An Affordable DIY Tabletop Micro-Centrifuge (12k RPM)

I was thinking about making an air powered tesla generator with several disks having angled recesses bored into them sealed off so that way 100uL eppendorf micro-centrifuge tubes could be placed inside of them. With even a normal powered blower engine like the one found on an electric leaf blower, you should be able to achieve at least 12k RPMs which would allow you to precipitate DNA and other protein products for at-home biotech projects. The lid over the top disk would have to seal well to ensure that nothing was expelled forcefully from the centrifuge by accident in case of a tube failure or an unintentional misbalancing event. Old CDRWs could even be used as the blades for the disks, allowing for the creation of such a device for zero cash upfront, merely utilizing the available resources that already exist in your own home.

What do you think? I know unless it was made from light-weight metal, it wouldn't have any longevity to it, but when you compare a $35 device that lasts a few weeks to the cost of a $10k device from Fischer, it seems pretty cost-effective in a pinch.

The main things would be balance and very slow acceleration and deceleration. I would say a small brushless hobby motor and controller of enough watts would be better/simpler.

oh...home made medical centrifuges 'caugh'
Isn't that what Iran already has tens of thousands of?

Being a bit snarky there, I like your idea though

X

originally posted by: XL5
The main things would be balance and very slow acceleration and deceleration. I would say a small brushless hobby motor and controller of enough watts would be better/simpler.

That was my thought as well, probably more than enough power for a light load to spin up fast enough for centrifuge speeds.

I shattered the a disk rim on one of my RCs wheels after installing a brushless and lipo back in the day, that was scary! Some sort of containment would definitely be a good idea.

I think balance will be the major issue though. Finding some sort of axle used in industry that is obsolete but when in use had to be well balanced would be a good start, probably buy for scrap value if your lucky.

a reply to: Nechash

A used/cheap drill press is already pullied for I think 3000 rpm with a 1750RPM electric motor. A split phase 3450 motor would give you 6000 RPM this kind of motor is found in blowers for home heating, and AC. I don't think your CD's will hold up under this kind of RPM they come apart to easy. The Fisher centrifuge that I looked at spins a 6000RPM. What you are proposing can be very dangerous. But if you can conceive of such a device then you are aware of the dangers. A plastic round made from some sort of machinable plastic such as delrin or teflon it needs to be hard with a center drilled in it with a grade 8 bolt and nylock nuts to place in the chuck. Also note the bearing in the head of the press won't last to long with this kind of RPM but should be good for a test.

If you could find a drill press for a test, I would take your tube holder to an automotive crankshaft grinder and have it balanced, or someone who makes fan blades. Also I would cut the center of an automotive rim out and use the outside as a safety guard should the whole thing come apart. Just some ideas, also note that a yard blower motor has very little torque for spinning anything other than the fan blade they use. Just be careful. I know I don't need to tell you that I just feel better if I do.

a reply to: MarlinGrace

The air current is what drives the disks, not a belt or shaft. It only has to be highly concentrated across the outside edges of the rows of disks in order to create motion. The overall power of the turbine is not very high, but the RPMs get very high due to the direction of the wind. Air resistance being the main reason things slow down in an atmospheric environment, once you get the air flowing along with the object, it moves readily.

a reply to: Nechash

What would you use it for?

a reply to: PhoenixOD

I don't really have a need for it presently, but I know a lot of people want to attempt home biotech startups, and it might enable people to transform e. coli to begin to produce DNA products for one type of assay or another. The human imagination is almost unlimited. If given the tools cheaply enough, it would be interesting to see the kind of molecular biology projects that even high school students could perform for their science fairs.

One thing is for certain, it is much easier to purify specific chemical products through centripetal means than it is through filtration. For instance, I was producing carbon-60 fullerene molecules to attempt to create a water soluble compound through nitrogenation of one of the surface sites. I wanted to see if I could create an anti-oxidant inhaler for the purposes of longevity benefits, and through filtration and using different solvents, I was able to get probably 99% pure C-60, but I'm sure there was still some C-70 in the samples, which is not safe for human ingestion. A centrifuge would have enabled me to get to a 100% purity, and considering that a very small amount of C-60 is needed as a daily supplement to be beneficial to mammalian biological systems, even being able to centrifuge a few mL at a time across several micro-centrifuge tubes would have been beneficial.

In the specific case of C-60, I am now wondering if it might have enough of an electric charge to be purified through electrophoresis. I never considered that at the time, but it might work. Anyway, those are some options if you can use a centrifuge that you wouldn't have otherwise.

For balance, you might try ball bearings in a sealed trak around the outside of the spin disk whatever it may be made of. Optical disk drives use that instead of getting them balanced.

a reply to: Nechash
Lol or you could use a harddrive thats spins at 10,000 rpms or higher

a reply to: devious003

An old multi-layer hard drive would make a natural tesla tubine if it were vented properly, but using an electric motor, the extra weight would probably prevent an HD from getting up to speed.

If you want something for fast rotation, go to the hardware store and buy a "mulitpurpose rotary tool". At least that way you can get a fairly well balanced motor mounted on a shaft good up to 50,000RPM, and usually with some form of speed control thrown in. However given the operating speeds it's capable of, the centrifuged platter which you attach to it would still need to be precisely balanced and contained.

You can look up the diy "do it your self" home made centrifuge on youtube. He even has speed controls on it. Go to youtube type "hard drive centrifuge" pick the one that says diy hard drive centrifuge. The hard drive has a knob for speed control and a small screen which tells rpms. Its small but you did say micro