[F.Lab] is really worried that we are going to prepare a DNA sample from saliva, dish soap, and rubbing alcohol in their 3D-printed centrifuge and then drink it like a shot. Perhaps they have learned from an horrific experience, perhaps biologists have different dietary requirements. Either way, their centrifuge is really cool. Just don’t drink the result. (Ed note: it’s the rubbing alcohol.)
The centrifuge was designed in Sketch-Up and then 3D printed. They note to take extra care to get high quality 3D prints so that the rotor isn’t out of balance. To get the high speeds needed for the extraction, they use a brushless motor from a quadcopter. This is combined with an Arduino and an ESC. There are full assembly instructions on Thingiverse.
[F.Lab] has some other DIY lab equipment designs, such as this magnetic stirrer. Which we assume you could use to make a shot if you wanted to. However, it’s probably not a good idea to mix lab supplies and food surfaces. Video after the break.
Continue reading “DNA Extraction With A 3D-Printed Centrifuge”
Microchips and integrated circuits are usually treated as black boxes; a signal goes in, and a signal goes out, and everything between those two events can be predicted and accurately modeled from a datasheet. Of course, the reality is much more complex, as any picture of a decapped IC will tell you.
[Jim Conner] got his hands on a set of four ‘teaching’ microchips made by Motorola in 1992 that elucidates the complexities of integrated circuitry perfectly: instead of being clad in opaque epoxy, these chips are encased in transparent plastic.
The four transparent chips are beautiful works of engineering art, with the chip carriers, the bond wires, and the tiny square of silicon all visible to the naked eye. The educational set covers everything from resistors, n-channel and p-channel MOSFETS, diodes, and a ring oscillator circuit.
[Jim] has the chips and the datasheets, but doesn’t have the teaching materials and lab books that also came as a kit. In lieu of proper pedagogical technique, [Jim] ended up doing what any of us would: looking at it with a microscope and poking it with a multimeter and oscilloscope.
While the video below only goes over the first chip packed full of resistors, there are some interesting tidbits. One of the last experiments for this chip includes a hall effect sensor, in this case just a large, square resistor with multiple contacts around the perimeter. When a magnetic field is applied, some of the electrons are deflected, and with a careful experimental setup this magnetic field can be detected on an oscilloscope.
[Jim]’s video is a wonderful introduction to the black box of integrated circuits, but the existence of clear ICs leaves us wondering why these aren’t being made now. It’s too much to ask for Motorola to do a new run of these extremely educational chips, but why these chips are relegated to a closet in an engineering lab or the rare eBay auction is anyone’s guess.
16A lot of engineers, scientists, builders, makers, and hackers got their start as children with LEGO. Putting those bricks together, whether following the instructions or not, really brings out the imagination. It’s not surprising that some people grow up and still use LEGO in their projects, like [Steve] who has used LEGO to build an optics lab with a laser beam splitter.
[Steve] started this project by salvaging parts from a broken computer projector. Some of the parts were scorched beyond repair, but he did find some lenses and mirrors and a mystery glass cube. It turns out that this cube is a dichroic prism which is used for combining images from the different LCD screens in the projector, but with the right LEGO bricks it can also be used for splitting a laser beam.
The cube was set on a LEGO rotating piece to demonstrate how it can split the laser at certain angles. LEGO purists might be upset at the Erector set that was snuck into this project, but this was necessary to hold up the laser pointer. This is a great use of these building blocks though, and [Steve] finally has his optics lab that he’s wanted to build for a while. If that doesn’t scratch your LEGO itch, we’ve also featured this LEGO lab which was built to measure the Planck constant.
Biohackers, fire up your laser cutters. [CopabX] has developed OpenFuge: a (relatively) low-cost, open-source centrifuge from powerful hobby electronic components. If you thought the VCR centrifuge wasn’t impressive, trolls be damned— OpenFuge can crank out 9000 RPM and claims it’s capable of an impressive 6000 G’s. [CopabX] also worked in adjustable speed and power, setting time durations, and an LCD to display live RPM and countdown stats.
