Day: October 28, 2019

Solenoid Engine Adds Three “Pistons”

October 28, 2019 by 9 Comments

The earliest piston engines typically had only one cylinder, and at best, produced horsepower measured in single digits. But once you have a working engine, it’s a relatively short step to adding cylinders and increasing the power output. [Emiel] made a similar upgrade to one of his engines recently, upgrading it from one cylinder to four. But this isn’t an internal combustion engine, it gets its power from electric solenoids.

We featured his single-cylinder build about a month ago, and since then he’s been busy with this impressive upgrade. The new engine features four cylinders arranged in a V4 pattern. Of course, this greatly increases the mechanical complexity. To start, he had to machine a crankshaft to connect all four “pistons” to a shared output shaft. He also had to build a set of cams in order to time the firing of the cylinders properly, so they don’t work against one another.

The build is just as polished and impressive as the last, which is saying a lot. [Emiel] has a quality machine shop and built the entire motor from scratch, including winding the solenoids, machining the connecting rods and shafts, and building a very picturesque wooden base for the entire contraption to sit on. It’s definitely worth checking out.

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Hacking Mars: InSight Mole Is On The Move Again

October 28, 2019 by 23 Comments

Your job might be tough, but spare a thought for any of the engineers involved in the Mars InSight lander mission when they learned that one of the flagship instruments aboard the lander, indeed the very instrument for which the entire mission was named, appeared to be a dud. That’s a bad day at work by anyone’s standards, and it happened over the summer when it was reported that the Mars Interior Exploration using Seismic Investigations, Geodesy and Heat Transport lander’s Heat Flow and Physical Properties Package (HP³), commonly known as “The Mole”, was not drilling itself into the Martian regolith as planned.

But now, after months of brainstorming and painstaking testing on Earth and on Mars, it looks as if the mole is working again. NASA has announced that, with a little help from the lander’s backhoe bucket, the HP³ penetrator has dug itself 2 cm into the soil. It’s a far cry from the 5-meter planned depth for its heat-transfer experiments, but it’s progress, and the clever hack that got the probe that far might just go on to salvage a huge chunk of the science planned for the $828 million program.

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Electricity Makes Soft Robotics More Like Us Meatbags

October 28, 2019 by 6 Comments

Building a future where robots work alongside humans relies heavily on soft robotics. Typically this means there will be an air compressor or a hydraulic system nearby, taking up precious space. But it doesn’t have to.

Engineers at the UC-San Diego Jacobs School have created a soft robotics system that uses electricity to control flexible actuators, much like our brains move our muscles. It works like this: sheets of heat-sensitive liquid crystal elastomer are sandwiched between two layers of standard elastomer. These layers are rolled into cylinders that can twist and bend in different directions depending on which of its six element(s) get electricity. Light up all six, and the tube contracts, forming the foundation for a good gripper. The team also built a tiny walker, pictured above.

The project is still in its infancy, so the actuators are slow to bend and even slower to return to their original shape, but it’s still a great start. Imagine all the soft robotic projects that can get off the ground without being shackled by the bulk and weight of an air compressor or fluid handling system. Watch it do various sped-up things after the break, like claw-machine gripping a bottle of chocolate rocks.

Speaking of delicious candy, edible soft robotics is totally a thing.

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World’s Smallest MIDI Synth, Now Even Better

October 28, 2019 by 6 Comments

We’re pretty sure there’s no internationally recognized arbiter of records like “World’s smallest full-featured polyphonic stereo MIDI synthesizer that fits in a DIN shell”. If there isn’t, there sure should be, and we’re pretty sure [mitxela]’s Flash-Synth would hold that particular record.

This is one of those lessons that some people just can’t leave a challenge alone. First [mitxela] built a MIDI synthesizer into a DIN connector, then a couple of months later he made a somewhat more streamlined version. While both were feats of engineering derring-do, neither was entirely satisfactory. With only square wave synthesis and a limit of eight voices, plus some unpleasant audio issues and a total lack of manufacturability, the next challenge was clear.

We won’t pretend to follow all the audio arcana, of which the video below and the build log have plenty, but the technical achievement is obvious enough. The Flash-Synth has an STM32, a tantalum SMD filter capacitor that dwarfs it, and a few support components on a flexible PCB that folds back on itself twice. This bit of circuit origami is connected to a 5-pin DIN plug and stuffed into the connector’s shell, which in turn mates to a custom-machined metal housing. A stereo audio jack lives at the other end of the assembly, and the whole synth is powered parasitically off the MIDI port.

The first half of the video below is mostly a demo that proves the synth sounds great and can do just about anything; skip to the 22-minute mark for the gory build details. Suffice it to say that [mitxela]’s past experience with ludicrous scale soldering served him well here.

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