This guide shows how to construct a good quality kaleidoscope from basic materials. There are quite a few components which go to make up this model and more simple designs exist on the internet but this model is both impressive and robust enough for classroom use.
Firstly the tube needs to be cut to approximately 20cm in length using a hacksaw. The tube is made from PVC and is a standard plumbing type available from most DIY stores. Use a round file to remove any sharp edges from the cut ends.
Fig 1: End cap for tube
End caps are also available from the same stores and should fit the end of the pipe snugly. Use an 8mm drill bit to make a hole in the end cap (see fig 1). This will be the viewing hole.
Fig 2: End if tube with larger half of Petri dish glued in place
Fig 2 shows the end of the tube with the larger half of a Petri dish glued securely in place using PVC cement. This not only helps hold the mirror assembly in place but also acts as a guide for the image 'slide'.
Fig 3: Acrylic mirror cut into 3 equal parts
The acrylic mirror needs to be cut into three equal parts per kaleidoscope. The length of the mirrors needs to be the same as the length of your tube (20cm) and width of each should be approximately 29mm (see fig 3). If possible use good quality heavy acrylic mirror and not the flexible type as the clarity of image may be compromised.
Figs 4, 5 and 6 show how the mirrors should be grouped together in a triangular formation and held together firmly with sticky tape. Ensure the mirror side is on the inside of the triangle and use several strips of tape to secure them well.
Figs 7, 8 and 9 shows how small pieces of self adhesive foam should be cut into rectangles and attached to the outside of the mirror assembly in order for it to sit tightly inside the tube. If you cannot find self adhesive foam, use double-sided sticky tape. The foam ensures there is no mirror movement inside the tube.
Fig 10: Foam pieces inside tube
Fig 11: Attach end cap
Once the mirror assembly is inside the tube, further foam pieces can be inserted (see fig 10) and the end cap attached (see fig 11). The cap should fit tightly but PVC cement can be used if this is loose.
Fig 12: Kaleidoscopic image
Look through the tube at something in the room and you should be able to see a kaleidoscopic image created by the internal mirrors (see fig 12).
Fig 13: Draw patterns and shapes on lid for an enhanced effect
Fig 14: Gently sand the outside surface to create an opaque surface
The other half of the Petri dish can be used to enhance the effect. By scribbling or drawing shapes with different colour permanent markers on the lid of the Petri dish, fantastic images can be created (see fig 13). The scribbles should be drawn on the inside of the dish lid and the outside gently sanded using sandpaper to create an opaque surface (see fig 14).
Fig 15: Finished kaleidoscope in use
Fig 16: Colours and shapes produced
The lid can be placed over the Petri dish attached to the far end of the tube and rotated to produce an array of colours and shapes (see fig 15 and 16).
The model should be very robust because of the strength of the PVC tubing. The only weak part will be the Petri dish end piece which may crack if dropped. This may be easily replaced if broken.
An assortment of Petri dish lids bearing different patterns and/or colours can be created for students to use or they may want to create their own.
The photographs on this page are courtesy of, and used with permission of, Dr. Mike Nofziger, Outreach Coordinator and Lecturer for the College of Optical Sciences, Univeristy of Arizona.