# High velocity rotation

Hi,

I am working on a project where I need to achieve very high velocity (not rpm). I am aiming for 1km/s so I am serioudly pushing the limits

I could really use some suggestions and ideas.

So far I have looked at

Spinning Disc : the centripetal G forces are huge unless diameter is several meters (is it possible to handle a million g force?)

Maglev in vacuum : I have experience with high rpm, not maglev, but in my experience balancing is very tricky for high rpm, this would be insane rpm so balancing would probably fail

maglev mag-drive circular tube (with vacuum perhaps) : This one actually seems feasible… but it is a crazy huge build. I am up for it but I would really appreciate some suggestions for design/parts/etc

rocket on a tether perhaps with guiderails : not to hard to build, might work, a bit crazy… asides from the limited burn time which would make repeated experiments cumbersome.

spin a very long arm : balancing, and size become issues. might work if I plan to take it to a parking lot/warehouse/etc… to use it.

Any ideas how to build any of these or any other design up to 1km/s?

**I need the high velocity to bring time dilation up to a measurable level. Sensors and detection are a separate project. First I just need some serious speed

This all seems a little lot beyond the scope of this Forum

…R

Haven’t we seen this subject in other posts?

Paul

1km/s > 2200mph
Edit: a 10' diameter disk spinning at 6260rpm is moving at about 1kps if my math is right.
20' needs 3130rpm

vinceherman:
Edit: a 10' diameter disk spinning at 6260rpm

How long would that take to cut through a human body if it escaped?

...R

The velocity V of a point on the rim of a spinning disk, radius R is V = 2PIf*R, where f is the disk rotational frequency in sec-1.

So for V = 1000 m/s and R = 0.1m, f = V/(2PI*R) = 1592 rotations per second or 95,500 RPM.
Radial acceleration of a point on the rim = ~ 106 g.

I need to achieve very high velocity (not rpm)

Need a really big disk, then.

I need the high velocity to bring time dilation up to a measurable level.

Define “measurable” and tell us how you will measure it.

GPS satellites would be an example of a “spinning disk” with R=20200 km.

vinceherman:
1km/s > 2200mph
Edit: a 10' diameter disk spinning at 6260rpm is moving at about 1kps if my math is right.
20' needs 3130rpm

And the acceleration on the edge is nearly 10^6 m/s^2, beyond the stresses in a jet engine
turbine disk...

The supersonic air-drag at these velocities is extreme, you'd need megawatt levels of power to
do this without a vacuum chamber.

What are you trying to achieve?

MarkT:
What are you trying to achieve?

...R

"Darwin Award" ;+}

I've built small electric motors using 1 inch Neodymium magnets that reached 50,000 RPM, high-speed rotation is mechanically easier to achieve with smaller systems in my humble experience but it of course depends on your load and release method.

Go to your nearest uranium isotope separation plant. There's one in Oak Ridge, Tennessee. One in France. Only a few around the world.

commonground:
“Darwin Award” ;+}

I’ve built small electric motors using 1 inch Neodymium magnets that reached 50,000 RPM, high-speed rotation is mechanically easier to achieve with smaller systems in my humble experience but it of course depends on your load and release method.

Yes, Celeroton do a 500,000rpm motor for driving micro-compressors, and I’m sure they have do jump
through a lot of hoops to achieve this and do it safely. “Special mechanical rotor construction for
highest stresses” is what their website says… No mechanical bearing can handle this BTW, they use
air or magnetic bearings.

MarkT:
Yes, Celeroton do a 500,000rpm motor for driving micro-compressors, and I'm sure they have do jump
through a lot of hoops to achieve this and do it safely. "Special mechanical rotor construction for
highest stresses" is what their website says... No mechanical bearing can handle this BTW, they use
air or magnetic bearings.

Thanks for the heads up on that one Mark, unfortunately i can't give Karma for another hour!

vasten:
I am working on a project where I need to achieve very high velocity (not rpm). I am aiming for 1km/s so I am serioudly pushing the limits

That's the kind of project that will a) need some very serious (government level?) funding and b) a team of PhDs in various disciplines.

Even if anyone here has the specialist knowledge you're looking for, you're asking in the wrong place since those same people will also be on the academic forums and at the academic conferences and be published and be working in their day jobs at internationally renowned research centres, and be waiting the call from Stockholm to go pick up a prize or two.

You can't possibly be contemplating this in your garden shed....

Robin2:
How long would that take to cut through a human body if it escaped?

At least the human won't see it coming.

not_a_noob:
You can't possibly be contemplating this in your garden shed....

Don't let Colin Furze know, he's got a bunker under his garden shed!

MarkT:
Don't let Colin Furze know, he's got a bunker under his garden shed!

Or maybe OP is Arthur Jackson, and has two sheds.

A friend of mine moved into a new property a while back which had 7 sheds, some with asbestos. I
think its rationalized down to 3 or 4 now, without asbestos. Off topic really, as high velocity rotation
is not involved.

Yes. You have to cut asbestos with slow velocity rotation and lots of water.