It had to happen.

My science clubbers got wind of the centrifuge's existence, and demanded to have a go with their own samples. Some of them made their own mixtures, just to see if they could be separated by sheer force of gravity.

The samples got spun up in batches of four:

Batch 1:
  • Hair gel mixed with pure blackcurrant juice (yellow tube)
  • Mud, water, pencil shavings and washing up liquid (blue tube)
  • Brown sauce (it's a British condiment) (orange tube)
  • Salad cream (light pink tube)

Batch 2:
  • Flour mixed with green food colouring, washing up liquid, water and rice mixed with blue food colouring. (green tube)
  • Strawberry jam (with bits) (dark pink tube)
  • Flour, water and green food colouring (orange tube)
  • Raspberry jam (no bits) (light pink tube)

Batch 3:
  • "American hot dog mustard" (yellow tube)
  • Melted Margarine (blue tube) (melted by floating tube in hot water for a couple of minutes)
  • Crunchy peanut butter (orange tube)
  • Rice, water and blue food colouring (green tube)

I've posted each sample as "before" and "after", to make the changes (where they occur) more obvious.

The shot of the inside of the centrifuge shows a thin beige line - the clubber who filled the peanut butter tube didn't clean the outside of the tube properly, and slowing from 13,000rpm to stationary in a few centimetres mashed the debris evenly around the centrifuge's innards. Fortunately it wiped off easily.

Watch out for the margarine...

Need some backgound?
Part One
Part Two - Blood!
Original Forum Thread

And a "How To" Instructable is in the pipeline, I'm just waiting for some information.
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zoltzerino6 years ago
Rather than separating mixtures, could you try compounds perhaps? Your school seems to have a rather flash science dept. ZZZZ
PortalForce6 years ago
Wow! This machine is cool! I really love the experiments you are doing! I was just wondering where can you get it? And how much will it cost in Canadian money? I wonder what happens if you put Non-Newtonian Fluid (Oobleck) in the microfuge? I want you to try it, you don't have to, but I wish you did. Thanks,
Kiteman (author)  PortalForce6 years ago
I got it for free, donated to the school through a government scheme, but you could try here.
nfitz6 years ago
As you showed in p1 you're trying to run a 13k rpm centrifuge with a 12w (12v 1A) power supply. I bet its doing < 2 krpm. Give it more AMPS.
Kiteman (author)  nfitz6 years ago
It's the power supply recommended by the manufacturer.
nfitz Kiteman6 years ago
ok , just a suggestion. No harm will come of trying a bigger psu at the same voltage. Good writeup.
Sunny1246137 years ago
ew i wouldn't try urine... but maybe is you try fatty yogurt or maybe some mayonaise
darth2o7 years ago
Urine, try urine!
urine for 1 hour at top speed would be interesting.
try soda please! 4.5 stars!
whatsisface7 years ago
You have to do a tiny martini in this. That's an order.
Sunny1246137 years ago
I have never seen an instructable like this before! Anyways it is GREAT!!!
Kiteman (author)  Sunny1246137 years ago
Thank you, I try my best.
Clayton H.7 years ago
How much would one of them fancy "centrifuges" cost and were can I receive one?
Kiteman (author)  Clayton H.7 years ago
Most lab centrifuges cost upwards of 150GBP. The one I have is a "Millennium Product" - for some reason, the university-based team that came up with them sent lots to schools for free. They can also be purchased for around 80GBP+taxes - follow the links I gave in the text to find the details.
How about American dollars? I want to see if I have enough.
Kiteman (author)  ItsTheHobbs7 years ago
Probably about $150, plus various taxes and shipping from this link.
Oh, ok. not enough....
Zorink Kiteman7 years ago
My dad got one for me a few years ago from the hospital he works at. They got new ones and were just going to throw the old ones out! Testing random stuff in it can be surprisingly entertaining. Blood is the most interesting thing we ever put in it. My diabetic friend came over and he used his finger pricker thing to get some of his. After an hour the top 60-80% was a yellow/clear (plasma), the bottom was a deep red (blood cells), and the very tip was black/gray(platelets and other stuff).
jackfr0st7 years ago
these are wonderful macro pictures!...and what are the layers in the margerine? and what are the size of the centerfuge "capsules"?
Kiteman (author)  jackfr0st7 years ago
Actually, those photos were a pig to take - for some reason my camera refused to focus on the tubes. I think it's the lack of contrast. I had to put my finger beside them, focus on my finger and then move my finger. The layers will be fats and water (there's a lot of water in margarine). The tubes are 1.5ml - about 1/4 of a teaspoon full.
I wonder if using white or black paper, split in half with each half on one side of the tube, would have helped....or something like that.
Goodhart7 years ago
I just found out that some portion of the Chocolate making process involves a centrifuge. :-)
article in the newest MAKE: Timothy and the Chocolate factory....
Kiteman (author)  Goodhart7 years ago
Hah, just typical...
It is only mentioned in the article....I didn't give away what it is mostly about :-)
jlkinetics7 years ago
Maybe someone has mentioned it already, but how about Ferrofluid, or Magnaview Fluid? my bottle says magnets permanently suspended in oil. lets see if that really means "permanently". Also try brewed coffee.
Kiteman (author)  jlkinetics7 years ago
Hmmm, coffee would be appropriate.
*sigh* I'm realizing a lot of other members are receiving "The Power" to feature.

Time to go look for part 2.

(+5/5 stars)
alexhalford7 years ago
How fast does a centrifuge spin? I ask because I have a vacuum cleaner motor that I have yet to find a decent use for...
Kiteman (author)  alexhalford7 years ago
This one goes up to 13,000rpm, depending on the input voltage.

Others are slower, others are faster, but the g-forces are a combination of the radius and the revs. Double the diameter of the device (at the same revs) and you will double the g-forces, but double the revs, and the forces go up four-fold.
And also, could I use a regular 555 astable oscillator with PWM to control the speed of an ac motor or would that only work with dc motors? So basically this circuit (see attached) with it's output going to the gate of a MOSFET. The MOSFET will then be the switch in the AC power cable. Would this work? Thanks for your help. AlexHalford
Kiteman (author)  alexhalford7 years ago
I think that circuit would behave quite differently - IC2 is specifically labelled with + and -, plus capacitors behave quite differently in an AC circuit.

And that circuit is only rated for 9V, not 120V or 240V.
Sorry I explained it poorly, I meant that this circuit would be powered by a 9v DC supply, and the output would go to a mosfet, which would be in the AC wire. This circuit would only provide the pulses to turn the mosfet on and off, only the mosfet would experience AC, the rest of the circuit would not. Like this (You'll forgive me I hope, the crudely drawn diagram):
Kiteman (author)  alexhalford7 years ago
I think you're best off asking somebody like Goodhart (or LasVegas if he's around).
Ok, thanks anyway.
Ok thanks, do you think a vacuum cleaner motor would do the job?
solo.card7 years ago
I'd have liked it if you used clear eppendorfs, some of 'em were a bit tricky to see through. I was surprised by the strawberry jam. I think you should definitely blast that one for a little longer. So through looking at your past instructables of yours, I have come to the conclusion that you are either a science teacher, or evil genius. I hope both.
bosherston7 years ago
Oh, I vaguely remember an O level physics lesson whereby a piece of cork and a paperclip were centrifuged - the cork sank and the paperclip rose? I don't remember the science behind it tho. Can you help Kiteman? Cheers.
yay I got to see my questions, the margarine was pretty nasty looking after, brown sauce seems alot more wholesome...
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