Need to track the moon phases for that perfect time to cast a spell? Worried about when you are due to change into a werewolf?
The following instructions are for a quick DIY Sun-Earth-Moon Orrery we did for a school project. This is suitable for ages 6 to 12 but may need adult supervision. We were inspired by this article in instructables.com but needed a much simpler design.
Please note, this material is provided for informational purposes only and is not a guide on how to create the designs. Please read our disclaimer.
First, measure the center hole for the main screw. This screw will support the Sun, Earth, and Moon.
Next, drill the hole and push the large screw through the hole and secure it with a washer and bolt.
Turn over the base and stick four foam pads on the bottom. We used one large foam pad for furniture and cut it into four pieces. These foam padding will prevent the center bolt from scratching the table when placed upright.
Turn the base back over and make sure the foam padding is tall enough to prevent the bolt from scratching the table. If not, then add another layer of foam. Next, screw another a nut to the halfway point on the bolt and then put a washer on top.
Now we need to make the support wire for the Earth. Take the larger wire and bend both ends using a screwdriver as shown. The goal is the make the loops tight enough so the bolts are secure when threaded through them.
Here, both ends are ready to secure the Earth to the center shaft. Notice one loop is smaller than the other. The larger loop is for the center bolt; the smaller one is for Earth’s bolt.
Now, thread the smaller bolt through the smaller loop.
Secure the bolt to the arm with a washer and nut. Then screw a nut halfway up the bolt. This bolt will serve as support for the Moon’s arm.
Next, create the Moon’s arm. Bend the thinner wire similar to the Earth’s arm but only put a loop on one end. Bend the other end up to support the Moon.
Now connect the thin wire to the screw on Earth’s arm and secure with a bolt.
And we are nearly there! Just connect the thick wire to the screw and put a washer and bolt on top. Make sure to screw on tightly, the weight of the arm can make it droop.
And finally we are ready to add the Sun, Earth, and Moon. The smallest ball is the Moon and goes on the smallest arm. The Earth is the mid-sized ball and put onto the outer bolt. The largest ball is the Sun and placed on the center bolts. You can paint the balls as the final step if you want to.
Putting it all together
Here are all the pieces laid out. We substitute the foam balls in one build with a ping pong ball for the Sun and felt balls for the Earth and Moon.
You now have your own Sun-Earth-Moon Orrery and predict the next eclipse or start planning for the next full moon!
Keep a watch out for werewolves!