Chemical Formulas 101

It seems like every other day we hear about some hacker, tinkerer, maker, coder or one of the many other Do-It-Yourself engineer types getting their hands into a complex field once reserved to only a select few. Costs have come down, enabling common everyday folks to equip themselves with 3D printers, laser cutters, CNC mills and a host of other once very expensive pieces of equipment. Getting PCB boards made is literally dirt cheap, and there are more inexpensive Linux single board computers than we can keep track of these days. Combining the lowering hardware costs with the ever increasing wealth of knowledge available on the internet creates a perfect environment for DIYers to push into ever more specific scientific fields.

One of these fields is biomedical research. In labs across the world, you’ll find a host of different machines used to study and create biological and chemical compounds. These machines include DNA and protein synthesizers, mass spectrometers, UV spectrometers, lyophilizers, liquid chromatography machines, fraction collectors… I could go on and on.

These machines are prohibitively expensive to the DIYer. But they don’t have to be. We have the ability to make these machines in our garages if we wanted to. So why aren’t we? One of the reasons we see very few biomedical hacks is because the chemistry knowledge needed to make and operate these machines is generally not in the typical DIYers toolbox. This is something that we believe needs to change, and we start today.

In this article, we’re going to go over how to convert basic chemical formulas, such as C9H804 (aspirin), into its molecular structure, and visa versa. Such knowledge might be elementary, but it is a requirement for anyone who wishes to get started in biomedical hacking, and a great starting point for the curious among us.

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Raspberry Pi Adds A Digital Dash To Your Car

Looking for a way to make your older car more hi-tech? Why not add a fancy digital display? This hack from [Greg Matthews] does just that, using a Raspberry Pi, a OBD-II Consult reader and an LCD screen to create a digital dash that can run alongside (or in front of ) your old-school analog dials.

[Greg’s] hack uses a Raspberry Pi Foundation display, which includes a touch screen, so you don’t need a mouse or other controls. Node.js displays the speed, RPM, and engine temperature (check engine lights and other warnings are planned additions) through a webpage displayed using Chromium. The Node page is pulling info from another program on the Pi which monitors the CAN Consult bus. It would be interesting to adapt this to use with more futuristic displays, maybe something like a pico projector and a 1-way mirror for a heads-up display.

To power the system [Greg] is using a Mausberry power supply which draws power from your car battery, but which also cleanly shuts down the Pi when the ignition is turned off so it won’t drain your battery. When you throw in an eBay sourced OBD-II Consult reader and the Consult Dash software that [Greg] wrote to interpret and display the data from the OBD-II Consult bus, you get a decent digital dash display. Sure, it isn’t a Tesla touchscreen, but at $170, it’s a lot cheaper. Spend more and you can easily move that 60″ from your livingroom out to your hoopty and still use a Raspberry Pi.

What kind of extras would you build into this system? Gamification of your speed? Long-term fuel averaging? Let us know in the comments.

UPDATE – This post originally listed this hack as working from the OBD-II bus. However, this car does not have OBD-II, but instead uses Consult, an older data bus used by Nissan. Apologies for any confusion!

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Songbird, A Mostly 3D Printed Pistol That Appears To Actually Work

[Guy in a garage] has made a 3D printed gun that not only appears to fire in the direction pointed, it can also do it multiple times. Which, by the standard of 3D printed guns, is an astounding feat. He started with .22 rifle cartridges but has since upgraded and tested the gun with .357 rounds. The link above is a playlist which starts of with an in-depth explanation of the .22 version and moves through design iterations

This gun prints on a standard FDM printer. Other 3D printable guns such as the infamous Liberator or the 3D printed metal gun need more exotic or precise 3D printing to work effectively. The secret to this gun’s ability is the barrel, which can be printed in nylon for .22 cartridges, or in ABS plus a barrel liner for .22 and .357 caliber.

A barrel liner is one way to repair a gun that has aged and is no longer shooting properly. Simply put, it is a long hardened metal tube with rifling on the inside. Some guns come out of the factory with one, and a gunsmith simply has to remove the old one and replace it. Other guns need to be bored out before a liner can be installed.

The metal liner surrounded by plastic offers enough mechanical strength for repeat firings without anyone losing a hand or an eye; though we’re not sure if we recommend firing any 3D printed gun as it’s still risky business. It’s basically like old stories of wrapping a cracked cannon in twine. The metal tries to expand out under the force of firing, but the twine, which would seem like a terrible material for cannon making, is good in tension and when wrapped tightly offers more than enough strength to hold it all together.

This is also how he got the .357 version to work. The barrel slots into the gun frame and locates itself with a rounded end. However, with the higher energy from a .357 round, this rounded end would act as a wedge and split the 3D printed frame. The fix for this was simple. Glue it back together with ABS glue, and then wrap the end of the assembly with a cable tie.

This is the first 3D printed gun we’ve seen that doesn’t look like a fantastic way to instantly lose your hand. It’s a clever trick that took some knowledge of guns and gunsmithing to put together. Despite the inevitable ethical, moral, and political debate that will ensue as this sort of thing becomes more prevalent, it is a pretty solid hack and a sign that 3D printing is starting to work with more formidable engineering challenges.