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by Procheta Mallik


Suspend a "moon" in the middle of a cardboard box and seal it. Illuminate the moon with an LED, make holes at specific locations around the box and observe the various phases of the moon: full, gibbous, half, crescent and new!

    • Scissors and cutters have functional sharp edges. Contact may result in injury. Always keep blades away from fingers and body. Handle with care.

    • Be mindful of the battery terminals, they can heat up or momentarily spark if an electrical short occurs.

  1. The box for this model must be of a minimum size. A box that is at-least  15 x 15  cm is recommended.
    • The box for this model must be of a minimum size. A box that is at-least 15 x 15 cm is recommended.

      • A height of at-least 9 cm is also recommended.

    • Make sure the box is closed on one side. One can either use tape or mechanically interleave the flaps.

    • Measure the face of the box and draw a line along the midpoint.

    • Extend this line to the other faces as well effectively making a line that bisects the box in half horizontally.

    • Start with a 2x2 cm foam peice and wooden skewer that's ~9 cm long.

    • Take a plastic /rubber ball that's 2.5 cm in diameter and find mold mark, if one exists.

    • Using scissors poke a hole in the ball at the point you identified in the previous step. This hole needs to be just large enough to push the skewer into the ball.

    • Using scissors make a hole in the middle of the foam square. This hole should but small, just enough to fit the skewer tightly.

    • Adjust the height of the ball till it's bisected in half equally by the line on the box.

    • Break off any excess of the skewer till is is flush with the bottom of the foam base.

    • Remove the skewer from the base and apply glue to the end .

    • Now mount it back on the foam and let it dry for 2 mins.

    • The ball is now ready to be painted.

    • For the paint you'll need , one or two sticks of chalk, some iron fillings (less than a gram), white (PVA) glue and water.

    • Start by folding a sheet of paper around the chalk piece.

    • Using a stone or other heavy object as a mortar crush the chalk into a fine dust.

      • Be sure to perform this step in a well ventilated are and avoid inhaling the dust produced.

    • Once the chalk has been powered, add the iron filings to it.

    • Take 10 ml of water in a cup and add to this a few drops (~3 ml) of white glue.

    • Add the chalk and iron powder to this cup as well.

    • Stir till you form a smooth paste.

    • Holding the moon at the base, twist the ball into the cup of paint. Do this till a uniform coat of the paint is formed around the ball.

    • Then leave the coat to dry.

    • Repeat this process two or three times, to form a thick coat of the paint. This will simulate the optical properties of the lunar surface.

    • Cut two card paper strips, these strips should be as wide as the box is tall and should be twice the length of its sides. In our example they are 9 cm wide and 30 cm long.

    • Line the walls of the box with glue.

    • Stick one of the card paper strips on two adjacent sides.

    • Stick the other strip to the other two sides of the box.

    • You should now have a box that's black on 4 of its sides.

    • Put a drop of glue on the bottom center of the box.

    • Glue the moon to this spot in the centre of the box.

    • Identify the polarity of the LEDs. The longer leg is positive.

    • Take 2 connecting wires and strip the insulation on both ends.

    • Connect the positive wire from the battery holder to the positive leg of the LED and the negative wire to the negative leg. The LED should light up.

    • Carefully, bend the terminals of the LED back onto themselves. This will prevent the wire from coming loose.

    • Make a hole in the middle of a side of the box. Use the line drawn earlier for reference and bisect it on any side to fine the center for that side.

    • Add a drop of glue to the hole and insert the led into it, such that the dome in on the inside of the box and is flush with inner walls of the box.

    • Test the LED and make sure that its light illuminates exactly half of the ball.

    • Now make eight holes as indicated in the sides of the box.

    • The holes correspond to the various phases of the moon. The hole that is near the light source is for the full moon and it can be made few centimeters above the LED hole.

    • The rest of the holes must be on the line drawn around the box.

    • Stick (glue) a ring magnet on each of the holes such that the hole in the box lines up with the hole in the magnet.

    • A second magnet should now be attracted to these holes from the outside of the box. These outer magnets will serve as covers to close the holes when now in use, keeping the inside of the box relatively dark.

    • Cut a cardboard paper square that fits the rig magnets. You'll need one piece for every magnet so eight in total.

    • Glue the paper square to the magnets.

    • These will serve as cover for the view-ports. Close the top of the box and the lunar box is ready.

    • Full Moon.

    • Waning gibbous

    • Half Moon

    • Waxing gibbous

    • New Moon

Finish Line

Kailash NR

Member since: 05/02/2017

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