My wife’s company, SAI Digital, wanted to show off inbound marketing techniques at a local business expo. The event had a carnival theme, and the staff wanted to feature a Plinko board.
I built this Plinko board using dry-erase board for the backing so it would be slick, and pex-covered bolts for pegs that had some bounce. To get the peg spacing just right, I created a triangle cardboard template based on the dimensions of the air hockey puck we would be using to play the game. The buckets at the bottom of the board were fronted by plexiglass and the SAI team branded each with a sticker.
The board and pegs were framed by white 1×4 boards on three sides. I left the top open so it would be easy to insert the chip. I cut a dado 3/4″ into the 1×4 boards and put a 1×3 into the back to give it support. I added a U-shaped leg on the bottom of the board and a fold-out leg off the back to help adjust the angle.
A Plinko board isn’t complete without lights, but I wanted the lights to flash in a carnival-type pattern. Luckily it was autumn, so I was able to easily find larger, round Christmas lights, which I then cut into two-bulb pairs and wired the neutrals of each pair to a busbar. I used an Arduino to run an 8-channel relay board, which switched the 120V lights on and off. I programmed a few functions — such as chase or alternating blinks — and then cycled through those in a sketch.
At first I was concerned with the audible click of the relays, but it turned out folks really liked it and said it added to the carnival feel of the board.
For safety, I placed a piece of plexiglass over the high voltage wiring on the back. This kept fingers out, while leaving the work visible for those who were curious how it worked.