Pinball machines are all about the "Theme" and the "Graphics." Unless you are a great artist, a DIY machine is just a board with flippers and a way to score points. Luckily, you can buy sheets of stickers on any possible theme at any scrap booking store. And that is what will make your project stand out. I built hundreds of these with my students as mathematics projects but you can build yours just for fun.
Step 1: Stuff You'll Need
A piece of solid plywood or hardboard at least 8"(20cm) x 16"(40cm). Some 3/8"(1cm) square dowel. Scrap pine, marbles, suitable glue and two #6x 1"(2.5 cm) round head screws. A fine tooth saw, drill, drill bits, a screwdriver and sandpaper are the only tools you'll need.
Step 2: "Frame It" and Flippers
Cut the square dowel to fit the four edges and glue them down to frame the board. Cut two pieces of square dowel about 4"(10 cm) long. Drill a hole slightly larger than your screw, directly in the centre of each. Cut two pieces of square dowel about 1 1/4"(3cm) long and glue to the end of each long piece on the same side as the hole. These are your flippers.
Step 3: Launching Tracks and Deflectors
Install your flippers. Drill a pilot hole slightly smaller than your screw 1 1/2"(7cm) above the bottom of the board on each long frame. Put a flipper on top of each hole so the holes line up and install a screw through each. Tighten just enough so the flipper flips without binding. Cut two pieces of dowel about 2"(5cm) long and glue down so there is a 1/16"(1mm) gap when the flipper is extended 90 degrees to the frame. These contain the marble so it can be launched. Cut two small pieces angled at 45 degrees and glue them down near the top left and right side so they touch the side frame. Leave a gap large enough for the marble to enter. These deflect the launched marble on to the playing surface and act as high scoring areas should a marble enter them.
Step 4: Scoring Areas and Graphics
Use the left over pieces of dowel to create catchment areas for the marbles to enter. These will be given values depending on the probability of the marble entering them. Easy= low score. Difficult= high score. Now get out your sheet of stickers and apply them where you want. Remember the title should be large and near the top.
Step 5: Scoring and Speed
Elevate the top edge of the board so the marbles roll toward the flippers. Play the game. Standard pinball gives you 3 plays so launch each marble separately from the right. You can re-play if one enters the left launching track. Remember you can tilt and bump the board too. Keep track of where the marbles go. Use a Sharpie to label each catchment area with a value. Numbers in the even thousands work best for easy score keeping. Also if the marble enters the space between the launching tracks it is out of play. Glue a piece of scrap pine to the underside of the top edge to keep it constantly elevated. The more elevation, the faster the game!