DIY Barometer: It’s For Your Health!

October 27, 2017 by James Hobson 13 Comments

[Taciuc Marius] and his colleague noticed that days with low atmospheric pressure plus caffeine in their system meant a spike in blood pressure. Considering how this might impact his cardiovascular health, he decided to make a relative pressure barometer out of a jar to help him decide whether he should really have another cup of coffee.

Aside from a 3D printer, you’ll need to assemble a small jar with a lid, some screws, lock washers, nuts, and a flexible membrane — a piece of a rubber glove or balloon will do nicely. [Marius] details the build process on his project page, advising others to print the parts at 0.2 resolution — potentially even upping the extrusion multiplier to 1.1 — to prevent gaps in the print that would compromise the airtight seal needed for the barometer to work properly.

Additionally, thick glue or epoxy is recommended for the rest of the assembly process — it doesn’t have to be pretty, but it does need to be sealed! The final product can be easily tested by simply holding the jar.

While this barometer helps one make healthy choices, not all are created equal. This one tells you flat out how you should consider getting to work, while others have been tricked into behaving like touch sensors.

Modular Storage With Peanut Butter And Lasers

August 23, 2017 by John Baichtal 22 Comments

I have storage on the mind, and it comes from two facts in my life:

First, I have tons of stuff in my workshop, far too much for the amount of space I have. A lot of this material is much easier to use if it’s well-organized. Think electronics, robotics, building sets. Modular parts that need to go together a certain way for them to be useful. It is imperative, therefore, that I come up with some sort of organization system to keep the chaos in check.

Second, my favorite tool is the laser cutter, born from my love for building vector designs. I can do art on the computer and have it manufactured in front of my eyes, and share my designs with someone else who can remix it into something even cooler.

So with those two facts in mind, I set about creating a modular storage system in Inkscape and cutting out the design from pine boards using a laser cutter. Let us go on a journey through my thought process:

Continue reading “Modular Storage With Peanut Butter And Lasers” →

Trimethyl Borate Lantern Built From Garbage

May 20, 2013 by Mike Szczys 18 Comments

scratch-build-lantern

This lantern was built from recyclable goods. It’s a bit dangerous when used like the image above, but [The Green Gentleman] does give you a few other options in his build instructions which make for much safer operation.

The lantern enclosure is made from old cans and a glass jar. He screwed a couple of boards together at a right angle to act as a jig for cutting the glass. The V-shape created by the boards holds the jar on its side, giving his glass cutting tool something to rest upon. He then turns the jar to score it around the top, and then bottom. He alternated pouring boiling and chilled water on the score mark to shock the glass into breaking along the line.

This makes up the clear part of the enclosure which is later mated with metal top and bottom pieces. From there he adds either an LED, an alcohol lamp, or the Trimethyl Borate lamp seen above. The first two are relatively safe, but the latter burns at around 1500 degrees F. We have reservations about using a plain old glass jar as the enclosure for something burning this hot. It really should be heat resistant glass.

More On GIFAR

August 6, 2008 by Kimberly Lau 9 Comments

[pdp] provides some perspective on the news regarding the GIFAR attack developed by researchers at NGS Software. As he explains, the idea behind the attack, which basically relies on combining a JAR with other files is not new. Combining JAR/ZIP files with GIF/JPG files will create hybrid files with headers at both the top and bottom of the file and allow them to bypass any image manipulation library as valid files. While tightened security and more stringent file validation practices are advisable, the problem is larger than just a vulnerability in browser security. ZIP is an incredibly generic packing technology used everywhere, from Microsoft files to Open Office documents, and of course, in JAR files. He closes with, “any file format that is based on ZIP, you allow your users to upload on your server, can be used in an attack”

[photo: Jon Jacobsen]

The GIFAR Image Vulnerability

August 4, 2008 by Benjamin Eckel 7 Comments

Researchers at NGS Software have come up with a method to embed malicious code into a picture. When viewed, the picture could send the attacker the credentials of the viewer. Social sites like Facebook and Myspace are particularly at risk, but the researchers say that any site which includes log ins and user uploaded pictures could be vulnerable. This even includes some bank sites.

The attack is simply a mashup of a GIF picture and a JAR (Java applet). The malicious JAR is compiled and then combined with information from a GIF. The GIF part fools the browser into opening it as a picture and trusting the content. The reality is, the Java VM recognizes the JAR part and automatically runs it.

The researchers claim that there are multiple ways to deal with this vulnerability. Sun could restrict their Virtual Machine or web applications could continually check and filter these hybrid files, but they say it really needs to be addressed as an issue of browser security. They think that it is not only pictures at risk, but nearly all browser content.
More details on how to create these GIFARs will be presented at this week’s Black Hat conference in Las Vegas.