3D Mouse With 3D Printed Flexures And PCB Coils

January 31, 2024 by 7 Comments

3D mice with six degrees of freedom (6DOF) motion are highly valued by professional CAD users. However, the entry-level versions typically cost upwards of $150 and are produced by a single manufacturer. [Colton Baldridge] has created the OS3M Mouse — an open source alternative using PCB coils and 3D printed flexures.

The primary challenges in creating a 6DOF input device, similar to the 3Dconnexion Space Mouse, lie in developing a mechanical coupling that enables full range motion, and electronics capable of precisely and consistently measuring this motion. After several iterations of printed flexure combinations and trip down the finite element analysis (FEA) rabbit hole, [Colton] had a working single-piece mechanical solution.

To measure the knob’s movement accurately, [Colton] employs inductive sensing. Inductance to Digital Converters (LDCs) assess the inductive alterations across three pairs of PCB coils, each having an opposing metal disk mounted on the knob. This setup allows [Colton] to use a Stewart platform‘s kinematic model calculate the  knob’s relative position. The calculation are done on an STM32 which also acts USB HID send the position data to a computer. For the demo [Colton] created a simple C++ app to translate the position data to Solidworks API calls.

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Illustrated Kristina with an IBM Model M keyboard floating between her hands.

Keebin’ With Kristina: The One With The Typewriter Orchestra

January 31, 2024 by 2 Comments

Have you ever wished you had more control over what goes into a kit keyboard build? Like, a whole lot more control? Well, that’s the idea behind the Akruvia 12×4 Playground by [iketsj].

Image by [iketsj] via YouTube

This is a 48-key ortholinear keyboard, but other than that, it’s a complete blank slate. The kit includes the PCB, diodes, RGB LEDs, and Kailh Choc V1 hot swap sockets, which is really the only choice you don’t have in the matter.

All the rest is up to you, thanks to a generous prototyping area that wraps around three sides of the keys. Bring your own microcontroller and anything else that sounds useful, like displays, rotary encoders, gesture sensors, pointing devices, you name it.
You could even magnetically link a macro pad to one side, as [iketsj] teases in the intro video. [iketsj] has made the kit available through links on their website, and you’ll find a product guide there as well.

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Making An Aircraft Wing Work For An Audience

January 31, 2024 by 3 Comments

Many of us will have sat and idly watched the flaps and other moving parts of an airliner wing as we travel, and it’s likely that most of you will know the basics of how an aircraft wing works. But there’s more to an aircraft wing than meets the eye, which is why the Aerospace Bristol museum has an Airbus A320 wing on display. [Chris Lymas] was part of the team which turned a surplus piece of aircraft into an interactive and working exhibit, and he told the Electromagnetic Field audience all about it in his talk Using Arduinos to Resurrect an Airliner Wing.

The talk starts with an explanation of how a variable surface wing works, and then starts to talk about the control systems employed. We’re struck with the similarity to industrial robots, in that this is a a powerful and thus surprisingly dangerous machine to be close to. The various moving surfaces are moved by a series of shafts and gearboxes, driven by a DC motor. Running the show is an Arduino Mega, which has enough interfaces for all the various limit switches.

It’s fascinating to see how the moving parts in an airliner wing work up close, and we’re impressed at the scale of the parts which keep us safe as we fly. Take a look, the video is below the break.

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The Cockpit Voice Recorder Controversy

January 31, 2024 by 75 Comments

Every time there’s a plane crash or other aviation safety incident, we often hear talk of the famous “black box”. Of course, anyone these days will tell you that they’re not black, but orange, for visibility’s sake. Plus, there’s often not one black box, but two! There’s a Flight Data Recorder (FDR), charged with recording aircraft telemetry, and a Cockpit Voice Recorder (CVR), designed to record what’s going on in the cabin.

It sounds straightforward enough, but the cockpit voice recorder has actually become the subject of some controversy in recent times. Let’s talk about the basics of these important safety devices, and why they’re the subject of some debate at the present time.

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Resistor Swap Gives Honda Insights More Power

January 31, 2024 by 122 Comments

A common complaint around modern passenger vehicles is that they are over-reliant on electronics, from overly complex infotainment systems to engines that can’t be fixed on one’s own due to the proprietary computer control systems. But even still, when following the circuits to their ends you’ll still ultimately find a physical piece of hardware. A group of Honda Insight owners are taking advantage of this fact to trick the computers in their cars into higher performance with little more than a handful of resistors.

