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Black Forest
11-16-2011, 04:23 AM
My daughter is doing a project for school. She has picked the Universe as her project. I would like to help her build a movable planet thingy with the sun in the middle and the planets revolving around the sun. Something maybe where she could turn a crank and the planets revolve......OR?

Edit: She asked if we couldn't build it out of metal so she could make it on the mill and lathe!!!!!! Am I raising her right or what!!!!!!!! She is 9 years old.

johnnyd
11-16-2011, 04:44 AM
What you are describing is an ORARY.....
There was an article in Digital Machinist some time ago about making one.
Contact Village Press & see if they still have a back copy of that issue.:)

SGW
11-16-2011, 07:44 AM
I think it's spelled "orrey," but whatever it is, that is what you are talking about. Try Google, maybe.

justanengineer
11-16-2011, 07:59 AM
It seems to me that this board could use another interesting project thread. Could we convince you to document the build a bit?

This sounds like a good opportunity to add a few pics to the kids' photo album and give her something to remember you by further down the road. Always glad to hear of people making time to spend with their kids in the shop.

MikeA
11-16-2011, 08:50 AM
It's spelled orrery and they are usually rather complex due to the gearing required to get the various speeds correct.

All the best,
Mike

vpt
11-16-2011, 08:57 AM
The simpler ones I have seen use a small chain and sprockets on each globe.

You planning on hand cranked or powered?

Ian B
11-16-2011, 09:18 AM
She has picked the Universe as her project.

Is that all? Couldn't she have picked something a bit bigger as a first project? :)

How about this:
http://brassorrery.blogspot.com/

Good luck, post pics please,

Ian

Tony
11-16-2011, 09:51 AM
[QUOTE=Ian B]Is that all? Couldn't she have picked something a bit bigger as a first project? :)


I believe current thinking says the universe is finite.. I say a black bean
bag on a wooden stand and a brass name plate that says "universe" would
do the trick. ;)

lynnl
11-16-2011, 10:33 AM
Is she planning to make it full scale?
...come to think of it, she already has one at her disposal, just take that one to school. :)

Mike Burdick
11-16-2011, 12:43 PM
Darn kids these days! When I was growing up we had NINE planets to model... now these lazy kids only have EIGHT! :mad:

What if she made a model of the planets and hung them with fishing string. Then move them a little bit at a time and photograph each move with her camera. At the end, she can put them together for a movie. Lighting would also be in play here. If this is too much work, then perhaps she could only do it with the earth and moon and show why we see the different phases.

.

Evan
11-16-2011, 01:24 PM
Hah. That depends on what you consider a planet. Things have changed alright but it sure isn't easier. We now have a huge herd of dwarf planets to consider.

http://ixian.ca/pics9/solarsystem.gif

My suggestion is to step back from the orrery idea. That's a very ambitious project as a first project. I would recommend making a solar system mobile instead. There will be plenty of work to do finding suitably sized balls for illustrating the relative sizes of the planets. It won't be possible to make it to scale but instead representative sizes and distances can be used. Painting them to resemble the actual planets should be a fun project.

See here: http://www.universetoday.com/15551/solar-system-mobile/

The great thing about doing this project right now is that it should be no problem finding the right sizes of globes for all the planets since it is coming up on Christmas.

BTW, Bruce, if you have somebody to look after the place for a day or two you should take the family and shoot on over to Rothenburg ob der Tauber and visit Kathe Wohlfahrt's Christmas Shop. It is incredible and loaded with any and every possible Christmas decoration known to mankind. It's like a huge maze and takes hours to visit. Rothenburg is also a very pretty town and worth a visit anyway if you haven't seen it.

BillTodd
11-16-2011, 01:44 PM
I want second what Evan has said and add:

Making an Earth and Moon to (a small) scale with correct spacing will usually impress.

If you make the Earth about 1/4" diameter it keeps the scale small enough to hold in the hand.

You can then ask members of the class to site down the line of the moon and earth to the Sun (which will be about the size of typical adult bicycle wheel - you'll need to do this outside) Get someone to walk away carrying the 'Sun' until the viewer can see that the sun looks the same size as the earth.

You can then explain how the moon just happens to be 400 times smaller than the Sun and, at this moment in time ('cos it's moving away slowly), 400 times as far away (which is why we see such a spectacular solar eclipse)

It will also give the class a practical demonstration of the shear scale of the solar system

Bill

Black Forest
11-16-2011, 01:52 PM
BTW, Bruce, if you have somebody to look after the place for a day or two you should take the family and shoot on over to Rothenburg ob der Tauber and visit Kathe Wohlfahrt's Christmas Shop. It is incredible and loaded with any and every possible Christmas decoration known to mankind. It's like a huge maze and takes hours to visit. Rothenburg is also a very pretty town and worth a visit anyway if you haven't seen it.


No way am I taking the wife there. She is already a Christmas freak and loves to buy Christmas stuff. I would go broke in that town!

Euph0ny
11-16-2011, 02:25 PM
No way am I taking the wife there. She is already a Christmas freak and loves to buy Christmas stuff. I would go broke in that town!

If you are where I think you are (southern Schwarzwald), you could hop across the Rhine to Riquewihr in France (Alsace) - Kathe Wolfahrt has a shop there too, rather nearer to you than Rothenburg, and it's a bit smaller than their "head office". I can't promise that the hit to your wallet will be smaller, though :cool:

If you're over that way, the medieval Hohkönigsburg (Haute Koenigsbourg) is right nearby, and well worth a visit if anyone in the family likes castles, dragons, princesses and knights in armour.

I visited both recently (my in-laws live in the northern Black Forest, so my wife and I are often in the area) and enjoyed myself immensely - in fact, I can hardly wait for Christmastime, so we can hang the new baubles on the tree.

Evan
11-16-2011, 02:42 PM
Incidentally, if you do visit Rothenburg, in the off season like now they still practice Ruhetag on Wednesday so many places are closed on Wednesday.

Smokedaddy
11-18-2011, 02:05 PM
You might find this helpful ...

http://www.exploratorium.edu/ronh/solar_system/

-SD: