Greg’s Orrery

From: Greg

Website: nolemonsnomelon.wordpress.com

Location: Broken Arrow, OK

Hobbyist or Pro: Hobbyist

Experience: 10+ yrs

Project Name: Orrery

Wood Species: Pine, Baltic Birch Ply

Finish Used: Spit coat of shellac followed by gloss Minwax wipe-on poly.

Project Description:
This may not qualify since I did some of it on a CNC router but it was certainly a fun project. I documented the build at my website.

This is called an orrery; it’s a mechanical model of the solar system. You turn the crank and the planets go around the sun realistically. That is, mercury goes around pretty fast, Saturn creeps along on the outside, etc. It’s really fun to turn the crank and watch everything work. It’s kind of mesmerizing. Each planet is attached to its gear below with a brass tube and these tubes are all concentric.

I made the gears using my friend’s CNC router. I had to design all the gears in CAD and then take them to his machine where we had to make a few more adjustments. These were made with a 1/8″ router bit. The machine itself is made by ShopBot and uses a Porter Cable variable speed router (I forget – the big one they sell). I did the largest gear by hand on the bandsaw just to convince myself that CNC was a smarter idea. It wasn’t faster though (although if I were to make a second one, it would go much faster.)

You can see a video of the Orrery in action!