Enforce clockwise spinning, but not counterclockwise

[nickek]

Hi!
I came across a toy, formed as a rod. When spinning that rod counterclockwise, the behavior is as expected. But turn the direction to clockwise spinning, it immediately slows down and ends up spinning counterclockwise.

See this YouTube clip. Anyone who has an explantation of this behavior?

Thanks!

 

[256bits]

Arbor Scientific.

This is what you bought.
http://www.arborsci.com/shop-by-topic/cool-tools/celt-rattleback
( See the notice on the bottom.)

Products being sold are not toys. They are for Educational / Laboratory use only. They are not for use by children 12 and under

Chuckle

You can get this one. See if you can try to figure out why it does that.
there is a video explanation.
http://www.arborsci.com/dynamic-celt

 

[Doc Al]

It's a really cool toy* called a Rattleback: Rattleback

*(do not eat)

 

[256bits]

So that is a Celtic Stone!

One of the links shows how to make your own from a spoon.
http://www.flinnsci.com/Documents/demoPDFs/PhysicalSci/PS10440.pdf

Great after dinner trick on the silverware.