed of your 3D printer.

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Superconference Submission Deadline Extended

Who among us doesn’t procrastinate from time to time? We can’t count the number of times that we’ve taken advantage of the Post Office staying open until midnight on April 15th. And when the 15th falls on a weekend? Two glorious additional days to put off the inevitable!

If you’ve been sitting on submitting your talk or workshop proposal to the 2018 Hackaday Superconference, we’ve got the next best thing for you: we’re extending the deadline until 5 pm PDT on September 10th.

The Hackaday Superconference is a singularity of hardware hackers: more of the best people in the same space at the same time than anywhere else. And that means that your ideas and experiences will be shared with the people most likely to appreciate them. From heroic hacks to creative robotics or untold hardware histories, if there’s a crowd who’ll appreciate how a serial console saved your bacon, it’s this one.

And if you give a talk or workshop, you get in free. But it’s more than that — there’s a different experience of a convention, even a tight-knit and friendly one like Hackaday’s Supercon, when you’re on the other side of the curtain. Come join us! We’d love to hear what you’ve got to say. And now you’ve got a little more time to tell us.

(If you want to get in the old-fashioned way, tickets are still available, but they won’t be once we announce the slate of speakers. You’ve been warned.)

Interactive KiCAD BOMs Make Hand Assembly A Breeze

We’ve all been there; you finally get the last DigiKey box and now your desk is covered in parts to stuff into a shiny new PCB you’ve been working on. First stop? Passive town, population endless waves of 1uF capacitors. The first one goes in the upper left, then a little below that, then… once you get to C157 it’s getting pretty hard to remember exactly which parts go where. Enter the literally named InteractiveHtmlBom (IHB) to smooth this process out.

IHB makes the frustrating task of mapping lines in a BOM to a physical position on a board easy. The classic method is of course, to look at the BOM, then search the board for that designator and place the component. (You left the designators in the silk, right?) Or to look at the BOM, ask your CAD package to search for that part in the layout, then place. IHB generates a document that does this automagically.

A sample file from a familiar project

Run the tool, either standalone or as a plugin for KiCAD 5.0, and you get a folder with the new interactive BOM in it. There are a few view options but generally it presents a view of the BOM with designators and value in one pane and a wonderful render of the top and/or bottom of the board in another pane. When you hover over a BOM line it highlights the relevant parts in the board view! There are toggles for filtering by top and bottom of board, marking which parts have been placed, light and dark mode, etc. Plus the ability to filter and sort by designator and value. We would have been impressed if it was just a generator/viewer for those slick scrollable/pannable board renders!

Check out a very long GIF demo after the break, or explore one of many pre-created demo BOMs here. We’re partial to the OSPx201.

Thanks [GregDavill] for the tip!

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When Are Dumb LEDs The Smart Choice?

A couple years ago I got into making electronic conferences badges by building a device for DEFCON 25 shaped like a dragonfly. Like all badges the most important design factor was quite literally how flashy it was, and two years ago I delivered on that with ten RGB LEDs. At the time I planned to hand-assemble each and every of the 105 badges at my kitchen table. Given those constraints, and a desire for electrical and programmatic simplicity, I landed on using APA102s (DotStar’s in Adafruit parlance) in the common 5050 sized package. They were easy to place, easy to design with electrically, simple to control, and friendly to a human pick-n-place machine. Though by the end of the production run I had discovered a few problems, the APA102s were a success.

This year I made a new and improved version of the dragonfly, but applying my lessons learned led me to choose a very different LED architecture than 2017. I swapped out the smart LEDs for dumb ones.

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