Build Your Own Solenoid Engine

September 25, 2019 by Bryan Cockfield 13 Comments

A solenoid engine is a curiosity of the electrical world. By all measures, using electricity to rotate something can be done almost any other way with greater efficiency and less hassle. But there’s just something riveting about watching a solenoid engine work. If you want to build one of your own and see for yourself, [Emiel] aka [The Practical Engineer] has a great how-to.

For this build though he used a few tools that some of us may not have on hand, such as a lathe and a drill press. The lathe was used to make the plastic spool to hold the wire, and also to help wind the wire onto the spool itself rather than doing it by hand. He also milled the wood mounts and metal bearings as well, and the quality of the work really shows through in the final product. The final touch is the transistor which controls power flow to the engine.

If you don’t have all of the machine tools [Emiel] used it’s not impossible to find substitute parts if you want to build your own. It’s an impressive display piece, or possibly even functional if you want your build to have a certain steampunk aesthetic (without the steam). You can even add more pistons to your build if you need extra power.

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Return Of The MITERS Journal

September 25, 2019 by Sharon Lin 4 Comments

After a long hiatus, the MIT Electronic Research Society, better known as MITERS, has released their summer 2019 edition of the MITERS Journal, officially known as Volume 43 Issue 1.

The latest edition features a throwback to the first journal published in 1976, showing that some things just never change:

“What is MITERS? MITERS is the MIT Electronic Research Society, a non-profit, student-run laboratory for MIT’s EE hackers. The Society provides work space, tools, low-cost parts and information to any number of the MIT community. We have a few good ‘scopes, various and sundry pieces of test equipment, a b’zillion power supplies, and Bertha, our beloved PDP-7 computer. (No snickers from the peanut gallery, please. Bertha is very sensitive.) We also have the most incredible plunder-trove on campus.”

– 1976 Journal 1 Number 1

The space remains a member-run project space and maker shop, providing the MIT community with access to tools, knowledge, and room to build projects. Continue reading “Return Of The MITERS Journal” →

Tinker Pilot Project Cranks Cockpit Immersion To 11

September 25, 2019 by Donald Papp 1 Comment

One of the more interesting ideas being experimented with in VR is 1:1 mapping of virtual and real-world objects, so that virtual representations can have physically interaction in a normal way. Tinker Pilot is a VR spaceship simulator project by [LLUÍS and JAVI] that takes this idea and runs with it, aiming for the ability to map a cockpit’s joysticks, switches, and other hardware to real-world representations. What does that mean? It means a virtual cockpit with flight sticks, levers, and switches that have working physical versions that actually exist exactly where they appear to be.

A few things about the project design caught our eye. One is the serial communications protocol intended to interface easily with microcontrollers, allowing for feedback between the program and any custom peripherals. (By the way, this is the same approach Kerbal Space Program took with KSPSerialIO, which enables custom mission control hardware at whatever level of complexity a user may wish to implement.)

The possibilities are demonstrated starting around 1:09 in the teaser trailer (embedded below) in which a custom controller is drawn up in CAD, then 3D-printed and attached to an Arduino, and finally the 3D model is imported into the cockpit as a 1:1 representation of the actual working unit, with visual positional feedback.

Unlike this chair experiment we saw which attached a Vive Tracker to a chair, there is no indication of needing positional trackers on individual controls in Tinker Pilot. In a cockpit layout, controls can be reasonably expected to remain in fixed positions relative to the cockpit, meaning that they can be set up as 1:1 representations of a physical layout and otherwise left alone. The kind of experimentation that is available today even to individual developers or small teams is remarkable, and it’s fascinating to see the ideas being given some experimentation.

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Smartphone Case Doubles As Chording Keyboard, With Gesture Inputs

September 25, 2019 by Donald Papp 6 Comments

Smartphones and other modern computing devices are wonderful things, but for those with disabilities interacting with them isn’t always easy. In trying to improve accessibility, [Dougie Mann] created TypeCase, a combination gestural input device and chording keyboard that exists in a kind of symbiotic relationship with a user’s smartphone.

With TypeCase, a user can control a computer (or the smartphone itself) with gestures, emulate a mouse, or use the device as a one-handed chording keyboard for text input. The latter provides an alternative to voice input, which can be awkward in public areas.

