DremelFuge - A One-Piece Centrifuge for Rotary Tools
by cathalgarvey, published
In the spirit of Open Source Hardware, Dremelfuge is now Open Source Hardware, according to the 0.3 standard found here: http://freedomdefined.org/OSHW
DremelFuge is a printable rotor for centrifuging standard microcentrifuge tubes and miniprep columns. Compared to the cost of a new centrifuge (priced by a fellow Thingiversian at $500 minimum on Froogle), a Dremelfuge is incredibly cheap. It can be used for DIYbio ( http://www.diybio.org ) or for some culinary uses. It requires industry standard 1.5ml/2ml Eppendorf/Microcentrifuge tubes.
- Used with a drill at 3000 RPM, the Dremelfuge will deliver over 400g, enough to comfortably spin down Miniprep samples (proven personally). It will likely achieve acceptable results at lower speeds, too.
- Used at 10krpm, on a Rotary tool for instance, a Dremelfuge should deliver over 4400g, more than enough to spin down bacterial cells.
- At 16krpm, Dremelfuge matches commercial centrifuges.
- On a Dremel 300, a maximum speed of 33krpm equates to a force of over 50,000 times earth's gravity, which puts it into so-called "Ultracentrifuge" territory. The latest version (as printed by Shapeways) has successfully spun tubes at this speed.
To see some picures of Dremelfuge used to spin down cells, see here:
Quick Video Intro to Dremelfuge: http://www.youtube.com/watch?v=86WnXeTZO_Y
(Update: This video hit over 1900 views! Thanks Makezine/Bre!)
A video of me using Dremelfuge practically in a tent, to extract DNA from a banana: www.youtube.com/watch?v=ZnyFwupk5KA
Dremelfuge is available for sale as a high-quality, robust print on Shapeways.com in two editions, each suited for up to six samples at a time: Dremelfuge Recessed Edition, to fit the cutting-tool-holder commonly found with rotary tools (5mm diameter bore), and Dremelfuge Chuck Edition, which can be quickly adapted for use in any machine with a chuck grip. They are both available here on my Shapeways shop:
Dremelfuge, as with any high-speed rotary tool, may cause personal harm or damage to property or persons in case of failure, and no guarantee, warranty, promise or suggestion of safety is made or offered by me (Cathal Garvey) with regard to DremelFuge.
Dremelfuge featured on Makezine:
Please let me know if Dremelfuge is of use to you! Please upload pictures of any printed Dremelfuges in the wild! :)
== License Stuff ==
DremelFuge makes use of the Shapes.scad script kindly released by Catarina Mota, which is released under the terms of the GNU General Public License as published by the Free Software Foundation. Many thanks to Catarina for this great workhorse script, as well as for letting me sidestep the "Inheritence Clause" of the license.
DremelFuge itself is released under an Attribution, Sharealike License. It's already available on Shapeways, and you're entitled to print it for yourself or someone else for free if you have a printer handy. As a personal favour, don't go undercutting me on Shapeways please, unless you have a significantly better version. And don't call it "Dremelfuge" if you do.
Dremelfuge is a home-made Centrifuge, a potentially hazardous tool. Use your own common sense, and don't take anything you've seen me do or say to be an endorsement of safety. Centrifuges require some care in order to be used safely, and a home-made centrifuge in particular will have hazards that you should be ready for if you try to use it.
If you want to use Dremelfuge, use your head and take safety precautions:
1) Print or buy Dremelfuge. If printed, use maximum infill for stability.
2) Attach Dremelfuge securely, either by tightening a chuck securely or screwing a rotary tool disc-holder securely to the center of the Dremelfuge.
3) Seat your drill or rotary tool so that Dremelfuge's shaft/axle is vertically oriented. Seat the drill/tool with the Dremelfuge into a metal chamber (such as a cooking pot) for safety, and wear eyegear and any other personal protective items you can muster in case of disintegration.
4) Starting at the lowest speed and ramping up, with no tubes or loads attached, test Dremelfuge for safety at whichever speeds you intend to use it.
5) Once proven safe at the intended speed, you can start to test and use Dremelfuge under load, that is with desired lab samples. Make certain at all times that identical tubes or columns are used, with identical amounts of fluid or mass on either side. Always balance the Dremelfuge perfectly, or accidents may result.
Here are some RCF values (g-forces) to expect when it is used with a standard 1.5ml microcentrifuge tube:
@3000 rpm - 453 rcf
@10000 rpm - 5,031 rcf
@16,680 rpm - 14,000 rcf (The highest on a standard lab centrifuge I use every day!)
@33,000 rpm - 51,520 rcf (Highest on a Dremel 300)
I have successfully spun full tubes at 33,000 RPM on a Shapeways printed Dremelfuge. "Innocent" brand smoothie sediments into pretty layers within a few seconds.
Flying bits of microcentrifuge tubes pose a blinding or injurous hazard. Dremelfuge is unlikely to break; I have yet to break one, whether from Shapeways or Makerbot.
If you enjoy Dremelfuge or feel it has aided you significantly, please consider a donation to the email address mentioned in the .scad file below, using Paypal.