Day: August 24, 2017

Floating Ants And Drops Of Liquid With An Acoustic Levitator

August 24, 2017 by 9 Comments

Amuse your friends, amaze your enemies, and perplex ants and other insects, insofar as they are capable of perplexment. Accomplish all this and more with this handy dandy homebrew acoustic levitator.

Before anyone gets to thinking about using this technique to build a hoverboard that actually hovers, it’s best that you scale your expectations way, way down. Still, being able to float drops of liquid and small life forms is no mean feat, and looks like a ton of fun to boot. [Asier Marzo]’s Instructable’s post fulfills a promise he made when he first published results for what the popular press then breathlessly dubbed a “tractor beam,” which we covered back in January. This levitator clearly has roots in the earlier work, what with 3D-printed hemispherical sections bristling with ultrasonic transducers all wired in phase. A second section was added to create standing acoustic waves in the middle of the space, and as the video below shows, just about anything light enough and as least as cooperative as an ant can be manipulated in the Z-axis.

There’s plenty of room to expand on [Asier]’s design, and probably more practical applications than annoying bugs. Surface-mount devices are pretty tiny — perhaps an acoustic pick and place is possible?

Continue reading “Floating Ants And Drops Of Liquid With An Acoustic Levitator” →

Ask Hackaday: Saving The World With Wacky Waving Inflatable Arm Flailing Tube Men

August 24, 2017 by 118 Comments

This is a solution to global warming. This solution will also produce electricity, produce rain in desertified areas, and transform the Sahara into arable land capable of capturing CO2. How is this possible? It’s simple: all we need to do is build a five-kilometer tall, twenty-meter wide chimney. Hot air, warmed by the Earth’s surface, will enter the base of the chimney and flow through turbines, generating electricity. From there, air will rise through the chimney, gradually cooling and transferring energy from the atmosphere at Earth’s surface to five kilometers altitude. This is the idea behind the Super Chimney, It’s an engineering concept comparable to building a dam across the Strait of Gibraltar, a system of gigantic mirrors in Earth’s orbit, or anything built under an Atoms for Peace project. In short, this is fringe engineering.

This is also, ‘saving the world with wacky waving inflatable arm flailing tube men.’

The idea of building tens of thousands of fabric chimneys, placing them all around the globe, and cooling the Earth while sequestering carbon dioxide is fantastic. Ideas are simple, implementation is something else entirely. There are also obvious problems with the physics presented in the Super Chimney presentation, but these problems don’t actually make a Super Chimney impossible. We need more eyes on this, so we’re opening this one up as an Ask Hackaday. What do you think of this audacious scheme, and is it even possible?

Continue reading “Ask Hackaday: Saving The World With Wacky Waving Inflatable Arm Flailing Tube Men” →

3D Printed Robotic Arms For Sign Language

August 24, 2017 by 30 Comments

A team of students in Antwerp, Belgium are responsible for Project Aslan, which is exploring the feasibility of using 3D printed robotic arms for assisting with and translating sign language. The idea came from the fact that sign language translators are few and far between, and it’s a task that robots may be able to help with. In addition to translation, robots may be able to assist with teaching sign language as well.

The project set out to use 3D printing and other technology to explore whether low-cost robotic signing could be of any use. So far the team has an arm that can convert text into finger spelling and counting. It’s an interesting use for a robotic arm; signing is an application for which range of motion is important, but there is no real need to carry or move any payloads whatsoever.

Closeup of hand actuators and design. Click to enlarge.

A single articulated hand is a good proof of concept, and these early results show some promise and potential but there is still a long ways to go. Sign language involves more than just hands. It is performed using both hands, arms and shoulders, and incorporates motions and facial expressions. Also, the majority of sign language is not finger spelling (reserved primarily for proper names or specific nouns) but a robot hand that is able to finger spell is an important first step to everything else.

Future directions for the project include adding a second arm, adding expressiveness, and exploring the use of cameras for the teaching of new signs. The ability to teach different signs is important, because any project that aims to act as a translator or facilitator needs the ability to learn and update. There is a lot of diversity in sign languages across the world. For people unfamiliar with signing, it may come as a surprise that — for example — not only is American Sign Language (ASL) related to French sign language, but both are entirely different from British Sign Language (BSL). A video of the project is embedded below.

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Finishing A Mini PS One: SLA Vs Extruded

August 24, 2017 by 24 Comments

One of the biggest lessons learned by first time 3D printer users is that not everything can be replicated and a printer is a machine and not a miracle worker. It has limitations in terms of what it can print as well as the quality of the output. For teeny tiny objects, the 0.8 mm nozzle will just not do and with resin printers on the rise, the question is, ‘are extruder printers obsolete?’

[Dorison Hugo] has made a mini version of the PS One using a Raspberry Pi which you can play games one. The kicker is that in his video, he does a comparison of an SLA printer and a cheaper extruder one for his enclosure. He goes through a laundry-list of steps to print, file, fill, repair, sand paint, sand, paint etc to try to get a good model replica of the original PS One. He then proceeds to print one with an SLA printer and finishes it to compare with the first model. The decals are printed on an inkjet for those who are wondering, and there is a custom cut heatsink in there as well that was salvaged from an old PC.

Spoiler alert! The SLA wins but in our view, just slightly. The idea is that with enough elbow grease and patience, you can get pretty close to making mini models with a cheaper machine. The SLA print needs work too but it is relatively less and for detailed models, it is a much better choice. We really enjoyed watching the process from start to finish including the Dremel work, since it is something that is forgotten when we see a 3D print. Creating something of beauty takes time and effort which stems from a passion to make.

Take a look at the video below of the time lapse and for  SLA printer fans, have a look at the DIY SLA printer which is a Hackaday Prize Entry this year. Continue reading “Finishing A Mini PS One: SLA Vs Extruded” →