The buttons and motion sensors allow for one-handed button and gestural input while holding the phone, and the Bluetooth connectivity means that the device acts and works just like a wireless mouse or keyboard. The electronics consist mainly of an Adafruit Feather 32u4 Bluefruit LE, and [Dougie] used 3D Hub’s on-demand printing service to create the enclosures once the design work was complete. Since TypeCase doubles as a protective smartphone case, users have no need to carry or manage a separate device.

TypeCase’s use cases are probably best expressed by [Dougie]’s demo video, embedded below. Chording keyboards have a higher learning curve, but they can be very compact. One-handed text input does remind us somewhat of a very different approach that had the user make gestures in patterns reminiscent of Palm’s old Graffiti system; perhaps easier to learn but not nearly as discreet.

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ESPcopter: A Fully Customizable Drone

September 25, 2019 by Sharon Lin 5 Comments

With so many capabilities for obstacle avoidance, the only natural progression for drones would be for them to be hand-controlled. For Turkish inventor [metehanemlik], even this wasn’t enough of a challenge, as he decided to create the ESP8266-Powered Mini Drone: ESPcopter, a programmable Arduino-compatible modular drone that is open to modding through expansion shields. Not only can DIY enthusiasts modify the algorithms used for obstacle avoidance, but the drone can be sized to whatever dimensions fit their needs.

The drone is almost entirely built from expansion shields, including the multi-ranger shield with four VL53L0x laser-ranging sensors on the forward, backward, right, and left directions of the drone. The website for the ESPcopter comes with an SDK that lets users easily modify the software running on the drone’s MCU as well as pinouts to better understand its hardware functionality. Impressively, it was fully funded through a 60-day crowdfunding campaign, and will be undergoing a second launch shortly, with some new and improved features.

Power comes from a 26 0mAh LiPo battery that allows for up to six minutes of flight time; includes a 3-axis gyroscope, accelerometer, and magnetometer; runs on an ESP8266-12S 32-bit MCU; fully charges within 45 minutes through a USB connection; weighs around 35 g; and is about 90 mm from motor to motor. Continue reading “ESPcopter: A Fully Customizable Drone” →

100 Year Old Atomic Clock

September 25, 2019 by Gregory L. Charvat 33 Comments

Precision time is ubiquitous today thanks to GPS and WWVB. Even your Macbook or smartphone displays time which is synchronized to the NIST-F1 clock, a cesium fountain atomic clock (aka the ‘Atomic Clock’) that is part of a global consortium of atomic clocks known as Coordinated Universal Time (UTC). Without precise timing there would be train collisions, markets would tumble, schools would not start on time, and planes would fall out of the sky.

But how was precision timing achieved in the 19th century during the era of steam, brass, and solenoids? One of the first systems of precision timing kept trains running safely and on time, rang the bells at school, and kept markets trading by using a special clock designed by the Self Winding Clock Company. Through measurements of celestial objects by the US Naval Observatory, and time synchronization pulses broadcast by the Western Union telegraph network, this system synchronized time across the United States in an era where the speed of our train system was out-pacing by the precision of our clocks.

Those clocks were designed so well that many of them are still around and functioning. One of these 100-year-old self-winding clocks made its way onto my workbench. I did what any curious hacker would do, figured out how the synchronization worked and connected it to a clock source with atomic precision. Let’s take a look!

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Bend Some Bars With A Flywheel

September 25, 2019 by Danie Conradie 16 Comments

The ability to look at a pile of trash, and see the for treasure is a skill we hold in high regard around here. [Meanwhile in the Garage] apparently has this skill in spades and built himself a metal bar bending machine using an old flywheel and starter pinion gear.

To bend metal using muscle power alone requires some sort of mechanical advantage. Usually this involves a bending tool with a long lever, but [Meanwhile in the Garage] decided to make use of the large gear ratio between a car’s starter motor and the flywheel it drives. This does away with the need for a long lever and allows bending to almost 270° with a larger radius. Lathe and milling work features quite prominently, including to make the bend formers, drive shaft and bushings and to modify the flywheel to include a clamp. The belt sander that is used to finish a number of the parts is also his creation. While the machine tools definitely helped, a large amount of creativity and thinking outside the box made this project possible and worth the watch.