Modding A Hot Wheels Car Into A Radio Controlled Drift Weapon

April 23, 2021 by 14 Comments

Hot Wheels are some of the most popular diecast toy cars worldwide. The car bodies are faithful recreations of the real thing, though the models are mere stationary playthings. That wasn’t good enough for [Jakarta Diecast Project], who set about modifying a little BMW E30 M3 into an awesome radio-controlled drift car.

The build starts by disassembling the original car, and pulling out the original wheels. The baseplate is then modified to accept a new rear suspension and axle assembly. A small DC motor is mounted to the assembly to drive the rear wheels. A set of front steering knuckles are then installed up front, with their own suspension and hooked up to a tiny servo for steering. Everything’s controlled by a compact off-the-shelf RC receiver, which even features a gyro to help keep the tiny car straight under acceleration. The bodyshell is then stripped of paint, and given a sweet bodykit, before receiving a lurid orange paint job and decals. It’s reattached to the car’s baseplate via magnets, which make taking the car apart easy when service or modifications are required.

While the build doesn’t go into the nitty gritty on some of the harder parts, like the construction of the incredibly complex front knuckles, it’s nonetheless a great guide to building such a tiny and well-presented RC car. In looks and performance, the result trounces typical commercial offerings in the same scale, as you’d expect from such a hand-crafted masterpiece. It may not be the smallest RC car we’ve featured, but it is one of the coolest. Video after the break.

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Ooohhh, That Smell: Arduino Monitors Air Quality

April 23, 2021 by 26 Comments

According to [Dr. Tom Lehrer’s] song Pollution, “Wear a gas mask and a veil. Then you can breathe, long as you don’t inhale!” While the air quality in most of the world hasn’t gotten that bad, there is a lot of concern about long-term exposure to particulates in the air causing health problems. [Ashish Choudhary] married an Arduino with a display and a pollution sensor to give readings of the PM2.5 and PM10 levels in the air.

The sensor uses a laser diode and a photodiode to detect and count particles, while a fan moves air through the system. If you aren’t up on pollution metrics, PM2.5 is a count of very fine particles (under 2.5 microns) and PM10 is a count of particles for 10 microns. You can find a datasheet for the device online.

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Pi-Based Spectrometer Puts The Complexity In The Software

April 23, 2021 by 43 Comments

Play around with optics long enough and sooner or later you’re probably going to want a spectrometer. Optical instruments are famously expensive, though, at least for high-quality units. But a useful spectrometer, like this DIY Raspberry Pi-based instrument, doesn’t necessarily have to break the bank.

This one comes to us by way of [Les Wright], whose homebrew laser builds we’ve been admiring for a while now. [Les] managed to keep the costs to a minimum here by keeping the optics super simple. The front end of the instrument is just a handheld diffraction-grating spectroscope, of the kind used in physics classrooms to demonstrate the spectral characteristics of different light sources. Turning it from a spectroscope to a spectrometer required a Raspberry Pi and a camera; mounted to a lens and positioned to see the spectrum created by the diffraction grating, the camera sends data to the Pi, where a Python program does the business of converting the spectrum to data. [Les]’s software is simple by complete, giving a graphical representation of the spectral data it sees. The video below shows the build process and what’s involved in calibrating the spectrometer, plus some of the more interesting spectra one can easily explore.

We appreciate the simplicity and the utility of this design, as well as its adaptability. Rather than using machined aluminum, the spectroscope holder and Pi cam bracket could easily be 3D-printer, and we could also see how the software could be adapted to use a PC and webcam.

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“Paper” Bottles For Your Fizzy Drinks (And Bottle Rockets)

April 23, 2021 by 144 Comments

A story that passed almost unnoticed was that the Coca-Cola company plan to run a limited trial of paper bottles. Wait, paper for a pressurized beverage? The current incarnation still uses a plastic liner and cap but future development will focus on a “bio-based barrier” and a bio composite or paper cap tethered to the vessel.

Given that plastic pollution is now a major global concern this is interesting news, as plastic drinks bottles make a significant contribution to that problem. But it raises several questions, first of all why are we seemingly unable to recycle the bottles in the first place, and given that we have received our milk and juice in paper-based containers for decades why has it taken the soda industry so long?

