A 20 Cent Centrifuge

The world owes a thank to to Manu Prakash and Saad Bhamla for this idea, and other ideas to bring technology to the undeveloped world.

About 75 years ago we used a button and string to fashion a toy similar to this. My Mother showed it to me, so the spinning toy idea is much older. I can believe 10000 rpm only with difficulty, but I can't at all believe 100000 rpm! Nor 30000 gs. After all the thing has to reverse rotation after every pull. But it still is a neat idea for a centrifuge.

The spinning toy is over 3000 years old.

It does not stop and reverse instantly.

Perhaps a decimal point was misplaced. Whatever the case, it is being used world wide now.

I will never argue with you.

A spinning object with 30,000 G force ... sounds like a dangerous toy!

The low mass enables it to survive the extreme G forces.

A flywheel battery relies on large mass built in stages of different materials, with the inside using cheaper weaker materials and the further out you go, the stronger the material must be.

Carbon fiber is normally on the outside layers, which is very light ,which trades mass for strength and size. Layers built up like an onion. A lot of calculations go into design of the flywheel battery.

https://en.wikipedia.org/wiki/Flywheel_energy_storage

The low mass of the object allows it to survive the extreme G force.

Flywheel batteries are used for energy storage and have been used in power grids for peak load management .

There was an attempt made in the past to use flywheel batteries in vehicles, but it did not work out, but I don't know why. Reportedly two 10 pound flywheels spinning in opposite directions could replace the batteries in a EV vehicle.

I think the problem might be in designing a flywheel that would stay together under the high stresses involved.

Currently , some buses use heavy flywheels in urban areas and recharge wirelessly at bus stops along the route.

https://en.wikipedia.org/wiki/Flywheel_energy_storage

I can imagine one of these embedded in the ground powering a house. Why not instead of batteries?

FAST?

Here is fast:https://newatlas.com/physics/fastest-spinning-object-300-billion-rpm/

300 Billion RPM!

The flywheel powered buses are like the little toy cars we had as kids, that you would hold and roll against the floor, and then let go, and they would take off like a rocket across the floor. Just an upsized version of that toy being electrically accelerated.

Here is a picture of a modern version of the toy.

The cars I remember had a clock spring that you would 'charge' by pulling backwards on the car and then let go. There was usually some sort of overrunning clutch between the wheels and the clock spring so it would continue to coast after the spring was unsprung.

Since vibration and size would not be a big factor, for a domestic flywheel it could be supported by magnetic bearings, and in a vacuum to reduce friction. The heavier the flywheel, the less RPM required to store the energy.

What I've read since my original post is one of the main problems besides the stress was a magnetic bearing that would support the flywheel when the vehicle hit bumps and rough roads.

The vehicle flywheel had to be small and light, so rpm had to be very high to store enough energy.

And the opposite of fast is slow.

HERE IS SLOW: over 13 billion years to complete one revolution of the output shaft.

https://youtu.be/8RhiBMpmlvw

... over 13 billion years to complete one revolution of the output shaft...

It may be slow, but it's got a lot of torque!

That is about the age of the universe.

I am pretty sure it will crack the concrete block.

I have seen a 1/16 hp motor pull 1/2inch anchors out of the floor and break #35 chain.

It was geared about like clock. You had to mark it to tell if the output shaft was moving.

I would not try that with a CD or a vehicle flywheel.

Race car flywheels have exploded amputating legs at high rpm.

Regulations now require a scatter shield around all racecar flywheels.

This includes scatter shields on tractors and trucks at pulls since they often (usually) use high RPMs.