Instructables
Picture of OpenFuge
IMG_20130525_163428.jpg
The OpenFuge is a relatively low cost open-source centrifuge for DIY biolabs and biohackers. It primarily uses commercial off the shelf parts with a few custom electronics. It aims to enable anyone to perform biological experiments, not just those with access to specialized labs.


Specs (Observed):
G-Force: 6000 G's
RPM: 9000 RPM
Size (closed lid): 15cm x 24cm x 20cm
Weight: 1.6 kg
Power Source: Four 18650 Lithium cells
Material Costs: $200


Features:
Adjustable speed and power
Can hold up to 4 Eppendorf tubes
Portable
Safety Interlock
Cleanable
Live RPM monitor and countdown



For DIY people head over to http://www.thingiverse.com/thing:151406/#files  and cut out the attached panels. Check out the Bill of Materials (BOM) for the list of parts needed. WARNING: LASER CUTTER REQUIRED (40 min)


For non-DIY people head over to https://www.tindie.com/products/CopabX/openfuge/ and purchase a kit. It comes with all electronics pre-soldered and pre-programmed.



 
Remove these adsRemove these ads by Signing Up

Step 1:

Step 2: Creating the Frame

Picture of Creating the Frame
DSC_2289.jpg
DSC_2296.jpg
Laser cut the files from Thingiverse. Make sure you have the smooth side of the wood facing the right direction.

If you do not have a laser cutter, you can print out the .dxf templates on paper. Tape the templates onto the material specified for the pattern, then cut the pattern on a scroll saw.


An optional step before assembling the frame is to apply a hydrophobic coating onto the parts of the hardwood frame that could be exposed to liquids. This makes for easier clean up in the event a tube shatters or aspirates. If you cannot find a hydrophobic coating, a heavy coating of enamel spray paint will also work.

My layer sequence:
3x Black Enamel Spray Paint
3x Hydrophobic Base Coat
3x Hydrophobic Top Coat
stett8 months ago
This is really cool! But I'm wondering if there's anyway to make something with more capacity for separating things in the kitchen. I'm really getting into modernist cuisine and they use a centrifuge for things like separating out the "tamari", oil, and "miso" from these nut fermentations (http://www.ediblegeography.com/the-misofication-of-manhattan/). It wouldn't really be practical to do in such small amounts. If I did a ferment it would probably be the capacity of a mason jar. Any ideas in how to build something at a reasonable cost with larger capacity?
CopabX (author)  stett8 months ago
I doubt that there is any way to spin a mason jar as the largest centrifuges I've seen spin samples half that size. I was thinking a disc or handcrank design, but I would need to know how many xG's are needed to separate the oils. You could always make a jig for a car wheel or washing machine and spin the jars that way...
mdeblasi111 months ago
Just yesterday, in the Kitchen, trying to separate tomato "plasma" from tomato solids, I said to myself, I wish there was such a thing as a kitchen centrifuge.
When I asked the GF where the lettuce centrifuge was, she didn't know. Then I found it. Turns out is called a salad spinner. If you could find some containers to fit, it might work for the tomatoes.
From now on it is a "lettuce centrifuge" in our house. Until complaints from the GF become too great.
it would be cool to see it equipped with some sort of vibration sensor to stop a catastrophic failure if its unbalanced
toyotero10 months ago
I just saw an article on popsci blog covering this device and your work.
Congrats on developing a great device.
http://goo.gl/RlC6pr
GS10410 months ago
This is one of the best things Ive seen on this site. Concept+directions+problem solving together with your support comments/logic are all A1. Great Job.
CopabX (author)  GS10410 months ago
Thanks!
dlebryk11 months ago
Great instructions. The build looks really cool.

I didn't notice a mention of safety concerns with this build. It has been a million years since I bought or used one of these - I used to use them every day. I recall that the commercial versions of these Eppendorf centrifuges usually have a cast circular body around them. In the event the rotor flies apart they can contain the parts. They also have a limiter for out of balance - oddly way too easy to get them out of balance accidentally (whoops I forgot a test tube, or I didn't add the 1 mL water to the counterbalance tube). I'd hate to see this ramp up and the motor go flying off the mounts.

Kudos on a really nice looking instructable.
CopabX (author)  dlebryk11 months ago
Thanks! I'm glad you like it.

Concerning safety, I've stress tested the fuges for up to 15 minutes fully loaded and haven't experienced anything problematic. I've also purposely destroyed the petals (poking sticks or running REALLY off-balance loads) to test the frame and center hub (which is why it only holds 4, not the usual 6 tubes) and found the wood and 5.5mm acrylic sheets hold fine. I have a safety switch to make sure it doesn't power up without the lid being closed, but I'm sure someone will just put a piece of tape over it. I'm also sure that the motor will hold since it is usually used for helicopters and gigantic rotors. I've seen these things smash into the ground and only have a slight wobble afterward.

I do have a backup plan, though, if problems do arise. I have plans for an adhesive mylar film to act as further protection on the acrylic sheets. The film is usually used for hurricane windows, so I'm sure it will work, too.

As for the balance sensor, I haven't come up with a way to sense an uneven load without having expensive sensors. It's a great idea, though, and I'm open to suggestions.
ecochran3 CopabX11 months ago
Have you thought of using an accelerometer as a balance sensor? You can get them for under $2 (not including shipping) from DigiKey, for starters. Just monitor it for spikes of excessive lateral acceleration, and especially spikes that gradually increase, such as those due to resonance. Of course, you'd need to determine a good baseline for normal readings due to vibration, but that should be enough to get you started.
yellowcatt CopabX11 months ago
I wonder if polycarbonate or PETG would be a better choice for the cover? Much more shatter resistant than acrylic.
CopabX (author)  yellowcatt11 months ago
Honestly, PETG is my favorite plastic.The only problem with it is that it burns when lazed and turns yellow. Then it isn't dimensionally accurate. I also thought of using Delrin, but then the lid wouldn't be clear.
biotoscano11 months ago
Hi! Have you considered to use a reed relay and magnets to control RPM?
CopabX (author)  biotoscano11 months ago
The speed is already controlled by a PWM signal.
juliamorley11 months ago
You should approach someone who is involved with medicine in developing countries - an affordable and almost flat-pack centrifuge could be something that their clinics could probably use :-)
spylock11 months ago
Well done,Im impressed.
jtechian11 months ago
Nicely done.. I was thinking of doing one a little bigger. What I have in mind is for reclaiming cooking oil by centrifuge to remove all solids from the oil.
Thank for re-inspiring me to get busy :)
Nickson Yap11 months ago
Man, I've been trying to find ways to measure RPM from non-sensored brushless motors.
There are ways to use hall sensors.
I've thought of using an optical sensor but I've never thought of such a simple way!
CopabX (author)  Nickson Yap11 months ago
I'm glad you like it. It was really easy to test sensor setups using the MSO-19 from Link Instruments. I tried a bunch of different ways of optically sensing the RPM (reading petals, reading center hub, etc.) but a passive IR sensor reading the main body ended up being the best.

http://www.linkinstruments.com/mso19.htm
spyder202111 months ago
looks cool, but what is it? Can you include a video of it working?
A centrifuge is a machine used to seperate organic matter of different densitys by centrifical force. Ex. Red blood cells from plasma.
diy_bloke11 months ago
I am all for DIY, even if sometimes you can't make it much cheaper yourself, but considering that laboratory centrifuges are available starting at around 50 USD, you got to be really dedicated to spend 200 USD on a DIY, espcially if it is a kit :-)