# One for Oliver - precise mechanical planetarium



## JOAT (Apr 9, 2010)

If this isn't his cuppa, I don't know what is.
How to Build a Precise Mechanical Planetarium


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## RainMan 2.0 (May 6, 2014)

Cool concept, looks kinda ugly though?


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## CharlesWebster (Nov 24, 2015)

That's not a planetarium, it's an Orrery!

From wikipedia dictionary

Orrery:
a mechanical model of the solar system, or of just the sun, earth, and moon, used to represent their relative positions and motions


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## difalkner (Jan 3, 2012)

And while it is cool it's not really precise as advertised. He states the reasons why he didn't make it full size but one thing I missed in reading, and maybe he mentioned it, is that some of the planets are on a tilted axis of rotation relative to the bulk of the planets. Small detail, though. It's still cool.

David


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## harrysin (Jan 15, 2007)

It wouldn't surprise me if in a week or two Oliver posted his version, I base this on some of his great past projects.


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## JOAT (Apr 9, 2010)

CharlesWebster said:


> That's not a planetarium, it's an Orrery!


I don't name 'em, I just post 'em.


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## DesertRatTom (Jul 3, 2012)

An interesting gadget. Lots of gearing. I guess each gear must have a precisely computed number of teeth to keep the motions correctly relative to the others, or the main drive gear. And then there's Pluto, with its eccentric orbit that bobs above and below the plane of the other planets. I think it's something of a miracle of computation.


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## CharlesWebster (Nov 24, 2015)

JOAT said:


> I don't name 'em, I just post 'em.


Just correcting the terminology!

Comes from having been a technical writer for 30+ years ;-)


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## JOAT (Apr 9, 2010)

CharlesWebster said:


> Just correcting the terminology!
> 
> Comes from having been a technical writer for 30+ years ;-)


Correct away. As long as you don't think I named it. :grin:


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## RainMan 2.0 (May 6, 2014)

CharlesWebster said:


> Just correcting the terminology!
> 
> Comes from having been a technical writer for 30+ years ;-)


Charles, can you help people who don’t talk good ? :grin:


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## DesertRatTom (Jul 3, 2012)

Glad for the correction. Precise language is a good thing.


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## CharlesWebster (Nov 24, 2015)

RainMan 2.0 said:


> Charles, can you help people who don’t talk good ? :grin:


No but I can help them write better. That's what an editor does :wink:


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