Photo projector
A photo projector is simply a device powered by a light source that projects an image of a photo onto a wall or screen. Many of us have grown up with Viewmasters, which are retail reels of photo slides that are inserted into manual or powered projectors that allow viewers to see images up close with a hand-held device and held up to the eye or projected onto a screen. This guide shows make a basic projector out of wood, magnifying lenses and other objects, not unlike that of the Viewmasters.
Instructions
1. Make the photo projector base. Cut a wood board to 5 by 16 inches. Cut a ¼-inch-wide by 10-inch-long slot completely through the board with a router an inch from the front of the short end of the board and 2 ½ inches from either side of the length of the wood board. Attach four rubber bumpers at the four corners on the underside of the wood base with screws or glue.
2. Make the lens holders and light stand. Mark the exact center of each of the 5-inch wood squares by measuring with a ruler and pencil. Each of the squares needs a piece cut out for the lens, photo slide and light source, such that they all line up perfectly even though the shapes are different. Draw a 65 mm diameter circle within the squares using a compass--it must be precisely 65 mm because of the lens size. Cut the circles out. Cut one of the squares exactly in half to create two half circles. Insert one grub or set screw about halfway into each of the two whole squares.
3. Make the photo slide holder. Draw a 2-inch square in the center of the uncut wood square and the two 5-inch plywood squares. Cut the square out of the wood square and one of the plywood squares and also cut a half circle out of the top of them to create a spot to pull inserted slides out. Cut the square out of the other plywood square but this time cut one end completely to the edge of the wood. Remove this piece of wood and discard it, so that it is a U-shaped frame. Glue the U-shaped plywood piece directly above the square of wood that was just cut. Glue the other piece of plywood onto the U-shaped plywood piece.
4. Attach the lenses to the lens holders. Push a 65 mm lens into each of the two squares with the circles cut out until they are firmly in place.
5. Attach the lenses to the slide holder. Lay the photo slide holder on a flat surface. Place one lens directly over the square hole. Attach three edges of the lens with a piece of cardboard or metal and screw each piece to the plywood to hold the lens in place. Turn the slide holder over and repeat the process with the other lens.
6. Make and attach the light source holder. Take one wood square that has been cut in half and screw it vertically onto the wood base at the end opposite of the slot with the wood square's half circle facing upwards. Screw the other half circle piece in place about 2 ½ inches from the previous one.
7. Attach the lens holders to the base. Place one lens holder vertically onto the board approximately 5 inches from the end of the board with the light source holders. The grub screw will fit through the previously cut slot about 1 inch from the beginning of the slot. Fit a washer over the protruding grub screw beneath the base, then attach a wing nut to it and tighten it until snug. Repeat the process with the other lens holder. Attach this one approximately 2 ½ inches from the opposite end of the slot. Place the photo slide holder between the two lens holders at an angle, such that one end of the slide holder is 4 ½ inches from the first lens holder and the other end of the slide holder is 4 ½ inches from the other lens holder. Attach the lens holder to the base with a screw and washer from the underside of the slot.
8. Attach the light source. Set a flashlight onto the two light source holders with the light bulb facing the lens holders. It should be balanced between the two half circles.
9. Create a slide. Cut a thin and flexible piece of plastic or cardboard to 2 ½ by 8 ½ inches. Fold it at the 4-inch and 8-inch lengths. Cut a 2-inch square box out of the two layers of plastic or cardboard. Fold the excess ½ inch length over the two layers, creating a slide that holds the photo transparencies.
10. Create a photo transparency. Find a photo that is about 2 inches square and print it onto a piece of plastic transparency paper. Cut the square out so that it is 2 ½ inches wide. Place the square into the slide that you made in Step 9. Tape the ½-inch flap over the ends of the two layers, creating a pocket to hold the photo within the slide.
11. Operate the photo projector. Insert the slide with the photo facing upside down into the slide holder. Turn the flashlight on and the photo image should appear right side up on a wall or screen.
