DIY centrifuges, used centrifuges, and a fun experiment.

The background that led to the experiment

I had been thinking about building a centrifuge out of a blender but first I decided to research what other people had done before I tried my own hand at it.  I ran across a number of designs which included  “Dremmelfuge“” and a handheld centrifuge which will eventually damage something.  The best of centrifuges was one that used mixing bowls and a blender.

My own thought was to attach the caps of dry-erase board markers to a blender rotor using wire and gorilla glue.  In my design I wanted to use the blender pitcher as a safety vessel for in the likely event something went flying – but this provided a lot of design challenges.  Ultimately I decided that my idea was bad and most of the other designs were too risky.  If I were to ever revisit centrifuge construction definitely would make a variant of the blender which used mixing bowls.

All of this ended with me surfing eBay and discovering it was not too expensive to just buy a used centrifuge (from $100-150) – which I did.  I manged to find the centrifuge depicted below.  I find the aesthetic design to be quite pleasing and it is a bit sad that this style is not used anymore.  Now that I have a centrifuge, it is time to use it (see below for more)!

My little buddy. Cheap and effective.

A quick centrifuge explanation

Centrifuges spin samples around extremely fast (often >10,000 RPM).  Doing so causes centripetal force to be exerted upon the samples.  In the case of my centrifuge, it spins fast enough for the samples to have the force of 13000 times earths gravity exerted upon them.


What happens when ketchup, milk, sriracha sauce, and russian salad dressing are exposed to 13,000 x earth gravity for 30 minutes?


The source material precentrifugation.

Here are the specimens, precentrifugation.  From left to right we have non-fat milk (Trade Joe’s), Ketchup (Heinz), Sriracha Sauce (Huy Fong Foods) and Russian Saland Dressing (Wish Bone).

First we load the machine…

Rotor with tubes.

Next we run the machine for 30 minutes and we get….

sriracha sauce 13000 x g 30min

Separated out kind of like blood  (serum on top, cells on the bottom).  I would guess that the bottom layer is chili pepper fragments.

russian salad dressing 13000g 30min

This salad dressing has A LOT of ingredients and I will even try to guess as to which layer is what.

nonfat milk 13000g 30min

Milk proteins should be what has collected at the bottom.

heinz ketchup 13000g 30min

The ketchup surprisingly did not separate into layers.

My take home message from this experience was that sometimes the effort and danger in building something myself may not be worth it when one considers the cost and value of used equipment.


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5 Responses to “DIY centrifuges, used centrifuges, and a fun experiment.”

  1. antreas111 Says:

    It’s a fantastic and interesting experiment!!!

  2. Jacob Avera Powell Says:

    I’ve Heard Ketchup acts the way it does, because it acts like a ? Newtonian fluid, something about it is both a solid and a liquid-
    forgive me if I’m saying this wrong.

  3. Jacob Avera Powell Says:

    Ok I totally screwed that up. its a Non-Newtonian fluid.

    Wikipedia says-A non-Newtonian fluid is a fluid whose flow properties differ in any way from those of Newtonian fluids.

  4. free Says:

    What’s Taking place i am new to this, I stumbled upon this I’ve discovered It
    absolutely helpful and it has helped me out loads.
    I hope to contribute & assist different customers like its aided me.

    Good job.

  5. ilas Says:

    Hi.. im trying to build a small blood centrifuge with cooler for my school project. I was thinking about blender too and as i typed the word in search engine, i found your site :). Do you think it would be possible to build a centrifuge for just one test tube? I’ve seen centrifuge with specimens balancing the weight on each site. As mine is only a model and I planned to attach the test tube on the motor via a grip and it would spin on the spot. I am thinking whether it would make any difference from the centrifuges which rotate in a certain circle. Thank you very much 🙂

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