When I did this project, I created a web page illustrating how I designed and made it. Then, my web page photo hoster got out of business, so all the photos were not displayed correctly. Below, is the web page re-created.
When I was a kid in the 1960's, we had this game. Each peg, or 3/4" dowel, was split on one end. You started the dowel in the hole with the un-split end, then drove the peg down until it was flush. You could turn over the game, then pound it back the other way.
The modern versions of this game use an o-ring type piece of plastic with 4 nubs to create friction on the wood pegs. After a little bit of use, the nubs wear down, and the pegs just fall through the hole.
My wife brought me the worn out toy, and asked me to fix it, or come up with a new design.
I remembered a design I tried back in the early 1980's when my kids were small. It called for a piece of spring steel to create the friction........and I had trouble with the spring steel, and gave up making one.
I went to my library, and I still have the 1981 book. It is out of print now.
On the modern game, the dowels are 3-1/8" long and about 3/4" diameter. I like the longer dowels from a choking point of view.
On the wooden locks that I build, Ash wood is used as the spring in all of these locks. It works very well for the lock application.
So on my design, I knew the dowel size.........and that I wanted to use an Ash spring. I went into Sketchup and came up with my own design.......
After 5 years and 5 grandkids using the toy, it still works just like it did when it was new :) The ash spring has held up fine, and continues to apply enough pressure to the pieces going by.