So where did this idea come from? Well my wife loved playing pachinko when she was a child at her grandparent’s house. So when we found a old pachinko machine at a garage sale, it was bought. Well it sat for a few years and Christmas was coming; I decided it was time to do something with it besides tripping over it.
So the plan was always to build a case around it, but doing just that seemed kind of lame. I then started to think of other things she liked and bubble gumball machines came to mind, now to build it. Of course, I try to use some kind of CPU in my projects and a computer was overkill (ok so was a microprocessor) so I went with an Arduino type board. You have to love these little devices, they are cheap and have a great deal of possible uses. Plus there is a great community of developers for help or code snippets.
The first step was to build the case and not tip my wife off, so I told her I was building something for work, that worked as she was surprised at Christmas(of course I kept the pachinko out of the case until Christmas). The next step was to figure out what type of wood to use. I went with Oak plywood, it would be easy to work with and give me the look I wanted once it was stained and finished. I purchased a 4 x 8 sheet from Home Depot and drew a pattern on it with a pencil in the shapes I wanted. I did not want it perfectly straight and made it with a little angle on the sides. I also knew I would need a compartment where both the gumball mechanics and any electronics would need to be placed. In addition I wanted it to be locked and covered. So all of these parts would also need to be also cut from the Oak plywood. In building the compartment, it also would serve as a shelf for the pachinko machine to rest on so the weight of it would not rest solely on any screws from the sides or top. After cutting, gluing and measuring for the proper spacing for the pachinko machine I had a case I was starting to like.
With the case starting to come together I turned my attention to the mechanics of the bubble gum machine. It needed to first work, second be refillable fairly easily and finally prevent the candy from just falling on the floor. To meet all of these requirements, PVC pipe came to mind. The reason is you can get it in different sizes, it is easy to put together, you can clean it and it is pretty cheap. I decided to go with the four inch pipe. This would hold a great deal of candy between refills, there were also plenty of reducers so I could “funnel” the candy down the chute. First I made a little dock to hold the reservoir straight up, next I cut a circle of wood and fashioned a thin piece of metal to act as the dispenser. The challenge here was to make the slot in the side to line up with the board. The best process was cut the slot in the pipe, put the circle board in the pipe, slide in the metal plate and then screw the wood circle in place from outside the pipe. I cut a one inch hole in both the wood circle and the metal plate this allowed for everything that I tested to work great. (Hot Tamales candy, Skittles, Gumballs). Screws on both sides of the metal plate acted as guides when the plate moved back and forth.
Now with the candy ready to go we needed a way to dispense the “reward”. For this I used a cheap hobby servo. The concept, when the switch is triggered, the servo will move to the left for two seconds (open, holes in wood and metal plate lined up) and then move back to the right(closed, holes in wood and metal plate do not line up). I happened to have a BoArduino from another project I was doing so I used it, however any Arduino would work. If you can not soldier then do not use the BoArduino as it is a kit you have to put together. The code was very simple since all I was doing was looking for a “contact” from a switch that would trigger the servo to move back and forth. To power everything, my first thought was I had a 6 volt gel battery around and was going to use that, however after a month it would die and not run anything. So I modified the power setup and just used a 6 volt wall wart and have not had a single problem since then except reloading the balls for the game and refilling the payout…
Probably the single biggest challenge was the “switch”. My first thought was to use a simple contact switch. I needed to fabricate a mount for the switch, however what I found out was the mechanics of the levers were too good. Anything, no matter how light of a touch that interfered with the levers seemed to jam them and either always left it on or never paid out.
After much trial and error, I remembered I had bought some conductive ribbon (for some future project 
) . With this I connected one wire to the pachinko machine with a screw and gave it a little loop. The other wire to the switch, I wrapped it around a length of the conductive ribbon and looped the other end of the ribbon to one of the levers that moved on a pay out. When the pay out happened, the ribbon touched the other looped wire and we have “contact”. The arduino was happy and so was I. I did however apply a little bit of electric tape looped around the other end of the lever to counter balance the touching of the ribbon to the wire this worked perfectly.
On the pachinko machine itself. I did have to take it completely apart and clean out the wasp nest, and other gunk that was gumming up the tracks that the balls followed. The Glass had been replaced with Plexiglas and that needed to be replaced as I was trying to keep the Pachinko experience as close to original as I could and the balls hitting glass sound much better than Plexiglas. The brass nails were tarnished, but luckily or not the Marine Corps taught us over and over how to use this stuff called “brasso” it is a pain, but it does work. In fact it worked like a champ and really cleaned up the brass nails that the balls would bounce on. I also had to change the locks as the keys for the pachinko machine’s lock were lost. Not a big deal as I wanted matching keys for locking the dispenser and the pachinko machine, these were easily found on the internet.
And there you have it a Pachinko Gum Ball dispenser. I had to cheat a great deal to test it; I found out I evidently am not a very good Pachinko player as I lost way more than I would ever win. Christmas came and my wife loved it, we have now gone through a huge bag of Skittles, Hot Tamales and a few bags of Gum Balls. So I would have to consider it a successful project…
