Metal Casting With Single Shelled PLA Masters

[3DTOPO] does a lot of metal casting (video link, embedded below). That’s obvious by the full and appropriate set of safety gear, a rarity on YouTube.

They had all the equipment to do it the normal way: craft or CNC out a master, produce a drag and a copy, make any necessary cores, and finally; pour the mold. This is a long and tedious process. It has a high rate of error, and there is a parting line.

Another set of methods are the lost ones. With these methods the master is produced out of a material like foam or wax. The master is surrounded by refractory and then melted, burned, or baked out of the mold. Finally the metal is poured in. Theoretically, a perfect reproduction is made without ever having to open the mold.
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DEF CON Uber Badge So Hot It’s Radioactive

I went to the Opening Ceremonies of DEF CON 23 this morning to get more information on the badge challenge and I was not disappointed. The talk covered the Uber badge, which is hot in a literally radioactive sense. This badge, which is also known as the black badge, is reserved for people who are first to solve one of the official DEF CON challenges. It grants lifetime free admission and opens just about any door when listed on your resume.

Lichtenberg Figures

The triangle of acrylic itself is adorned with Lichtenberg Figures. This is a bolt of lightning on the badge. By building up extremely high voltages, the discharge leaves a unique pattern. In this case it was a 5 million volt, 150 kW particle accelerator that made the figures.

There is a medallion affixed to this triangular base-plate which is obviously part of the puzzle everyone is trying to solve this weekend. What is less clear is how the radioactive isotopes of this badge play into this challenge.

Whoa, oh, oh, oh, I’m Radioactive, Radioactive

Trinitie Photo by Shaddack -  CC BY 3.0
Trinitie Photo by Shaddack – CC BY 3.0

[LoST] took inspiration from [Richard Feynman] to a new level with this badge. [Feynman] was involved with “The Gadget” experiment which I know better as Trinity, the first detonation of a nuclear weapon. This badge contains isotopes from that detonation.

Trinitite (get it, from the Trinity explosion?) is a green glassy substance generated from a Plutonium-based bomb explosion. [LoST] made a point of explaining that the samples of Trinitite in this badge create a unique radioactive signature that not only traces back to this explosion, but actually indicates a precise distance form the epicenter of the explosion.

Also embedded in the badge are glass spheres doped with 3% Uranium 238. Tritium, used in exit signs, is a third source of radioactivity on the badge. This is joined by another marker that is a combination of Uraninite, Pitchblende, Carnotite, Gummit, and Yellowcake.

Interesting story, Tritium is highly regulated in this country but it is hypothetically possible to import it from Europe by a seller who ships it sealed inside packets of coffee. Hypothetically.

The opening ceremonies talk concluded with some inspirational remarks from [Dark Tangent]. Pictures of that as well as a few of [L0ST’s] slides are found below. If you’re working on the badge challenge, join in on the collaborative Badge deciphering we’ve started on Hackaday.io. If you’re at DEF CON, make sure to show up for breakfast with us on Sunday.

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DEFCON 22: The Badge Designers

If you go to DEFCON next year (and you should), prepare for extreme sleep deprivation. If you’re not sleep deprived you’re doing it wrong. This was the state in which we ran into [LosT] and [J0nnyM@c], the brains behind the DEFCON 22 badge and all of the twisted tricks that torture people trying to solve the badge throughout the weekend. They were popular guys but wait around until late into the night and the throngs of hint-seekers subside just a bit.

Plans, within plans, within plans are included in the “crypto” which [LosT] talks about in the interview above. We were wondering how hard it is to produce a badge that is not only electrically perfect, but follows the planned challenge to a ‘T’. This includes things like holding off soldering mask from some pads, and different ones on a different version of the badge. Turns out that you just do as well as you can and then alter the puzzle to match the hardware.

Speaking of hardware. A late snafu in the production threw the two into a frenzy of redesign. Unable to use the planned chip architecture, [J0nnyM@c] stepped up to transition the badges over to Propeller P8X32a chips, leveraging a relationship with Parallax to ensure they hardware could be manufactured in time for the conference.

If you haven’t put it together yet, this is that same chip that Parallax just made Open Source. The announcement was timed to coincide with DEFCON.