Flexible PCBs Make The Fins Of This Robotic Fish

We love a little outside-the-box thinking around here, and anytime we see robots that don’t use wheels and motors to do the moving, we take notice. So when a project touting robotic fish using soft-actuator fins crossed the tip line, we had to take a look.

It turns out that this robofish comes from the fertile mind of [Carl Bugeja], whose PCB motors and flexible actuators have been covered here before. The basic concept of these fish fins is derived from the latter project, which uses coils printed onto both sides of a flexible Kapton substrate. Positioned near a magnet, the actuators bend when a current runs through them. The video below shows two prototype robofish, each with four fins. The first is a scrap of foam with a magnet embedded; the fins did flap but the whole thing just weighed too much. Version two was much lighter and almost worked, but the tether to the driver is just too stiff to allow it to really flex its fins.

It looks like it has promise though, and we’re excited to see where [Carl] take this. Perhaps schools of tiny robofish patrolling for pollution?

Continue reading “Flexible PCBs Make The Fins Of This Robotic Fish”

Perf Board Pyrotechnics Courtesy Of A High-Voltage Supply

You may have asked yourself at one time or another, “Self, what happens when you pass 100 thousand volts through a printed circuit board?” It’s a good question, and [styropyro] put together this fascinating bit of destructive testing to find out.

Luckily, [styropyro] is well-positioned to explore the high-voltage realm. His YouTube stock-in-trade is lasers, ranging from a ridiculously overpowered diode-laser bazooka to a bottle-busting ruby laser. The latter requires high voltage, of course, and his Frankenstein’s lab yielded the necessary components for this destructive diversion. A chopper drives dual automotive ignition coils to step the voltage up to a respectable 100 kV. The arcs across an air gap are impressive enough, but when applied to a big piece of copper-clad protoboard, the light show is amazing. The arcs take a seemingly different path across the board for each discharge, lighting up the path with an eerie blue glow accompanied by a menacing buzz. Each discharge path may be random, but they all are composed of long stretches across the rows and columns of copper pads that never take the more direct diagonal path. [styropyro]’s explanation of the math governing this behavior is feasible, but really we just liked looking at the pretty and dangerous display. Now if only the board had been populated with components…

No, there’s not much of a hack here, but it’s cool nonetheless. And it’s probably a well-earned distraction from his more serious stuff, like his recent thorough debunking of the “Chinese laser rifle” that was all over the news a while back.

Continue reading “Perf Board Pyrotechnics Courtesy Of A High-Voltage Supply”

Friday Hack Chat: Motors Made Out Of PCBs

One of the most amazing technological advances found in this year’s Hackaday Prize is the careful application of copper traces turned into coils. We’ve seen this before for RFID tags and scanners, but we’ve never seen anything like what Carl is doing. He’s building brushless motors on PCBs.

All you need to build a brushless motor is a rotor loaded up with super powerful and very cheap magnets, and a few coils of wire. Now that PCBs are so cheap, the coils of wire are easily taken care of. A 3D printer and some eBay magnets finish off the rest. For this week’s Hack Chat, we’re talking with Carl about PCB motors.

Carl Bugeja is a 23-year old electronics engineer who is trying to design new robotics technology. His PCB Motor design won the Open Hardware Design Challenge and will be going to the Finals of the Hackaday Prize. This open-source PCB motor is a smaller, cheaper, and easier to assemble micro-brushless motor.

[Carl]’s main project, the PCB Motor is a stator that is printed on a 4-layer PCB board. The six stator poles are spiral traces wound in a star configuration. Although these coils produce less torque compared to an iron core stator, the motor is still suitable for high-speed applications. [Carl]’s been working on other PCB motor designs, like the Linear PCB motor which is a monorail on a PCB and the Flexible PCB actuator where the coils of wire are tucked inside Kapton.

During this Hack Chat, we’re going to be discussing:

  • The design and construction of brushless motors
  • How to drive these motors
  • PCB applications beyond standard circuitry
  • Building accessible robotics technology

You are, of course, encouraged to add your own questions to the discussion. You can do that by leaving a comment on the Hack Chat Event Page and we’ll put that in the queue for the Hack Chat discussion.join-hack-chat

Our Hack Chats are live community events on the Hackaday.io Hack Chat group messaging. This week is just like any other, and we’ll be gathering ’round our video terminals at noon, Pacific, on Friday, August 10th. Need a countdown timer? You wouldn’t if we switched to universal metric time.

