Gumball machines are pretty interesting if you take a minute to think about it. Today, I’ll walk you through the whole process of putting a coin in, turning the handle, and watching a gumball come out. No shopping mall would be complete without a gumball machine. The actual mechanism has had many improvements over the last century. The interesting thing here, is that without a coin, you can’t turn the handle either way. When you put a coin in, the handle only turns clockwise. One full turn, you can hear some clicking noises inside and then the gumball comes out. Let’s take a look inside. The main parts of the mechanism are the dispensing disk, the chute, the coin bin, and the coin mechanism. By far the most complex piece is the coin mechanism. Let’s start there. This is the face plate, the back plate, the coin receiving disk, the ratchet gear, the spur gear, and the turn handle. The turn handle goes through all the pieces here. Notice how the rod is not a perfect cylinder. It’s mostly flat on top. The coin receiving disc fits perfectly onto the flat part. When the handle turns, the disc turns with it. Let’s take a look at how a coin goes in it slides and fits right into the disc. The coin moves with the disc, slides along the edge and falls into the coin bin below. Both gears have similar holes in the center with a flat part on top. When the handle turns, they will turn as well. This gear is called the ratchet gear. It only allows rotation in one direction. This piece is called the pawl; as it rotates the pawl slides over the teeth on the gear. If you try and rotate the other way, no can do. The ratchet gear is also the reason why you hear clicking noises when you turn the handle. So, either way, you’ll never be able to turn the handle counterclockwise. We got that part figured out; Turn it clockwise – you can only do that when there is a coin in there. On the back plate, there’s a tiny piece screwed in here that prevents us from turning. It ends up hitting a wall where the coin would normally be. Let’s get a closer look at that. When a coin is in there, that piece gets bent outward just enough so we can rotate now. Now maybe your gumball machine is in your home or at work and you want to allow anyone to get candy. You can always remove this piece altogether. No coin? No problem. Gumballs for everyone! I will just briefly mention that most machines will have extra guards in place to prevent tampering. We can’t make it too easy to get free gumballs. The last piece on the coin mechanism is the spur gear; To show you what it does. We need to look at some of the other pieces first Right below all the gumballs, we have a few different layers. There’s kind of a dish that goes on first, it has an opening into the chute. Then the dispenser disc goes on followed by another separator. Interesting part here is the disc; It has gear teeth on the bottom that mesh with the spur gear on the coin mechanism. When the spur gear turns, so does the dispenser disc. One complete revolution of the spur gear means the disc only has one third of a revolution. Now let’s put this all together. Turning handle causes the spur gear to turn which then causes the dispensing disc to turn; taking exactly one gumball with it. The disk turns just enough to drop the gumball into the chute and make somebody very happy. Most gumball machines these days you can customize. This piece on top of the disc controls how big the opening is. Maybe you have smaller candies in your machine and you don’t want as many to fit through. It just depends on how generous you’re feeling to the little kids. The last thing I’ll mention here, is that you can’t really get to the inside parts unless you have the key to the very top here. Once you open it, then you can disassemble the machine from the top down.