The relatively simple modification to the first-generation Insight involves a shunt resistor, which lets the computer sense the amount of current being drawn from the hybrid battery and delivered to the electric motor. By changing the resistance of this passive component, the computer thinks that the motor is drawing less current and allows more power to be delivered to the drivetrain than originally intended. With the shunt resistor modified, which can be done with either a bypass resistor or a custom circuit board, the only other change is to upgrade the 100 A fuse near the battery for a larger size.

With these two modifications in place, the electric motor gets an additional 40% power boost, which is around five horsepower. But for an electric motor which can output full torque at zero RPM, this is a significant boost especially for a relatively lightweight car that’s often considered under-powered. It’s a relatively easy, inexpensive modification though which means the boost is a good value, although since these older hybrids are getting along in years the next upgrade might be a new traction battery like we’ve seen in the older Priuses.

Thanks to [Aut0l0g1c] for the tip!

Overview of the Gwyscope SPM controller.

Low-Cost DSP For Scanning Probe Microscopy

January 31, 2024 by 3 Comments

A scanning probe microscope comes in a wide variety of flavors, they all produce a set of data points containing the measurements at each location. Usually these data points form a regular 2D grid, but it can be more beneficial to change the density of measurements at certain locations, or even the height, which creates a much more complex probing path and subsequent (XYZ) data set.

Yet this should not deter anyone, as [Miroslav Valtr] and colleagues demonstrate in a July 2023 article in Hardware X where they use a Red Pitaya SBC along with custom Eurocard-format PCBs to create a low-cost-ish (<1,500 USD) open hardware Digital Signal Processor (DSP) they call Gwyscope.

How the Gwyscope controller fits into an example of a scanning probe microscope setup. (Credit: Miroslav Valtr et al., 2023)
How the Gwyscope controller fits into an example of a scanning probe microscope setup. (Credit: Miroslav Valtr et al., 2023)

The Red Pitaya itself is used as a convenient hybrid FPGA-based module with on-board signal processing hardware, with its Xilinx Zynq ARM-FPGA chip providing both an FPGA section to implement the feedback loop module in Verilog, as well as the means to run a Linux instance with the C-based software that connects via Ethernet to a remote workstation. This communication is based around the GwyFile library, which is part of the Gwyddion project. The scanning paths are generated using libgwyscan (see this presentation for an introduction).

The resulting scan data is saved as an XYZ data file, which can be read with the Gwyddion visualization and analysis program. Although far from a quick & easy afternoon project for the casual hobbyist, it could be a boon for universities and laboratories.

Thanks to [Nicolae Irimia] for the tip.

Swapping Nunchucks For A Steering Wheel

January 30, 2024 by 4 Comments

Rather than chasing pure performance and high quality graphics like other gaming companies, Nintendo has made a name for themselves over the last few decades by favoring not only artistic design and gameplay, but the physical design of the game systems. Of course the hybrid handheld Switch console is among these, but it also includes things like the novel design of the Nintendo 64 controller and, of course, the Wii nunchuck controllers. They’re not always met with resounding approval, though. Some of us tend to prefer more traditional gamepad design, and will go to extreme lengths to get it like this D-pad for playing Mario Kart Wii.

Rather than simply building a compatible controller for the Wii, or even using a GameCube controller, this controller setup takes a more roundabout approach. A Wiimote is placed in a holster built from Lego, and the game is set up to recognize it as if it were being used in its steering wheel mode. The Lego holster has a servo attached which can tilt the Wiimote from side to side, mimicking a player holding it to play the game, with another set of servos set up to press the various buttons. To control the controller, a homebrew D-pad built on perfboard with an Arduino at its core is used to send commands to the servos, allowing for a more standard controller layout to be used for the classic kart racing game than the steering wheel Wiimote allows.

While it’s quite obvious that there are simpler, easier solutions that avoid the sometimes awkward nature of using Wiimotes, we certainly appreciate the Rube Goldberg-like approach to setting up your gaming experience exactly the way you like. Whether that’s setting up an antique CRT effect for the authentic retro gaming experience or building a complete racing simulator from scratch, the gaming experience is ripe for personalization and unique builds like this one.

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