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 Friday; join whenever you want and you can see what the community is talking about.

Delta Printer Morphs Into CNC Flat Coil Winder

Anyone who has ever wound a coil by hand has probably idly wondered “How do they do this with a machine?” at some point in the tedious process. That’s about when your attention wanders and the wire does what physics wants it to do, with the rat’s nest and cursing as a predictable result.

There’s got to be a better way, and [Russ Gries] is on his way to finding it with this proof-of-concept CNC flat coil winder. The video below is a brief overview of what came out of an intensive rapid prototyping session. [Russ] originally thought that moving the coil would be the way to go, but a friend put him onto the idea of using his delta-style 3D-printer to dispense the wire. An attachment somewhat like a drag knife was built, but with a wire feed tube and a metal roller to press the wire down onto an adhesive surface. The wire feed assembly went through a few design iterations before he discovered that a silicone cover was needed for the roller for the wire to properly track, and that the wire spool needed to be fed with as little friction as possible. Fusion 360’s CAM features were used to design the tool paths that describe the coils. It seems quite effective, and watching it lay down neat lines of magnet wire is pretty mesmerizing.

We’ve seen a couple of cylindrical coil winding rigs before, but it looks like this is the first flat coil winder we’ve featured. We can’t help but wonder about the applications. Wireless power transfer comes to mind, as do antennas and coils for RF applications. We also wonder if there are ways to use this to make printed circuit boards. Continue reading “Delta Printer Morphs Into CNC Flat Coil Winder”

Mechanisms: Solenoids

Since humans first starting playing with electricity, we’ve proven ourselves pretty clever at finding ways to harness that power and turn it into motion. Electric motors of every type move the world, but they are far from the only way to put electricity into motion. When you want continuous rotation, a motor is the way to go. But for simpler on and off applications, where fine control of position is not critical, a solenoid is more like what you need. These electromagnetic devices are found everywhere and they’re next in our series on useful mechanisms.

Continue reading “Mechanisms: Solenoids”

DIY Magnetic Actuator, Illustrated And Demonstrated

Electromagnetic actuators exert small amounts of force, but are simple and definitely have their niche. [SeanHodgins] took a design that’s common in flip-dot displays as well as the lightweight RC aircraft world and decided to make his own version. He does a good job of explaining and demonstrating the basic principles behind how one of these actuators works, although the “robotic” application claimed is less clear.

It’s a small, 3D printed lever with an embedded magnet that flips one way or another depending on the direction of current flowing through a nearby coil. Actuators of this design are capable of fast response and have no moving parts beyond the lever itself, meaning that they can be made very small. He has details on an imgur gallery as well as a video, embedded below.

Continue reading “DIY Magnetic Actuator, Illustrated And Demonstrated”

A Brushless Motor On A PCB, Made From PCB

At Hackaday, we really appreciate it when new projects build on projects we’ve featured in the past. It’s great to be able to track back and see what inspires people to pick up someone else’s work and bring it to the next level or take it down a totally new path.

This PCB brushless motor is a great example of the soft collaboration that makes the Hackaday community so powerful. [bobricius] says he was inspired by this tiny PCB BLDC when he came up with his design. His write-up is still sparse at this point, but it looks like his motor is going to be used to drive a small robot. As with his inspiration, this motor has the stator coils etched right into the base PCB. But there are some significant improvements, like increasing the stator coil count from six to eight, as well as increasing the overall size of the motor. [bobricius] has also done away with the 3D-printed rotor of the original, opting to fabricate his rotor from stacked PCBs with cutouts for 5-mm neodymium magnets. We like the idea of using the same material throughout the motor, and it also raises the potential for stacking a second stator on the other side of the rotor, which might help mechanically and electrically. Even still, the prototype seems to hold its own in the video below.

This is [bobricius]’ second entry in the 2018 Hackaday Prize so far, after his not-a-Nixie tube display. Have you entered anything yet? Get to it! Prizes, achievements, and glory await.

Continue reading “A Brushless Motor On A PCB, Made From PCB”