Miniature Revolving Solar System

Materials:

• Light weight clay
• Lightbulb
• Small clock
• Brass wire
• Bamboo skewer
• Hard drive platter
• Stand

Tools:

• Glue: PVA, Super Glue, and hot glue
• Printer and paper
• Needle nose pliers
• Sharpie pens, gold and copper model paint, nail polish

I measured the diameter of my light bulb, as you can see I used a globe sphere which is rounder than your average bulb.  I determined how large I could make the planets and how far apart to space them. I cut eight pieces of wire making sure that they were long enough to wrap around the skewer.  I then bent up one end for placing the planet on.

I used La Doll Premier Lightweight Stone Clay which is super light weight and ideal for this project.  If the planets were much heavier it would likely unbalance the skewer and effect the rotation.  I rolled out the little balls for the planets, they are obviously not to scale.  Mercury was the smallest and Jupiter the biggest, and of course I added the ring for Saturn.  I stuck them on the wire and let them dry overnight (it is an air dry clay).

Once the planets had dried I coloured them.  Sharpies work well with this type of clay.  I made Mercury grey, Venus yellowy-white, Earth blue and green, Jupiter yellow with brown and green stripes, Saturn yellowy-white, Uranus green and Neptune blue.  The colours turned out really vibrant which didn't quite suite an orrery. So I mixes some gold paint with a pale pink nail polish and covered the planets to give it an antique-like appearance.  When the paint had dried I glued the planets to the wire with super glue (unfortunately the glue seems to interact with Sharpies and cause Saturn to bleed a red colour).

As you can see from my pictures I had intended to use a marble for the sun. It turned out to be a bit too heavy to work properly.  I ended up making the sun from the light weight clay.  I stuck a piece of wire in it so that I could hold it while I painted it.  I coloured it with orange and yellow sharpies and then painted it over with a mix of gold paint and nail polish.

For the rotation/revolution of the planets I was using the second hand mechanism on the clock.  The way the hand fits into the clock mechanism seems to vary from clock to clock.  For the one I had, the hand fit in with a pin.  I was able to fit the pointy end of a bamboo skewer into the slot and have it rotate freely.  I used that to hold the planets and the sun.  I formed a little pedestal for the sun to fit on the skewer with the light weight clay, painted it with copper paint and glued it to the pedestal.

I then glued the sun to the pedestal and painted the bamboo skewer with gold paint.

I hollowed out the the light bulb using the following instructions. To make the bulb safer to work with  I put hot glue around the glass edge of the opening.  I added a circle of cardboard painted with copper paint and glued it around the opening to cover the unevenness of the glass.

I  had a stand lying around the house that was perfect for my imitation orrery.  When I placed the clock on the stand and put the  hard drive platter on there was a bit of a gap.  The gap seemed a perfect place to add some gears.  Unfortunately, I didn't have any large gears lying around and I didn't know how to make them.  I wandered around the aisles of a dollar store and came upon a cheap Spirograph toy which of course had little plastic gears.  I painted them gold, I also had to trim a few so that the clock will fit and then glued them to the stand with PVA glue. 

Most orreries I've seen have a plate or dial on the base depicting astrological symbols, months and seasons.  I design my own on my computer to fit on the hard drive platter. I wanted it to have an aged look so I aged the paper first  with tea.  I glued it to the hard platter with PVA and then added more glue over top as a varnish (decoupage).

I painted the top of the clock mechanism with gold paint. Then glued it to the back of the hard drive platter. I also taped the back with duct tape.  I added a small nut on the clock mechanism around the hands to provide stability for when the skewer is placed in.  The plate and clock fit snugly between the gears on the base.  I didn't glue it on since I need access to the battery.

This was the really tricky part. I was worried that I wouldn't be able to fit all of the planets into the bulb. I started by adding Mercury,  which was placed closest to the sun and near the top of the skewer just under the pedestal. I wrapped the wire around the stem, trimmed off the excess wire and tightened it with needle nose pliers.  I added Venus and Earth next and placed them further out.  At this point I could still fit the sun and 3 planets into the bulb.  With the remaining planets I had attached them while holding the planets in the light bulb. I did this by wrapping the wire around the skewer, trimming it and then sliding it up the skewer moving the planet into the light bulb and tightening the wire when it is correctly placed. Once all of the planets are on I slotted the skewer into the clock mechanism and put the battery in the clock. 

I wrapped a bit of wire on the base of the skewer to give it a bit more stability.  As you can see from the video the movement isn't very smooth, some times it skips or stalls and has an occasional wobble.