And it’s portable. Four 18650 lithium cells plug into the back, making this centrifuge a truly unique little build. The muscle comes from a DC outrunner brushless motor similar to the ones that can blast you around on a skateboard but with one key difference; an emphasis on RPMs over torque. We’re not sure exactly which motor is pictured, but one suggestion on the bill of materials boasts a 6000 KV rating, and despite inevitable losses, that’s blazing fast at nearly 15V.
You’ll want to see the demonstration video after the break, but also make time to swing by Thingiverse for schematics and recommended parts.
Continue reading “OpenFuge: an open-source centrifuge”
VCR’s practically scream “tear me open!” with all those shiny, moving parts and a minimal risk that you’re going to damage a piece of equipment that someone actually cares about. Once you’ve broken in, why not hack it into a centrifuge like [Kymyst]? Separating water from the denser stuff doesn’t require lab-grade equipment. As [Kymyst] explains: you can get a force of 10 G just spinning something around your head. By harvesting some belt drives from a few VCR’s, however, he built this safer, arm-preserving motor-driven device.
[Kymst] dissected the video head rotor and cassette motor drive down to a bare minimum of parts which were reassembled in a stack. A bored-out old CD was attached beneath the rotor while a large plastic bowl was bolted onto the CD. The bowl–here a microwave cooking cover–acts as a protective barrier against the tubes spinning inside. The tube carriers consist of plastic irrigation tubing fitted with a homemade trunnion, which [Kymyst] fashioned from some self-tapping screws and a piece of PVC. At 250 rpm, this centrifuge reaches around 6 G and best of all, gives a VCR something to do again. Take a look at his guide and make your own, particularly if your hackerspace has a bio lab.
[Ezra] used the parts he had lying around to build a self-contained dual screen shop computer. What might one name such a project? Obviously you’d call it the Dr. FrankenComputer.
The lower monitor is a dell desktop flat screen. During prototyping [Ezra] used the stand to support everything. But to keep his work space clear the final version has been mounted to the wall in the corner of his lab. The upper display is the LCD from a Compaq laptop which he wasn’t using. The laptop still works and we believe that’s what is driving the Fedora system. A bracket mounted to the desktop screen’s inner skeleton supports the laptop screen and motherboard. One power supply feeds everything and connects to an outlet in the wall behind the monitors. The keyboard and mouse are wireless, as is the computer’s connection to the network.
The only thing we would worry about in our own shop is sawdust filling the heat sinks and other components of the motherboard. Perhaps his lab is electronic projects only or he has a dust cover that he uses when the system isn’t in use.
We think that anyone who’s done at-home PCB fabrication will appreciate the tidiness that [Fran] maintains throughout her etching process. She recently posted a three-part video tutorial which showcases her techniques. As you can see in the screenshot above, her habits reek of top-notch laboratory skills.
Regular readers can probably guess what circuit she’s etching. It’s the test boards for her LVDC reverse engineering. She is using the toner transfer method, but in a bit different way than most home-etchers do. She uses the blue transfer paper made for the job, but before transferring it to the copper clad she uses a light box (kind of like the X-ray film viewer at the doctor’s office) to inspect for any gaps where toner did not adhere. From there she uses a heat press to apply the resist. This is a heck of a lot easier than using a clothes iron, but of course you’ve got to have one of these things on hand to do it this way.
The second part of the tutorial is embedded after the break. We chose this segment because it shows off how [Fran] built her own chemical hood. It’s a clear plastic storage container lying upside down. A work window has been cut out of the front side, and a 4-inch exhaust hose added to the top. [Fran’s] lab has a high volume low velocity fan to which it connects to whisk the fumes outside.
Continue reading “[Fran’s] PCB etching techniques”