Fidget Spinners Put The ‘S’ In STEAM Education

Centrifuges are vital to the study of medicine, chemistry, and biology. They’re vital tools to separate the wheat from the chaff figuratively, and DNA from saliva literally. Now, they’re fidget spinners. [Matlek] designed a fidget spinner that also functions as a simple lab centrifuge.

The centrifuge was designed in Fusion 360, and was apparently as easy as drawing a few circles and hitting copy and paste. Interestingly, this fidget spinner was designed to be completely 3D printable, including the bearings. The bearing is a standard 608 though, so if you want to get some real performance out of this centrispinner, off-the-shelf bearings are always an option. The design of this fidget spinner holds 2 mL and 1.5 mL vials, but if your lab has 500 μL tubes on hand, there are handy 3D printable adapters.

Still think using a toy to do Real Science™ is dumb? Contain your rage, because a few months ago a few folks at Stanford devised a way to build a centrifuge out of paper. This paperfuge can — at least theoretically — save lives where real commercial centrifuges or even electricity aren’t available. Fidget spinners save humanity once again.

DNA Extraction With A 3D-Printed Centrifuge

[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”

Centrifuge Spins Samples up to 400g

We were curious to see when someone would use a 3D printing pen for something other than art. It might not look very pretty, but [Techmeology] “drew” this centrifuge mount for a motor in order to spin some test tube samples.

It’s kind of hard to see in the picture, but the test tube holder “arms” are detachable, and when the motor spins up it opens like an umbrella. Pretty much all the parts are recycled, and the motor came from an old appliance, making the cost of this project negligible — a good use case for any remote location that might require custom parts or repairs.

As for actually fabricating functional items with the 3D printing pen, [Techmeology] offers some useful tips for drawing brackets on his site. For instance, wrap the parts for which you need mounting brackets in paper. This provides a barrier while drawing your design in molten plastic.

There are a few other tricks that can be performed by 3D printing pens, like using them to “weld” parts back together. If you don’t already have one you could just use a soldering iron for this purpose — or make your own 3D printing pen using LEGO and a hot glue gun.

Take Your Samples for a Spin with the RWXBioFuge

We have a confession to make: we love centrifuges. We’ve used all shapes and sizes, for spinning bags of whole blood into separate components to extracting DNA, and everything in between. Unfortunately, these lab staples are too expensive for many DIY-biologists unless they buy them used or build them themselves. [Pieter van Boheemen] was inspired by other DIY centrifuges and decided to make his own, which he named the RWXBioFuge.

[Pieter] designed the RWXBioFuge using Sketchup, OpenSCAD, and InkScape. It features a Thermaltake SMART M850W ATX power supply, an R/C helicopter Electronic Speed Controller (ESC), and brushless outrunner motor. For user output it utilizes a 16×2 LCD character display with an I2C interface.The frame is laser-cut from 3mm MDF while the 3D-printed PLA rotor was designed with OpenSCAD.

An Arduino handles the processing side of things. [Pieter] used an Arduino Ethernet – allowing a web interface to control the centrifuge’s settings and operation from a distance. We can see this being useful in testing out the centrifuge for any rotor/motor balance issues, especially since [Pieter] states that it can be configured to run >10,000 rpm. We wouldn’t want to be in the room if pieces start flying off any centrifuge at that speed!  However, we feel that when everything’s said and done, you should have a centrifuge you can trust by your side when you’re at your lab bench.

While there are similarities to the Openfuge, the larger RWXBioFuge has rotor capacities of eight to twenty 1.5-2.0ml microcentrifuge tubes. Due to the power supply, it is not portable and a bit more expensive, but not incredibly so. There are some small touches about this centrifuge that we really like. The open lid detector is always a welcome safety feature. The “Short” button is very handy for quick 5-10 second spins.

A current version of the RWXBioFuge is being used at the Waag Society’s Open Wetlab. [Pieter’s] planned upgrades for the next version include a magnetic lid lock, different rotor sizes, an accelerometer to detect an improperly balanced rotor, and optimizing the power supply, ESC, and motor setup. You can never have enough centrifuges in a lab, and we are looking forward to seeing this project’s progress!

Check out a few more pictures of the RWXBioFuge after the break.

Continue reading “Take Your Samples for a Spin with the RWXBioFuge”

Circular Saws In the Kitchen, Good Idea or Best Idea?

Kitchen centrifuge using a circular saw

[Mike Warren] was contemplating risky but exciting projects he could do when he came up with this magnificent contraption. A centrifuge made out of an old circular saw!

First question — why? Well if you’re a foody or you enjoy the study of molecular gastronomy, bringing a centrifuge to the kitchen can allow for some more technical dishes. It suddenly becomes possible to separate food based on its density, just like how it works in the lab. Practical applications for super fancy dishes — we’re not too sure — but it involves relatively unsafe power tools and food so we felt obliged to share it!

Let’s start off with the generic warning — in fact, [Mike] states this before the Instructable begins:

Do not replicate this project, it is incredibly dangerous!

The project makes use of an old corded circular saw, a few salad bowls, some threaded rod, a few nuts, some binder clips and some metal plates to hold the plastic test tubes. At 4900RPM (the speed of his saw),he’s calculated his G-Force to be around 1879G’s. Holy cow. A person passes out at around 10Gs, and a bullet fired from a typical handgun is well over 50,000 — on the extreme end of things, a professional lab ultra-centrifuge can hit over 300,000.

These all of course pale by comparison to the Large Hadron Collider, which can accelerate protons at approximately 190,000,000G’s! And to conclude, this is what happens when lab centrifuges blow up. Don’t do it — but do watch the following video and enjoy!

Continue reading “Circular Saws In the Kitchen, Good Idea or Best Idea?”

OpenFuge: an open-source centrifuge


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 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.