Introduction: Constellation Projector (From a Coffee Cup)

In this instructable, you will learn how to build a simple projector (in our case, for constellations).

Here is a little background on constellations:

Constellations are "pictures" or arrangements of stars in the night sky. Similar to connecting the dots, you can "draw" images. These images made of stars are called constellations, and they often hold significant importance in our daily lives. For example, one of the stars in the constellation of Ursa Minor (the "little dipper") is the north star, and has been used in navigating on the sea for centuries.

For more on constellations, see:

You can skip the electrical part of this instructable by using a flashlight to illuminate the projector and provide the light.

P.S. We apologize beforehand that the cup we used was not a coffee cup. I did not have access to a cup when I made this instructable.

But now to start the instructable...

*This project was done with the help of legoguru4u (camera and knife work).

Step 1: The Materials

To do this instructable, you will need:

1 Paper coffee cup
1 White LED(Optional)
1 Toggle switch (Optional)
Battery Pack that holds 2 AAA or 2 AA batteries (Optional)
Wire (Optional)
Constellation Templates (I recommend printing the templates on card-stock)

(See here:

You will use:
Scissors/Craft Knife
Tape/Hot Glue
Needle (type used for sewing) or a knife
Soldering Iron with Solder (Optional)

Step 2: Making a Slide

The projector slide is the part of the projector that you will use to project the image of a constellation.

First, take the template and cut out the circles for the constellations. Then use the knife to poke holes in the circles where the dots indicate a star.

Step 3: Make the Projector

This is when the cup you are using comes in. Trace around the edge of the constellation circle with a sharpie onto the bottom of the cup. Then, with the craft knife, slowly and carefully cut the bottom out of the cup. This should leave a circular hole in the cup that allows the constellation "slide" to rest on top without falling.

Next, cut a small hole closer to the base of the cup. This hole will be the placement for the switch, so make sure that the switch fits nice an snug.

Step 4: Electrical (Optional)

This is the electrical part of the project. You are going to need to solder a circuit so that you can turn the light on and off. Solder wires to the leads of the LED, and solder the wire from the positive terminal on the LED to the positive lead from the battery pack. Then solder the negative lead on the battery pack to a pin of the switch, and solder the wire from the negative terminal on the LED to another pin on the switch. Cover your connections with tape.

Step 5: Put It Together!

Inststall the circuit into the projector housing (cup) and secure it with glue. Make sure the toggle on the switch pokes out of the slot on the cup. Also be sure to point the LED straight up through the hole in the cup.

If you are using a flashlight, just point it upwards through the hole in the cup.

You are ready to go! Turn on the light and put a slide of the constellation you want on top.


Coffee Cup Challenge

Participated in the
Coffee Cup Challenge