Plastic soft drink bottles are made from Polyethylene terephthalate or PET, the same polyester polymer as the one used in Dacron or Terylene fabrics. They’re blow-moulded, which is to say that an injection-moulded preform something like a plastic test tube with a screw top fitting is expanded from inside in a mould by compressed gas. As anyone who has experimented with bottle rockets will tell you, they are immensely strong, and as well as being cheap to make and transport they are also readily recyclable when separated from their caps.

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Hackaday Podcast 115: AI Is Bad At Linux Terminal, Puppeting Pico In Python, 3D Scanning Comes Up Short

April 23, 2021 by 2 Comments

Hackaday editors Mike Szczys and Elliot Williams pull back the curtain on a week of excellent hacks. We saw an awesome use of RGB LEDs as a data channel on a drone, and the secrets of an IP camera’s OS laid bare with some neat reverse engineering tools. There’s an AI project for the Linux terminal that guesses at the commands you actually want to run. And after considering how far autopilot has come in the aerospace industry, we jump into a look at the gotchas you’ll find when working with models of 3D scanned objects.

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (~60 MB)

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An Anamorphic Lens Adapter For Very Pretty Video

April 23, 2021 by 11 Comments

Anamorphic lenses are a great way to shoot in widescreen, but they’re prohibitively expensive on digital formats. Enthusiasts have experimented with using anamorphic adapter lenses from old projectors, but focusing can be a chore and results sub-par. [Andrew] found a way to use these cheap old anamorphic adaptors on a modern camera without sacrificing too much functionality.

Pretty, no?

Anamorphic filming techniques came about in the era of film. The aim was to record cinema-style widescreen footage on 3:2 aspect ratio 35 mm film. The way this was done was by using a lens that squeezes a wide aspect ratio to fit the format, and then a corresponding lens to squeeze it back on the projector. This allows for higher resolution than simply letterboxing onto the 35 mm frame and wasting the extra space.

Adam’s hack involves 3D printing a lens housing that pairs an anamorphic projector adapter lens with a Sony E-mount taking lens. Gears are set up so that both lenses can be focused together, rather than typical adapter setups that require the user to juggle multiple focus rings at once. This makes the rig much more usable in real shoots where there’s no time for messing about.

It’s a useful hack, and one we could imagine quite a few low-budget filmmakers will be rushing out to replicate. Files are on Thingiverse for the eager. Consider whipping yourself up a camera slider while you’re at it for really boss shots. Video after the break.

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This Week In Security: NAME:WRECK, Signal Hacks Back, Updates, And More

April 23, 2021 by 9 Comments

NAME:WRECK is a collection of vulnerabilities in DNS implementations, discovered by Forescout and JSOF Research. This body of research can be seen as a continuation of Ripple20 and AMNESIA:33, as it builds on a class of vulnerability discovered in other network stacks, problems with DNS message compression.

Their PDF Whitepaper contains a brief primer on the DNS message format, which is useful for understanding the class of problem. In such a message, a DNS name is encoded with a length-value scheme, with each full name ending in a null byte. So in a DNS Request, Hackaday.com would get represented as [0x08]Hackaday[0x03]com[0x00]. The dots get replaced by these length values, and it makes for an easily parsable format.

Very early on, it was decided that continually repeating the same host names in a DNS message was wasteful of space, so a compression scheme was devised. DNS compression takes advantage of the maximum host/domain length of 63 characters. This max size means that the binary representation of that length value will never contain “1”s in the first two digits. Since it can never be used, length values starting with a binary “11” are used to point to a previously occurring domain name. The 14 bits that follow this two bit flag are known as a compression pointer, and represent a byte offset from the beginning of the message. The DNS message parser pulls the intended value from that location, and then continues parsing.

The problems found were generally based around improper validation. For example, the NetX stack doesn’t check whether the compression pointer points at itself. This scenario leads to a tight infinite loop, a classic DoS attack. Other systems don’t properly validate the location being referenced, leading to data copy past the allocated buffer, leading to remote code execution (RCE). FreeBSD has this issue, but because it’s tied to DHCP packets, the vulnerability can only be exploited by a device on the local network. While looking for message compression issues, they also found a handful of vulnerabilities in DNS response parsing that aren’t directly related to compression. The most notable here being an RCE in Seimens’ Nucleus Net stack. Continue reading “This Week In Security: NAME:WRECK, Signal Hacks Back, Updates, And More” →