Pinball Machine

For my systems and control project for GCSE I made a pinball machine. This was a very cool project... if a not a little stressful sometimes. But I spent a lot of time on this project and thought it was defiantly worth sharing. I based my pinball machine on the science fiction comedy red dwarf as it is one of my favorite shows. However my classmates based there pinball machines on different subjects so it is a good project no matter what your interests are.

First I had cut out all the pieces on the laser cutter out of 3mm acrylic. Then made sure that it all fitted together tightly. I had left off a few holes so I had to drill into the acrylic, this is so that the wires can comfortably fit through the machine without making a mess. I glued some of the small parts to the machine with UHU multipurpose glue. However superglue or tensol cement would have also worked. To make the firing pin I used a screw, some washers, a spring, and a nut. This works well and the screw allows you to adjust the power of the firing pin. I also used lots of vinyl stickers to decorate the machine.

As part of the project I had to use at least 2 mechanisms. In the end I used 2 cams and a chain and sprocket.

For the first cam (the red one) I used some spare acrylic to make the egg shaped cam. The red acrylic was slightly thicker than the rest as it was 5mm thick and the rest was 3mm. This was good as it allowed the follower to easily slide up and down past 2 pieces of 3 mm acrylic. This cam was slightly difficult as it was in the same spot as my scorbard. this meant I had to put it behind the 3 LEDs.

For cam 2 ( the small white one) I used a circular piece of acrylic with a semicircle of acrylic on it. This cam was simply to press a switch. As part of my design I made it so that you only have about 20 seconds to score 3 goals. This was so the system knew wen time was up.

The chain and sprocket was mainly to attach everything to one single motor. I used a chain and 3 pre-made nylon gears to attach all 3 parallel shafts. The gears on the motor and the first cam was small so these would spin faster than the gray gear for the timer.

The motor was put into this small plasic container with lots of gears. This was to increase the torque of the motor and to reduce the speed. I had to attach flying leads onto my motor then the container was then glued onto a shelf on my pinball machine. I tested if it all worked by supplying it with some power. I had to adjust some of the larger gears so that the mechanisms didn't jam.

I wanted the scoreboard to know whenever you have scored or missed a shot. To do this I set up a system between an LDR and an LED when the light is blocked from the LDR then the system knows if the user has scored or missed. This system was all hidden underneath the top layer of the pinball machine. This meant when the ball fell in a hole it would go directly onto this surface.

I wanted to know my score as I was playing so I set up 3 LEDs to show me. I put them in some clear acrylic with etched lines in. This is so the acrylic etched marks will collect the light and make the numbers glow. I put all 3 squares of clear acrylic in a line. With black vinyl stickers in the middle so that whwn one is glowing they dont all glow.

Before soldering anything onto the circuit board I made sure all my wires were neet. I did this by twisting the witres with a drill before I soldered them to the component. Then I also labled the wires up so i know what i was soldering to each section. The circuit board I was given came as a kit for everyone in the class. I had to solder all the components onto the board myself. I am a beginner at soldering but even I found this quite strait forward following the diagram.

To program the circuit board I used a program called flowol. I first selected the 20M2 chip before putting the program I wanted in. I also did a lot of program development but in the end I used the last 2 images to program the chip. This not only counted your score but also gave you a time limit.

For my prodject I had to create a long power point explaining every detail. There was about 25 slides in the end. I got a very good mark and was proud of my work.

There you go! that's the finished pinball machine. This was quite a long prodject and took most of the lessons in one year of school to create. Therefore I couldn't put every little detail of my manufacture into this 'ible. So if you have any questions about anything I am happy to try and give my advice and knowledge. Hope you enjoyed reading. :)