Help me make this rotating globe

April 8, 2014 7:40 AM

Making a desktop clock out of a 24-hour clock movement, a globe, and an LED. Help me design it within!

I have purchased the 24-hour high-torque movement.

Most importantly, I need to buy the globe, but I can't tell from online descriptions how heavy different globes are. Can you recommend a globe that I can, using hot glue or something similar, attach to this movement?

Less importantly, roughly 50% of the earth is hit by sunlight, so I need a battery-powered LED device that will hit 50% of the globe, and is able to change elevation relative to the globe as the seasons change. Do you have any suggestions for how to create this?

posted by rebent to Technology (2 answers total)

If you can build gears for the movement, then you could get a second one to mount the first one on. It's role would be to slowly (as in one complete revolution per year) rotate the globe relative to a fixed light which would represent the sun. You'd have to mount the globe on this second movement at an angle to (approximately) simulate the seasonal progression.
posted by Poldo at 8:33 AM on April 8, 2014 [1 favorite]

Globes are usually made from cardboard or light plastic, and spinning one on its axis doesn't take a lot of effort (because it's spinning at a constant rate, and the axis goes through its CG) -- so I'm sure a 12" globe would be fine.

Instead of changing elevations of the light for seasons, it would probably be easier to mount the globe+movement at an angle of 23.5 degrees and have the "sun" be fixed at the same height as the globe's center. You can now simulate seasons by turning the globe on its base (hope that makes sense).
posted by phliar at 10:10 AM on April 8, 2014 [1 favorite]