Ball-Game

Sometime in the summer of 2019, I stumbled upon a game known as Ice Cold Beer in an arcade bar in San Francisco. It was a simple game, but very, very frustrating. After shelling out all my coins there and having to retreat home for the night, I got the bright idea to recreate the game at home so that I could practice and be a pro by the time I returned (spoiler: I haven’t gone back since)

Development

With some research, I figured out the actual arcade game’s mechanism, which was two lead screws driven by motors and a bar mechanism on a pivoting linkage. That seemed too complex for what I wanted to build, so I opted for using fishing line and pulleys, with hobby grade servos. Window shade pulleys did the trick, and rubber grommets snugly fit on the servo horn while providing a track and enough friction to pull the fishing line.

Once I showed that worked out pretty well, I looked into making the ball return mechanism - a few tracks of wood that would guide the ball back to central return area, and a small linear motor to push the ball back into play. Detecting the ball had returned was hard. Initially I tried a circuit that would complete when the steel ball fell onto two metal tracks, but was unable to maintain continuity for a reliable enough period to detect the ball accurately. Then, I tried using tiny push button switches, but the ball wasn’t heavy enough and there wasn’t enough room to create a lever arm. I settled on using an LED and photoresistor, which worked easily and could be applied to the target sensing as well.

Designing and cutting out the panels to enclose the game was fairly straightforward. I used 3/8” thick polystyrene sheets that were cheap, lightweight and easy to cut. The game board and base are wood LDF boards, which was difficult to get clean holes cutout - I’d eventually want to update this to a laser cut plastic sheet if possible.

An Arduino Mega runs the game, controlling the servos, LED’s and LCD screen and taking input from the start button, toggle switches and photoresistors. Eventually I want to add a speaker and play some fun 8bit tunes during gameplay.

Example Gameplay