Head Scratcher: Rattleback

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wood_fly
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Model of CNC Machine: Axiom AR8 Pro V5+Jetch Laser+Rotary

Head Scratcher: Rattleback

Post by wood_fly »

Ok, this is COOL. It's called a Rattleback and it is one of the best things I have carved yet using Aspire. Why? Because I could download the STL, put a chunk of Walnut in my machine and an hour later had this Physics-defying toy. You heard me: it ONLY spins to the LEFT. If you try to spin it to the right, it does ~2 turns, wobbles and REVERSES course ... North of the Equator that is.

If you want the full-on physics explanation, try this:

If you want to make one of your own, simply search for Rattleback STL and go to town. As I understand it, it is an Australian toy...wow!
PXL_20210601_184149557.jpg

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adze_cnc
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Re: Head Scratcher: Rattleback

Post by adze_cnc »

wood_fly wrote:
Tue Jun 01, 2021 8:07 pm
Physics-defying toy…

If you want the full-on physics explanation, try this….
Not physics defying but human intuition defying. If it was physics defying there wouldn’t be a “full-on physics explanation” of why it works.

In 1985 Fine Woodworking magazine featured making one: https://www.sfu.ca/phys/demos/demoind ... celt.html

My grade 8 science teacher had one back 40-odd years ago and it was called a “celt” then.

wood_fly
Vectric Apprentice
Posts: 75
Joined: Tue Jan 24, 2012 8:42 am
Model of CNC Machine: Axiom AR8 Pro V5+Jetch Laser+Rotary

Re: Head Scratcher: Rattleback

Post by wood_fly »

So I packed it in my bag and took it on a recent flight to Rio ... any guesses on the effect on spin?

That was fun to watch the passengers get confounded in the back <g>

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