Jiffy 3D Aluminum

HacDC community member Julia Longtin and collaborator, Mason Mooney, have been developing a fascinating method to 3D print aluminum via a lost PLA method. It is remarkable for its use of commonly available consumer products such as microwave ovens, sugar, and hair spray. They have posted it to Hackaday and we are sure you'd agree that it deserves as many up votes as possible! Please spread the word if you agree!

Finished aluminum part, after removing from mold

“Our system uses consumer microwave units to perform burn-out of PLA from molds, and a second microwave to liquify aluminium, to be poured into the mold. 3d printer inspired mechanics will move the aluminium from the microwave, into the target mold under human control across the network, so that there is no risk to the person operating the machine.

“Lost PLA is usually dangerous, and time consuming. with this, we can go from [PLA] printed part to cast aluminium part in 3 hours!”

UPDATE (8/20/14): Julia et al. made the front of Hackaday!

USASEF 2014: Report from the field

Splat-shaped, acrylic give-aways engraved with the HacDC logo and domain.

HacDC member, condew, laser cut and engraved 2,042 “splats” of which 1,148 were given away to visitors to our table.

On Friday 25 April, Arte Technica reported:

Thanks to the generosity of Gary Mauler and Robot Fest we really do have an awesome location. Condew’s Arduino LED and hydrometer demo was in fact the highlight of our exhibit today. And the splats he made are going fast. They’re such a hit! Hope you can meet Danish, he is great with the crowds and has also decided to do add his own Arduino demo for our exhibit on Sunday.

The highlight of our day, after the close of Sneak Peek Friday, was a personal demo at our exhibit by the co-Founder of Backyard Brains. Ag4ve, condew, Danish, myself and eventually nearby exhibitors and even passers-by, witnessed an Giant South American Cockroach (Blaberus giganteus) turn right and around, and again, because of a miniature open source neural interface controlled by an iOS app.

FYI—Backyard Brains is looking forward to mirage335’s BioSignal Amplifier demo this weekend, and would enjoy a “Hangout” with other Biohacker enthusiasts at HacDC if there’s interest.

Last but not least, today’s heroes are Lee (N4TCW) and ITechGeek. Lee and his ARRL team literally opened doors for and helped HacDC quickly get to its destination. ITechGeek really busted his hump for us. He setup our very noticeable RasPi server with hacdc.org and wiki.hacdc.org and ALSO went to the space at 05:00, waited, and then helped with multiple transports. Of course, also of note was the staging by condew, Dan B., ag4ve and myself, but ITechGeek and Lee were singularly instrumental in getting us this far.

So even with a couple hours of sleep, all in all a good start.

The festival lasted through Sunday and our table had an estimated 3,000 to 5,000 visitors.

We’ve Adopted a Scanning Electron Microscope (SEM)!

SEM newly installedIt’s our pleasure to announce that HacDC is now the proud owner of a scanning electron microscope (SEM)! An SEM is a scientific instrument capable of producing extremely high-magnification images: magnifications of 5,000x to 500,000x are routinely achieved by these machines. Additionally, SEMs can be interfaced with additional detectors to examine the atomic composition and other characteristics of both organic and inorganic samples. These makes them extremely useful machines for imaging, scientific analysis, and even processes such as e-beam lithography.

If you’re unfamiliar with the incredible images that SEMs can produce, check out this gallery.

Our machine is an older, second-hand model, and was graciously donated to us by 757 Labs. It’s a Cambridge Stereoscan 200 from 1983. Despite its age, it was widely renowned for being a very versatile machine, and all the electronics are well within the realm of being understandable and repairable by the hobbyists and professionals at the hackerspace. It’s currently undergoing member-driven inspection and repair.

Its current status, as well as information about planned projects, can be found on our wiki.

For the inquiring mind: the theory of operation of a standard SEM is relatively straightforward: a metal specimen chamber and hollow column are pumped down to near-vacuum (between 10e-8 to 10e-11 atmospheres!) via the operation of a roughing pump and a turbomolecular or oil diffusion pump. A power supply then runs current through a tungsten filament to cause thermionic emission of electrons—very similar to the operation of a light bulb. Another power supply creates a voltage relative to a nearby anode, which accelerates the electrons to a high energy, adjustable from 1 to 40 keV (kiloelectronvolts). The electrons spray out from the filament towards the anode, but are gradually reduced down to a very small spot size via a series of electromagnetic lenses and one or more metal apertures. This small spot of electrons finally hits the sample. Additional circuitry deflects the small spot of electrons over the sample’s surface, effectively scanning it across the area to be examined, much like a beam inside of a cathode ray television. At this point secondary and backscattered electrons are kicked out of the sample and detected by a sensor inside the chamber, which passes the signal along to processing circuitry, ultimately resulting in an image being displayed on a TV.

If you’re as excited as we are by these images and would like to make your own, or if you’d like to learn more about the nitty-gritty details above, you’re probably the sort of person we’re looking for! We’d love to find members who would like to assist with the repair and operation of the machine, as well as planning future improvements.

(Written by: Dan K and Phil S)

Tinfoil Tuesdays

When: 7pm Every Tuesday Night @ HacDC

A night to talk about security and privacy related things and to teach others about how to protect themselves online. We reference the 7-layer OSI model in the context of security and engage in productively paranoid activities.

Helpful resources:

  • Prism Break: Stop reporting your online activities to the American government with these free alternatives to proprietary software.
  • Tails: A live operating system, that you can start on almost any computer from a DVD, USB stick, or SD card. It aims at preserving your privacy and anonymity.
  • UnlistMy.Info: Find out which top Online sites store data about you, and tell them to unlist your info.

Red Pills: