The church I attend has a separate Children’s Church which offers age-appropriate teaching and activities during the Sunday morning “grown-up” service. One of the games they play is Plinko, invented or at least made famous on The Price is Right game show (https://www.youtube.com/watch?v=cDwr_JanlAQ
). Someone had previously made them a Plinko board out of plywood which used wood screws for the pegs and old compact discs for the game pieces. It was fairly heavy when they had to move it out of storage for use, and the discs sometimes broke or got stuck between the screws.
Anyway, they asked if I could make them a new one, and since this is a natural application for a CNC router and a fun little project, I accepted their request. I wanted to create a board which was durable, played like the real thing, was made from materials commonly available at big box stores, was reasonably inexpensive, and which minimized the amount of my time I spent constructing it.
It needed to be less than 4 ft square so that two boards could be cut from sheet material and because small children would be using it (I think they have steps or a stool for the smallest kids). My preference was melamine since that already had a slick surface, but the downside was its weight. The other driving decision was what to use for the game disc since that would drive the peg arrangement and overall size. In looking online I found that air hockey discs were commonly used and were basically indestructible, so that’s what I went with. I got the large ones (3-1/4-inch diameter), which were still smaller than the CDs they were previously using, so I could fit more slots in the same width. Here’s what I came up with:
I designed the side and bottom pieces to be cut out of solid pine boards, but I ended up using ¾-inch plywood so I could cut them all at once. The melamine extends to the outside edges of the pieces, so I cut matching recesses in the sheet to aid in installation and to reduce the height the pieces protruded above the melamine. The pieces are currently just screwed into the melamine; my intention was for them to be removed and painted, then glued and screwed back into place (by someone other than me, haha!)
Since the big box stores only have ¾-inch melamine sheets, that’s what I used. To reduce the weight, and because I could, I incorporated some pockets in the back side.
The intersections correspond to the peg locations so that full depth was available for the pegs (finish nails). I was concerned with the nails loosening over time, so I did not pre-drill any holes, I just used the CNC to machine some locating divots with a V-bit, and I hand nailed the #4 finish nails into place. I thought I might have to use #6 nails but did not want to because they stuck out too far. So far I’m happy with the shorter #4 nails, but I could go to the larger nails if necessary.
I added a couple of utility hinges and legs on the back so the game can be self supporting. I wanted to put some chains on the legs to keep them from extending too far and falling, but the children’s leader wanted it before I could buy some and add them, so he’ll have to do it.
Here’s a short video of the playing action (https://youtu.be/-DQam_DIxBg
). I’m pretty pleased with how it turned out, and so was the recipient!