[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!
“Why?” Careful! You’ll loose your geek cred asking questions like that! :D
I thought it was obvious; get the bits out of orange juice! smooth all the way!
At least he took pretty good safety precautions. Not that dangerous when you’re outside a steel enclosed container.
Yea and those 3 clips are sure to hold up against any malfunction.
He could solder both bowls together.
Only if he never wanted to get the tubes back…
Soldering some locks would be better.
Visualize whirled peas.
http://instantrimshot.com/
The angle of the test tubes seems to defeat the logic behind centrifuging to separate materials by density. I posted a $ 5.00 really easy centrifuge two years ago with a video with the tubes traveling radially. There is no comparison with mine as it is only a cheap alternative. Cool hack though!
http://www.observationsblog.com/4/post/2012/09/homemade-centrifuge-for-five-dollars.html
makes me want to design a cordless drill “centrifuge” bit and 3d print it
you could skip the first part, although designing is half (or more) of the fun.
http://www.thingiverse.com/thing:1483
needs a rotating tube holder so that they go horizontal when the revs kick up.
Yes. The big commercial units have that built into the rotors for the big tubes and bottles. Surprisingly, for the small tubes (<50ml) the rotors themselves are built so the cavities are fixed at like 40 degrees. So the sample "pellets" of the densest materials form just off of the bottom of the tube to one side.
“centrifuges do blow up” I’ve actually worked on that exact model of machine, and yes, occasionally rotors get micro-fractures in them or they react badly to reagents (read: mercury in an aluminum low-speed rotor) and things go…”pear-shaped” is being too charitable. As for G forces, if you use a machine that spins at 100,000 RPM, you can actually get close to 1,000,000 G’s! They have to be run under total vacuum to prevent heating due to the friction of the rotor and the air! It can actually separate chromosomes at that speed! One centrifuge that size had a “rotor failure” and it destroyed the 10’x6′ room it was in! It happened overnight on a long run so no one was hurt.
How precisely does a machine that spins at 100,000 rpm have to be balanced? What kind of materials are required to survive such immense forces?
Dremel™ should start to make kitchen attachments for their rotary tools.
They’d finally be used to do something useful. If you want to do any serious job you buy a PROXXON.
Another site to view before contemplating this:
http://www.chem.purdue.edu/chemsafety/newsandstories/centrifugedamages.htm
Also, if you are Iranian: do not network it.
I want more tests. Coffee, eggs (would they scramble?), etc. I can’t believe he didn’t try pulling the fat out of milk. The Man Whose Seen Some Shi+ mentioned heat from friction. Could you cook bacon via super-high-speed centrifuge and simultaneous pull all the liquid fat from it?
Could you sift flour, or better yet, force flour through a super-fine grate to get the lightest cake flour possible?
So many possibilities…
sifting particulate would need something to keep the particles moving after hitting the high G spin. Otherwise, you’d just get a clump of different sized particles that pack tight, or block up that fine grate.
As for eggs, you can pull the water apart from the fat if I recall some molecular gastro books. They’d scramble at the low speed, but if you can avoid that they should separate into the fat, the water, and the other proteins. Cream from milk is easy enough. Bacon, being a solid, would be tough; it might heat enough to fry in a kitchen hack, but you’d only get the liquid pooled at the top of the tube on top of the bacon that should have slid down from the force. Density wins out, remember.